中文摘要：

目的 分析线粒体DNA（mitochondriaDNA，mtDNA）变异与2型糖尿病（T2DM）及其并发症的关系，探讨mtDNA检测对于T2DM的诊断价值。方法 采用PCR产物直接测序法对浙江籍汉族人群中无血缘关系的315例T2DM患者及158名正常对照个体的mtDNA片段（nt3153～nt3551）进行分析，同时对每例患者作常规生化检测。结果 T2DM患者组和健康对照组与标准序列比对存在着大量的基因变异位点，具有中国汉族人的多态性。把患者检测到的变异位点结合临床资料分析发现T3183A、A3243G、T3290C、T3338C、T3398C、G3421A、C3435T等基因变异与糖尿病家族史或并发症有密切联系。比较有家族史和无家族史的有基因变异的T2DM患者，有家族史组发病年龄较无家族史组明显提前[（47．7±11．1）岁与（55.1±13．8）岁，t=2．489，P〈0．05]，有家族史组的体重指数（BMI）显著低于无家族史组[（20．59±5．16）ks／m^2与（23．82±2．32）kg／m^2，t=3．234，P〈0．01]，差异有统计学意义；而两组的甘油三酯（TG）[（1．32±0．60）mmol／L与（1．33±0．68）mmol／L，t=0．071，P〉0．05]、总胆固醇（TC）[（4．07±1．23）mmol／L与（4．13±0．72）mmol／L，t=0．277，P〉0．05]、空腹血糖（FBG）[（9．27±2．52）mmol／L与（9．49±3．36）mmol／L，t=0．308．P〉0．05]等差异无统计学意义。结论 中国汉族人mtDNA存在多态性，T2DM患者mtDNA中存在着大量的变异位点，尽管mtDNA变异位点与糖尿病特征、家族史或并发症有一定关系，但目前尚不能作为诊断T2DM的独立指标。

英文摘要：

Objective To investigate the relationship between mitochondria DNA （mtDNA） variations and type 2 diabetes mellitus and its complications. Methods Direct sequencing of PCR product was applied to study the variations of mtDNA fragments （ nt3153- nt3551 ） in 315 unrelated T2DM patients and 158 normal controls from Zhejiang province. Biochemistry tests were also performed on serum samples of all the subjects. Results Compared to Cambridge standard sequence, various variations in the mtDNA were observed on both patients and controls. It was shown that T3183A, A3243G, T3290C, T3338C, T3398C, G3421A and C3435T were closely related to family histories of diabetes mellitus and occurrence of complications. Among patients with such genovariations, those with family histories of diabetes had an earlier onset of diabetes and a lower BMI than those without family histories of the disease [ （47. 7 ± 11.1 ） years vs. （55.1 ± 13.8） years, t =2. 489, P 〈0. 05 and （20. 59±5.16） kg/m^2 vs （23.82 ±2. 32） kg/m^2, t = 3. 234, P 〈0. 01 ] . Serum levels of triglyceride, total cholesterol and fasting blood glucose were not significantly different between the two groups. Conclusions There exists mtDNA polymorphism in Chinese population. The variations may be related to the pathogenesis of T2DM but the existence of the variations are not diagnostic of the disease.