北京市郊区儿童维生素D营养状况与骨量的关系

Association between vitamin D status and bone mass of children in the suburbs of Beijing

目的了解北京市怀柔区儿童维生素D营养状况与骨量的关系,为改善我国儿童骨骼健康提供基础资料。方法采用横断面研究的方法 ,随机选取北京市怀柔区（北纬40.3°）381名7-11岁儿童,采集静脉血,用酶联免疫吸附法测定血清25-羟维生素D[25（OH）D]浓度,双能X线吸收仪测定前臂及全身骨矿物含量（BMC）、骨矿物密度（BMD）和骨面积（BA）。结果研究对象血清25（OH）D浓度平均为（44.4±12.5）nmol/L。血清25（OH）D浓度与身高、体重及全身和前臂的BMC、BMD和BA呈显著正相关（r=0.10~0.17;P〈0.05）;调整年龄、性别、身高和体重后,仅全身分部位中的左上肢BMC和左上肢及右上肢BA与血清25（OH）D浓度呈正相关（r=0.11-0.14;P〈0.05）,其余部位显著性消失。维生素D营养状况适宜儿童[25（OH）D〉50 nmol/L]的全身BMC比维生素D不足儿童[25（OH）D≤50 nmol/L]平均高4.2%（P〈0.05）,但调整混杂因素后差异消失。结论维生素D营养状况与北京郊区儿童体格发育正相关,从而对儿童骨量增加起到间接促进作用。

Objective To assess the association between vitamin D status and bone mass of children in Huairou district of Beijing and to provide scientific evidence for improving children′s bone health in China.Methods In a cross-sectional study,381 children aged 7-11 years were randomly recruited in Huairou district of Beijing.The concentration of 25-hydroxyvitamin D [25（OH）D]was determined by ELISA（IDS Ltd,UK）in a blood sample taken after an overnight fast.Bone mineral content（BMC）,bone mineral density（BMD） and bone area（BA） at total body and forearm were measured by dual energy X-ray absorptiometry（DEXA,Norland,USA）.Results The average serum 25（OH）D concentration was 44.4±12.5 nmol/L.Serum 25（OH）D concentration was significantly correlated with height,weight as well as BMC,BMD and BA of the total body and forearms（r=0.10-0.17,P0.05）.The correlation was still significant with the BMC of left arm and the BA of upper limbs after adjusting for age,gender,height and weight（r=0.11-0.14,P0.05）.The children with sufficient vitamin D[25（OH）D50 nmol/L]had 4.2% higher total body BMC than children with vitamin D deficiency [25（OH）D≤50 nmol/L].Conclusion Vitamin D had positive effect on anthropometric development,and indirectly increased bone mass accrual in Beijing children.