No abstract

Body composition, including bone, lean and fat mass, is known to be under complex physiologic and genetic regulation. The aim of the present study was to identify anthropometric, hormonal and genetic determinants of body composition in Brazilian physically active adolescent boys (12‐14y, n=47) by stepwise multiple regression analyze. Dependent variables were total body mineral content (TBMC), total body mineral density (TBMD), lean mass (LM) and percentage of body fat (%BF), assessed by DXA. Independent variables were chronological and bone age, weight, height, plasma testosterone and IGF‐1, serum iPTH, and VDR genotypes (FokI and TaqI). Results were as follows:*P<0.05, (P<0.01, #P<0.001Although body weight was the main factor influencing all the outcome variables, FokI polymorphisms appeared as a modest, but significant factor influencing TBMD and %BF. Our results support the complex regulation of body composition during adolescence. VDR‐ related mechanisms are possibly involved and appear to be sensitive to FokI polymorphisms.Financial support: CNPq and FAPERJ (Brazil).