oa The association of adiponectin gene polymorphism with gestational diabetes mellitus: The role of rs1501299 and rs2241766 variants

Background: Previous studies indicated changes of adiponectin levels during gestation. The adiponectin gene ADIPOQ is located on chromosome 3q27. The association of two single nucleotide polymorphisms (SNPs) (rs1501299 and rs2241766) in ADIPOQ gene with risk of gestational diabetes mellitus (GDM) was investigated among Arab pregnant women residing in Qatar. Methods: A case-control association study was performed on 115 pregnant women with GDM and 130 controls from Qatar. Genotypes were determined using TaqMan real time PCR assay. Fasting serum c-peptide, leptin and adiponectin levels were determined using Multiplex ELISA technique. Results: All SNPs were within the Hardy-Weinberg Equilibrium (HWE). The frequency distribution of the genotype 276 G-T (rs1501299) revealed that (40.9%), (45.6%), had GG and (53.0%), (44.0%) had GT, and (6.1%), (10.4%) had TT between GDM and control, respectively with P value= 0.261. The frequency distribution of the genotype 45T-G (rs2241766) revealed that (20.8%), (16.1%), had TT and (69.6%), (65.4%) had TG, and (9.6%), (18.5%) had GG between GDM and control, respectively with P value= 0.117. T and G alleles were the minor alleles for 276 G-T and 45T-G with a frequency of (0.11) and (0.22), respectively. Using recessive genetic model, the logistic regression analysis reveled that the Odds ratio and 95% CI was 2.14 (1.01-4.95), p=0.04 for 45T-G and was 1.79 (0.69-4.65), p=0.22 for 276 G-T. Serum c-peptide (ng/ml), and leptin (ng/ml) was significantly lower in subjects having GG versus TT+TG alleles of 45T-G with mean and SEM (7.6±1.8 Vs. 17.3 ±1.2, p= 0.002), and (21.5± 2.5 Vs. 42.1± 2.8, p=0.035). Similar significant findings were observed for TT versus TG+GG genotypes for SNP 276G-T. Adiponectin levels (µg/ml) were not significantly different in subjects having GG versus TG+TT genotypes for 45T-G and for TT versus TG+GG genotypes for 276G-T with mean and SEM (17.1± 1.8 vs. 17.2±2.3, p=0.892 and 16.5±3.24 Vs. 19.8 ±1.8, p= 0.478), respectively. Conclusion: GG carriers of 45T-G may increase the odds of getting GDM among Arab residents in Qatar. Decreased pancreatic secretory function (C-peptide) with increased adiposity (leptin) among GG carriers of 45T-G and TT carriers of 276GT may explain its roles in the development of GDM.