PLASMA HOMOCYST(E)INE, FOLATE, AND VITAMIN-B12 CONCENTRATIONS AND RISK FOR EARLY-ONSET CORONARY-ARTERY DISEASE

High plasma homocyst(e)ine (Hcy) concentrations may be a determinant o f coronary artery disease (CAD). Folate and vitamin B-12 are required for the primary metabolic pathway to reduce Hcy concentrations. The in terrelationships of Hcy and these two vitamin cofactors were investiga ted in a case-control study of 101 white males aged 30-50 y with angio graphically demonstrated CAD, and 108 white male, similarly aged, cont rol subjects living in the same community as the patients. The odds ra tio (OR) of CAD per quartile increase of plasma Hcy concentration base d on control values was 1.6 (95% CI: 1.3, 2.1). After age, HDL and LDL cholesterol, body mass index, smoking, hypertension, and diabetes wer e controlled for, Hcy remained an independent risk factor (OR: 1.4; 95 % CI: 1.0, 2.0). The OR change per quartile increase of folate concent ration was 0.8 (95% CI: 0.6, 1.0). This difference was reduced (OR: 0. 9; 95% CI: 0.7, 1.2) after Hcy adjustment. No difference in the geomet ric mean of vitamin B-12 concentration was found between patients and control subjects, both 5.8 nmol/L. However, after Hcy and the other CA D risk factors were controlled for, the OR per quartile increase in vi tamin B-12 concentration was 1.5 (95% CI: 1.0, 1.8). Reduction in plas ma Hcy by interventions to increase plasma folate concentration may de crease CAD risk.