RELATION OF OBESITY AND GENDER TO LEFT-VENTRICULAR HYPERTROPHY IN NORMOTENSIVE AND HYPERTENSIVE ADULTS

Although it is recognized that both hypertension and obesity are associated with increased left ventricular mass, the relative impacts of obesity, arterial hypertension, and gender on the prevalence of ventricular hypertrophy remain uncertain. Accordingly, echocardiographic left ventricular mass normalized for height to the power of the allometric or growth relation between ventricular mass and height was compared in 164 normotensive subjects (85 men [24 obese] and 79 women [28 obese], aged 45 +/- 12 years) and 475 hypertensive patients (325 men [126 obese] and 150 women [85 obese], aged 54 +/- 10 years) from an adult employed population. Gender-specific upper normal limits were used to identify ventricular hypertrophy. Left ventricular mass/height(2.7) was higher in obese than normal-weight normotensive subjects (P < .004) independently of the level of blood pressure and identified a higher prevalence of hypertrophy (mainly eccentric) in obese than in normal-weight normotensive subjects (14% versus 5%, P < .04), a difference that was not detected by left ventricular mass/body surface area. Left ventricular mass/height(2.7) identified hypertrophy in 52% of obese and 30% of normal-weight hypertensive patients (P < .0001) because of higher prevalences in obese than normal-weight patients of both eccentric (34% versus 20%) and concentric ventricular hypertrophy (18% versus 10%). The increase in left ventricular mass was independent of blood pressure values in obese normotensive women (but not men), and the prevalence of supranormal left ventricular mass/height(2.7) was even higher in hypertensive obese women (58%) than men (49%). Logistic analysis showed that body mass index was the main predictor of left ventricular hypertrophy in the entire population or hypertensive patients only (P < .0001 in both genders) and that the effect of blood pressure was smaller, especially in women. In conclusion, obesity is an independent stimulus to myocardial growth in the presence of normal blood pressure, and its effect is at least additive to that of high blood pressure in the presence of hypertension. The effect of obesity on cardiac anatomy is greater in women than in men, especially in the presence of arterial hypertension.