Objective: To analyze the relationship between serum vitamin D level and the risk of type 2 diabetes in Harbin residents. Methods: On April 2010, 24 communities in 7 districts of Harbin were selected as research sites using multi-stage stratified cluster random sampling method. A total of 9 734 residents aged 20-74 years was investigated using general questionnaire survey, dietary survey and biochemical indicators test and followed up from January 2015 to July 2016. A total of 4 721 subjects with serum vitamin D were included in the study. According to the quartile of baseline serum vitamin D, the subjects were divided into four groups, from Q1 to Q4 group. The multivariate logistic regression model was used to analyze the relationship between serum vitamin D and the risk of type 2 diabetes. A mediation analysis model was used to analyze the mediating role of insulin resistance in this risk relationship. Results: At the time of follow-up, 432 patients with type 2 diabetes were screened. The median (P(25), P(75)) age of the diabetic group and the non-diabetic group were 54 (49, 61) and 51 (43, 57) years, respectively, and males accounted for 40.5% (175 cases) and 35.5% (1 513 cases), respectively. The median (P(25), P(75)) serum vitamin D was 16.0 (13.5, 18.5) and 17.4 (14.3, 20.5) ng/ml, respectively. After relevant confounders and insulin resistance index (HOMA-IR) were adjusted, compared to the serum vitamin D level Q(1) group, the risk of diabetes was reduced by 40% in the Q(3) group with RR (95%CI) about 0.60 (0.44-0.82), while the risk of diabetes was reduced by 59% in Q(4) group with RR (95%CI) about 0.41 (0.29-0.57). Through mediation analysis, the Gutt index mediating effect representing peripheral insulin resistance was 53.8%, and the mediating effect of HOMA-IR representing hepatic insulin resistance was 6.6%. Conclusion: The risk of type 2 diabetes is low in Harbin residents with higher serum vitamin D level. Insulin resistance has a mediating effect on the relationship of vitamin D and the risk of type 2 diabetes.
目的： 分析哈尔滨居民血清维生素D水平与2型糖尿病发病风险的关联。 方法： 于2010年4月采取多阶段整群随机抽样方法，以哈尔滨7个区的24个社区为研究现场，对9 734名20~74岁居民进行问卷调查、膳食调查以及生化指标检测，于2015年1月至2016年7月进行随访，本研究共纳入4 721名检测了血清维生素D的调查对象。根据基线血清维生素D四分位数将调查对象分为Q1~Q4组，采用多因素logistic回归模型分析血清维生素D与2型糖尿病发病风险的关联。采用中介分析模型分析胰岛素抵抗在该风险关联中的中介作用。 结果： 随访时筛查出2型糖尿病患者432例。糖尿病组和未患糖尿病组年龄M（P(25)，P(75)）分别为54（49，61）、51（43，57）岁，男性分别占40.5%（175例）、35.5%（1 513名）。血清维生素D M（P(25)，P(75)）分别为16.0（13.5，18.5）、17.4（14.3，20.5）ng/ml。当调整相关混杂因素及稳态模型胰岛素抵抗指数（HOMA-IR）后，与血清维生素D水平Q(1)组相比，Q(3)组2型糖尿病发病风险减少40%，RR（95%CI）值为0.60（0.44~0.82）；Q(4)组2型糖尿病发病风险减少59%，RR（95%CI）值为0.41（0.29~0.57）。通过中介分析得出，代表外周胰岛素抵抗的Gutt指数中介效应为53.8%，代表肝脏胰岛素抵抗的HOMA-IR的中介效应为6.6%。 结论： 哈尔滨居民血清维生素D水平较高者2型糖尿病发病风险较低；胰岛素抵抗在维生素D与2型糖尿病发生风险关系中存在中介效应。.
Keywords: Cohort studies; Diabetes mellitus, type 2; Insulin resistance; Vitamin D.