Zinc transporter-8 gene (SLC30A8) is associated with type 2 diabetes in Chinese

Context: Several genome-wide association studies identified a strong association of SLC30A8 with type 2 diabetes in individuals of European ancestry. The effect of the association of rs13266634 with type 2 diabetes or related glycemic traits has not been fully extended to non-European populations, and a comprehensive examination of common variants in the gene has not yet been carried out in Han Chinese. Objective: The objective of the study was to investigate the association of SLC30A8 with type 2 diabetes in Chinese. Design: A comprehensive gene-based association study was performed using 14 tagging single-nucleotide polymorphism (SNPs) of SLC30A8 in Han Chinese subjects with normal glucose tolerance (NGT; n = 721), impaired glucose regulation (IGR; n = 375), and type 2 diabetes (n = 521). Results: A significant association for SNP rs13266634 was observed between patients with type 2 diabetes and NGT controls (P = 0.016). The association was also observed between combined type 2 diabetes/IGR and NGT subjects (P = 0.002). The adjusted odds ratios for homozygote CC vs. TT at this locus were 1.71 for type 2 diabetes (95% confidence interval 1.19-2.45, P = 0.002) and 1.77 for type 2 diabetes and IGR (95% confidence interval 1.29-2.42, P = 0.0001). We further studied the genotype-phenotype correlation in 70 Han Chinese using iv glucose tolerance test and found an association between SNP rs13266634 and acute insulin response to glucose and disposition index (adjusted P = 0.012 and 0.004, respectively). Conclusions: Our results provide evidence that SLC30A8 is a susceptible locus for type 2 diabetes in Chinese population, and its variant can influence insulin secretion.