蛋白酶体α亚单位6基因-8C/G位点多态性与甘肃东乡族人群肥胖症和胰岛素抵抗的关系

Proteasome subunit alpha type 6-8C/G gene polymorphism and obesity and insulin resistance in diabetic patients of Dongxiang Nationality

目的 探讨蛋白酶体α亚单位6(proteasome subunit alpha type 6,PSMA6)基因多态性与甘肃东乡族人群肥胖症和胰岛素抵抗的相关性.方法 采用聚合酶链反应(polymerase chain reaction,PCR)-限制性片段长度多态性(restriction fragment length polymorphism,RFLP)技术对2006年3月至2008年3月甘肃东乡族住院和门诊就诊的2型糖尿病患者117例和同期接受体检的144名糖耐量正常者PSMA6基因-8C/G酶切位点进行多态性分析.以体重指数≥25定义为肥胖症,据此将正常糖耐量组及2型糖尿病组进一步分为肥胖症亚组和正常体质量亚组.以胰岛素抵抗指数(insulin resistance index,HOMA-IR)男性＜4.31、女性＜4.51为分割点,将正常糖耐量组及2型糖尿病组进一步分为胰岛素抵抗亚组和非胰岛素抵抗亚组.以放射免疫法测定各组人群空腹血清胰岛素水平,采用氧化酶法测定空腹血清葡萄糖水平.应用t检验及卡方检验进行统计学分析.结果 PSMA6基因-8C/G位点多态性与甘肃东乡族人群2型糖尿病有关(x^2=5.805,P=0.016),其多态性分布具有人种和地域差异.肥胖症组和胰岛素抵抗组PSMA6基因-8C/G位点G等位基因携带者(CG+GG)基因频率显著高于非肥胖症组和非胰岛素抵抗组(x^2=11.584,P=0.001;x^2=4.506,P=0.034).在正常糖耐量组,胰岛素抵抗亚组G等位基因携带者(CG+GG)基因型频率及G等位基因频率均显著高于非胰岛素抵抗亚组,差异有统计学意义(x^2=6.265,P=0.012;X2=4.572,P=0.033).结论 PSMA6基因-8C/G位点多态性与甘肃东乡族人群肥胖症和胰岛素抵抗相关,其多态性具有人种和地域差异.

Objective To study the association of proteasome subunit alpha type 6 (PSMA6) gene -8C/G polymorphism with obesity and insulin resistance in diabetic patients of Dongxiang Nationality.Methods The genotypes of-8C/G variant in PSMA6 gene were determined by polymerase chain reaction restriction fragment length polymorphisms assay in 117 patients with type 2 diabetes mellitus and 144 individuals with normal glucose tolerance (NGT) from March 2006 to March 2008.According to body mass index (BMI) or insulin resistance index (HOMA-IR),the patients in the type 2 diabetes mellitus group and NGT group were assigned into the obesity subgroup and normal body weight subgroup or insulin resistance subgroup and non-insulin resistance subgroup,respectively.Meanwhile,the fasting insulin and glucose levels were measured via radioimmunoassay.Results The genotype or allele frequencies of-8C/G variant in PSMA6 gene of type 2 diabetes mellitus group was significantly different from that of the NGT group (x^2 =5.805,P =0.016),either between patients with obesity and normal body weight subjects (x^2= 11.584,P=0.001),or between patients with insulin resistance and non-insulin resistance subjects (x^2 = 4.506,P=0.034).Moreover,the frequency of CG + GG genotype and allele C of insulin resistance subjects was significantly higher than that of the non-insulin resistance subjects in the NGT group(x^2 = 6.265,P =0.012;x^2=4.572,P=0.033).Conclusion The PSMA6-8C/G polymorphism is associated with diabetes and insulin resistance and closely related to obesity in people of Dongxiang Nationality.