Association of single nucleotide polymorphism at position 45 in adiponectin gene with plasma adiponectin level and insulin resistance in obesity

Abstract

Objective To explore the association of single nucleotide polymorphism at position 45 (SNP45) in adiponectin gene with plasma adiponectin level and insulin resistance in obesity in Quanzhou area of Fujian province.Methods Two hundred and forty-eight patients with obesity and 225 normal control subjects were enrolled in this study.Fasting insulin (FINS) were measured by radioimmunoassay and fasting plasma glucose (FPG),total cholesterol (TC),triglyceride (TG),high density lipoprotein-cholesterol (HDL-C),low density lipoprotein-cholesterol (LDL-C) were measured by BECKMAN DXC800 biochemistry analyzer.Body mass index (BMI),waist to hip ratio,homeostasis model assessment of insulin resistance (HOMA-IR) were calculated.Plasma adiponectin levels were examined by means of enzyme-linked immunosorbentassy.The adiponectin gene SNP45 was identified by PCR-restriction fragment length polymorphism.Results ① Frequencies of GG+GT genotype in obesity group and normal control group were 61％ and 44％ respectively(x2=14.182,P＜0.01),and G allele frequencies were 35％ and 25％(~=10.708,P＜0.01).②In obesity group,the subjects with SNP45 GG+GT genotype had higher TG and LDL-C levels than those with TT genotype (t=2.604,P＜0.01; t=5.507,P＜0.01),and had lower adiponectin level than those with TT genotype (t=2.275,P＜0.05),and had significantly lower HDL-L level than those with TT genotype (t=10.100,P＜ 0.01).③ In normal control group,the subjects with SNP45 GG +GT genotype had significantly lower adiponectin,TG,TC levels than those with TT genotype (t=2.510,P＜0.05; t=2.922,P＜0.01; t=3.272,P＜ 0.01).④Logistic analysis proved that the SNP45 GG+GT genotype in obesity group was associated with decreased risk of plasma adiponectin level (OR=0.810,95％CI:0.673-0.975,P＜0.05),and with increased risk of HOMA-IR (OR=1.746,95％CI:1.060-2.875,P＜0.05).The SNP45 GG+GT genotype in normal control group was associated with increased risk of HOMA-IR (OR=3.962,95％CI:1.089-14.411,P＜0.05).Conclusions ①The distribution of adiponection of genotype and allele frequencies of the SNP45 were different in obesity and normal control groups.②The SNP45 in adiponectin was associated with obesity,insulin resistance and the total cholesterol,triglyceride,high density lipoprotein,low density lipoprotein levels.③The SNP45 in adiponectin was associated with the fasting adiponectin levels in obesity group. Key words: Obesity; Adiponectin; Single nucleotide, polymorphism; Insulin resistance; Radioimmunoassay