Association of Apal polymorphism of VDR gene with obesity in Iranian population

Introduction: Identifying the risk factors of obesity as a problem facing communities is crucial given its complexity. The vitamin D receptor (VDR) gene has been reported as a candidate for this disease in literature. Objective: To investigate the association of Apal, Bsml and Taql polymorphisms of VDR gene with obesity in part of Iranian population. Material and methods: In this study, genotypes of 348 obese (BMI >= 30 kg/m(2)) and 320 non-obese (BMI: 18.5-24.9 kg/m(2)) were analyzed by using PCR-RFLP method. The levels of FBS, TG, Total Cholesterol, HDL- Cholesterol and LDL- Cholesterol were measured by using an automatic biochemical analyzer. Results: The present findings showed significantly higher BMI, FBS and TG in the obese group compared to in the controls. In the obese individuals, the frequency of genotype AA was 47.1% and that of combined genotype Aa+aa 52.9%, whereas these figures were respectively 30% and 70% in the controls [P=0.024, 95% confidence interval (CI)=1.100-3.933, odds ratio (OR)=2.08]. The frequencies of A and a alleles for the Apal polymorphism were statistically significant in the two groups (allele A vs. a, P=0.017). No significant relationships were also observed between Taql genotypes and alleles in the controls and obese subjects. Conclusion: The present study found VDR Apal (rs7975232 C/A) polymorphism appeared to be a risk factor for obesity. In particular, A allele and genotype of AA in Apal were associated with the obesity phenotypes.