成都地区汉族人群PPARGC1A基因Thr394Thr位点G/A多态性与2型糖尿病及胰岛素抵抗的相关性研究

目的 了解中国成都地区汉族人群过氧化物酶体增殖物激活受体γ辅助激活因子-1α基因(peroxisome proliferator-activated receptor gamma,coactivator 1 alpha,PPARGC1A;又名PGC-1α)Thr394Thr位核苷酸G/A的基因型分布,探讨该多态性与2型糖尿病(type 2 diabetes mellitus,T2DM)、胰岛素抵抗及其他代谢异常的关系.方法 应用聚合酶链反应-限制性片段长度多态性技术检测151例无亲缘关系的T2DM患者和156名糖耐量正常对照者PPARGC1A基因Thr394Thr位核苷酸G/A多态性.所有研究对象均测定血糖、胰岛素、血脂,测量身高、体重、腰围、血压.结果 与正常对照组相比,T2DM组的体重指数、腰围、血压、甘油三酯水平均显著增高(P＜0.05),而高密度脂蛋白胆固醇(high density lipoprotein-cholesterol,HDL-C)水平显著降低(P＜0.05).A等位基因的频率在T2DM及正常对照组分别为22.5%、18.6%,AG基因型频率在两组分别为43.7%、37.2%,差异无统计学意义.在T2DM组中,AA+AG基因型的空腹胰岛素、稳态模型评估法胰岛素抵抗指数(homeostasis model aseessment-insulin resistance,HOMA-IR)及腰围明显高于GG基因型,HDL-C显著低于GG基因型(P＜0.05).无论T2DM和正常对照,A等位基因携带者HOMA-IR明显高于GG者.结论 PPARGC1A基因Thr394Thr位核苷酸G/A多态性与胰岛素抵抗存在明显相关,并可能与T2DM患者中心性肥胖及低HDL-C水平相关,其与T2DM发病的关系有待进一步研究.

PPARGC1A gene Thr394Thr G/A polymorphism and its association with type 2 diabetes mellitus and insulin resistance in a Chinese population

Objective To examine the association of the Thr394Thr polymorphism of PPARGC1A gene with type 2 diabetes (T2DM), insulin resistance (IR) and other metabolic disorders in a Chinese population. Methods Three hundred and seven subjects including 151 T2DM patients and 156 normal glucose tolerant controls (NC) were enrolled in this study. The Thr394Thr G/A polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).Glucose, insulin, lipids levels were determined in all subjects. Body mass index (BMI), waist circumferences, index of homeostasis model assessment-insulin resistance (HOMA-IR) and blood pressure were also measured. Results The diabetic subjects had higher levels of BMI, waist circumferences, blood systolic pressure, triglycerides and lower levels of high density lipoprotein-cholesterol(HDL-C) compared with those of control subjects (P＜0. 05). About 43.7% (66/151) of the T2DM subjects had the AG genotype, while 37.2% (58/156) in the NC group. The frequency of the A allele was 0. 225 in T2DM, and 0. 186 in the NC subjects. There were no significant differences either in genotype or allelic distribution of G/A polymorphism between the two groups. In the T2DM group, subjects with AA and GA genotypes had significantly higher levels of HOMA-IR, waist circumferences and lower levels of HDL-C (P＜0.05) than those carrying GG genotype. HOMA-IR in subjects with AA and AG were significantly higher than those with GG genotype in both groups. Conclusion The A allele of the Thr394Thr (G→A) polymorphism of the PPARGC1A gene was associated with insulin resistance, and may be related to central obesity and decreased HDL-C levels in Chinese population. The relationship between this polymorphism and T2DM needs further investigation.