KCNQ1 genetic variants are associated with obesity in the type 2 diabetic patients of han chinese ancestry

Abstract

Obesity has become a worldwide epidemic, and it is closely related to an elevated risk of developing type 2 diabetes. Obesity-associated genes exert influences on type 2 diabetes. However, whether genes associated with type 2 diabetes also confer susceptibility to obesity is still unclear. The aim of this study is to explore the association between the type 2 diabetes susceptibility gene KCNQ1 and obesity in a large Chinese Han population. In this cross-sectional study, we recruited 6668 adults comprising 3259 type 2 diabetic patients and 3409 non-diabetic control subjects from Shanghai and 6606 adults including 5962 type 2 diabetic patients and 644 non-diabetic controls from Hong Kong. rs2237892 and rs2237895 at KCNQ1 were genotyped for each participant. Anthropometric parameters including height,weight, waist circumference and hip circumference were measured and body mass index (BMI) and waist-hip ratio were calculated.Both single nucleotide polymorphisms (SNPs) were associated with overweight and obesity in type 2 diabetic patients (OR 1.129, 95% CI 1.054-1.208, P=0.0005 for rs2237892; OR 1.121, 95% CI 1.054-1.193, P=0.0003 for rs2237895). Both SNPs were also associated with BMI in type 2 diabetic patients (P=2.78null10-6 for rs2237892; P=1.98null10-5 for rs2237895). Moreover, a significant evidence for association with waist circumference ((beta)=0.0030 (plus or minus) 0.0010 per T allele, P=0.002 ) were found for rs2237892. However, neither an association with the risk of being overweight and obese nor associations with quantitative traitswas detected for these SNPs in non-diabetic controls.Our findings indicated that KCNQ1 was associated with obesity in the type 2 diabetic patients of Han Chinese ancestry.