海口地区0~6岁儿童25羟维生素D水平及维生素D受体基因多态性与骨密度关联性分析

目的 调查海口地区0~6岁儿童血清25羟维生素D[25-（OH）D]水平及维生素D受体（VDR）基因多态性与骨密度（BMD）的关联性。方法 选取2020年1—12月在海南省某专科医院医学中心进行健康体检的0~6岁健康儿童作为调查对象,检测其血清25-（OH）D水平、VDR基因多态性及BMD,比较不同性别、年龄、体质指数（BMI）、BMD儿童的血清25-（OH）D水平,比较BMD正常和异常儿童的VDR基因多态性,分析VDR基因多态性与BMD的关联性。结果 共纳入1 580名0~6岁健康儿童,男童838人,女童742人,平均年龄（2.49±1.20）岁。血清25-（OH）D水平为（34.66±5.87）ng/mL,维生素D缺乏、不足、充足儿童比例分别为4.49%、21.01%、74.49%。不同性别儿童血清25-（OH）D水平、维生素D营养状态分布差异无统计学意义（均P>0.05）;不同年龄、BMI、BMD儿童血清25-（OH）D水平、维生素D营养状态分布差异有统计学意义（P<0.05或P<0.01）。基因分型检测结果显示,0~6岁健康儿童VDR基因ApaⅠ位点存在多态性,基因型为AA、Aa、aa。BMD正常和异常儿童VDR基因ApaⅠ位点基因型、等位基因分布差异有统计学意义（均P<0.01）。多因素Logistic回归分析结果显示,VDR基因ApaⅠ位点基因型aa型（OR=3.729）、携带a等位基因（OR=2.656）儿童发生BMD异常的风险较高。结论 海口地区0~6岁儿童血清25-（OH）D水平与儿童年龄、BMI、BMD有关,且儿童VDR基因多态性与BMD异常的发生密切相关。

Investigation of 25-hydroxyvitamin D levels in children aged 0-6 years in Haikou and the relationship between vitamin D receptor gene polymorphism and bone mineral density

Objective To investigate the levels of serum 25-hydroxyvitamin D [25-（OH）D] in children aged 0-6 years in Haikou and the relationship between vitamin D receptor （VDR） gene polymorphism and bone mineral density （BMD）. Methods Healthy children aged 0 - 6 years who underwent physical examination in Hainan Women and Children's Medical Center from January to December 2020 were selected as the subjects to detect the serum 25-（OH）D levels, VDR gene polymorphism and BMD. The serum 25-（OH）D levels of children with different gender, age, body mass index （BMI） and BMD, the VDR gene polymorphism of children with normal and abnormal BMD were compared, and the relationship between VDR gene polymorphism and BMD was analyzed. Results A total of 1 580 healthy children aged 0-6 years were investigated, including 838 boys and 742 girls, with an average age of （2.49±1.20） years. The serum 25-（OH）D level was （34.66±5.87） ng/mL, and the proportion of children with vitamin D deficiency, insufficiency, and sufficiency was 4.49%, 21.01%, and 74.49%, respectively. There was no significant difference in serum 25-（OH）D levels and vitamin D nutritional status between children of different genders （both P>0.05）. There were significant differences in serum 25-（OH）D levels and vitamin D nutritional status between children with different age groups, BMI and BMD （P<0.05 or P<0.01）. The results of genotyping showed that there were polymorphisms in APa Ⅰ locus of VDR gene in healthy children aged 0-6 years, and the genotypes were AA, Aa, and aa. There were significant differences in genotype and allele distribution of APaⅠ locus of VDR gene between normal and abnormal BMD children （all P < 0.01）. Multivariate Logistic regression analysis showed that children with Apa Ⅰ genotype aa of VDR gene （OR = 3.729） and a allele （OR = 2.656） had a higher risk of abnormal BMD. Conclusion The level of serum 25-（OH）D in children aged 0-6 years in Haikou is related to children's age, BMI and BMD, and the VDR gene polymorphism in children is closely related to the occurrence of abnormal BMD.