Association of vitamin D status and genetic variants with type 2 diabetes in a Costa Rican population

Abstract

Aim: To assess the association between plasma 25-hydroxyvitamin D levels, gene polymorphisms involved in vitamin D metabolism, and the risk of type 2 diabetes in a Costa Rican population. Methods: 578 adults were enrolled in a case-control study from an urban Costa Rican population. Blood samples were collected to measure circulating vitamin D levels, glucose, hemoglobin A1c, lipid profile, and for the genotyping of 14 vitamin D related SNPs. The associations between plasma 25-hydroxyvitamin D levels, clinical and biochemical variables, gene polymorphisms, and type 2 diabetes were tested. Results: Classical risks factors as body mass index (OR: 1.13, p <0.001), and arterial hypertension (OR: 3.31, p <0.001) were associated with type 2 diabetes. In addition, type 2 diabetes was associated with 25-hydroxyvitamin D levels (OR: 0.97, p = 0.023). Polymorphisms in the GC gene (rs4588, rs7041, rs3755967, and rs22522679) were associated with plasma levels of vitamin D (all-p values <0.036). None of the SNPs assessed were associated with type 2 diabetes. Conclusion: Our findings suggest that GC gene polymorphisms contribute to interindividual variability in vitamin D status. Although these variants were not directly associated with type 2 diabetes in the present study, their potential role in vitamin D–related metabolic pathways warrant further investigation.