IMPORTANCE OF OBESITY, RACE AND AGE TO THE CARDIAC STRUCTURAL AND FUNCTIONAL-EFFECTS OF HYPERTENSION

Objectives. The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy. B ackground. Obesity, race and age each have important effects on the in cidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifes tations of hyperte nsion. Methods. Left ventricular structure and function were assessed with two dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from bod y mass index), age, race, blood pressure, physical activity, plasma re nin activity, urinary sodium excretion, hematocrit, heart rate and ser um lipids. Results. Left ventricular hypertrophy was common (63% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis , body mass index was the strongest predictor of left ventric ular mas s and magnified the slope relation of blood pressure to left ventricul ar mass. Despite a greater prevalence of ECG left ventric ular hypertr ophy in blacks (31%) than in whites (10%), left ventric ular mass and echocardiographic prevalence of left ventricular hypertrophy did not d iffer by race. However, septal, posterior left ventricular and relativ e wall thickness were greater in black than in white men. Conclusions. Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy in men, even in those with mild to mo derate hypertension of sufficient severity to be associated with a hig h prevalence of left ventricular hyper trophy. Moreover, independent e ffects of systolic blood pressure on left ventricular mass are amplifi ed by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associat ed with greater relative wall thickness, itself a predictor of unfavor able cardio vascular outcome.