Aim: Vitamin D could have a direct effect on adipocyte differentiation and metabolism and might be involved in glucose regulation of insulin secretion. In recent years several polymorphisms in the gene encoding the vitamin D receptor (VDR), which are potent to alter the activity of VDR protein, have been described. The present study aimed to investigate the prevalence of the VDR BsmI polymorphism and its association with anthropometric and biochemical features of metabolic syndrome in postmenopausal women.
Materials and methods: We studied 351 randomly selected healthy postmenopausal women, with mean age of 55.43 +/- 2.75 years and mean body mass index (BMI) of 27.5 +/- 4.78 kg/m2, to evaluate the frequency of BsmI polymorphism (by restriction fragment length polymorphism-polymerase chain reaction) in the VDR gene and to find out whether there is an association between this polymorphism and BMI, total fat volume and visceral fat (as determined by total body dual-energy X-ray absorptiometry), blood pressure, lipid profile (total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides) glucose and fasting insulin in the whole group, as well as subgroups of obese and non-obese women.
Results: The prevalence of BsmI genotypes in the study group was 51.0% Bb, 37.3% bb and 11.7% BB. Genotype distribution did not differ from that expected under Hardy-Weinberg equilibrium conditions (chi2 = 2.95, p = 0.22). Apart from LDL-C levels (F = 3.46, p = 0.032), there were no significant differences in anthropometric or metabolic parameters between genotypes.
Conclusions: The BsmI polymorphism in the VDR gene does not seem to predispose to obesity and insulin resistance, but the BB genotype is connected with an unfavorable lipid profile.