Abstract
Eighty-seven male volunteers were grouped according to bone age (BA): 10–12 years (n=25), 13–15 years (n=36), and 16–18 years (n=26), and the following were recorded for each: weight (kg), height (m), BMI (kg/m2), calcium intake from three 24-h food recalls (mg/day), puberty evaluation by Tanner stages, bone biomarker (BB) evaluation, serum osteocalcin (OC), bone alkaline phosphatase (BAP), carboxyterminal telopeptide (S-CTx), and bone mineral density (BMD) evaluations by dual-energy X-ray absorptiometry (g·cm2) in the lumbar spine, proximal femur, and the whole body. BBs showed similar behaviors, and very high median values were observed for individuals aged 13–15 years (BAP=155.50 IU/L, OC=41.63 ng/mL, S-CTx=2.09 ng/mL). Lower median BB values were observed with advancing BA between 16 and 18 years (BAP=79.80 IU/L, OC=27.80 ng/mL, S-CTx=1.65 ng/mL). Stepwise multiple regression analysis showed body weight associated with BA as independent variables with greater determination power for S-CTx (r2=0.40) and OC (r2=0.21). For BAP, stepwise analysis showed body weight and whole-body BMD (r2=0.34). All predictive models showed significance (p<0.01). A high turnover for both bone formation and resorption biomarkers, particularly from 13 to 15 years of BA, were observed along with very low values in the 16–18 age range. Weight and BA were significant in determining predictive equations of OC and of S-CTx, whereas for BAP, weight and BMD of full body were selected.
©2012 by Walter de Gruyter Berlin Boston
