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.