[Study on the association between vitamin D and body fat distribution in children and adolescents].

Objective: To investigate the association of vitamin D with distribution of body fat in children and adolescents. Methods: Data were obtained from the baseline survey of School-based Cardiovascular and Bone Health Promotion Program in 2017. Multiple linear regression and multinomial logistic regression models were applied to analyze the relationships of body mass index (BMI), fat mass index (FMI), trunk fat mass index (TFMI), appendicular fat mass index (AFMI), and visceral fat area(VFA) with vitamin D level and status in children and adolescents. Results: A total of 11 960 children and adolescents were included in the analysis (boys accounting for 49.7%). The average age and serum vitamin D level of study population were (11.0±3.3) years and (35.0±11.9) nmol/L, respectively. The deficiency rate of vitamin D was 37.2%. Gender-specific associations of BMI, FMI, TFMI, and AFMI with vitamin D level were found (P for interaction <0.05): they were inversely associated with vitamin D level in boys (BMI: β=-0.56; FMI: β =-0.59; TFMI: β=-0.60; AFMI: β=-0.59; all P<0.05), but not in girls (P>0.05). VFA was positively associated with vitamin D deficiency and insufficiency in both boys and girls, and the risks of vitamin D deficiency and insufficiency all increased by 17%(95%CI: 9%-25%) for per increment of standard deviation in VFA. Conclusions: The higher level of visceral fat was associated with the lower vitamin D levels in children. Abdominal obese children and boys with excessive body fat are the key population in the prevention and control of vitamin D deficiency.目的： 探讨儿童身体脂肪分布与维生素D营养状况的关系。 方法： 研究对象来自“儿童青少年心血管与骨健康促进项目”2017年北京基线调查。采用多重线性回归和无序多分类logistic回归分析BMI、全身体脂肪质量指数（FMI）、躯干脂肪质量指数（TFMI）、四肢脂肪质量指数（AFMI）和内脏脂肪面积（VFA）与维生素D水平及营养状况的关系。 结果： 共纳入11 960名儿童［年龄（11.0±3.3）岁，男童占49.7%］进行分析，血清25（OH）D水平为（35.0±11.9） nmol/L，维生素D缺乏率为37.2%。BMI、FMI、TFMI和AFMI与维生素D的关联性具有性别差异（交互P<0.05），在男童中呈负相关（BMI：β=-0.56；FMI：β=-0.59；TFMI：β=-0.60；AFMI：β=-0.59；均P<0.05），在女童中关联无统计学意义（均P>0.05）。VFA与维生素D缺乏和不足风险在男女童中均呈正相关，VFA每增加1个标准差，维生素D缺乏和不足的患病风险均增加17%（95%CI：9%~25%）。 结论： 儿童内脏脂肪水平越高维生素D水平越低，腹型肥胖儿童和体脂肪过多的男童是维生素D缺乏防控的重点人群。.