Risk factors for hypertension in obese women. The role of weight cycling.

Objective: To study significant factors associated with the risk of hypertension among obese women, with and without a history of weight cycling (WC). Design: Case-control study. Setting: Obesity Clinic of Chieti University, Italy. Subjects: A group of 258 obese women aged 25-64y (103 cases with hypertension and 155 controls) were recruited. All obese subjects had the same clinical characteristics, were without a family history for hypertension, were non-smokers, had normal lipidemic profiles and normal glucose tolerance, were not taking any medication and were otherwise healthy. Intervention: In the weight cycling women, the history of WC was established on the basis of at least five weight losses in the previous 5 y due to dieting, with a weight loss of at least 4.5 kg per cycle. A logistic regression model adjusted for confounding variables such as waist-to-hip ratio (WHR) and weight cycling history parameters was used and the odds ratio (OR) with 95% confidence intervals was calculated. Results: The risk of hypertension increases in subjects with larger WHR (OR 7.8; 95% CI 3.4-17.9) and with a positive history for WC (OR 4.1; 95% CI 2.4-6.9). Further, in obese patients with WC, the weight cycling index and the sum of the weight regained are also important risk factors for hypertension. Conclusions: These findings could support the hypothesis that it is the combined exposure of central-type obesity and WC that strongly raises the risk of hypertension.