Age characteristics of bone metabolic index in healthy children and adolescents aged 5 to 14 years

doi:10.19538/j.ek2017100610

Abstract：Objective To study the gender and age distribution of bone metabolic markers in healthy children and adolescents (5-14 years old).Methods Detailed clinical documents were collected,and morning fasting 5 mL venous blood samples were drawn from 273 cases of the healthy volunteers and healthy school children.Automatic electrochemi-luminescence immunoassay analyzer was applied for the tests of bone formation markers [Procollagen type 1 nitrogenous propeptides (P 1NP),Osteocalcin (O C)] and bone resorption marker [β-Cross-linked C-terminal telopeptide of type 1 collagen (β-CTx)].The bone metabolic markers were used to calculate percentile values for the 5th,10th,25th,50th,75th,90th,and 95th percentiles in the 3 age groups respectively.Results The variation trends of bone formation markers (P1NP,OC) and bone resorption marker (β-CTx) in two gender groups were similar:being relatively low in preschool age and school age period,gradually increasing during preadolescence,reaching peak in adolescence and declining rapidly after adolescence.There were no significant differences in bone formation markers P 1NP (P =0.404) and 0C (P =0.766) between male and female groups,but there was significant difference in bone resorption marker β-CTx(P =0.01).Conclusion There are no statistically significant differences in the serum levels of P1NP or OC between male and female groups in the bone formation markers of healthy children aged 5-14 years.There is significant difference in bone resorption marker β-CTx between the two groups,the level of the boys being higher than the girls.According to the age distribution of the reference values,the increasing trend of bone metabolic parameters of the female group will appear 1 or 2 years earlier,the peak value being lower.