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nfcorpus-corpus-MED-3231 | null | The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?
This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3230 | null | Estimated net acid excretion inversely correlates with urine pH in vegans, lacto-ovo vegetarians, and omnivores.
OBJECTIVE: Diet affects urine pH and acid-base balance. Both excess acid/alkaline ash (EAA) and estimated net acid excretion (NAE) calculations have been used to estimate the effects of diet on urine pH. This study's goal was to determine if free-living vegans, lacto-ovo vegetarians, and omnivores have increasingly acidic urine, and to assess the ability of EAA and estimated NAE calculations to predict urine pH. DESIGN: This study used a cross-sectional design. SETTING AND PARTICIPANTS: This study assessed urine samples of 10 vegan, 16 lacto-ovo vegetarian, and 16 healthy omnivorous women in the Boston metropolitan area. Six 3-day food records from each dietary group were analyzed for EAA content and estimated NAE, and correlations with measured urine pH were calculated. RESULTS: The mean (+/- SD) urine pH was 6.15 +/- 0.40 for vegans, 5.90 +/- 0.36 for lacto-ovo vegetarians, and 5.74 +/- 0.21 for omnivores (analysis of variance, P = .013). Calculated EAA values were not significantly different among the three groups, whereas mean estimated NAE values were significantly different: 17.3 +/- 14.5 mEq/day for vegans, 31.3 +/- 8.5 mEq/day for lacto-ovo vegetarians, and 42.6 +/- 13.2 mEq/day for omnivores (analysis of variance, P = .01). The average deattenuated correlation between urine pH and EAA was 0.333; this value was -0.768 for estimated NAE and urine pH, with a regression equation of pH = 6.33 - 0.014 NAE (P = .02, r = -0.54). CONCLUSIONS: Habitual diet and estimated NAE calculations indicate the probable ranking of urine pH by dietary groups, and may be used to determine the likely acid-base status of an individual; EAA calculations were not predictive of urine pH. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3236 | null | Nutrient based estimation of acid-base balance in vegetarians and non-vegetarians.
A first objective of the present study was to estimate the acid-base balance of the food intake in vegetarians and non-vegetarians. A second objective was to evaluate if additional input of specific food items on the existing potential renal acid load (PRAL) list was necessary for the comparison of the two dietary patterns. Thirty vegetarians between the age of 18 and 30 years were matched for sex, age and BMI with 30 non-vegetarians. Based on the 3-days food diaries the acid-base status of the food intake was estimated using the PRAL method. Mean PRAL values as estimated with the standard table yielded an alkaline load of -5.4 +/- 14.4 mEq/d in the vegetarians compared to an acid load of 10.3 +/- 14.4 mEq/d in the nonvegetarians (p<0.001). Mean PRAL values as estimated with the extended table yielded an alkaline load of -10.9 +/-19.7 mEq/d in the vegetarians compared to an acid load of 13.8 +/- 17.1 mEq/d for the non-vegetarians (p<0.001). The findings of this study indicate that vegetarian food intake produces more alkaline outcomes compared to non-vegetarian diets. The use of the standard PRAL table was sufficient for discrimination between the two diets. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3217 | null | Age and systemic acid-base equilibrium: analysis of published data.
To investigate whether systemic acid-base equilibrium changes with aging in normal adult humans, we reviewed published articles reporting the acid-base composition of arterial, arterialized venous, or capillary blood in age-identified healthy subjects. We extracted or calculated blood hydrogen ion concentration ([H+]), plasma bicarbonate concentration ([HCO3(-)]), blood PCO2, and age, and computed a total of 61 age-group means, distributed among eight 10-year intervals from age 20 to 100 years. Using linear regression analysis, we found that with increasing age, there is a significant increase in the steady-state blood [H+] (p < .001), and reduction in steady-state plasma [HCO3(-)] (p < .001), indicative of a progressively worsening low-level metabolic acidosis. Blood PCO2 decreased with age (p < .05), in keeping with the expected respiratory adaptation to metabolic acidosis. Such age-related increasing metabolic acidosis may reflect in part the normal decline of renal function with increasing age. The role of age-related metabolic acidosis in the pathogenesis of the degenerative diseases of aging warrants consideration. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3237 | null | Diet-induced metabolic acidosis.
The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products, generating the accumulation of non-metabolizable anions and a lifespan state of overlooked metabolic acidosis, whose magnitude increases progressively with aging due to the physiological decline in kidney function. In response to this state of diet-derived metabolic acidosis, the kidney implements compensating mechanisms aimed to restore the acid-base balance, such as the removal of the non-metabolizable anions, the conservation of citrate, and the enhancement of kidney ammoniagenesis and urinary excretion of ammonium ions. These adaptive processes lower the urine pH and induce an extensive change in urine composition, including hypocitraturia, hypercalciuria, and nitrogen and phosphate wasting. Low urine pH predisposes to uric acid stone formation. Hypocitraturia and hypercalciuria are risk factors for calcium stone disease. Even a very mild degree of metabolic acidosis induces skeletal muscle resistance to the insulin action and dietary acid load may be an important variable in predicting the metabolic abnormalities and the cardiovascular risk of the general population, the overweight and obese persons, and other patient populations including diabetes and chronic kidney failure. High dietary acid load is more likely to result in diabetes and systemic hypertension and may increase the cardiovascular risk. Results of recent observational studies confirm an association between insulin resistance and metabolic acidosis markers, including low serum bicarbonate, high serum anion gap, hypocitraturia, and low urine pH. Copyright © 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3455 | null | Exercise-induced lipid peroxidation: Implications for deoxyribonucleic acid damage and systemic free radical generation.
Exercise-induced deoxyribonucleic acid (DNA) damage is often associated with an increase in free radicals; however, there is a lack of evidence examining the two in parallel. This study tested the hypothesis that high-intensity exercise has the ability to produce free radicals that may be capable of causing DNA damage. Twelve apparently healthy male subjects (age: 23 ± 4 years; stature: 181 ± 8 cm; body mass: 80 ± 9 kg; and VO(2max) : 49 ± 5 ml/kg/min) performed three 5 min consecutive and incremental stages (40, 70, and 100% of VO(2max) ) of aerobic exercise with a 15-min period separating each stage. Blood was drawn after each bout of exercise for the determination of ex vivo free radicals, DNA damage, protein carbonyls, lipid hydroperoxide (LOOH) concentration, and a range of lipid-soluble antioxidants. Lipid-derived oxygen-centered free radicals (hyperfine coupling constants a(Nitrogen) = 13.7 Gauss (G) and aβ(Hydrogen) = 1.8 G) increased as a result of acute moderate and high-intensity exercise (P < 0.05), while DNA damage was also increased (P < 0.05). Systemic changes were observed in LOOH and for lipid-soluble antioxidants throughout exercise (P < 0.05); however, there was no observed change in protein carbonyl concentration (P > 0.05). These findings identify lipid-derived free radical species as possible contributors to peripheral mononuclear cell DNA damage in the human exercising model. This damage occurs in the presence of lipid oxidation but in the absence of any change to protein carbonyl concentration. The significance of these findings may have relevance in terms of immune function, the aging process, and the pathology of carcinogenesis. Copyright © 2010 Wiley-Liss, Inc. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3456 | null | Acute and chronic watercress supplementation attenuates exercise-induced peripheral mononuclear cell DNA damage and lipid peroxidation.
Pharmacological antioxidant vitamins have previously been investigated for a prophylactic effect against exercise-induced oxidative stress. However, large doses are often required and may lead to a state of pro-oxidation and oxidative damage. Watercress contains an array of nutritional compounds such as β-carotene and α-tocopherol which may increase protection against exercise-induced oxidative stress. The present randomised controlled investigation was designed to test the hypothesis that acute (consumption 2 h before exercise) and chronic (8 weeks consumption) watercress supplementation can attenuate exercise-induced oxidative stress. A total of ten apparently healthy male subjects (age 23 (SD 4) years, stature 179 (SD 10) cm and body mass 74 (SD 15) kg) were recruited to complete the 8-week chronic watercress intervention period (and then 8 weeks of control, with no ingestion) of the experiment before crossing over in order to compete the single-dose acute phase (with control, no ingestion). Blood samples were taken at baseline (pre-supplementation), at rest (pre-exercise) and following exercise. Each subject completed an incremental exercise test to volitional exhaustion following chronic and acute watercress supplementation or control. The main findings show an exercise-induced increase in DNA damage and lipid peroxidation over both acute and chronic control supplementation phases (P< 0.05 v. supplementation), while acute and chronic watercress attenuated DNA damage and lipid peroxidation and decreased H₂O₂ accumulation following exhaustive exercise (P< 0.05 v. control). A marked increase in the main lipid-soluble antioxidants (α-tocopherol, γ-tocopherol and xanthophyll) was observed following watercress supplementation (P< 0.05 v. control) in both experimental phases. These findings suggest that short- and long-term watercress ingestion has potential antioxidant effects against exercise-induced DNA damage and lipid peroxidation. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3449 | null | Antigenotoxic activity of watercress extract in an in vitro mammalian system using comet assay.
Watercress (Cruciferae), an integral part of Mediterranean diets, is a nutritive food which is used in the treatment of several diseases. Oxidative DNA damage seems to play a crucial role in chronic, aging-related diseases and it is considered an important and probably carcinogenic factor. The aim of this work was to determine the impact of watercress extract on cell viability and its potential antigenotoxic properties against induced oxidative damage, using a comet assay and peripheral blood cells as an in vitro model. An aqueous extract of the leaves was prepared using a juice processor, centrifuged, filtered and preserved at -20 °C. Two concentrations of the aqueous extract (13.2 and 26.4 mg/mL) were assayed. No differences were found in cell viability between the control and treated groups at any time. Significant antigenotoxic effects were observed for both concentrations, expressed as the damage index (p = 0.005 at 30 min; p < 0.001 at 60 and 90 min), the percentage reductions in damage being similar between them (67.1-75.2% respectively). These results suggest that the consumption watercress in the diet is a powerful tool for improving health and the quality of life. Copyright © 2011 John Wiley & Sons, Ltd. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3457 | null | Oxidative DNA damage in human peripheral leukocytes induced by massive aerobic exercise.
Reactive oxygen species produced during vigorous exercise may permeate into cell nuclei and induce oxidative DNA damage, but the supporting evidence is still lacking. By using a 42 km marathon race as a model of massive aerobic exercise, we demonstrated a significant degree of unrepaired DNA base oxidation in peripheral immunocompetent cells, despite a concurrent increase in the urinary excretion of 8-hydroxy-2'-deoxyguanosine. Single cell gel electrophoresis with the incorporation of lesion-specific endonucleases further revealed that oxidized pyrimidines (endonuclease III-sensitive sites) contributed to most of the postexercise nucleotide oxidation. The oxidative DNA damage correlated significantly with plasma levels of creatinine kinase and lipid peroxidation metabolites, and lasted for more than 1 week following the race. This phenomenon may be one of the mechanisms behind the immune dysfunctions after exhaustive exercise. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3458 | null | Does physical activity induce DNA damage?
The single cell gel electrophoresis (SCG) assay (comet assay) is a sensitive technique for detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells. This technique was used to study peripheral blood cells from three volunteers after physical activity. The test subjects had to run on a treadmill and were checked for blood pressure and ECG, lactate concentration and creatine kinase activity. Blood was taken before and several times during and after the run. In a first multiple step test, the volunteers ran as long as possible with increasing speed. In a second test they had to run for 45 min with a fixed individual speed which was defined to ensure an aerobic metabolism. In the first test, the white blood cells of all subjects showed increased DNA migration in the SCG assay. The effect was seen 6 h after the end of the exercise and reached its maximum 24 h later. After 72 h, DNA migration decreased to about control level. The distribution of DNA migration among cells clearly demonstrated that the majority of white blood cells exhibited increased DNA migration and that the effect was not only due to a small fraction of damaged cells. From the same blood samples, blood cultures were set up to study a possible effect on the frequency of sister chromatid exchanges (SCE), another indicator for genotoxic effects. However, there was no significant increase in SCE in any of the cultures. In the second exercise, during aerobic metabolism, the effect on DNA migration was not seen.(ABSTRACT TRUNCATED AT 250 WORDS) |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3453 | null | Supplementation with vitamin C and N-acetyl-cysteine increases oxidative stress in humans after an acute muscle injury induced by eccentric exercise.
There has been no investigation to determine if the widely used over-the-counter, water-soluble antioxidants vitamin C and N-acetyl-cysteine (NAC) could act as pro-oxidants in humans during inflammatory conditions. We induced an acute-phase inflammatory response by an eccentric arm muscle injury. The inflammation was characterized by edema, swelling, pain, and increases in plasma inflammatory indicators, myeloperoxidase and interleukin-6. Immediately following the injury, subjects consumed a placebo or vitamin C (12.5 mg/kg body weight) and NAC (10 mg/kg body weight) for 7 d. The resulting muscle injury caused increased levels of serum bleomycin-detectable iron and the amount of iron was higher in the vitamin C and NAC group. The concentrations of lactate dehydrogenase (LDH), creatine kinase (CK), and myoglobin were significantly elevated 2, 3, and 4 d postinjury and returned to baseline levels by day 7. In addition, LDH and CK activities were elevated to a greater extent in the vitamin C and NAC group. Levels of markers for oxidative stress (lipid hydroperoxides and 8-iso prostaglandin F2alpha; 8-Iso-PGF2alpha) and antioxidant enzyme activities were also elevated post-injury. The subjects receiving vitamin C and NAC had higher levels of lipid hydroperoxides and 8-Iso-PGF2alpha 2 d after the exercise. This acute human inflammatory model strongly suggests that vitamin C and NAC supplementation immediately post-injury, transiently increases tissue damage and oxidative stress. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3534 | null | Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage
Background Numerous antioxidant and anti‐inflammatory agents have been identified in tart cherries. Objective To test the efficacy of a tart cherry juice blend in preventing the symptoms of exercise induced muscle damage. Methods This was a randomised, placebo controlled, crossover design. Fourteen male college students drank 12 fl oz of a cherry juice blend or a placebo twice a day for eight consecutive days. A bout of eccentric elbow flexion contractions (2 × 20 maximum contractions) was performed on the fourth day of supplementation. Isometric elbow flexion strength, pain, muscle tenderness, and relaxed elbow angle were recorded before and for four days after the eccentric exercise. The protocol was repeated two weeks later with subjects who took the placebo initially, now taking the cherry juice (and vice versa). The opposite arm performed the eccentric exercise for the second bout to avoid the repeated bout protective effect. Results Strength loss and pain were significantly less in the cherry juice trial versus placebo (time by treatment: strength p<0.0001, pain p = 0.017). Relaxed elbow angle (time by treatment p = 0.85) and muscle tenderness (time by treatment p = 0.81) were not different between trials. Conclusions These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise was 22% with the placebo but only 4% with the cherry juice. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3464 | null | Consumption of Bing sweet cherries lowers circulating concentrations of inflammation markers in healthy men and women.
The purpose of this study was to determine the effects of consuming sweet cherries on plasma lipids and markers of inflammation in healthy humans. Healthy men and women (n = 18) supplemented their diets with Bing sweet cherries (280 g/d) for 28 d. After a 12-h fast, blood samples were taken before the start of cherry consumption (study d 0 and 7), 14 and 28 d after the start of cherry supplementation (study d 21 and 35), and 28 d after the discontinuation (study d 64) of cherry consumption. After cherries were consumed for 28 d, circulating concentrations of C-reactive protein (CRP), regulated upon activation, normal T-cell expressed, and secreted (RANTES), and NO decreased by 25 (P < 0.05), 21 (P < 0.05), and 18% (P = 0.07) respectively. After the discontinuation of cherry consumption for 28 d (d 64), concentrations of RANTES continued to decrease (P = 0.001), whereas those of CRP and NO did not differ from either d 7 (pre-cherries) or d 35 (post-cherries). Plasma concentrations of IL-6 and its soluble receptor, intercellular adhesion molecule-1, and tissue inhibitor of metalloproteinases-2 did not change during the study. Cherry consumption did not affect the plasma concentrations of total-, HDL-, LDL-, and VLDL- cholesterol, triglycerides, subfractions of HDL, LDL, VLDL, and their particle sizes and numbers. It also did not affect fasting blood glucose or insulin concentrations or a number of other chemical and hematological variables. Results of the present study suggest a selective modulatory effect of sweet cherries on CRP, NO, and RANTES. Such anti-inflammatory effects may be beneficial for the management and prevention of inflammatory diseases. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3460 | null | Massage therapy attenuates inflammatory signaling after exercise-induced muscle damage.
Massage therapy is commonly used during physical rehabilitation of skeletal muscle to ameliorate pain and promote recovery from injury. Although there is evidence that massage may relieve pain in injured muscle, how massage affects cellular function remains unknown. To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage. Muscle biopsies were acquired from the quadriceps (vastus lateralis) at baseline, immediately after 10 min of massage treatment, and after a 2.5-hour period of recovery. We found that massage activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal-regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α)], and mitigated the rise in nuclear factor κB (NFκB) (p65) nuclear accumulation caused by exercise-induced muscle trauma. Moreover, despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury. In summary, when administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3465 | null | Effect of blueberry ingestion on natural killer cell counts, oxidative stress, and inflammation prior to and after 2.5 h of running.
Blueberries are rich in antioxidants known as anthocyanins, which may exhibit significant health benefits. Strenous exercise is known to acutely generate oxidative stress and an inflammatory state, and serves as an on-demand model to test antioxidant and anti-inflammatory compounds. The purpose of this study was to examine whether 250 g of blueberries per day for 6 weeks and 375 g given 1 h prior to 2.5 h of running at ∼72% maximal oxygen consumption counters oxidative stress, inflammation, and immune changes. Twenty-five well-trained subjects were recruited and randomized into blueberry (BB) (N = 13) or control (CON) (N = 12) groups. Blood, muscle, and urine samples were obtained pre-exercise and immediately postexercise, and blood and urine 1 h postexercise. Blood was examined for F₂-isoprostanes for oxidative stress, cortisol, cytokines, homocysteine, leukocytes, T-cell function, natural killer (NK), and lymphocyte cell counts for inflammation and immune system activation, and ferric reducing ability of plasma for antioxidant capacity. Muscle biopsies were examined for glycogen and NFkB expression to evaluate stress and inflammation. Urine was tested for modification of DNA (8-OHDG) and RNA (5-OHMU) as markers of nucleic acid oxidation. A 2 (treatment) × 3 (time) repeated measures ANOVA was used for statistical analysis. Increases in F₂-isoprostanes and 5-OHMU were significantly less in BB and plasma IL-10 and NK cell counts were significantly greater in BB vs. CON. Changes in all other markers did not differ. This study indicates that daily blueberry consumption for 6 weeks increases NK cell counts, and acute ingestion reduces oxidative stress and increases anti-inflammatory cytokines. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3461 | null | Acute inflammation: the underlying mechanism in delayed onset muscle soreness?
It is well documented in animal and human research that unaccustomed eccentric muscle action of sufficient intensity and/or duration causes disruption of connective and/or contractile tissue. In humans, this appears to be associated with the sensation of delayed onset muscle soreness (DOMS). During the late 1970's, it was proposed that this sensation of soreness might be associated with the acute inflammatory response. However, subsequent research failed to substantiate this theory. The present article suggests that the results of much of the research concerning DOMS reflect events typically seen in acute inflammation. Similarities between the two events include: the cardinal symptoms of pain, swelling, and loss of function; evidence of cellular infiltrates, especially the macrophage; biochemical markers such as increased lysosomal activity and increased circulating levels of some of the acute phase proteins; and histological changes during the initial 72 h. In the final section of this paper, a theoretical sequence of events is proposed, based on research involving acute inflammation and DOMS. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3473 | null | Orange juice improved lipid profile and blood lactate of overweight middle-aged women subjected to aerobic training.
OBJECTIVE: This study investigated how consumption of orange juice associated with aerobic training affected serum lipids and physical characteristics of overweight, middle-aged women. METHODS: The experimental group consisted of 13 women who consumed 500 mL/d of orange juice and did 1h aerobic training 3 times a week for 3 months. The control group consisted of another 13 women who did the same aerobic training program but did not consume orange juice. RESULTS: At the end of the experiment, the control group lost an average of 15% of fat mass (P<0.05) and 2.5% of weight (P<0.05), whereas the experimental group lost 11% of fat mass and 1.2% of weight (P<0.05). Consumption of orange juice by the experimental group was associated with increased dietary intake of vitamin C and folate by 126% and 61% respectively. Serum LDL-C decreased 15% (P<0.05) and HDL-C increased 18% (P<0.05) in the experimental group, but no significant change was observed in the control group. Both groups improved the anaerobic threshold by 20% (P<0.05), but blood lactate concentration decreased 27% in the experimental group compared to the 17% control group, suggesting that experimental group has less muscle fatigue and better response to training. CONCLUSIONS: The consumption of 500 mL/d of orange juice associated with aerobic training in overweight women decreased cardiovascular disease risk by reducing LDL-C levels and increasing HDL-C levels. This association also decreased blood lactate concentration and increased anaerobic threshold, showing some improvement in the physical performance. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3469 | null | Postprandial glycemic response to orange juice and nondiet cola: is there a difference?
The purpose of this study was to compare the effects of unsweetened fruit juice and regular, decaffeinated soda on postprandial serum glucose levels in individuals with non-insulin-dependent diabetes mellitus (NIDDM) when these liquids are ingested separately as part of mixed meals. Eighteen individuals with NIDDM consumed three test breakfasts calculated using the diabetic exchange meal-planning system. Foods were identical in each of the breakfasts except for foods in the fruit exchange. Carbohydrate-equivalent amounts of fresh orange slices, unsweetened orange juice, and regular, decaffeinated Coke were consumed in breakfasts 1, 2, and 3, respectively. Serum glucose samples were drawn at fasting and 1, 2, and 3 hours postprandially. No difference was found in the postprandial serum glucose response when Coke versus orange juice was consumed in the breakfast. These findings question the appropriateness of using unsweetened fruit juices in routine meal planning for individuals with NIDDM. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3481 | null | Pancreatic lipase inhibitors from natural sources: unexplored potential.
The prevalence of obesity is increasing at an alarming rate, but, unfortunately, only a few medications are currently on the market. Obesity is primarily regarded as a disorder of lipid metabolism and the enzymes involved in this process could be selectively targeted to develop antiobesity drugs. Recently, newer approaches for the treatment of obesity have involved inhibition of dietary triglyceride absorption via inhibition of pancreatic lipase (PL) as this is the major source of excess calories. Natural products provide a vast pool of PL inhibitors that can possibly be developed into clinical products. This article reviews various extracts and secondary metabolites from plants and microbial origin with PL inhibitory activity that can be focused for drug development programs. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3471 | null | HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia.
BACKGROUND: Orange juice-a rich source of vitamin C, folate, and flavonoids such as hesperidin-induces hypocholesterolemic responses in animals. OBJECTIVE: We determined whether orange juice beneficially altered blood lipids in subjects with moderate hypercholesterolemia. DESIGN: The sample consisted of 16 healthy men and 9 healthy women with elevated plasma total and LDL-cholesterol and normal plasma triacylglycerol concentrations. Participants incorporated 1, 2, or 3 cups (250 mL each) of orange juice sequentially into their diets, each dose over a period of 4 wk. This was followed by a 5-wk washout period. Plasma lipid, folate, homocyst(e)ine, and vitamin C (a compliance marker) concentrations were measured at baseline, after each treatment, and after the washout period. RESULTS: Consumption of 750 mL but not of 250 or 500 mL orange juice daily increased HDL-cholesterol concentrations by 21% (P: < 0.001), triacylglycerol concentrations by 30% (from 1.56 +/- 0.72 to 2.03 +/- 0.91 mmol/L; P: < 0.02), and folate concentrations by 18% (P: < 0.01); decreased the LDL-HDL cholesterol ratio by 16% (P: < 0.005); and did not affect homocyst(e)ine concentrations. Plasma vitamin C concentrations increased significantly during each dietary period (2.1, 3.1, and 3.8 times, respectively). CONCLUSIONS: Orange juice (750 mL/d) improved blood lipid profiles in hypercholesterolemic subjects, confirming recommendations to consume >/=5-10 servings of fruit and vegetables daily. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3518 | null | Melatonin in traditional Mediterranean diets.
Compared with other industrialized countries, the lower incidence of chronic-degenerative disorders in Mediterranean populations has been emphasized in recent decades. The health-promoting effects arising from Mediterranean dietary habits have been attributed to the large intake of plant foodstuffs rich in bioactive phytochemicals, such as melatonin. Recently, it has been suggested that melatonin present in edible plants may improve human health, by virtue of its biological activities and its good bioavailability. Plant melatonin, besides contributing to optimize the physiological functions regulated, in humans, by endogenous melatonin, may be involved in nutritional therapy to reduce the risk of cancer, cardiovascular and neurodegenerative diseases in western populations. In this view, the presence of melatonin in some Mediterranean foods and beverages adds a new element to the hypothesis of health benefits associated to Mediterranean dietary patterns, although the available data are still preliminary and incomplete. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3519 | null | Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality.
BACKGROUND: Tart Montmorency cherries have been reported to contain high levels of phytochemicals including melatonin, a molecule critical in regulating the sleep-wake cycle in humans. PURPOSE: The aim of our investigation was to ascertain whether ingestion of a tart cherry juice concentrate would increase the urinary melatonin levels in healthy adults and improve sleep quality. METHODS: In a randomised, double-blind, placebo-controlled, crossover design, 20 volunteers consumed either a placebo or tart cherry juice concentrate for 7 days. Measures of sleep quality recorded by actigraphy and subjective sleep questionnaires were completed. Sequential urine samples over 48 h were collected and urinary 6-sulfatoxymelatonin (major metabolite of melatonin) determined; cosinor analysis was used to determine melatonin circadian rhythm (mesor, acrophase and amplitude). In addition, total urinary melatonin content was determined over the sampled period. Trial differences were determined using a repeated measures ANOVA. RESULTS: Total melatonin content was significantly elevated (P < 0.05) in the cherry juice group, whilst no differences were shown between baseline and placebo trials. There were significant increases in time in bed, total sleep time and sleep efficiency total (P < 0.05) with cherry juice supplementation. Although there was no difference in timing of the melatonin circardian rhythm, there was a trend to a higher mesor and amplitude. CONCLUSIONS: These data suggest that consumption of a tart cherry juice concentrate provides an increase in exogenous melatonin that is beneficial in improving sleep duration and quality in healthy men and women and might be of benefit in managing disturbed sleep. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3532 | null | Application of LC and LC-MS to the analysis of melatonin and serotonin in edible plants.
Melatonin is a neurohormone produced by the pineal gland of animals. Serotonin is a monoamine neurotransmitter and one of the precursors of melatonin biosynthesis. These two indoleamines have recently been reported to have widespread occurrence in many edible plants. Consuming foodstuffs containing melatonin and serotonin could raise their physiologic concentrations in blood and enhance human health. Literature concerning analytical methods suitable for determination of melatonin and serotonin in edible plants is limited, although several liquid chromatographic (LC) techniques have been used for their quantification. Liquid chromatography-mass spectrometry (LC-MS) methods combine selectivity, sensitivity, and high precision, and enable the simultaneous determination of melatonin and serotonin. This work reviews LC and LC-MS techniques used to determine melatonin and serotonin, and the available data on melatonin and serotonin levels in edible plants. © 2011 Crown Copyright |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3533 | null | Effects of a Tart Cherry Juice Beverage on the Sleep of Older Adults with Insomnia: A Pilot Study
This study ascertained whether a proprietary tart cherry juice blend (CherryPharm, Inc., Geneva, NY, USA) associated with anecdotal reports of sleep enhancement improves subjective reports of insomnia compared to a placebo beverage. The pilot study used a randomized, double-blind, crossover design where each participant received both treatment and placebo for 2 weeks with an intervening 2-week washout period. Sleep continuity (sleep onset, wake after sleep onset, total sleep time, and sleep efficiency) was assessed by 2-week mean values from daily sleep diaries and disease severity by the Insomnia Severity Index in a cohort of 15 older adults with chronic insomnia who were otherwise healthy. The tart cherry juice beverage was associated with statistically significant pre- to post-treatment improvements on all sleep variables. When compared to placebo, the study beverage produced significant reductions in insomnia severity (minutes awake after sleep onset); no such improvements were observed for sleep latency, total sleep time, or sleep efficiency compared to placebo. Effect sizes were moderate and in some cases negligible. The results of this pilot study suggest that CherryPharm, a tart cherry juice blend, has modest beneficial effects on sleep in older adults with insomnia with effect sizes equal to or exceeding those observed in studies of valerian and in some, but not all, studies of melatonin, the two most studied natural products for insomnia. These effects, however, were considerably less than those for evidence-based treatments of insomnia: hypnotic agents and cognitive-behavioral therapies for insomnia. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3524 | null | Diet promotes sleep duration and quality.
Sleep, much like eating, is an essential part of life. The mechanisms of sleep are only partially clear and are the subject of intense research. There is increasing evidence showing that sleep has an influence on dietary choices. Both cross-sectional and epidemiologic studies have demonstrated that those who sleep less are more likely to consume energy-rich foods (such as fats or refined carbohydrates), to consume fewer portions of vegetables, and to have more irregular meal patterns. In this narrative review, we pose the opposite question: can ingested food affect sleep? The purpose of this review is to discuss the evidence linking diet and sleep and to determine whether what we eat and what kind of nutrients we obtain from the food consumed before bedtime matter. In addition, scientific evidence behind traditional sleep-promoting foods such as milk and some herbal products is briefly described. These are reviewed using data from clinical trials, mostly in healthy subjects. In addition, we discuss the possible mechanisms behind these observations. Lastly, we summarize our findings that emerging evidence confirms a link between diet and sleep. Overall, foods impacting the availability of tryptophan, as well as the synthesis of serotonin and melatonin, may be the most helpful in promoting sleep. Although there are clear physiological connections behind these effects, the clinical relevance needs to be studied further. Copyright © 2012 Elsevier Inc. All rights reserved. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3527 | null | Melatonin for the prevention and treatment of jet lag.
BACKGROUND: : Jet-lag commonly affects air travellers who cross several time zones. It results from the body's internal rhythms being out of step with the day-night cycle at the destination. Melatonin is a pineal hormone that plays a central part in regulating bodily rhythms and has been used as a drug to re-align them with the outside world. OBJECTIVES: : To assess the effectiveness of oral melatonin taken in different dosage regimens for alleviating jet-lag after air travel across several time zones. SEARCH STRATEGY: : We searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE, PsychLit and Science Citation Index electronically, and the journals 'Aviation, Space and Environmental Medicine' and 'Sleep' by hand. We searched citation lists of relevant studies for other relevant trials. We asked principal authors of relevant studies to tell us about unpublished trials. Reports of adverse events linked to melatonin use outside randomised trials were searched for systematically in 'Side Effects of Drugs' (SED) and SED Annuals, 'Reactions Weekly', MEDLINE, and the adverse drug reactions databases of the WHO Uppsala Monitoring Centre (UMC) and the US Food & Drug Administration. SELECTION CRITERIA: : Randomised trials in airline passengers, airline staff or military personnel given oral melatonin, compared with placebo or other medication. Outcome measures should consist of subjective rating of jet-lag or related components, such as subjective wellbeing, daytime tiredness, onset and quality of sleep, psychological functioning, duration of return to normal, or indicators of circadian rhythms. DATA COLLECTION AND ANALYSIS: : Ten trials met the inclusion criteria. All compared melatonin with placebo; one in addition compared it with a hypnotic, zolpidem. Nine of the trials were of adequate quality to contribute to the assessment, one had a design fault and could not be used in the assessment. Reports of adverse events outside trials were found through MEDLINE, 'Reactions Weekly', and in the WHO UMC database. MAIN RESULTS: : Nine of the ten trials found that melatonin, taken close to the target bedtime at the destination (10pm to midnight), decreased jet-lag from flights crossing five or more time zones. Daily doses of melatonin between 0.5 and 5mg are similarly effective, except that people fall asleep faster and sleep better after 5mg than 0.5mg. Doses above 5mg appear to be no more effective. The relative ineffectiveness of 2mg slow-release melatonin suggests that a short-lived higher peak concentration of melatonin works better. Based on the review, the number needed to treat (NNT) is 2. The benefit is likely to be greater the more time zones are crossed, and less for westward flights. The timing of the melatonin dose is important: if it is taken at the wrong time, early in the day, it is liable to cause sleepiness and delay adaptation to local time. The incidence of other side effects is low. Case reports suggest that people with epilepsy, and patients taking warfarin may come to harm from melatonin. REVIEWER'S CONCLUSIONS: : Melatonin is remarkably effective in preventing or reducing jet-lag, and occasional short-term use appears to be safe. It should be recommended to adult travellers flying across five or more time zones, particularly in an easterly direction, and especially if they have experienced jet-lag on previous journeys. Travellers crossing 2-4 time zones can also use it if need be. The pharmacology and toxicology of melatonin needs systematic study, and routine pharmaceutical quality control of melatonin products must be established. The effects of melatonin in people with epilepsy, and a possible interaction with warfarin, need investigation. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-3539 | null | Effect of kiwifruit consumption on sleep quality in adults with sleep problems.
Numerous studies have revealed that kiwifruit contains many medicinally useful compounds, among which antioxidants and serotonin may be beneficial in the treatment of the sleep disorders. The aim of this study was to evaluate the effects of kiwifruit on sleep patterns, including sleep onset, duration, and quality. In this study, we applied a free-living, self-controlled diet design. Twenty-four subjects (2 males, 22 females) 20 to 55 years of age consumed 2 kiwifruits 1 hour before bedtime nightly for 4 weeks. The Chinese version of the Pittsburgh Sleep Quality Index (CPSQI), a 3-day sleep diary, and the Actigraph sleep/activity logger watch were used to assess the subjective and objective parameters of sleep quality, including time to bed, time of sleep onset, waking time after sleep onset, time of getting up, total sleep time, and self-reported sleep quality and sleep onset latency, waking time after sleep onset, total sleep time, and sleep efficiency before and after the intervention. After 4 weeks of kiwifruit consumption, the subjective CPSQI score, waking time after sleep onset, and sleep onset latency were significantly decreased (42.4%, 28.9%, and 35.4%, respectively). Total sleep time and sleep efficiency were significantly increased (13.4% and 5.41%, respectively). Kiwifruit consumption may improve sleep onset, duration, and efficiency in adults with self-reported sleep disturbances. Further investigation of the sleep-promoting properties of kiwifruit may be warranted. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1342 | null | The Efficacy of Paroxetine and Placebo in Treating Anxiety and Depression: A Meta-Analysis of Change on the Hamilton Rating Scales
Background Previous meta-analyses of published and unpublished trials indicate that antidepressants provide modest benefits compared to placebo in the treatment of depression; some have argued that these benefits are not clinically significant. However, these meta-analyses were based only on trials submitted for the initial FDA approval of the medication and were limited to those aimed at treating depression. Here, for the first time, we assess the efficacy of a selective serotonin reuptake inhibitor (SSRI) in the treatment of both anxiety and depression, using a complete data set of all published and unpublished trials sponsored by the manufacturer. Methods and Findings GlaxoSmithKline has been required to post the results for all sponsored clinical trials online, providing an opportunity to assess the efficacy of an SSRI (paroxetine) with a complete data set of all trials conducted. We examined the data from all placebo-controlled, double-blind trials of paroxetine that included change scores on the Hamilton Rating Scale for Anxiety (HRSA) and/or the Hamilton Rating Scale for Depression (HRSD). For the treatment of anxiety (k = 12), the efficacy difference between paroxetine and placebo was modest (d = 0.27), and independent of baseline severity of anxiety. Overall change in placebo-treated individuals replicated 79% of the magnitude of paroxetine response. Efficacy was superior for the treatment of panic disorder (d = 0.36) than for generalized anxiety disorder (d = 0.20). Published trials showed significantly larger drug-placebo differences than unpublished trials (d’s = 0.32 and 0.17, respectively). In depression trials (k = 27), the benefit of paroxetine over placebo was consistent with previous meta-analyses of antidepressant efficacy (d = 0.32). Conclusions The available empirical evidence indicates that paroxetine provides only a modest advantage over placebo in treatment of anxiety and depression. Treatment implications are discussed. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1343 | null | Selective publication of antidepressant trials and its influence on apparent efficacy.
BACKGROUND: Evidence-based medicine is valuable to the extent that the evidence base is complete and unbiased. Selective publication of clinical trials--and the outcomes within those trials--can lead to unrealistic estimates of drug effectiveness and alter the apparent risk-benefit ratio. METHODS: We obtained reviews from the Food and Drug Administration (FDA) for studies of 12 antidepressant agents involving 12,564 patients. We conducted a systematic literature search to identify matching publications. For trials that were reported in the literature, we compared the published outcomes with the FDA outcomes. We also compared the effect size derived from the published reports with the effect size derived from the entire FDA data set. RESULTS: Among 74 FDA-registered studies, 31%, accounting for 3449 study participants, were not published. Whether and how the studies were published were associated with the study outcome. A total of 37 studies viewed by the FDA as having positive results were published; 1 study viewed as positive was not published. Studies viewed by the FDA as having negative or questionable results were, with 3 exceptions, either not published (22 studies) or published in a way that, in our opinion, conveyed a positive outcome (11 studies). According to the published literature, it appeared that 94% of the trials conducted were positive. By contrast, the FDA analysis showed that 51% were positive. Separate meta-analyses of the FDA and journal data sets showed that the increase in effect size ranged from 11 to 69% for individual drugs and was 32% overall. CONCLUSIONS: We cannot determine whether the bias observed resulted from a failure to submit manuscripts on the part of authors and sponsors, from decisions by journal editors and reviewers not to publish, or both. Selective reporting of clinical trial results may have adverse consequences for researchers, study participants, health care professionals, and patients. Copyright 2008 Massachusetts Medical Society. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1344 | null | Deception as treatment: the case of depression.
Is it ever right to prescribe placebos to patients in clinical practice? The General Medical Council is ambivalent about the issue; the American Medical Association asserts that placebos can be administered only if the patient is (somehow) 'informed'. The potential problem with placebos is that they may involve deception: indeed, if this is the case, an ethical tension arises over the patient's autonomy and the physician's requirement to be open and honest, and the notion that medical care should be the primary concern. This paper examines the case of depression as an entry point for understanding the complexities of the prescription of placebos. Recent important meta-analyses of antidepressants claim that they are not significantly more effective in a clinical setting than placebos. Given that antidepressants have numerous adverse side effects and are hugely expensive, this provocative research has serious potential ethical and practical implications for patients and medical providers. Should placebos be prescribed in place of antidepressants? The case of depression highlights another important issue which medical ethical codes have hitherto overlooked: well-being is not synonymous with being realistic about oneself, one's circumstances and the future. While severely depressed individuals are unduly pessimistic about themselves and the world around them, treatment of depressed individuals can be deemed successful when patients have successfully attained those positive illusions that are indicative of psychological health. This is exactly what successful psychological treatments of depression seem to achieve. It is therefore possible that there may be a limited unavoidable role for deception in medicine. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1345 | null | Challenging Received Wisdom: Antidepressants and the Placebo Effect
This article explores the reaction when an article challenging received wisdom is published and covered extensively by the media (1). The article in question was a meta-analysis of antidepressant clinical trials indicating that for most patients, difference between drug and placebo was not clinically significant. Reactions ranged from denial that the effects of antidepressants are so small to criticisms of the clinical trials that were analyzed. Each of these reactions is explored and countered. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1355 | null | Exercise for the treatment of depression and anxiety.
Depression and anxiety are the most common psychiatric conditions seen in the general medical setting, affecting millions of individuals in the United States. The treatments for depression and anxiety are multiple and have varying degrees of effectiveness. Physical activity has been shown to be associated with decreased symptoms of depression and anxiety. Physical activity has been consistently shown to be associated with improved physical health, life satisfaction, cognitive functioning, and psychological well-being. Conversely, physical inactivity appears to be associated with the development of psychological disorders. Specific studies support the use of exercise as a treatment for depression. Exercise compares favorably to antidepressant medications as a first-line treatment for mild to moderate depression and has also been shown to improve depressive symptoms when used as an adjunct to medications. While not as extensively studied, exercise has been shown to be an effective and cost-efficient treatment alternative for a variety of anxiety disorders. While effective, exercise has not been shown to reduce anxiety to the level achieved by psychopharmaceuticals. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1347 | null | Antidepressants and the placebo response.
AIMS: To evaluate new generation antidepressants in relation to the placebo response. METHODS: I review meta-analyses in which response to antidepressant medication and response to placebo were calculated. RESULTS: All but one of these meta-analyses included unpublished as well as published trials. Most trials failed to show a significant advantage of SSRIs over inert placebo, and the differences between drug and placebo are not clinically significant for most depressed patients. Documents obtained from the U.S. Food and Drug Administration (FDA) revealed an explicit decision to keep this information from the public and from prescribing physicians. CONCLUSIONS: Because they do not incur drug risks, exercise and psychotherapy, which show at benefits at least equal to those of antidepressants, may be a better treatment choice for depressed individuals. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1348 | null | Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration
Background Meta-analyses of antidepressant medications have reported only modest benefits over placebo treatment, and when unpublished trial data are included, the benefit falls below accepted criteria for clinical significance. Yet, the efficacy of the antidepressants may also depend on the severity of initial depression scores. The purpose of this analysis is to establish the relation of baseline severity and antidepressant efficacy using a relevant dataset of published and unpublished clinical trials. Methods and Findings We obtained data on all clinical trials submitted to the US Food and Drug Administration (FDA) for the licensing of the four new-generation antidepressants for which full datasets were available. We then used meta-analytic techniques to assess linear and quadratic effects of initial severity on improvement scores for drug and placebo groups and on drug–placebo difference scores. Drug–placebo differences increased as a function of initial severity, rising from virtually no difference at moderate levels of initial depression to a relatively small difference for patients with very severe depression, reaching conventional criteria for clinical significance only for patients at the upper end of the very severely depressed category. Meta-regression analyses indicated that the relation of baseline severity and improvement was curvilinear in drug groups and showed a strong, negative linear component in placebo groups. Conclusions Drug–placebo differences in antidepressant efficacy increase as a function of baseline severity, but are relatively small even for severely depressed patients. The relationship between initial severity and antidepressant efficacy is attributable to decreased responsiveness to placebo among very severely depressed patients, rather than to increased responsiveness to medication. Editors' Summary Background. Everyone feels miserable occasionally. But for some people—those with depression—these sad feelings last for months or years and interfere with daily life. Depression is a serious medical illness caused by imbalances in the brain chemicals that regulate mood. It affects one in six people at some time during their life, making them feel hopeless, worthless, unmotivated, even suicidal. Doctors measure the severity of depression using the “Hamilton Rating Scale of Depression” (HRSD), a 17–21 item questionnaire. The answers to each question are given a score and a total score for the questionnaire of more than 18 indicates severe depression. Mild depression is often treated with psychotherapy or talk therapy (for example, cognitive–behavioral therapy helps people to change negative ways of thinking and behaving). For more severe depression, current treatment is usually a combination of psychotherapy and an antidepressant drug, which is hypothesized to normalize the brain chemicals that affect mood. Antidepressants include “tricyclics,” “monoamine oxidases,” and “selective serotonin reuptake inhibitors” (SSRIs). SSRIs are the newest antidepressants and include fluoxetine, venlafaxine, nefazodone, and paroxetine. Why Was This Study Done? Although the US Food and Drug Administration (FDA), the UK National Institute for Health and Clinical Excellence (NICE), and other licensing authorities have approved SSRIs for the treatment of depression, some doubts remain about their clinical efficacy. Before an antidepressant is approved for use in patients, it must undergo clinical trials that compare its ability to improve the HRSD scores of patients with that of a placebo, a dummy tablet that contains no drug. Each individual trial provides some information about the new drug's effectiveness but additional information can be gained by combining the results of all the trials in a “meta-analysis,” a statistical method for combining the results of many studies. A previously published meta-analysis of the published and unpublished trials on SSRIs submitted to the FDA during licensing has indicated that these drugs have only a marginal clinical benefit. On average, the SSRIs improved the HRSD score of patients by 1.8 points more than the placebo, whereas NICE has defined a significant clinical benefit for antidepressants as a drug–placebo difference in the improvement of the HRSD score of 3 points. However, average improvement scores may obscure beneficial effects between different groups of patient, so in the meta-analysis in this paper, the researchers investigated whether the baseline severity of depression affects antidepressant efficacy. What Did the Researchers Do and Find? The researchers obtained data on all the clinical trials submitted to the FDA for the licensing of fluoxetine, venlafaxine, nefazodone, and paroxetine. They then used meta-analytic techniques to investigate whether the initial severity of depression affected the HRSD improvement scores for the drug and placebo groups in these trials. They confirmed first that the overall effect of these new generation of antidepressants was below the recommended criteria for clinical significance. Then they showed that there was virtually no difference in the improvement scores for drug and placebo in patients with moderate depression and only a small and clinically insignificant difference among patients with very severe depression. The difference in improvement between the antidepressant and placebo reached clinical significance, however, in patients with initial HRSD scores of more than 28—that is, in the most severely depressed patients. Additional analyses indicated that the apparent clinical effectiveness of the antidepressants among these most severely depressed patients reflected a decreased responsiveness to placebo rather than an increased responsiveness to antidepressants. What Do These Findings Mean? These findings suggest that, compared with placebo, the new-generation antidepressants do not produce clinically significant improvements in depression in patients who initially have moderate or even very severe depression, but show significant effects only in the most severely depressed patients. The findings also show that the effect for these patients seems to be due to decreased responsiveness to placebo, rather than increased responsiveness to medication. Given these results, the researchers conclude that there is little reason to prescribe new-generation antidepressant medications to any but the most severely depressed patients unless alternative treatments have been ineffective. In addition, the finding that extremely depressed patients are less responsive to placebo than less severely depressed patients but have similar responses to antidepressants is a potentially important insight into how patients with depression respond to antidepressants and placebos that should be investigated further. Additional Information. Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050045. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1349 | null | Antidepressants and the Placebo Effect
Antidepressants are supposed to work by fixing a chemical imbalance, specifically, a lack of serotonin in the brain. Indeed, their supposed effectiveness is the primary evidence for the chemical imbalance theory. But analyses of the published data and the unpublished data that were hidden by drug companies reveals that most (if not all) of the benefits are due to the placebo effect. Some antidepressants increase serotonin levels, some decrease it, and some have no effect at all on serotonin. Nevertheless, they all show the same therapeutic benefit. Even the small statistical difference between antidepressants and placebos may be an enhanced placebo effect, due to the fact that most patients and doctors in clinical trials successfully break blind. The serotonin theory is as close as any theory in the history of science to having been proved wrong. Instead of curing depression, popular antidepressants may induce a biological vulnerability making people more likely to become depressed in the future. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1350 | null | A Pill for the Ill? Patients’ Reports of Their Experience of the Medical Encounter in the Treatment of Depression
Background Starting in the 1960s, a broad-based patients’ rights movement began to question doctors’ paternalism and to demand disclosure of medical information, informed consent, and active participation by the individual in personal health care. According to scholars, these changes contributed to downplay the biomedical approach in favor of a more patient-oriented perspective. The Swedish non-profit organization Consumer Association for Medicines and Health (KILEN) has offered the possibility for consumers to report their perceptions and experiences from their use of medicines in order to strengthen consumer rights within the health care sector. Methodology In this paper, qualitative content analysis was used to analyze 181 KILEN consumer reports of adverse events from antidepressant medications in order to explore patients’ views of mental ill health symptoms and the doctor-patient interaction. Principal Findings Overall, the KILEN stories contained negative experiences of the patients’ medical encounters. Some reports indicated intense emotional outrage and strong feelings of abuse by the health care system. Many reports suggested that doctors and patients had very different accounts of the nature of the problems for which the patient was seeking help. Although patients sought help for problems like tiredness and sleeplessness (often with a personal crisis of some sort as a described cause), the treating doctor in most cases was exceptionally quick in both diagnosing depression and prescribing antidepressant treatment. When patients felt they were not being listened to, trust in the doctor was compromised. This was evident in the cases when the doctor tried to convince them to take part in medical treatment, sometimes by threatening to withdraw their sick-listing. Conclusions Overall, this study suggests that the dynamics happening in the medical encounter may still be highly affected by a medical dominance, instead of a patient-oriented perspective. This may contribute to a questionable medicalization and/or pharmaceuticalization of depression. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1351 | null | Conflicts of interest in psychiatry: strategies to cultivate literacy in daily practice.
The relationship between psychiatry and pharmaceutical companies has come under scrutiny during the past decade. Concerns are growing that financial ties of psychiatrists to the pharmaceutical industry may unduly influence professional judgments involving the primary interests of patients. Such conflicts of interest threaten the public trust in psychiatry. The goal of conflict of interest policies is to protect the integrity of professional judgment and to preserve public trust. The disclosure of individual and institutional financial relationships is a critical but limited first step in the process of identifying and responding to conflicts of interest. Conflict of interest policies and procedures can be strengthened by engaged psychiatrists, researchers, institutions, and professional associations in developing policies and consensus standards. Research on conflicts of interest can provide a stronger evidence base for policy design and implementation. Society has traditionally granted the medical profession considerable autonomy and may be willing to continue do so in the case of conflicts of interest. Nevertheless, concern is growing that stronger measures are needed. To avoid undue regulatory burdens, psychiatrists can play a vital role in designing responsible and reasonable conflict of interest policies that reduce the risks of bias and the loss of trust. Psychiatrists and the institutions that carry out research, education, clinical care, and practice guideline development must recognize public concerns about conflicts of interest and take effective measures soon to maintain public trust with a cultural change in the practice of psychiatry, from reactive treatment-seeking for mental illness to proactive advocacy for patients. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1352 | null | Primum Non Nocere: An Evolutionary Analysis of Whether Antidepressants Do More Harm than Good
Antidepressant medications are the first-line treatment for people meeting current diagnostic criteria for major depressive disorder. Most antidepressants are designed to perturb the mechanisms that regulate the neurotransmitter serotonin – an evolutionarily ancient biochemical found in plants, animals, and fungi. Many adaptive processes evolved to be regulated by serotonin, including emotion, development, neuronal growth and death, platelet activation and the clotting process, attention, electrolyte balance, and reproduction. It is a principle of evolutionary medicine that the disruption of evolved adaptations will degrade biological functioning. Because serotonin regulates many adaptive processes, antidepressants could have many adverse health effects. For instance, while antidepressants are modestly effective in reducing depressive symptoms, they increase the brain’s susceptibility to future episodes after they have been discontinued. Contrary to a widely held belief in psychiatry, studies that purport to show that antidepressants promote neurogenesis are flawed because they all use a method that cannot, by itself, distinguish between neurogenesis and neuronal death. In fact, antidepressants cause neuronal damage and mature neurons to revert to an immature state, both of which may explain why antidepressants also cause neurons to undergo apoptosis (programmed death). Antidepressants can also cause developmental problems, they have adverse effects on sexual and romantic life, and they increase the risk of hyponatremia (low sodium in the blood plasma), bleeding, stroke, and death in the elderly. Our review supports the conclusion that antidepressants generally do more harm than good by disrupting a number of adaptive processes regulated by serotonin. However, there may be specific conditions for which their use is warranted (e.g., cancer, recovery from stroke). We conclude that altered informed consent practices and greater caution in the prescription of antidepressants are warranted. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1353 | null | The drugs don’t work? antidepressants and the current and future pharmacological management of depression
Depression is a potentially life-threatening disorder affecting millions of people across the globe. It is a huge burden to both the individual and society, costing over £9 billion in 2000 alone: the World Health Organisation (WHO) cited it as the third leading cause of global disability in 2004 (first in the developed world), and project it will be the leading cause by 2030. The serendipitous discovery of antidepressants has revolutionized both our understanding and management of depression: however, their efficacy in the treatment of depression has long been debated and recently been brought very much into the public limelight by a controversial publication by Kirsch, in which the role of placebo response in antidepressant efficacy trials is highlighted. Whilst antidepressants offer benefits in both the short and long term, important problems persist such as intolerability, delayed therapeutic onset, limited efficacy in milder depression and the existence of treatment-resistant depression. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1354 | null | Antidepressant Drug effects and Depression Severity: A Patient-Level Meta-Analysis
Context Antidepressant medications represent the best established treatment for Major Depressive Disorder (MDD), but there is little evidence that they have a specific pharmacological effect relative to pill-placebo for patients with less severe depression. Objective To estimate the relative benefit of medication vs placebo across a wide range of initial symptom severity in patients diagnosed with depression. Data Sources Pubmed, PsycINFO, and the Cochrane Library databases were searched from January 1980 through March 2009, along with references from meta-analyses and reviews. Study Selection Randomized placebo-controlled trials of FDA approved antidepressants in the treatment of Major or Minor Depressive Disorder were selected. Studies were included if their authors provided the requisite original data, they comprised adult outpatients, included a medication vs placebo comparison for at least 6 weeks, did not exclude patients on the basis of a placebo washout period, and utilized the Hamilton Rating Scale for Depression. Data from six studies (718 patients) were included. Data Extraction Individual patient-level data were obtained from study authors. Results Medication vs placebo differences varied substantially as a function of baseline severity. Among patients with Hamilton scores below 23, Cohen’s d-type effect sizes for the difference between medication and placebo were estimated to be < .20 (a standard definition of a small effect). Estimates of the magnitude of the superiority of medication over placebo increased with increases in baseline Hamilton severity and crossed the NICE threshold for a clinically significant difference at a baseline score of 25. Conclusions The magnitude of benefit of antidepressant medication compared with placebo increases with severity of depression symptoms, and may be minimal or nonexistent, on average, in patients with mild or moderate symptoms. For patients with very severe depression, the benefit of medications over placebo is substantial. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1463 | null | Role of insulin in the pathogenesis of free fatty acid-induced insulin resistance in skeletal muscle.
Insulin resistance is a pathophysiological link of obesity to type 2 diabetes. The initial cause of insulin resistance is critical for prevention and treatment of type 2 diabetes. Lipotoxicity is a well-known concept in the explanation of initiation of insulin resistance. Although there are several prevailing hypotheses about the cellular/molecular mechanisms of lipotoxicity, such as inflammation, oxidative stress, hyperinsulinemia, and ER stress, the relative importance of these hypothesized events remains to be determined. The role of hyperinsulinemia is relatively under documented in the literature for the initiation of insulin resistance. In this review, an interaction of fatty acid and beta-cells, and a synergy between free fatty acids (FFAs) and insulin are emphasized for the role of hyperinsulinemia. This article presents the evidence about FFA-induced insulin secretion in vitro and in vivo, recent advances in the molecular mechanism of FFA action in beta-cells, a role of GPR40 in the development of insulin resistance, and the negative feedback loop of the insulin receptor signal pathway. The negative feedback loop is discussed in detail with a focus on IRS-1 serine kinases. This article provides a substantial support for the role of insulin in the early stages of FFA-associated insulin resistance. The hypothesis of insulin's role in lipotoxicity is referred to as the "insulin hypothesis" in this review. According to this hypothesis, prevention of increased beta-cell response to glucose may be a potential approach for early intervention of metabolic syndrome. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1454 | null | Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study.
AIMS/HYPOTHESIS: The amount and quality of fat in the diet could be of importance for development of insulin resistance and related metabolic disorders. Our aim was to determine whether a change in dietary fat quality alone could alter insulin action in humans. METHODS: The KANWU study included 162 healthy subjects chosen at random to receive a controlled, isoenergetic diet for 3 months containing either a high proportion of saturated (SAFA diet) or monounsaturated (MUFA diet) fatty acids. Within each group there was a second assignment at random to supplements with fish oil (3.6 g n-3 fatty acids/d) or placebo. RESULTS: Insulin sensitivity was significantly impaired on the saturated fatty acid diet (-10%, p = 0.03) but did not change on the monounsaturated fatty acid diet (+2%, NS) (p = 0.05 for difference between diets). Insulin secretion was not affected. The addition of n-3 fatty acids influenced neither insulin sensitivity nor insulin secretion. The favourable effects of substituting a monounsaturated fatty acid diet for a saturated fatty acid diet on insulin sensitivity were only seen at a total fat intake below median (37E%). Here, insulin sensitivity was 12.5% lower and 8.8% higher on the saturated fatty acid diet and monounsaturated fatty acid diet respectively (p = 0.03). Low density lipoprotein cholesterol (LDL) increased on the saturated fatty acid diet (+4.1%, p < 0.01) but decreased on the monounsaturated fatty acid diet (MUFA) (-5.2, p < 0.001), whereas lipoprotein (a) [Lp(a)] increased on a monounsaturated fatty acid diet by 12% (p < 0.001). CONCLUSIONS/INTERPRETATION: A change of the proportions of dietary fatty acids, decreasing saturated fatty acid and increasing monounsaturated fatty acid, improves insulin sensitivity but has no effect on insulin secretion. A beneficial impact of the fat quality on insulin sensitivity is not seen in individuals with a high fat intake (> 37E%). |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1455 | null | Lipotoxicity: Effects of Dietary Saturated and Transfatty Acids
The ingestion of excessive amounts of saturated fatty acids (SFAs) and transfatty acids (TFAs) is considered to be a risk factor for cardiovascular diseases, insulin resistance, dyslipidemia, and obesity. The focus of this paper was to elucidate the influence of dietary SFA and TFA intake on the promotion of lipotoxicity to the liver and cardiovascular, endothelial, and gut microbiota systems, as well as on insulin resistance and endoplasmic reticulum stress. The saturated and transfatty acids favor a proinflammatory state leading to insulin resistance. These fatty acids can be involved in several inflammatory pathways, contributing to disease progression in chronic inflammation, autoimmunity, allergy, cancer, atherosclerosis, hypertension, and heart hypertrophy as well as other metabolic and degenerative diseases. As a consequence, lipotoxicity may occur in several target organs by direct effects, represented by inflammation pathways, and through indirect effects, including an important alteration in the gut microbiota associated with endotoxemia. Interactions between these pathways may perpetuate a feedback process that exacerbates an inflammatory state. The importance of lifestyle modification, including an improved diet, is recommended as a strategy for treatment of these diseases. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1456 | null | Veganism and its relationship with insulin resistance and intramyocellular lipid.
OBJECTIVE: To test the hypothesis that dietary factors in the vegan diet lead to improved insulin sensitivity and lower intramyocellular lipid (IMCL) storage. DESIGN: Case-control study. SETTING: Imperial College School of Medicine, Hammersmith Hospital Campus, London, UK. SUBJECTS: A total of 24 vegans and 25 omnivores participated in this study; three vegan subjects could not be matched therefore the matched results are shown for 21 vegans and 25 omnivores. The subjects were matched for gender, age and body mass index (BMI). INTERVENTIONS: Full anthropometry, 7-day dietary assessment and physical activity levels were obtained. Insulin sensitivity (%S) and beta-cell function (%B) were determined using the homeostatic model assessment (HOMA). IMCL levels were determined using in vivo proton magnetic resonance spectroscopy; total body fat content was assessed by bioelectrical impedance. RESULTS: There was no difference between the groups in sex, age, BMI, waist measurement, percentage body fat, activity levels and energy intake. Vegans had a significantly lower systolic blood pressure (-11.0 mmHg, CI -20.6 to -1.3, P=0.027) and higher dietary intake of carbohydrate (10.7%, CI 6.8-14.5, P<0.001), nonstarch polysaccharides (20.7 g, CI 15.8-25.6, P<0.001) and polyunsaturated fat (2.8%, CI 1.0-4.6, P=0.003), with a significantly lower glycaemic index (-3.7, CI -6.7 to -0.7, P=0.01). Also, vegans had lower fasting plasma triacylglycerol (-0.7 mmol/l, CI -0.9 to -0.4, P<0.001) and glucose (-0.4 mmol/l, CI -0.7 to -0.09, P=0.05) concentrations. There was no significant difference in HOMA %S but there was with HOMA %B (32.1%, CI 10.3-53.9, P=0.005), while IMCL levels were significantly lower in the soleus muscle (-9.7, CI -16.2 to -3.3, P=0.01). CONCLUSION: Vegans have a food intake and a biochemical profile that will be expected to be cardioprotective, with lower IMCL accumulation and beta-cell protective. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1457 | null | A high-fat diet coordinately downregulates genes required for mitochondrial oxidative phosphorylation in skeletal muscle.
Obesity and type 2 diabetes have been associated with a high-fat diet (HFD) and reduced mitochondrial mass and function. We hypothesized a HFD may affect expression of genes involved in mitochondrial function and biogenesis. To test this hypothesis, we fed 10 insulin-sensitive males an isoenergetic HFD for 3 days with muscle biopsies before and after intervention. Oligonucleotide microarray analysis revealed 297 genes were differentially regulated by the HFD (Bonferonni adjusted P < 0.001). Six genes involved in oxidative phosphorylation (OXPHOS) decreased. Four were members of mitochondrial complex I: NDUFB3, NDUFB5, NDUFS1, and NDUFV1; one was SDHB in complex II and a mitochondrial carrier protein SLC25A12. Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC1) alpha and PGC1beta mRNA were decreased by -20%, P < 0.01, and -25%, P < 0.01, respectively. In a separate experiment, we fed C57Bl/6J mice a HFD for 3 weeks and found that the same OXPHOS and PGC1 mRNAs were downregulated by approximately 90%, cytochrome C and PGC1alpha protein by approximately 40%. Combined, these results suggest a mechanism whereby HFD downregulates genes necessary for OXPHOS and mitochondrial biogenesis. These changes mimic those observed in diabetes and insulin resistance and, if sustained, may result in mitochondrial dysfunction in the prediabetic/insulin-resistant state. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1458 | null | Higher insulin sensitivity in vegans is not associated with higher mitochondrial density.
BACKGROUND/OBJECTIVES: Vegans have a lower incidence of insulin resistance (IR)-associated diseases and a higher insulin sensitivity (IS) compared with omnivores. The aim of this study was to examine whether the higher IS in vegans relates to markers of mitochondrial biogenesis and to intramyocellular lipid (IMCL) content. SUBJECTS/METHODS: Eleven vegans and 10 matched (race, age, sex, body mass index, physical activity and energy intake) omnivorous controls were enrolled in a case-control study. Anthropometry, bioimpedance (BIA), ultrasound measurement of visceral and subcutaneous fat layer, parameters of glucose and lipid homeostasis, hyperinsulinemic euglycemic clamp and muscle biopsies were performed. Citrate synthase (CS) activity, mitochondrial DNA (mtDNA) and IMCL content were assessed in skeletal muscle samples. RESULTS: Both groups were comparable in anthropometric and BIA parameters, physical activity and protein-energy intake. Vegans had significantly higher glucose disposal (M-value, vegans 8.11±1.51 vs controls 6.31±1.57 mg/kg/min, 95% confidence interval: 0.402 to 3.212, P=0.014), slightly lower IMCL content (vegans 13.91 (7.8 to 44.0) vs controls 17.36 (12.4 to 78.5) mg/g of muscle, 95% confidence interval: -7.594 to 24.550, P=0.193) and slightly higher relative muscle mtDNA amount (vegans 1.36±0.31 vs controls 1.13±0.36, 95% confidence interval:-0.078 to 0.537, P=0.135). No significant differences were found in CS activity (vegans 18.43±5.05 vs controls 18.16±5.41 μmol/g/min, 95% confidence interval: -4.503 to 5.050, P=0.906). CONCLUSIONS: Vegans have a higher IS, but comparable mitochondrial density and IMCL content with omnivores. This suggests that a decrease in whole-body glucose disposal may precede muscle lipid accumulation and mitochondrial dysfunction in IR development. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1459 | null | Integrating Mechanisms for Insulin Resistance: Common Threads and Missing Links
Insulin resistance is a complex metabolic disorder that defies a single etiological pathway. Accumulation of ectopic lipid metabolites, activation of the unfolded protein response (UPR) pathway and innate immune pathways have all been implicated in the pathogenesis of insulin resistance. However, these pathways are also closely linked to changes in fatty acid uptake, lipogenesis, and energy expenditure that can impact ectopic lipid deposition. Ultimately, accumulation of specific lipid metabolites (diacylglycerols and/or ceramides) in liver and skeletal muscle, may be a common pathway leading to impaired insulin signaling and insulin resistance. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1460 | null | Mechanisms underlying skeletal muscle insulin resistance induced by fatty acids: importance of the mitochondrial function
Insulin resistance condition is associated to the development of several syndromes, such as obesity, type 2 diabetes mellitus and metabolic syndrome. Although the factors linking insulin resistance to these syndromes are not precisely defined yet, evidence suggests that the elevated plasma free fatty acid (FFA) level plays an important role in the development of skeletal muscle insulin resistance. Accordantly, in vivo and in vitro exposure of skeletal muscle and myocytes to physiological concentrations of saturated fatty acids is associated with insulin resistance condition. Several mechanisms have been postulated to account for fatty acids-induced muscle insulin resistance, including Randle cycle, oxidative stress, inflammation and mitochondrial dysfunction. Here we reviewed experimental evidence supporting the involvement of each of these propositions in the development of skeletal muscle insulin resistance induced by saturated fatty acids and propose an integrative model placing mitochondrial dysfunction as an important and common factor to the other mechanisms. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1461 | null | Intramyocellular triglyceride content is a determinant of in vivo insulin resistance in humans: a 1H-13C nuclear magnetic resonance spectroscopy as...
Insulin resistance is the best prediction factor for the clinical onset of type 2 diabetes. It was suggested that intramuscular triglyceride store may be a primary pathogenic factor for its development. To test this hypothesis, 14 young lean offspring of type 2 diabetic parents, a model of in vivo insulin resistance with increased risk to develop diabetes, and 14 healthy subjects matched for anthropomorphic parameters and life habits were studied with 1) euglycemic-hyperinsulinemic clamp to assess whole body insulin sensitivity, 2) localized 1H nuclear magnetic resonance (NMR) spectroscopy of the soleus (higher content of fiber type I, insulin sensitive) and tibialis anterior (higher content of fiber type IIb, less insulin sensitive) muscles to assess intramyocellular triglyceride content, 3) 13C NMR of the calf subcutaneous adipose tissue to assess composition in saturated/unsaturated carbons of triglyceride fatty acid chains, and 4) dual X-ray energy absorption to assess body composition. Offspring of diabetic parents, notwithstanding normal fat content and distribution, were characterized by insulin resistance and increased intramyocellular triglyceride content in the soleus (P < 0.01) but not in the tibialis anterior (P = 0.19), but showed a normal content of saturated/unsaturated carbons in the fatty acid chain of subcutaneous adipocytes. Stepwise regression analysis selected intramyocellular triglyceride soleus content and plasma free fatty acid levels as the main predictors of whole body insulin sensitivity. In conclusion, 1H and 13C NMR spectroscopy revealed intramyocellular abnormalities of lipid metabolism associated with whole body insulin resistance in subjects at high risk of developing diabetes, and might be useful tools for noninvasively monitoring these alterations in diabetes and prediabetic states. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
nfcorpus-corpus-MED-1474 | null | Free fatty acids and skeletal muscle insulin resistance.
PURPOSE OF REVIEW: Acute exposure to fatty acids causes insulin resistance in muscle, and excess dietary lipid and obesity are also strongly associated with muscle insulin resistance. Relevant mechanisms, however, are still not fully elucidated. Here we examine the latest evidence as to why lipids might accumulate in muscle and the possible mechanisms for lipid-induced insulin resistance. RECENT FINDINGS: Muscle lipid metabolites such as long chain fatty acid coenzyme As, diacylglycerol and ceramides may impair insulin signalling directly. Crosstalk between inflammatory signalling pathways and insulin signalling pathways, mitochondrial dysfunction and oxidative stress have also been put forward as major contributors to the development or maintenance of lipid-induced insulin resistance in muscle. Several animal models with gene deletions in pathways of fatty acid synthesis and storage also show increased metabolic rate, reduced intramuscular lipid storage and improved insulin action when challenged with a high lipid load. SUMMARY: Studies in genetic and dietary obese animal models, genetically modified animals and humans with obesity or type 2 diabetes suggest plausible mechanisms for effects of fatty acids, lipid metabolites, inflammatory pathways and mitochondrial dysfunction on insulin action in muscle. Many of these mechanisms, however, have been demonstrated in situations in which lipid accumulation (obesity) already exists. Whether the initial events leading to muscle insulin resistance are direct effects of fatty acids in muscle or are secondary to lipid accumulation in adipose tissue or liver remains to be clarified. |
nfcorpus-queries-PLAIN-1667 | null | muscle health |
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