Association of genetic variants in IGF-1 gene with susceptibility to gestational and type 2 diabetes mellitus

Abstract

Abstract IGF-1 has a pivotal role in regulating glucose homeostasis and sensitivity to insulin. The present study aimed at evaluating the association of three SNPs of IGF-1, rs35767, rs5742612, and rs2288377 with gestational diabetes mellitus (GDM) and type-2 diabetes mellitus (T2DM) risk. A total of 505 pregnant women (180 with T2DM, 160 GDM patients and 165 controls) were recruited. The SNPs of IGF-1 gene (rs35767, rs5742612 and rs2288377) were genotyped by real time polymerase chain reaction using Taqman® allelic discrimination assays. The TT genotype of rs35767and rs5742612 was associated with an elevated risk of T2DM and GDM compared to controls. In the dominant model, the CT\u202f+\u202fTT genotype of rs35767 and rs5742612 had an increased risk of developing GDM and T2DM in comparison to the CC genotype. In the recessive model, the TT genotype revealed a higher risk of developing T2DM and GDM than the CT\u202f+\u202fCC genotype. Moreover, IGF-1 rs2288377 was not found to be significantly associated. In addition, the individuals carrying TT genotype of rs35767 exhibited an elevated BMI in T2DM and GDM patients. However, carriers of the TT genotype in rs5742612 had an elevated BMI in pregnant women with T2DM. Conclusions Human IGF-1 gene may be a candidate gene for GDM and T2DM risk, as our study suggests a significant association between the IGF-I rs35767 and rs5742612 polymorphisms and the risk of T2DM and GDM in pregnant women, whereas there was no association for rs2288377.