Abstract:OBJECTIVE: To study the characteristics of bone mineral content (BMC) accretion and the correlation with sex maturity and physical development in adolescents. METHODS: In 161 healthy children aged 9～20 years, the BMC and total alkaline phosphatase (TALP) level were measured using the single photon absorptiometer (SPA) and biochemical methods respectively; the serum levels of bone gla protein (BGP), estrogen and testosterone were determined using RIA; the height and weight were measured routinely and the sex maturity rating was assessed using the Tanner's criteria. RESULTS: The periods of peak height and weight velocity in boys and girls were 11.5 ～13.7 and 9.7 ～11.3 years respectively. The peak BMC accrual occurred in 13.7～16.2 and 11.3 ～13.7 years in boys and girls respectively. BMC accretion in females was earlier compared with males and revealed a significant decline after 16 years of age. The accretion of BMC was highly correlated with the sex maturity rating and there were significant differences in BMC between different pubertal stages (P<0.01). The positive correlations between serum BGP and TALP levels and age were noted (r= 0.59 and r= 0.63 , respectively, both P< 0.01 ). The periods of peak serum BGP and ALP levels and peak height velocity (PHV) were coincident. CONCLUSIONS: There is a close correlation between BMC accretion and sex maturity. There is an asynchrony between BMC accrual and physical development in puberty.
