Association of rs13266634 polymorphism in zinc transporter solute carrier family 30-member 8 gene with gestational diabetes mellitus

Abstract

Objective To study the single nucleotide polymorphism of rs13266634 (the genotype and the frequency) in SLC30A8 gene and its association with Gestational Diabetes Mellitus and relevant metabolic parameters. Methods A total of 451 24-28 weeks of pregnant women who visited Affiliated Hospital of Jining Medical College from October 2010 to March 2012 were enrolled in this case-control study. All the participants underwent 75 g oral glucose tolerance test (OGTT), 203 of them were diagnosed GDM (GDM group), and the others (248) were normal glucose tolerance (NGT group). The rs13266634 polymorphism in SLC30A8 gene was genotyped in 203 patients with Gestational Diabetes Mellitus and 248 pregnant women with normal glucose tolerance by PCR-RFLP analysis (polymerase chain reaction-restriction fragment length polymorphism). Meanwhile clinical characteristics such as body mass index(BMI), blood pressure(Bp), triglycerides (TG), total cholesterol (TC), low density lipoprotein cholesterin (LDL-C), high density lipoprotein cholesterin (HDL-C), etc were measured and calculated. HOMA-β and HOMA-IR were used to estimate β-cell function and insulin resistance. We used t-testing of independent samples to compare the difference between two groups and used analysis of variance to test the difference among the several groups. χ2analysis was used to compare the difference in genotype and allele frequencies. Logistic regression analysis was used to test for association between rs13266634 polymorphism in SLC30A8 gene and GDM. Results (1)In GDM group, the frequency of CC genotype (42.9%, 87/203) and C allele (65.5%, 266/406)were significantly higher than those (31.4%, 78/248 and 56.0%, 278/496)in the NGT group (χ2 were 6.259 and 8.362, both P<0.05); The TT genotype(11.8%, 24/203) and T allele(34.5%, 140/406) were significantly lower than those(19.4%, 48/248 and 44.0%, 218/496) in the NCT group (χ2 were 4.721 and 8.362, both P<0.05). (2)The C-allele significantly increased GDM risk with an allelic odd ratio (OR) of 1.49(OR=1.490, 95%CI: 1.136-1.953, P=0.004); Compared with non-carriers, homozygous carriers of C-allele were liable to have GDM with OR of 2.60(OR=2.600, 95%CI: 1.321-5.119, P=0.006). (3)From CC→CT→TT gene, HOMA-β level showed a growing trend (5.1±0.5→5.4±0.6→5.6±0.6, P<0.01). Conclusions The rs13266634 polymorphism in SLC30A8 gene is association with GDM in Shandong Jining, the C-allele might be a risk factor for GDM. SLC30A8 gene might be one of susceptible genes of GDM in this area. Key words: Single nucleotide polymorphism; SLC30A8 gene; Gestational diabetes mellitus; Association study