Background The solute carrier family 30 A8 zinc transporter (SLC30A8) plays a vital role in insulin synthesis and secretion. This study aimed to investigate the association of rs13266634 C/T polymorphism in the Solute carrier family 30 member 8 (SLC30A8) gene with GDM risk among Iraqi pregnant women in addition to examine maternal serum zinc transporter 8 (ZnT8) and antibodies to ZnT8 (anti-ZnT8 Abs) levels during pregnancy both in women with or without GDM and their associations with SLC30A8 rs13266634 C/T SNP.
Methods A case-control study was carried out from November 2022- May 2023 in Baghdad Teaching Hospital/ Pregnancy Care unit/ Baghdad- Iraq. The study sample included 17–43-year-old women; 52 pregnant women with GDM and 50 non-GDM control pregnant women. GDM was diagnosed by the obstetrician based on HbA1c test and ultrasound. GDM risk was tested in a multivariable model, adjusted for age, gravidity and different pregnancy complications. Blood samples were collected from all participants and were genotyped for the rs13266634 SNP by Taqman Real Time quantitative polymerase chain reaction RT-PCR technique.
Results SLC30A8 rs13266634 C/T SNP was associated with an increased risk of GDM. The T allele frequency of SLC30A8 rs13266634 C/T SNP was significantly different between GDM and controls (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.3535 – 4.2959; P = 0.002). TT genotype versus CC genotype was significantly associated with higher GDM risk (OR = 48; 95% CI: (2.5235 to 91.7594); P = 0.01), and subjects with CT+TT genotype were more likely to have GDM compared to those with CC genotypes, (OR =3.2; 95% CI: 1.2475 – 8.2995; P = 0.009). Serum ZnT8Ab concentration was significantly increased among the GDM and non-GDM who had CT genotype (OR =6.500; 95% CI: 1.787- 23.644; P = 0.003).
Conclusions Our study shows that Iraqi pregnant women who are T allele carriers have a higher risk of GDM unlike C allele carriers. ZnT8Ab is protective from GDM while ZnT8 is an independent risk factor which was significantly higher in the GDM subjects.
