Association of VDR gene ApaI polymorphism with obesity in Iranian population
Farzad Rashidi, Maryam Ostadsharif
Introduction: Identifying obesity risk factors as a health problem facing communities is crucial given its complexity. The vitamin D receptor gene has been reported as a possible cause of this disease. Objective: To study the association of the VDR gene ApaI, BsmI, and TaqI polymorphisms with obesity in an Iranian population. Material and methods: We analyzed the genotypes of 348 obese (BMI≥30 kg/m2 ) and 320 non-obese people (BMI: 18.5-24.9 kg/m2 ) using PCR-RFLP. We measured FBS, TG, total cholesterol, and HDL and LDL cholesterol levels in an automatic biochemical analyzer. Results: We found significantly higher BMI, FBS, and TG levels in the obese group compared to the control. In the obese individuals, the frequency of genotype AA was 47.1% and that of the combined Aa+aa genotype, 52.9% while in the control group they were 30% and 70%, respectively (p=0.024, 95% confidence interval (CI)=1.100-3.933, odds ratio (OR)=2.08). A and a alleles frequencies for the ApaI polymorphism were statistically significant in the two groups (allele A vs. a; p=0.017). No significant relationship was observed between TaqI genotypes and alleles in the control and obese subjects. Conclusion: We found that VDR ApaI (rs7975232 C/A) polymorphism appeared to be a risk factor for obesity. Especially, the A allele and the AA genotype in ApaI were associated with the obesity phenotypes.
Keywords: Obesity/genetic, vitamin D, polymorphism, genetic, body mass index, Iran