KCNQ1 gene polymorphisms are associated with lipid parameters in a Chinese Han population

BACKGROUND Four single nucleotide polymorphisms (SNPs) (rs2237892, rs2237895, rs2237897, and rs2283228) in KCNQ1 are reported to be associated with type 2 diabetes mellitus (T2DM), possibly caused by a reduction in insulin secretion and higher fasting glucose, but the results are inconsistent. We investigated whether these 4 genetic markers are associated with serum lipid metabolism in a middle-aged Chinese Han population. METHODS We enrolled 398 consecutive patients, including 180 with premature coronary artery disease (CAD) (male < 55 years, female < 65 years) and 218 controls without documented CAD. All subjects were genotyped for 4 SNPs by using the ligase detection reaction method. Fasting blood sugar (FBS) and plasma concentrations of total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1(apo A1), and apolipoprotein B (apo B) were determined by standard biochemical methods. Main anthropometric and metabolic characteristics are analyzed among 3 genotypes at rs2283228, rs2237895, rs2237897, or rs2237892 in KCNQ1. RESULTS The 3 genotypes AA, AC, and CC were present in rs2283228 and rs2237895, and the 3 genotypes CC, CT, and TT were present in rs2237897 and rs2237892. The minor genotypes CC at rs2283228 and TT at rs2237892 were associated with higher levels of TG (P = 0.007 and 0.026, respectively). Furthermore, subjects with the CC genotype at rs2283228 had lower levels of HDL-C and apo A1 than in the other 2 genotype groups (P = 0.052 and 0.055, respectively). No other associations were detected between these 4 SNPs and FBS or other lipid parameters. CONCLUSIONS Our data suggest that rs2283228 and rs2237892 in KCNQ1 are associated with lipid metabolism in a middle-aged Chinese Han population.