Association between plasma homocysteine levels and coronary artery disease: a population-based study in northern Greece

OBJECTIVE: Elevated plasma total homocysteine (tHcy) levels constitute a risk factor for coronary artery disease (CAD). We prospectively examined the association of fasting tHcy levels in patients in Northern Greece who had established CAD. PATIENTS AND METHODS: Plasma fasting tHcy levels were measured in 42 patients with angiographically documented CAD and compared to 42 age-, sex-, BMI- and smoking habit-matched control subjects. We also determined the plasma vitamin B(12), folic acid and lipoprotein levels in all patients and controls. Conventional risk factors for CAD were also estimated. RESULTS: In a univariate analysis, tHcy (micromol/l) levels were higher in patients compared to controls almost reaching statistical significance (13 (7-41) vs 11.3 (4-39); p= 0.07). Multivariate analysis of conventional risk factors showed that tHcy levels were not an independent risk factor for CAD. However, tHcy levels were significantly higher in patients with a previous history of myocardial infarction compared to patients without such a history and to controls (15 (8.8-29) vs 11.7 (7-41); p = 0.007 and 15 (8.8-29) vs 11.3 (4-39); p = 0.002, respectively). Hyperhomocysteinaemia (> 15 micromol/l) was detected in 35.7% of patients and 11.9% of controls (p < 0.05). CONCLUSIONS: In Northern Greece, plasma tHcy levels may not be an independent risk factor for CAD in patients with angiographically documented CAD. However, patients with CAD have a trend towards higher tHcy levels. Additionally, plasma tHcy levels may be associated with the development of myocardial infarction.