Impact of obesity on left ventricular systolic function in hypertensive subjects with normal ejection fraction

We sought to investigate the potential impact of obesity on left ventricular (LV) systolic function in patients with hypertension and normal ejection fraction (EF). In 112 hypertensive subjects with echocardiographic evidence of normal EF, M-mode left atrio-ventricular plane displacement, and Tissue Doppler-derived peak systolic velocity of the mitral annulus were measured and used as sensitive indices of longitudinal LV systolic dysfunction. The midwall stress-shortening relation was considered as a sensitive load-independent measure of circumferential LV myocardial contractility. There were no differences in either atrio-ventricular plane displacement or peak systolic velocity between normal weight, overweight, and obese subjects. In contrast, circumferential myocardial contractility tended to be reduced in overweight (90.3+/-14.4%) and was significantly depressed in obese (85.9+/-14.3%) as compared to normal weight individuals (95.3+/-14.8%; P=0.042). Multivariate analysis confirmed an independent negative association between body mass index (BMI) and myocardial contractility. The impact of BMI category on circumferential function did not differ between the study population and age- and gender-matched controls, suggesting additive interaction, rather than synergistic, between overweight-obesity and hypertension.