THE INFLUENCE OF BODY-COMPOSITION ON LEFT-VENTRICULAR MASS AND OTHER ECHOCARDIOGRAPHIC AND DOPPLER MEASUREMENTS IN 70-YEAR-OLD MALES

Heart morphology and function are often related to body size. The most common way to standardize for body composition is to divide these mea sures by body surface area (BSA). It has, however, been suggested that left ventricular mass (LV mass) ought to be indexed for height and th at cardiac output is influenced by the body fat distribution. As part of a health screening programme of 70-year-old males in Uppsala, Swede n, 100 consecutive men were investigated with echocardiography and Dop pler with regard to cardiac morphology and function. These measures we re related to an evaluation of body composition using an X-ray method (dual energy X-ray absorptiometry). Lean body mass was strongly relate d to BSA and body weight (r=0.90 and 0.89, respectively; P<0.0001), an d to a lesser degree to height (r=0.70, P<0.0001). In the healthy part of the population (n=39), relationships between LV mass on the one ha nd and lean body mass, BSA and height on the other were seen (r=0.51, 0.51 and 0.50, respectively; P<0.01). Stroke volume calculated accordi ng to Teichholtz (but not when calculated with Doppler) showed a signi ficant correlation to lean body mass (r=0.38, P<0.05). Also, left vent ricular diameter and the thickness of the free wall were related to le an body mass (r=0.40 and 0.39, respectively; P<0.05). All of the evalu ated relationships were generally weaker and in most cases no longer s ignificant when evaluated in the part of the population with diseases known to affect the heart. No significant correlations were seen betwe en the size of the left atrium, septal thickness or indices of diastol ic function (EIA-ratio, isovolumic relaxation time, deceleration time) and the indices of body composition. No measures of cardiac morpholog y and function were significantly related to the amount of body fat or body bone. LV mass, stroke volume and left ventricular diameter were found to be correlated with lean body mass, but not with the amount of fat, in healthy 70-year-old males. Theoretically, it is optimal to ad just for lean body mass, but in clinical practice, BSA is to be prefer red.