Correlation Between Levels of Plasma Homocysteine and Coronary Atherosclerosis and Its Pathogenesis MechanismAtherosclerosis is one of the main diseases to threaten human's health for the time being. In many countries, especially in the developed countries like America and some west European countries, its prevalence rates and death rates are increasing quickly. In our country since 1980s atherosclerosis has also been taking on obvious ascending trend and has become the leading cause of death in many cities and regions. It is a very important subject for medical science to investigate the pathogenesis and its prevention and cure strategies. There are quite a number of "normal "persons with coronary heart disease, who are with low scores of coronary risk factors. Besides, there are still many difficulties in correcting or killing the coronary risk factors. So it bears very important theoretical and practical significances to lucubrate the etiological factors and their pathogenesis for atherosclerosis and to develop simple, effective and efficient diagnostic and therapeutic means.There has been a wealth of epidemiological evidence that there are association between hyperhomocysteinemia and coronary heart disease, cerebral stroke and occlusive peripheral vascular disease. During the past years there were many reports published on these findings. But there are also some problems left, for example most investigations were based on in-vitro experiments where homocysteine concentrations were used as high as 10-100 times those inside human body and with relatively short intervention period. And most of the conclusions remained to be confirmed in human. There are some researches results that could not be proven in the patients with coronary heart diseases. And many studies used simple observational factors lacking of systematism. Some case-control studies have yielded contradictory results. Up till now good-sized clinical investigations need to be further conducted to make certain the cause-and-effect relation between elevation of plasma homocysteine and atherosclerosis. Maybe studies using systemic and multifactor to elucidate the interactive relation between homocysteine and atherosclerosis at a clinical level could solve the present problem but there were few reports till now.The objective of this study is to investigate from multi-angles which and how many factors there are influencing levels of plasma homocysteine, to demonstrate the interactive relationship between plasma homocysteine and coronary lesions and coronary risk factors, to explore the possible pathogenesis mechanisms for homocysteine to cause coronary heart disease and to provide clinical evidences for treatment of atherosclerosis.The subjects were 74 cases of patients undergoing selective coronary angiographies. Patients with acute myocardial infarction needed a 3-week interval after onset of cardiac attack before recruited. The subjects were divided into different type groups according to different criteria for recruiting. They were divided into coronary angiography positive or negative group based on the angiographic outcome, coronary artery disease (CAD) or non-CAD groups according to the diagnostic standards/criteria for ischemic cardiomyopathy suggested by WHO, and high- or low-risk groups according to how many major conventional coronary risk factors they had. The high-risk group consisted of the patients who had =>3 risk factors and the low-risk group consisted of the patients who had <3 risk factors. These risk factors including male gender, advanced age that was defined age >45 years in men or age>55 years old in women, cigarette smokers were defined as those who smokedregularly on admission or number of cigarette smoked per day multipled years smoked ^400, hypertension was diagnosed if blood pressure was > 140/90 mmHg on 3 occasions or if the patient was taking antihypertensive medications. Diabetes mellitus was diagnosed if the fasting plasma glucose concentration was >125mg/dl on 2 separate occasions or if the pat