Bret Goodpaster

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..In summary, mitochondrial "deficiency" is not merely a reduced energy generation or low fatty acid oxidation; this concept should be expanded to numerous additional important functions, many of which can cause IR if perturbed...

..These dynamic PET imaging studies indicate that both quantity and quality of specific AT depots have distinct roles in systemic insulin resistance and may help explain the metabolically obese but normal-weight phenotype...

..Skeletal muscle lipid is associated with obesity and type 2 diabetes and may be altered by diet, physical activity, and weight loss...

..The balance between storage and use of muscle triglycerides is likely a key to the interaction between dysregulated fat and glucose metabolism by healthy and insulin resistant muscle...

..3 +/- 5.7%). In conclusion, regular physical activity prevents both the age-associated loss of muscle strength and increase in muscle fat infiltration in older adults with moderate functional limitations...

..We determined whether patterns of regional fat deposition are associated with metabolic syndrome in older adults...

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..The review particularly emphasizes methods to characterize regional fat distribution and ectopic fat (fat contained within other tissues) including specific applications and implications of region-specific or tissue-specific fat content...

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..The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking...

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..Adipose tissue produces "adipocytokines" of uncertain clinical significance...

..CONCLUSION: Race differences in AT distribution extend to IMAT, a depot that may influence race-ethnicity differences in dysglycemia...

..To determine whether lower lean mass and higher fat mass have independent effects on the loss of strength and muscle quality in older adults and might explain part of the effect of age...

..Because of the potential importance of subsarcolemmal mitochondria for signal transduction and substrate transport, this deficit may contribute to the pathogenesis of muscle insulin resistance in type 2 diabetes...

..In conclusion, exercise combined with weight loss enhances postabsorptive fat oxidation, which appears to be a key aspect of the improvement in insulin sensitivity in obesity...

..This change in the size of lipid droplets, likely coupled with a concomitant increase in oxidative enzyme capacity, is correlated to improved IS...

..We conclude that improved skeletal muscle ETC activity following moderate WL and improved aerobic capacity contributes to associated alleviation of insulin resistance...

..Therefore, several key deleterious effects of aging and/or obesity on the metabolic profile of skeletal muscle can be reversed with only moderate increases in physical activity...

..CONCLUSIONS Insulin resistance may not be characteristic of aging but rather associated with obesity and physical inactivity...

..In addition to both invasive (muscle biopsy) and noninvasive methods, techniques to assess other lipids within muscle will be reviewed...

..05). DISCUSSION: During moderate exercise, obese sedentary men have increased rates of fatty-acid oxidation from nonplasma sources and reduced rates of CHO oxidation, particularly muscle glycogen, compared with lean sedentary men...

..6 AU. The percentage of type I fibers significantly increased (P < 0.05) from 35.4 +/- 2.1 to 40.1 +/- 2.3%. In conclusion, exercise training increases IMCL in older persons in parallel with an enhanced capacity for fat oxidation...

..Further defining the links between muscle lipid accumulation and insulin action should help develop more effective strategies to prevent or treat type 2 diabetes and other obesity-associated disorders...

..We examined the effect of C-reactive protein (CRP) and interleukin-6 (IL-6) on the incident mobility limitation in older adults with and without diabetes...

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..The purpose of this study was to examine whether thyroid hormone status is related to the improvement in insulin sensitivity and physical fitness after weight loss and exercise training...

..01). In conclusion, exercise enhances mitochondria ETC activity in older human skeletal muscle, particularly in subsarcolemmal mitochondria, which is likely related to the concomitant increases in mitochondrial biogenesis...

..In conclusion, older men were more fatigue resistant than women, although in both men and women greater fatigue was not related to muscle weakness...

..Defining mechanisms by which dysregulation of fatty acid metabolism and persistent lipid oversupply alter insulin action may help to target more effective strategies to prevent or treat type 2 diabetes...

..Weight loss alone, however, significantly improves neither efficiency nor utilization of fat during exercise...

..Aging is associated with a loss of muscle mass and increased body fat. The effects of diet-induced weight loss on muscle mass in older adults are not clear...

..Although obesity is strongly associated with diabetes, the greater prevalence of diabetes in persons of African ancestry than in those of other ancestries cannot be explained simply by differences in total or central adiposity...

..Poor peripheral nerve function is prevalent in diabetes and older populations, and it has great potential to contribute to poor physical performance...

..Skeletal muscle fat has been identified as an important depot that increases with aging and may contribute to the development of diabetes...

..03 and 0.007, respectively). Our results suggest a novel association between common nonsynonymous coding variants in CPT1B and ectopic skeletal muscle fat among middle-aged and older African ancestry men...

..This inflexibility in fuel selection by skeletal muscle appears to be related to the accumulation of imTG and is an important aspect of IR of skeletal muscle in obesity and type 2 DM...

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..The specific activity of NADH oxidase (per mg cardiolipin) and NADH oxidase/citrate synthase and NADH oxidase/beta-HAD ratios are reduced two- to threefold in both T2DM and obesity...

..Weight loss may contribute to the loss of lean mass with age...

..Although muscle strength and mass are highly correlated, the relationship between direct measures of low muscle mass (sarcopenia) and strength in association with mortality has not been examined...

..To determine whether sensory and motor nerve function is associated cross-sectionally with quadriceps or ankle dorsiflexion strength in an older community-based population...

..In conclusion, diabetes is associated with lower skeletal muscle strength and quality. These characteristics may contribute to the development of physical disability in older adults with diabetes...

..This maintenance of muscle mass and strength may decrease or eliminate the falls, functional decline, and loss of independence that are commonly seen in aging adults...

..To examine the association between hospitalization and annual changes in body composition and strength in older adults...

..Sarcopenia is thought to be accompanied by increased muscle fat infiltration. However, no longitudinal studies have examined concomitant changes in muscle mass, strength, or fat infiltration in older adults...

..Our study examined the utility of preoperative weight loss with a liquid low-calorie diet (LCD) as a method of risk reduction...

..This technology is widely used in other medically ill populations but not yet in liver transplantation...

..In this review, we examine recent studies utilizing dynamic in-vivo PET imaging in assessing insulin resistance in humans...

..We also hypothesized that the expression of key skeletal muscle proteins involved in lipid droplet hydrolysis, DAG formation, and fatty-acid partitioning and oxidation would be associated with the lipotoxic phenotype...

..Evidence suggests that the degree of gluteal-femoral adiposity may be inversely associated with coronary artery disease (CAD) risk; however, this association has not been evaluated in type 1 diabetes (T1D)...

..Low albumin concentrations in older persons increase the risk of poor health outcomes, including functional decline...

..This study aims to investigate whether low muscle mass, low muscle strength, and greater fat infiltration into the muscle predict incident mobility limitation...

..This is an important finding in light of the importance of these process variables in behavior change and quality of life...

..We created a prediction rule in one sample and prospectively validated it for incident diabetes in a separate cohort...

..Our aim was to determine whether low leg muscle mass and greater fat infiltration in the muscle were associated with poor lower extremity performance (LEP)...

..Therefore, the purpose of this study was to determine whether estrogen use is associated with enhanced muscle composition and, if so, whether this translates into improved strength and physical function...

..To examine whether adiponectin is independently associated with diabetes and whether adiponectin and other adipocytokines account for the relationship between fat and diabetes...

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..Interventions to augment mitochondrial density and/or function are likely to improve the balance between FA uptake and oxidation and should be applied to prevent and/or treat insulin resistance...

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..The aim of the study was to investigate longitudinal changes of muscle mass and strength in community-dwelling older adults with and without type 2 diabetes...

..Among US adults, serum leptin concentrations are higher in women than in men and are higher in blacks than in whites independent of anthropometric measures of body fatness...

..Exercise is associated with mortality benefits but simply expending energy through any activity in an individual's free-living environment may confer survival advantages...

..Although several studies have described adaptations in muscle after reduced physical activity, the change in IMAT in healthy young adults is unknown...

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..Concern about the potential risks associated with hormone replacement therapy (HRT) has left post-menopausal women and healthcare providers searching for safe and effective means for cardiovascular disease (CVD) risk factor reduction...

..001, respectively). Findings from the current report support the utility of the LDCW to identify women at higher risk for CVD who may be candidates for further cardiovascular testing or intensive lifestyle intervention...

..The purpose of this study was to examine the relationship of metabolic syndrome to several adipokines and the role of total and visceral adiposity in influencing this relationship in older adults...

..Information emanating from this study would thus help to determine the most effective treatments to prevent weight regain and to improve outcomes of these patients following surgery. ..

..Resistance to the action of insulin to stimulate glucose uptake into muscle is a major risk factor to develop diabetes. This proposed research will identify causes for type 2 diabetes and point to new targets for effective treatment. ..

..Information emanating from this study would thus help to determine the most effective treatments to prevent weight regain and to improve outcomes of these patients following surgery. ..

..Resistance to the action of insulin to stimulate glucose uptake into muscle is a major risk factor to develop diabetes. This proposed research will identify causes for type 2 diabetes and point to new targets for effective treatment. ..

..Ultimately this should help identify mechanisms and therapeutic targets implicated in skeletal muscle metabolic dysregulation. ..

..Information emanating from this study would thus help to determine the most effective treatments to prevent weight regain and to improve outcomes of these patients following surgery. ..