醛糖还原酶和内皮型一氧化氮合酶基因多态性并存与糖尿病肾病发病的相关性

背景有关资料显示,醛糖还原酶基因启动子区C-106T多态和内皮型一氧化氮合酶基因第七外显子GLU298ASP(894G→T)多态与糖尿病肾病有关,上述基因多态并存时,2型糖尿病患者糖尿病肾病的发病风险是否明显增加有待进一步研究.目的探讨染色体7q35区醛糖还原酶基因启动子区C-106T多态和内皮型一氧化氮合酶基因第七外显子GLU298ASP(894G→T)多态并存时与中国北方汉族人群糖尿病肾病发病的关系.设计病例-对照,对比观察.单位青岛大学医学院附属医院内分泌科.对象选择2002-11/2005-04在青岛大学医学院附属医院内分泌科住院2型糖尿病患者139例,男54例,女85例,年龄(64±8)岁.符合1999年世界卫生组织关于糖尿病诊断和分类标准.根据24 h尿微量白蛋白排泄率分为2组糖尿病肾病组61例和非糖尿病肾病组78例.选择同期本院体检健康成人63名为对照组,男24名,女39名;年龄50～78 岁.纳入对象均为汉族,且对检测项目知情同意.方法运用聚合酶链反应限制性片段长度多态性技术、DNA测序技术及琼脂糖凝胶电泳分离技术检测纳入对象的醛糖还原酶基因启动子区C-106T多态位点和内皮型一氧化氮合酶基因第7外显子GLU298ASP(894G→T)多态位点的等位基因和基因型.主要观察指标①醛糖还原酶和内皮型一氧化氮合酶基因多态性.②糖尿病肾病危险因素的多元逐步回归分析结果.③醛糖还原酶C-106T多态和内皮型一氧化氮合酶894G→T多态与糖尿病肾病相对危险度.结果2型糖尿病患者139例和健康人63名全部进入结果分析.①糖尿病肾病组内皮型一氧化氮合酶基因第7外显子894G→T多态位点的T等位基因和TG基因型频率明显高于非糖尿病肾病组和对照组(χ2=8.261,19.629,P＜0.01).②糖尿病肾病组醛糖还原酶基因启动子区C-106T多态位点的T等位基因和CT基因型频率明显高于非糖尿病肾病组和对照组(χ2=6.343,8.940,P＜0.05,0.01).③将上述基因多态联合分析发现,糖尿病肾病组的TG/CT基因型频率明显高于非糖尿病肾病组和对照组(χ2=6.972,P＜0.01);GG/CC基因型频率显著低于非糖尿病肾病组和对照组(χ2=13.304,P＜0.01).④糖基化血红蛋白、收缩压、总胆固醇、内皮型一氧化氮合酶基因的第七外显子894G→T多态及醛糖还原酶基因启动子区C-106T多态均是糖尿病肾病的独立危险因素(Wald=5.627,4.92,P＜0.05).⑤GG/CC基因型可能是糖尿病肾病的保护基因型(OR=0.25,P＜0.01);GG/CT或TG/CC基因型携带者糖尿病肾病的危险性增加2.3倍,TG/CT基因型携带者糖尿病肾病的危险性增加4.8倍.结论内皮型一氧化氮合酶基因第7外显子894G→T多态位点的T等位基因和TG基因型和醛糖还原酶基因启动子区C-106T多态位点的T等位基因和CT基因型增加2型糖尿病患者发生糖尿病肾病的危险性,两种基因多态并存时,糖尿病肾病的发病风险明显增加.

Coexistence of aldose reductase gene and endothelial nitric oxide synthase polymorphisms associates with diabetic nephropathy

BACKGROUND: It has been demonstrated that the C-106T polymorphism at promotor region of aldose reductase gene and GLU298ASP (894G→T) polymorphism at exon 7 of endothelial nitric oxide synthase (eNOS) gene are associated with diabetic nephropathy, it should be further studied wnether the risk for diabetic nephropathy will increase when the above polymorphic sites coexist.OBJECTIVE: To investigate the association between the coexistence of the polymorphisms of both the C-106T at promotor region of aldose reductase gene and GLU298ASP (894G→T) at axon 7 of eNOS gene in chromosome 7q35 region and the genesis of diabetic nephropathy in northern Chinese Hah people.DESIGN: A case-controlled, comparative observation.SETTING: Department of Endocrinology, the Affiliated Hospital of Medical College, Qingdao University.PARTTCIPANTS; Totally 139 inpatients with type 2 diabetes mellitus were selected from the Department of Endocrinology, the Affiliated Hospital of Medical College, Qingdao University from November 2002 to April 2005,including 54 males and 85 females, (64±8) years of age. Inclusive criteria: Accorded with the standards of diabetic diagnosis and classification by WHO in 1999. According to the 24-hour urinary albumin excretion rate (UAER), they were divided into diabetic nephropathy group (n =61) and non-diabetic nephropathy group (n =78). Meanwhile, 63 healthy controls were selected as the control group, including 24 males and 39 females, 50-78 years of age. All the enrolled subjects were Han people. Informed contents were obtained from all the subjects.METHODS: The genotypes and alleles of polymorphisms of GLU298ASP(894G→T) at exon 7 of eNOS gene and C-106T at promotor region of aldose reductase gene were detected by polymerase chain reaction restriction-fragment length polymorphism technique (PCR-RFLP), DNA sequencing technique and agarose gel electrophoresis separation technique.Then the frequency of genotypes and alleles were compared.MAIN OUTCOME MEASURES: ① Polymorphisms of eNOS gene and aldose reductase gene; ② Results of the multivariant stepwise regression analysis of risk factors for diabetic nephropathy; ③ Polymorphisms of aldose reductase C-106T and eNOS 894G→T and the relative risk of diabetic nephropathy.RESULTS: All the 139 patients with type 2 diabetes mellitus and 63 healthy adults were involved in the analysis of results. ① The frequencies of the T allele and TG genotype at exon 7 894G→T polymorphic site of eNOS gene in the diabetic nephropathy group were significantly higher than those in the non-diabetic nephropathy group and control group (χ2=8.261, 19.629, P ＜ 0.05). ② The frequencies of the T allele and CT genotype at promotor region of aldose reductase gene in the diabetic nephropathy group were significantly higher than those in the non-diabetic nephropathy group and control group (χ2=6.343, 8.940, P ＜ 0.05, 0.01). ③ After associated analysis on the above gene polymorphisms, it was found that the frequency of TG/CT genotype in the diabetic nephropathy group were significantly higher than that in the non-diabetic nephropathy group and control group (χ2=6.972, P ＜ 0.01); whereas the frequency of GG/CC genotype was significantly lower than that in the non-diabetic nephropathy group and control group (χ2=13.304, P ＜ 0.05). ④Glycosylated hemoglobin (GHbA1c), systolic blood pressure, total cholesterol, polymorphisms of 894G→T at exon 7 of eNOS gene and C-106T at promotor region of aldose reductase gene were all the independent risk factors for diabetic nephropathy (Wald =5.627, 4.92, P ＜ 0.05). ⑤ GG/GC genotype might be the protective genotype for diabetic nephropathy (OR=0.25, P ＜ 0.01); The risk for diabetic nephropathy in the carrier of GG/CT or TG/CC genotype increased by 2.3 times and risk for diabetic nephropathy in the carrier of TG/CT genotype increased by 4.8 times.CONCLUSION: The coexistence of polymorphisms of 894G→T at exon 7 of eNOS gene and C-106T at promotor region of aldose reductase gene can increase the risk of diabetic nephropathy in patients with type 2 diabetes mellitus. And the TG/CT haplotype formed by the coexistence of polymorphism of these two genes is probably the predisposing genotype for diabetic nephropathy.