Effect of weight loss and lifestyle changes on vascular inflammatory markers in obese women - A randomized trial

Context Obesity is an independent risk factor for cardiovascular disease, which may be mediated by increased secretion of proinflammatory cytokines by adipose tissue. Objective To determine the effect of a program of changes in lifestyle designed to obtain a sustained reduction of body weight on markers of systemic vascular inflammation and insulin resistance. Design and Setting Randomized single-blind trial conducted from February 1999 to February 2002 at a university hospital in Italy. Patients One hundred twenty premenopausal obese women (body mass index greater than or equal to30) aged 20 to 46 years without diabetes, hypertension, or hyperlipidemia. Interventions The 60 women randomly assigned to the intervention group received detailed advice about how to achieve a reduction of weight of 10% or more through a low-energy Mediterranean-style diet and increased physical activity. The control group (n = 60) was given general information about healthy food choices and exercise. Main Outcome Measures Lipid and glucose intake; blood pressure; homeostatic model assessment of insulin sensitivity; and circulating levels of interleukin 6 (IL-6), interleukin 18 (IL-18), C-reactive protein (CRP), and adiponectin. Results After 2 years, women in the intervention group consumed more foods rich in complex carbohydrates (9% corrected difference; P<.001), monounsaturated fat (2%; P-.009), and fiber (7 g/d; P<.001); had a lower ratio of omega-6 to omega-3 fatty acids (-5; P<.001); and had lower energy (-310 kcal/d; P<.001), saturated fat (-3.5%; P=.007), and cholesterol intake (-92 mg/d; P<.001) than controls. Body mass index decreased more in the intervention group than in controls (-4.2; P<.001), as did serum concentrations of IL-6 (-1.1 pg/mL; P=..009), IL-18 (-57 pg/mL; P=.02), and CRP (-1.6 mg/L; P=.008), while adiponectin levels increased significantly (2.2 mug/mL; P=.01). In multivariate analyses, changes in free fatty acids (P=.008), IL-6 (P=.02), and adiponectin (P=.007) levels were independently associated with changes in insulin sensitivity. Conclusion In this study, a multidisciplinary program aimed to reduce body weight in obese women through lifestyle changes was associated with a reduction in markers of vascular inflammation and insulin resistance.