Association of body surface area and body composition with heart structural characteristics of female swimmers

In healthy nonathletic populations, some left ventricle (LV) parameters such as LV mass (LVM) and LV end diastolic dimension (LVEDD) can be predicted by some of body size parameters such as body surface area (BSA), fat-free mass (FFM), and height (H). These body size parameters use to remove covariate influence of body size from cardiac dimension variables and allow comparisons to be made between individuals and groups of different body size. Endurance exercise has been associated with changes in LV size and body composition of athletes. The aim of this study was to evaluate in 30 trained female swimmers (12-17 y) possible correlations between BSA, FFM, fat mass (FM) determined by bioelectrical impedance analyzer(BIA); and a range of cardiac dimensions derived by echocardiography. Univariate correlations were studied between left ventricular and body size variables. Stepwise multiple linear regression was performed to determine the best determinants of LV variables. LVM and LVEDD had a significant relation with FFM (P<0.001) and BSA (p<0.05). Left ventricle posterior wall thickness (PWT) had a significant relation with BSA (p<0.001) and FFM (p<0.005). No relation was found between heart's structural variable (LVM, LVEDD, LVESD and PWT) and FM. Using a multivariate regression analysis, FFM was the only independent predictor of both LVM (R2=0.541, P<0.001) and LVEDD (R2=0.189, P<0.05). These results suggest that Correction of LVM and LVEDD by FFM in athletes may be more appropriate than other measures of body size for indexing absolute amounts of LV dimension. Yet further researches in other athletes are required to confirm these findings.