Effects of weight loss on insulin sensitivity and arterial stiffness in overweight adults.
ABSTRACT Obesity is characterized by metabolic and vascular abnormalities. We examined the effects of weight loss on insulin sensitivity and arterial stiffness in overweight adults. Twelve (9 females; 3 males) overweight (body mass index, 30.3 +/- 3.7) adults (54.9 +/- 3.9 years) without diabetes or vascular disease were counseled by a registered dietician to lose weight over 6 months. Vascular structure, function, and wall mechanical properties were measured via ultrasound. Intravenous glucose tolerance test, 24-hour blood pressure, body composition (dual-energy x-ray absorptiometry), and lipids were also assessed. There were significant reductions in body mass (86.3 +/- 14.2 vs 79.5 +/- 13.8 kg, P < .0001) and percentage of fat (44.3% +/- 7.0% vs 41.0% +/- 8.5%, P < .01) after weight loss. There were significant improvements in total cholesterol (6.0 +/- 0.9 vs 5.0 +/- 0.8 mmol/L, P < .0001), low-density lipoprotein cholesterol (3.9 +/- 0.7 vs 3.2 +/- 0.6 mmol/L, P < .0001), triglycerides (3.4 +/- 2.3 vs 2.4 +/- 0.9 mmol/L, P < .05), and insulin sensitivity (3.3 +/- 1.7 vs 5.4 +/- 1.6 microU x 10(-4) min(-1) mL(-1), P < .0001) after weight loss. Brachial artery compliance (P < .05) and distensibility (P < .05) curves over the physiologic pressure range improved, whereas endothelial function and intima-media thickness remained unchanged. In overweight adults, 6 months of weight loss resulted in improvements in body composition, insulin sensitivity, lipid profile, and brachial artery compliance and distensibility.
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ABSTRACT: PURPOSE.: Given the role of arterial wall elasticity in the development of cardiovascular disease, carotid artery compliance and distensibility have been used commonly over the last decade as predictors of cardiovascular risk, although their gender differences remain unknown. The purpose of our study was to evaluate the impact of gender on carotid arterial elasticity in a large sample of children and adults. METHODS.: Carotid artery compliance and distensibility were measured with ultrasonography in 294 children (157 boys, 137 girls; ages 6-18 years) and 604 adults (291 men, 311 women; ages 18-49 years) previously recruited for a study investigating cardiovascular risk factors. An independent sample t test was used to compare demographic and carotid artery elasticity values by age and gender. RESULTS.: No significant gender difference in carotid arterial compliance and distensibility was observed in children. Women had significantly greater cross-sectional compliance than men (0.004 ± 0.000 versus 0.003 ± 0.000 1/mmHg, p = 0.041). CONCLUSIONS.: We found significant gender difference in carotid compliance in adults, but not in children, suggesting that gender differences in arterial stiffness are not present early in life but emerge later in adulthood. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012.Journal of Clinical Ultrasound 12/2012; · 0.70 Impact Factor
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ABSTRACT: BACKGROUND Obesity and aging are associated with increased arterial stiffness as indicated by an increased pulse-wave velocity (PWV). We evaluated the independent and combined effects on PWV and body composition of a hypocaloric diet and low-intensity resistance exercise training (LIRET) with slow movement. METHODS Forty-one postmenopausal women (mean age, 54±6 years; body mass index (BMI), 33.8±0.5kg/m(2)) were randomly assigned to LIRET (n = 14), diet (n = 13), or diet + LIRET (n = 14) for 12 weeks. The women's PWV, mean arterial pressure (MAP), body composition by dual-en ergy x-ray absorptiometry (DXA), and plasma adipokine and insulin levels were measured before and after the interventions. RESULTS Body weight (P = 0.0001), trunk-fat mass (FM, P = 0.0001), and the serum concentration of leptin (P = 0.02 and P = 0.004) decreased similarly with diet and diet + LIRET, but not with LIRET alone. Leg lean mass (LM) decreased (P = 0.02) with diet, but did not change with diet + LIRET or with LIRET alone. Leg muscle strength increased similarly with LIRET (P = 0.001) and diet + LIRET (P = 0.0001), but did not change with diet alone. Brachial-ankle PWV (baPWV) decreased with diet (P = 0.04) and diet + LIRET (P = 0.01), whereas femoral-ankle PWV (legPWV) decreased only with diet (P = 0.01). Mean arterial pressure (MAP) decreased after LIRET (P = 0.03), diet (P = 0.04), and diet + LIRET (P = 0.004). Carotid-femoral PWV, serum adiponectin concentration, and insulin were not significantly affected by the interventions examined in the study. The reductions in baPWV and legPWV were correlated with one another (r = 0.73, P = 0.0001), and the reductions in legPWV and trunk FM were also correlated with one another (r = 0.36, P = 0.03). CONCLUSIONS A hypocaloric diet decreases baPWV mainly by reducing legPWV, and this reduction is related to the loss of truncal fat. Although LIRET alone does not affect PWV or body composition, LIRET combined with diet improves baPWV and muscle strength while preventing loss of lean body mass in obese postmenopausal women.American Journal of Hypertension 03/2013; 26(3):416-23. · 3.67 Impact Factor
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ABSTRACT: OBJECTIVE: This study aims to examine the independent and combined impact of hypocaloric diet and low-intensity resistance exercise training (LIRET) on aortic hemodynamics and appendicular skeletal muscle mass (ASM) in obese postmenopausal women. METHODS: Forty-one obese postmenopausal women (mean [SD] age, 54  y) were randomly assigned to LIRET (n = 13), diet (n = 14), or diet + LIRET (n = 14). Body weight, waist circumference, aortic systolic blood pressure, aortic pulse pressure, augmentation index, subendocardial viability ratio (SEVR; myocardial perfusion), and heart rate (HR) were measured before and after 12 weeks. ASM was assessed by dual-energy x-ray absorptiometry. RESULTS: Body weight (P < 0.001) and waist circumference (P < 0.01) decreased similarly after diet and diet + LIRET compared with no changes after LIRET. ASM did not change after diet + LIRET, and the decrease observed after diet (P < 0.001) was significant compared with LIRET. Aortic systolic blood pressure decreased similarly after LIRET (P < 0.05), diet (P < 0.01), and diet + LIRET (P < 0.01). Aortic pulse pressure (P < 0.05) decreased similarly after diet and diet + LIRET, but not after LIRET. SEVR (P < 0.01) increased similarly in both diet groups, whereas HR (P < 0.01) decreased only after diet. Changes in SEVR (P < 0.05) and HR (P< 0.01) with diet were different compared with LIRET. The augmentation index did not change in any group. CONCLUSIONS: Our findings suggest that diet-induced weight loss may reduce cardiovascular risk by improving SEVR via HR and aortic pulse pressure reductions in obese postmenopausal women. LIRET prevents ASM loss associated with hypocaloric diet but has no additive effects on aortic hemodynamics.Menopause (New York, N.Y.) 03/2013; · 3.08 Impact Factor