【作者】 彭姝彬；

【导师】 黄青阳；

【作者基本信息】 华中师范大学 ， 生物化学与分子生物学， 2007， 硕士

【摘要】 目的：2型糖尿病是一种常见的代谢性疾病，具有复杂的遗传背景。因其高度的遗传异质性，国际上不同种族间关于2型糖尿病易感区域及候选基因的报道存在较大的差异。本研究选择了编码胰岛β细胞K_ATP通道两个亚基的KCNJ11基因和SUR1基因作为候选基因，探讨KCNJ11基因E23K多态性和SUR1基因第16外显子-3t／c多态性与湖北汉族人群2型糖尿病的相关性。方法：采用同胞对（家系内对照）和随机病例-对照两种实验设计。利用聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）技术分析湖北地区400例样本KCNJ11基因E23K多态性，病例125人，对照275人。应用PCR-RFLP技术分析了464例样本的SUR1基因16-3t／c多态性，病例306人，对照158人，其中包括70个2型糖尿病同胞对。所有受试对象均测定身高、体重、腰围、臀围、血压和空腹血糖等生理生化指标，计算体重指数（BMI）和腰臀比（WHR）。将所有样本分为三组进行分析：所有病例与对照、2型糖尿病人与正常同胞以及随机病例与无亲缘关系的正常对照。病例与对照两样本间临床变量均数比较采用独立样本t检验，同胞对采用配对t检验，各基因型间均数比较采用单因素方差分析。组间基因型及等位基因频率比较采用x²检验，相关分析采用Logistic回归。统计学处理采用SPSS11.5统计软件。结果：（1）所有研究对象与随机病例—对照设计中，KCNJ11基因E23K多态性基因型频率与等位基因频率在2型糖尿病组与对照组间有显著性差异（P＜0.05或P＜0.01）；Logistic回归分析表明：随机病例-对照中，单因素回归发现KCNJ11基因E23K变异与2型糖尿病显著相关（EK与EE相比OR=2.000，P=0.028；KK与EE相比OR=2.373，P=0.004），经年龄、性别、血压和肥胖等多因素调整后仍存在显著相关性（EK与EE相比OR=1.978，P=0.039；KK与EE相比OR=2.472，P=0.004）；在所有研究对象中，无论是单因素还是经年龄、性别、血压和肥胖等多因素调整，KK基因型与2型糖尿病呈显著正相关（未调整前OR=2.303，P=0.004；调整后OR=2.341，P=0.006）。（2）三组实验设计中，SUR1基因16-3t／c多态性的基因型频率和等位基因频率在2型糖尿病组和对照组间均无显著性差异（P＞0.05），将所有样本以性别、年龄和BMI水平分层分析后也未观察到显著性差异。Logistic回归分析表明：无论是单因素还是经年龄、性别、血压和肥胖等多因素调整，16-3t／c多态性均与2型糖尿病无显著相关性。方差分析结果显示，在所有受试对象和病例组中SUR1基因三种基因型间的腰围和臀围有显著差异。另外，在病例组与对照组间临床资料的比较中BMI有显著差异，病例组显著高于对照组，单因素Logistic回归分析表明肥胖是2型糖尿病的独立危险因素。结论：在湖北汉族人群中，2型糖尿病的发生发展与KCNJ11基因E23K多态性相关联，但与SUR1基因16-3t／c多态性相关不显著。KCNJ11基因是湖北汉族人的一个2型糖尿病易感基因。更多还原

【Abstract】 Objective: Type 2 diabetes (T2DM) is a common metabolic disease with complex genetic components. A number of susceptibility loci and candidate genes for T2DM have been reported, but the results are inconsistent among different populations because of the genetic heterogeneity. Objective of this study is to test the association between KCNJ11 E23K and SUR1 16-3t/c polymorphisms and T2DM in Han Chinese in Hubei.Methods: Both sib-pairs (within-family control) and random case-control designs were used. The KCNJ11 gene E23K polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 400 subjects. The 16-3t/c polymorphism in the SUR1 gene was analyzed using PCR-RFLP in 464 case-control subjects. Height, weight, waist circumference, hip circumference, blood pressure and fasting blood glucose were measured, and the body mass index (BMI) and waist to hip ratio (WHR) were calculated in all subjects. All subjects were divided into three groups: all T2DM patients and controls, sib-pairs of patients and controls, T2DM patients and unrelated controls. Independent-sample t test was used to compare means between two groups, while paired-sample t test was used for the comparison of sib-pairs means. ANOVA was employed to compare the differences of clinical characteristics between genotypes. Chi-square test was employed to test the differences of genotypic and allelic frequencies between cases and controls. Association analyses were done by logistic regression. All statistical analyses were performed with the software of SPSS 11.5 for windows.Results: (1) There were significant differences in the genotypic and allelic frequencies of the KCNJ11 gene E23K polymorphism between cases and controls in random case-control designs and all subjects studied (P< 0.05 or P < 0.01) . Logistic regression analysis indicated that KCNJ11 gene E23K polymorphism was significantly related to T2DM in random case-control design, and KK genotype is associated with T2DM in all subjects studied.(2) No differences of the genotypic and allelic frequencies of the SUR1 gene 16-3t/c polymorphism were observed between cases and controls in both of study designs. In stratified analysis on the basis of sex, age and BMI level, there were also no significant differences. After adjusting sex, age, hypertension and obesity, there were still no significant differences. However, the result of univariate analysis showed that there were significant differences in waist circumference and hip circumference among three genotypes of SUR1 gene in cases and all subjects. In addition, significant difference in BMI was observed, the cases being obviously higher than the controls. Logistic regression analysis showed that BMI was one of the independent risk factors for T2DM.Conclusion: T2DM is not associated with 16-3t/c polymorphism of the SUR1 gene. The KCNJ11 gene E23K polymorphism is associated with T2DM and may be a susceptibility locus for T2DM in Han Chinese in Hubei.更多还原