Relationship between left ventricle and body composition in young male and female athletes

Purpose: Competitive sports induce gradual cardiac adaptations in young athletes. During growth, changes occur in their body composition. The purpose of this study is to provide the left ventricular parameters indexed for body composition during young athletes’ growth. Methods: 220 young athletes (110 females and 110 males) aged from 8 to 19 years old were enrolled. An accurate body composition analysis and echocardiography were performed. The left ventricular parameters were then indexed to the body surface area formula with the data related to body composition (fat-free mass and body cellular mass). Results: The left ventricular and body composition parameters increased continuously during growth and no differences between the sexes were found before puberty. Higher fat mass was found in females from 12 years old (Fat Mass Index: Female=4.8±1.8kg/m2, Male=3.6±0.9 kg/m2; p<0.05). Cardiac differences started at 13 years old, with a greater left ventricular mass in males (Female=110.9±20.2 g, Male=128.7±23.7 g; p<0.05). The indexing of the left ventricle to the body composition parameters increased the age of onset of these cardiological differences to 14 years old with fat-free mass (Female=91.8±18.7 g/m2, Male=105.0±19.5 g/m2; p<0.05), or to 15 years old with body cell mass (Female=124.3±17.9 g/m2, Male=145.8±28.5 g/m2; p<0.05). Conclusions: Differences between the sexes appear to start after puberty. The above indexing was used in order to normalize the differences between the sexes according to body composition. This study reports the reference values for age and gender of the left ventricular parameters indexed for metabolically active mass.