Division of Epidemiology, Department of Medicine, Institute of Medicine and Public Health, Vanderbilt University School of Medicine, Nashville, TN 37203-1738, USA.
Int J Obes (Lond). 2012 Sep;36(9):1252-5. doi: 10.1038/ijo.2011.246. Epub 2011 Dec 13.
Vitamin D deficiency has been consistently associated with obesity. However, it is unclear whether vitamin D deficiency is the cause or consequence of obesity. We investigated this question by evaluating the association between genetic variants in vitamin D metabolism pathway genes and obesity-related traits. Using directly genotyped and imputed data from a genome-wide association study of 6922 women aged 25-70 years, we examined the association of 198 single-nucleotide polymorphisms (SNPs) in vitamin D pathway genes (CYP27A1, CYP27B1, CYP24A1, CYP2R1, group-specific component (GC) and vitamin D nuclear receptor (VDR)) with body mass index (BMI) and body weight. Per allele beta (β) estimates were calculated for this association using linear regression models, controlling for age, square of age, menopausal status and sample sets. Overall, only two SNPs (rs2248359 in CYP24A1 and rs10832313 in CYP2R1) had a nominally significant association with BMI and weight (P<0.05 for all), with no variation observed by menopausal status, physical activity or dietary energy intake. None of the SNPs examined in the VDR gene were associated with BMI or weight. Our findings suggest that common genetic variants in vitamin D pathway genes do not have a major role in obesity among Chinese women. This comprehensive evaluation of genetic polymorphisms in vitamin D metabolism-related genes and obesity-related traits did not provide strong evidence to support low vitamin D levels as a cause of obesity.
维生素 D 缺乏与肥胖症一直存在关联。然而，目前尚不清楚维生素 D 缺乏是肥胖的原因还是结果。我们通过评估维生素 D 代谢途径基因中的遗传变异与肥胖相关特征之间的关系来研究这个问题。利用来自年龄在 25-70 岁之间的 6922 名女性的全基因组关联研究中直接基因分型和推断的数据，我们研究了维生素 D 途径基因（CYP27A1、CYP27B1、CYP24A1、CYP2R1、组特异性成分（GC）和维生素 D 核受体（VDR））中 198 个单核苷酸多态性（SNP）与体重指数（BMI）和体重之间的关联。使用线性回归模型，我们针对年龄、年龄平方、绝经状态和样本集进行了校正，计算了每个等位基因的β估计值。总体而言，只有两个 SNP（CYP24A1 中的 rs2248359 和 CYP2R1 中的 rs10832313）与 BMI 和体重有显著的关联性（所有 SNP 的 P 值均<0.05），但未观察到绝经状态、身体活动或膳食能量摄入的影响。VDR 基因中检查的 SNP 与 BMI 或体重均无关联。我们的研究结果表明，中国女性中维生素 D 途径基因中的常见遗传变异对肥胖的作用不大。对维生素 D 代谢相关基因和肥胖相关特征的遗传多态性进行全面评估，并未提供强有力的证据支持低维生素 D 水平是肥胖的原因。
