Cardiovascular disease (CVD) remains the leading cause of death in women. CVD risk rises sharply with menopause, likely due to the coincident rise in insulin resistance and related atherogenic changes that together comprise the insulin resistance syndrome (IRS), a cluster of metabolic and hemodynamic abnormalities strongly implicated in the pathogenesis and progression of CVD. There is growing evidence that the practice of yoga may offer a safe and cost-effective strategy for reducing IRS-related risk factors for CVD. However, rigorous studies in Western populations are few and the effects of yoga on CVD risk profiles in healthy postmenopausal women have not been studied. This GCRC-approved randomized controlled trial will investigate the effects of an 8 week intensive lyengar yoga program on IRS-related indices of CVD risk in this population. Participants will be 60 healthy, sedentary postmenopausal women aged 50-75 years who are overweight and/or have a first degree relative with type 2 diabetes mellitus or essential hypertension. African American women will be oversampled. Our primary aim is to evaluate the effects of lyengar yoga on change in insulin sensitivity as estimated by the QUICKI, a measure that combines excellent reliability and validity with minimal subject burden. Our secondary aims are: 1) to assess the effects of yoga on other markers of insulin resistance (fasting glucose, insulin, glycated hemoglobin), and related indices of CVD risk, including measures of sympathetic activation, dyslipidemia, endothelial function, inflammation, coagulopathy, visceral adiposity, insulin-like growth factor bioavailability, heart rate variability, psychological morbidity, and sleep disturbance; and 2) to evaluate and optimize the overall protocol design, including recruitment, and retention rates, protocol adherence, and instrument burden in both minority and non-minority participants. The intervention will comprise 8 weeks of structured lyengar yoga training, including two 90 minute classes/week in addition to daily directed yoga practice at home. The control group will complete an 8 week standardized educational film program designed to be easily replicable and to assure comparability of time, staff attention, and social interaction. Both groups will also receive standard American Heart Association materials regarding menopause, aging, and heart disease in women. Before and after the 8 week treatment period, fasting blood samples will be collected, and specific markers of insulin resistance and related physiological, anthropometric, and psychological indices of CVD risk will be measured. This pilot study will yield important information on the potential utility of yoga in reducing CVD risk in postmenopausal women, a population at increased risk for CVD and related chronic disorders. Findings of this study will also provide critical preliminary and feasibility data to support a larger, 3-arm, multi-ethnic RCT investigating the influence of yoga practice on IRS-related indices of CVD risk in women post-menopause. ? ? ?
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