Association between vitamin D receptor ApaI and TaqI gene polymorphisms and gestational diabetes mellitus in an Iranian pregnant women population

• We studied the association between VDR ApaI and TaqI gene polymorphisms and GDM.
• A significant difference was found in the genotype distribution between GDM and non-GDM groups.
• Subjects with ApaI CC genotype and TaqI TT genotype were found significantly more likely to develop GDM.

It has been proposed that variants of the nuclear vitamin D receptor (VDR) gene are associated with a susceptibility to type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM). Our study was aimed to evaluate a possible association between the VDR ApaI (rs7975232) and TaqI (rs731236) gene polymorphisms and susceptibility to GDM in an Iranian pregnant women population. This case–control study was performed on a population of pregnant Iranian women, including 157 GDM and 157 non-GDM subjects.VDR ApaI and TaqI polymorphisms were assessed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Our finding showed that the genotypes frequency of VDR ApaI polymorphism was significantly different between GDM and non-GDM groups (χ2 = 8.5, P = 0.014). The CC genotype increased the risk of GDM as compared to the AA genotype (AA vs.CC, OR = 2.996, 95% CI = 1.278–7.022, P = 0.012). The genotype and allele frequencies of VDR TaqI polymorphism were significantly different between GDM and non-GDM subjects (χ2 = 7.27, P = 0.026, χ2 = 4.08, P = 0.043 respectively). A significant protection was shown against GDM in VDR TaqI genotypes and allele (TT vs.TC, OR = 0.523, 95% CI = 0.23–0.84, P = 0.007, TT vs. TC + CC, OR = 0.546, 95% CI = 0.35–0.86, P = 0.009, T vs. C, OR = 0.711, 95% CI = 0.511–0.99, P = 0.043). In conclusion, our findings show a significant association between VDR ApaI and TaqI gene polymorphisms and the GDM at the investigated loci.