Obesity
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Randomized Controlled Trial Comparative Study
Effects of a low carbohydrate weight loss diet on exercise capacity and tolerance in obese subjects.
Dietary restriction and increased physical activity are recommended for obesity treatment. Very low carbohydrate diets are used to promote weight loss, but their effects on physical function and exercise tolerance in overweight and obese individuals are largely unknown. The aim of this study was to compare the effects of a very low carbohydrate, high fat (LC) diet with a conventional high carbohydrate, low fat (HC) diet on aerobic capacity, fuel utilization during submaximal exercise, perceived exercise effort (RPE) and muscle strength. ⋯ On both diets, perception of effort during submaximal exercise and handgrip strength decreased (P
0.25). An LC weight loss diet shifted fuel utilization toward greater fat oxidation during exercise, but had no detrimental effect on maximal or submaximal markers of aerobic exercise performance or muscle strength compared with an HC diet. Further studies are required to determine the interaction of LC diets with regular exercise training and the long-term health effects. -
Randomized Controlled Trial Multicenter Study
Enhanced weight loss with pramlintide/metreleptin: an integrated neurohormonal approach to obesity pharmacotherapy.
The neurohormonal control of body weight involves a complex interplay between long-term adiposity signals (e.g., leptin), and short-term satiation signals (e.g., amylin). In diet-induced obese (DIO) rodents, amylin/leptin combination treatment led to marked, synergistic, fat-specific weight loss. To evaluate the weight-lowering effect of combined amylin/leptin agonism (with pramlintide/metreleptin) in human obesity, a 24-week, randomized, double-blind, active-drug-controlled, proof-of-concept study was conducted in obese or overweight subjects (N = 177; 63% female; 39 +/- 8 years; BMI 32.0 +/- 2.1 kg/m(2); 93.3 +/- 13.2 kg; mean +/- s.d.). ⋯ The greater reduction in body weight was significant as early as week 4, and weight loss continued throughout the study, without evidence of a plateau. The most common adverse events with pramlintide/metreleptin were injection site events and nausea, which were mostly mild to moderate and decreased over time. These results support further development of pramlintide/metreleptin as a novel, integrated neurohormonal approach to obesity pharmacotherapy.
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Despite the growing epidemic of extreme obesity in the United States, weight management is not adequately addressed in primary care. This study assessed family physicians' practices and attitudes regarding care of extremely obese patients and factors associated with them. A cross-sectional, self-administered survey was mailed to 500 family physicians in New Jersey (NJ) during March-May 2008. ⋯ Many providers encountered challenges performing examinations on extremely obese patients. More education of primary care physicians, particularly on bariatric surgery, specific examination techniques, and availability of community resources for obese persons is needed. Further research is needed to determine if interventions to increase knowledge of physicians will lead to less negative attitudes toward weight loss and extremely obese patients.
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Inflammation and insulin resistance associated with visceral obesity are important risk factors for the development of type 2 diabetes, atherosclerosis, and the metabolic syndrome. The 12/15-lipoxygenase (12/15-LO) enzyme has been linked to inflammatory changes in blood vessels that precede the development of atherosclerosis. The expression and role of 12/15-LO in adipocytes have not been evaluated. ⋯ Consistent with impaired insulin signaling, we found that insulin-stimulated 3T3-L1 adipocytes exhibited decreased IRS-1(Tyr) phosphorylation, increased IRS-1(Ser) phosphorylation, and impaired Akt phosphorylation when treated with 12/15-LO product. Taken together, our data suggest that 12/15-LO products create a proinflammatory state and impair insulin signaling in 3T3-L1 adipocytes. Because 12/15-LO expression is upregulated in visceral adipocytes by high-fat feeding in vivo and also by addition of palmitic acid in vitro, we propose that 12/15-LO plays a role in promoting inflammation and insulin resistance associated with obesity.
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Most studies of the economic costs of childhood obesity have focused upon hospitalization for comorbidities of obesity, whereas increased expenditures may also be the result of additional outpatient/emergency room visits or prescription drug expenditures. To quantify the magnitude of increased health-care utilization and expenditures among overweight and obese children, we performed descriptive, bivariate, and multivariable analyses on data from 6- to 19-year olds in the 2002-2005 Medical Expenditure Panel Survey (MEPS), a national probability survey of the noninstitutionalized civilian population in the United States. Compared with normal/underweight children, we found that children who were obese during both years of the MEPS had USD194 higher outpatient visit expenditures, USD114 higher prescription drug expenditures, and USD12 higher emergency room expenditures. ⋯ Increased costs and utilization were concentrated among adolescents, though 6-11-year-old children who were obese in both years did have more outpatient visits and expenditures than other children. Extrapolated to the nation, elevated BMI in childhood was associated with USD14.1 billion in additional prescription drug, emergency room, and outpatient visit costs annually. Although further research is needed to identify effective interventions, the immediate economic consequences of childhood obesity are much greater than previously realized, and further reinforce efforts to prevent this major comorbidity are needed.