Relationship between vitamin D receptor BsmI and FokI polymorphisms and anthropometric and biochemical parameters describing metabolic syndrome

Introduction.?It was found that vitamin D may have a direct effect on adipocyte differentiation and metabolism and might be involved in the glucose regulation of insulin secretion, as suggested from the discovery of a nuclear localization of 1,25-(OH)₂D₃ in pancreatic islets. In recent years, several polymorphisms in the VDR gene which are able to alter the activity of VDR protein have been described. The BsmI and FokI polymorphisms were described in relation to obesity and type 2 diabetes.

The aim of the study was to find whether there are associations between BsmI and FokI polymorphisms and anthropometric (BMI, WHR, BP) and biochemical parameters describing metabolic syndrome.

Materials and methods.?Studied were 176 randomly selected men aged 25–65 years (mean: 51.99 years) with a mean BMI of 28.06 kg/m². Two polymorphisms of the VDR gene (FokI and BsmI) were explored using the PCR-RFLP method. Serum glucose, insulin, total cholesterol, LDL, HDL, and TG were measured using commercially available kits.

Results.?It was found that BB carriers tend to have higher BMI (29.00 ± 3.74 versus 26.81 ± 3.76, p = 0.024) and waist circumference (101.79 ± 10.59 versus 96.23 ± 10.35, p = 0.014) compared with the bb genotypes. Similarly, FF and Ff carriers had higher fasting insulin levels than the ff genotypes (12.30 ± 10.26 versus 9.76 ± 5.88, p = 0.001 and 9.76 ± 5.88 vs. 6.35 ± 2.64, p = 0.008), and lover cHDL levels in comparison to ff genotypes (52.28 ± 10.02 versus 60.63 ± 16.58, p = 0.015 and 53.70 ± 12.03 versus 60.63 ± 16.58, p = 0.032. Besides these, no significant differences were found.

Conclusions.?The BsmI VDR polymorphism seems to influence BMI, while the FokI VDR polymorphism appears to affect insulin sensitivity and serum cHDL level.