Replication of previous genome-wide association studies of and SNPs in a gestational diabetes mellitus case-control sample from Han Chinese population.

Four novel glucose metabolism risk loci (1 rs4746822, rs6517656, rs13342232 and rs998451) were identified in recent genome-wide association studies (GWAS) of Afro-Caribbean, European, Hispanic, Thai, Mexican, Latin American and Indian populations. None of the abovementioned SNPs has been reported in a Han Chinese population. To replicate the relationships between 1 rs4746822, rs6517656, rs13342232 and rs998451 with gestational diabetes mellitus (GDM) in a Han Chinese population. This was a case-control study which enrolled 334 pregnant women with GDM and 367 pregnant women with normal glucose tolerance. The linear regression and logistic regression were used to estimate the association between SNPs with the risk of GDM, HOMA-IR and fasting insulin levels. The fasting insulin concentration and HOMA-IR were log10 transformed before analysis. No significant differences in the alleles and genotypes of rs13342232, 1 rs4746822 and rs6517656 were observed between cases and controls. After adjusting the weekly BMI growth, pre-pregnancy BMI and maternal age, under the additive model, rs13342232 was associated with logfasting serum insulin (Beta=0.046, =0.016), logHOMA-IR level (Beta=0.061, =0.003) and fasting plasma glucose level (Beta=0.164, =0.011); 1 rs4746822 was associated with OGTT 2-hr plasma glucose level (Beta=0.239, =0.016); and rs6517656 was associated with logfasting serum insulin (Beta=-0.053, =0.044) and logHOMA-IR level (Beta=-0.060, =0.048). After correction for multiple testing, the associations of and 1 with glucose metabolism remained statistically significant. The A allele of rs998451 was not detected in this population. 1 rs4746822, rs6517656 and rs13342232 are associated with glucose metabolism in pregnant women of Han Chinese.