Clinical Research Of Mitochondria DNA4977bp Deletion In Coronary Atherosclerotic Heart Disease

Objective : To see whether peripheral blood mitochondrial DNA4977bp (mtDNA4977bp) deletion correlates with stability and severity of coronary atherosclerosis and other established cardiovascular risk factors. Methods:Patients group: we studied 90 hospitalized unrelated patients with coronary atherosclerotic heart disease(CAD) who were diagnosed by coronary angiography(CAG) in Cardiovascular Medical Department of Changhai Hospital from July 2006 to November 2006. The severity of atherosclerotic lesions of the coronary artery was assessed by the number of diseased coronary branches and Gensini score. The CAD patients were further divided into subgroups according to the clinical types, the number of diseased coronary branches and Gensini score. The patients were devided into angina pectoris or acute myocardial infarction according to the clinical types, were devided into one-vessel, two-vessel or three-vessel disease on the basis of the number of diseased coronary branches and devided into 0 to 20 score, 20 to 40 score or above 40 score according to the Gensini score. Control group: we selected 60 healthy subjects matched for the age with the patients group. MtDNA4977bp deletion relative amount, white blood cell(WBC) count, high sensitive C reactive protein(hsCRP), lipids(TC, TG, LDL-C, HDL-C), plasma glucose(FPG, 2HPG), blood pressure(SBP, DBP) and body mass index(BMI) were measured, and age, sex and prior medical histories including hypertension, diabetes mellitus and smoking status were obtained before CAG in all subjects. Clinical parameters and biochemical indicators were compared statistically between the subgroups, and correlation coefficient of mtDNA4977bp deletion relative to WBC, hsCRP and other conventional risk factors for CAD was calculated. Results: 1) The incidence and relative amount of mtDNA4977bp deletion in peripheral blood in CAD patients were significantly higher than those in controls. 2) No significant differences were found in the incidence and relative amount of mtDNA4977bp deletion between the patients with angina pectoris and the patients with acute myocardial infarction. MtDNA4977bp deletion incidence and relative amount were correlated with the number of diseased coronary branches and Gensini score. 3) MtDNA4977bp deletion relative amount was positively correlated with age, SBP, DBP, FPG, 2HPG, TC and LDL-C; negatively correlated with HDL-C; and not correlated with smoking status, body mass index, WBC and hsCRP. Conclusion: Peripheral blood mtDNA4977bp deletion relative amount can be used as a parameter to predict pathological severity of coronary atherosclerosis, though it is not correlated with stability of atherosclerotic lesions of the coronary artery. It may be involved in the pathogenesis of coronary atherosclerosis.