BACKGROUND
The mitochondrial DNA 5178 C>A polymorphism (Mt5178A) has been reported to the be associated with longevity, serum lipid levels and acute myocardial infarction in Japanese population. However, most of the studies on this subject have been confined to the Japanese population, and there have been fewer studies that tried to prove the association between Mt5178A polymorphism and type 2 diabetes or diabetic macrovascular complication. METHODS: The mt5178A polymorphism was genotyped in 658 type 2 diabetic patients and 334 non-diabetic controls subjects, and information on all the subjects' coronary heart disease and cerebrovascular disease was obtained from chart records. The anthropometric parameters, fasting blood glucose, insulin and lipid profiles were then measured. RESULTS: The frequency of the Mt5178A genotype in the control group (109/334; 32.6%) was not different from that found in the type 2 diabetic patients (223/658; 33.9%). The prevalence of cerebrovascular disease and coronary heart disease in the type 2 diabetic patients was not different between the Mt5178A genotype and the Mt5178C genotype. However, after adjustments for age and the body mass index, the HDL cholesterol concentration in men carrying the Mt5178A genotype was significantly higher than the HDL cholesterol concentration in men carrying the Mt5178C genotype (P = 0.007). The triglyceride concentration in women carrying the Mt5178A genotype was significantly lower than that in women carrying the Mt5178C genotype (P = 0.007). In addition, the frequency of the Mt5178A genotype in the control group increased with advanced age (P = 0.002). CONCLUSION: We could not find the association between Mt5178A and type 2 diabetes or diabetic macrovascular complication. However, the Mt5178 C>A polymorphism is associated with serum lipid levels and its frequency is increased with advanced age