Elevation of plasma homocysteine has been recognized as one of the risk factors of atherosclerotic disease. The objectives of this study are: (1) to investigate the level of plasma homocysteine and the prevalence of hypehomocysteinemia (2) to find out the role of homocysteine in coronary artery disease and the proper cut-off point of plasma homocysteine to evaluate the presence of coronary artery disease; (3) to understand the control condition of tranditional risk factors of cardiovascular disease, especially hypertension, dyslipidemia, and diabetes mellitus.

The study subjects were recruited from the ambulatory setting of cardiology in National Taiwan University Hospital.

Inclusion Criteria:

Patient > 65 y/o or < 50y/o Scr<=1.5mg/dL

Exclusion Criteria:

• Scr> 1.5mg/dl pregnancy alcohoism