Associations of common polymorphisms in GCKR with type 2 diabetes and related traits in a Han Chinese population: a case-control study.

BACKGROUND

Several studies have shown that variants in the glucokinase regulatory protein gene (GCKR) were associated with type 2 diabetes and dyslipidemia. The purpose of this study was to examine whether tag single nucleotide polymorphisms (SNPs) in the GCKR region were associated with type 2 diabetes and related traits in a Han Chinese population and to identify the potential mechanisms underlying these associations.

METHODS

We investigated the association of polymorphisms in the GCKR gene with type 2 diabetes by employing a case-control study design (1118 cases and 1161 controls). Four tag SNPs (rs8179206, rs2293572, rs3817588 and rs780094) with pairwise r2>0.8 and minor allele frequency>0.05 across the GCKR gene and its flanking regions were studied and haplotypes were constructed. Genotyping was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy using a MassARRAY platform.

RESULTS

The G alleles of GCKR rs3817588 and rs780094 were associated with an increased risk of type 2 diabetes after adjustment for year of birth, sex and BMI (OR=1.24, 95% CI 1.08-1.43, p=0.002 and OR=1.22, 95% CI 1.07-1.38, p=0.002, respectively). In the non-diabetic controls, the GG carriers of rs3817588 and rs780094 were nominally associated with a lower plasma triglyceride level compared to the AA carriers after adjustment for year of birth, sex and BMI (p for trend=0.00004 and 0.03, respectively). Furthermore, the association of rs3817588 with plasma triglyceride level was still significant after correcting for multiple testing.

CONCLUSIONS

The rs3817588 A/G polymorphism of the GCKR gene was associated with type 2 diabetes and plasma triglyceride level in the Han Chinese population.