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 parameter, which is usually indexed to body surface area to allow comparisons to be made between individuals and groups of different body size. However, in obese subjects, using left ventricular mass indexed to body surface area may inappropriately normalize left ventricular mass.


OBJECTIVE
The aim of this study was to investigate the relationships between left ventricular mass and body composition and to determine the best determinants of left ventricular mass.


METHODS
Echocardiography and dual-energy X-ray absorptiometry were performed in 106 subjects under primary care. Half were hypertensive subjects and the others were normotensive age- and sex-matched control subjects. Univariate correlations were studied between left ventricular mass and height, height1.5, height2.7, weight, body surface area, body mass index, waist: hip ratio, fat-free mass, bone mineral content and fat mass. Stepwise multiple linear regression was performed to determine the best determinants 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 (R2 = 0.30, P= 0.0001) by multivariate analysis. Fat mass did not correlate with left ventricular mass (r= -0.005, P= 0.96). Other measures of body size, including body surface area, waist: hip ratio, bone mineral content, weight, height, height 1.5, height2.7 and body mass index all were correlated with, but were not independent determinants of, left ventricular mass.


CONCLUSIONS
Left ventricular mass is independently determined by fat-free mass but by no other measures of body size or composition. Specifically, left ventricular mass was neither correlated with nor determined by fat mass. None of the other measures of body size determined left ventricular mass. It may be more appropriate to index left ventricular mass to fat-free mass rather than to measures of body size which include fat mass.
Department of Medicine, University of Auckland School of Medicine, New Zealand. g.whalley@auckland.ac.nz
G A
GA
Whalley
G D
GD
Gamble
R N
RN
Doughty
A
A
Culpan
L
L
Plank
S
S
MacMahon
N
N
Sharpe
D000368:Aged; D001827:Body Height; D015992:Body Mass Index; D001830:Body Surface Area; D001835:Body Weight; D015519:Bone Density; D004452:Echocardiography; D005223:Fats / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D016277:Ventricular Function, Left
D005223:Fats