Effects of sibutramine-induced weight loss on cardiovascular system in obese subjects

To assess efficacy of sibutramine in obese subjects, and influence on hemodynamics, valve function and left ventricular (LV) geometry and performance.

Three-month double-blind, parallel groups, randomized, placebo-controlled of 15 mg o.i.d. sibutramine administration combined with diet. Twenty-five to 65 year-old males or postmenopausal females, were enrolled if their BMI was between 30 and 40 kg/m(2), without evidence of concomitant diseases. Body weight, BMI, blood pressure (BP), echocardiographic LV mass, cardiac output, and diastolic function were measured. Body weight and BMI were better reduced with sibutramine (weight loss of 5% or more in 9 of 11 patients) than placebo group (weight loss of 5% or more in 5 of 9 patients; all p<0.05). Systolic and diastolic BP decreased similarly in both arms. No difference in mean heart rate was detected between treatments. The two groups had slightly different LV geometry at baseline. LV mass decreased with weight loss, more in the sibutramine group (p<0.05), due to reduction in LV chamber size. Stroke volume tended to be reduced in the sibutramine group, influencing diastolic pattern. E/A ratio tended to decrease in the sibutramine group without changes in isovolumic relaxation time and deceleration time of E velocity. No onset or increased severity of valve regurgitation was detected.

Combined to hypocaloric diet, sibutramine increases weight loss in obese individuals. Weight changes have positive effect on reduction of BP and contribute to reduce LV mass, the hallmark of markers of preclinical cardiovascular disease and most powerful predictor of adverse outcome.