Hyperhomocysteinemia and Low Pyridoxal Phosphate Common and Independent Reversible Risk Factors for Coronary Artery Disease

Background High plasma homocysteine is associated with premature coronary artery disease in men, but the threshold concentration defining this risk and its importance in women and the elderly are unknown. Furthermore, although low B vitamin status increases homocysteine, the link between these vitamins and coronary disease is unclear. Methods and Results We compared 304 patients with coronary disease with 231 control subjects. Risk factors and concentrations of plasma homocysteine, folate, vitamin B12, and pyridoxal 5′-phosphate were documented. A homocysteine concentration of 14 μmol/L conferred an odds ratio of coronary disease of 4.8 (P<.001), and 5-μmol/L increments across the range of homocysteine conferred an odds ratio of 2.4 (P<.001). Odds ratios of 3.5 in women and of 2.9 in those 65 years or older were seen (P<.05). Homocysteine correlated negatively with all vitamins. Low pyridoxal 5′-phosphate (<20 nmol/L) was seen in 10% of patients but in only 2% of control subjects (P<.01), yielding an odds...