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 electrochemiluminescence immunoassay analyzer was applied for the tests of bone formation markers［Procollagen type 1 nitrogenous propeptides（P1NP），Osteocalcin（OC）］ 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 P1NP（P＝0.404） and OC （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.

Key words: child；bone metabolic marker；procollagen type 1 N-terminal propeptide；osteocalcin； &beta, -Cross-linked C-terminal telopeptide of type 1 collagen

摘要：

目的　研究5～14岁健康儿童青少年骨代谢标记物的性别和年龄分布。方法　选择2013年1月至2014年1月中国人民解放军总医院儿童医学中心和首都儿科研究所附属儿童医院招募的健康儿童青少年及接受入学体检的健康儿童青少年共273名，对其进行详细的临床资料收集。按照骨代谢标记物数值进行年龄段划分，并计算骨代谢标记物数值的第5、10、25、50、75、90、95百分位。结果　骨形成标记物和骨吸收标记物在不同性别中变化趋势一致，在学龄前期及学龄期水平较低，在青春前期开始增高，青春期达到峰值，并在青春期后快速降低。男性和女性的骨形成标记物：血清Ⅰ型前胶原氨基端延长肽（P1NP）（P＝0.404）及血清骨钙素（OC）（P＝0.766）比较差异均无统计学意义（P＞0.05）；骨吸收标记物：血清β-Ⅰ型胶原分解代谢产物C端交联肽（β-CTx）差异有统计学意义（P＝0.010）。结论　5～14岁健康儿童不同性别骨形成标记物血清P1NP、OC差异没有统计学意义，骨吸收标记物血清β-CTx差异有统计学意义。根据参考值的年龄分布特点，女性骨代谢指标增高的趋势较男性提前1～2岁，峰值低于男性。

关键词: 儿童, 骨代谢标志物, Ⅰ型前胶原氨基端延长肽, 骨钙素, &beta, -Ⅰ型胶原的分解代谢产物C端交联肽