The influence of the adiponectin gene on adiponectin concentrations and parameters of metabolic syndrome in non-diabetic Korean women

Background: Concentrations of adiponectin, the protein product of the adipoctye C1q and collagen-domain-containing (ADIPOQ) gene are associated with type 2 diabetes and coronary artery disease. We investigate the association of single-nucleotide polymorphisms (SNPs) in the ADIPOQ gene with adiponectin concentrations, and to parameters of metabolic syndrome. Methods: 867 unrelated, non-diabetic Korean women, 20 to 69 y, were genotyped for 8 SNPs in the ADIPOQ gene (- 11391G > A, - 11377C > G, H241P, Y111H, G90S, R221S, 45T > G, 276G > T). Adiponectin, a homeostasis model assessment of insulin resistance (HOMA-IR), and metabolic parameters were measured. Results: Carriers of genotype T/T at position 276 had significantly higher adiponectin concentrations than G/G carriers (P = 0.005). Homozygous carriers of the TG haplotype (i.e., individuals who were T/T at 45 and G/G at 276) and heterozygous carriers of the TG haplotype (TG/X) had lower adiponectin concentrations than non-TG carriers (P < 0.001). Significant associations between SNP at 276 and serum concentrations of triglyceride (P = 0.013), insulin (P = 0.013) and HOMA-IR (P = 0.012) were found. The 45-276 haplotypes had associations identical to the 276G > T SNP. In subgroup analysis, subjects carrying the TG haplotype had significantly lower adiponectin concentrations than non-TG carriers in both normal weight (P < 0.001) and overweight-obese (P = 0.009) subgroups. The association of the TG haplotype with increasing insulin concentrations was significant among overweight-obese subjects (P = 0.004), but was not significant among normal weight subjects. A similar association was found between the 45-276 haplotype and HOMA-IR. Conclusion: There is a strong association of the adiponectin SNP276 genotypes and the adiponectin 45-276 haplotypes with circulating adiponectin concentrations in non-diabetic Korean women. In addition, this haplotype is associated with increased insulin concentrations and insulin resistance index only in overweight-obese individuals.