Left ventricular mass correlates with fat-free mass but not fat mass in adults

Background Left ventricular mass is associated with body size, obesity and blood pressure. Echocardiography is routinely used to estimate this paramet er, which is usually indexed to body surface area to allow comparisons to b e made between individuals and groups of different body size. However, in o bese subjects, using left ventricular mass indexed to body surface area may inappropriately normalize left ventricular mass. Objectives The aim of this study was to investigate the relationships betwe en left ventricular mass and body composition and to determine the best det erminants of left ventricular mass. Subjects and methods Echocardiography and dual-energy X-ray absorptiometry were performed in 106 subjects under primary care. Half were hypertensive s ubjects and the others were normotensive age- and sex-matched control subje cts. Univariate correlations were studied between left ventricular mass and height, height(1.5), height(2.7), weight, body surface area, body mass ind ex, waist : hip ratio, fat-free mass, bone mineral content and fat mass. St epwise multiple linear regression was performed to determine the best deter minants of left ventricular mass. Results Fat-free mass was correlated with left ventricular mass (r = 0.53, P = 0.0001) and was the only independent predictor of left ventricular mass (R-2 = 0.30, P = 0.0001) by multivariate analysis. Fat mass did not correl ate with left ventricular mass (r = -0.005, P = 0.96). Other measures of bo dy size, including body surface area, waist : hip ratio, bone mineral conte nt, weight, height, height(1.5), height(2.7) and body mass index all were c orrelated with, but were not independent determinants of, left ventricular mass. Conclusions Left ventricular mass is independently determined by fat-free m ass but by no other measures of body size or composition. Specifically, lef t ventricular mass was neither correlated with nor determined by fat mass. None of the other measures of body size determined left ventricular mass. I t may be more appropriate to index left ventricular mass to fat-free mass r ather than to measures of body size which include fat mass. J Hypertens 199 9, 17:569-574 (C) Lippincott Williams & Wilkins.