Vitamin D receptor FokI (rs2228570) polymorphism in diabetic patients

Abstract

Background: Vitamin D is a steroid hormone. Many biological actions are triggered by vitamin D. FoKI (rs2228570) is VDR single  nucleotide polymorphism. The FokI polymorphism is recognized by a start-codon alteration from cytosine to thymine, which results in  three amino acids shorter protein. T2DM has been associated with the FokI VDR gene polymorphism. The aim of this study was to  determine the relationship between the VDR gene polymorphism FokI and T2DM in Egyptians.

Method: This study was carried out on 111  subjects: 37 healthy individuals, 37 obese non-insulin-dependent diabetic patients with BMI > 30 kg/m², and 37 non-obese non- insulin-dependent diabetic patients with BMI < 24 kg/m². VDR FokI genotype was determined by PCR-RFLP, and the 25(OH)D level was  measured using the ELISA method.

Results: Diabetic patients had a significantly higher prevalence of the polymorphic genotype of the  VDR FokI polymorphism (ff) than the control group (OR = 4.9, 95% CI = 1.94-12.36, p = 0.0007). The FokI (f allele) allele frequency was  greater in the T2DM obese patients than in the control group and T2DM non-obese patients (p < 0.0001). Diabetic patients had lower 25- hydroxyvitamin D (25(OH)D) levels than individuals in the control group (P< 0.001).

Conclusions: The VDR polymorphism FokI's f allele  and f genotype may increase the risk of diabetes in Egyptians.