In this study we tested the hypothesis that red blood cell
5-methyltetrahydrofolate, a long-term marker of the
folate status, is associated with the severity of
coronary artery disease and whether this association is independent of
homocysteine,
vitamin B12, plasma
5-methyltetrahydrofolate, 5,10-methyltetrahyrofolate
reductase C677T genotype, and other cardiovascular risk factors. Two hundred and fifty-one angiographically documented patients aged <70 years with single, double, or triple
coronary artery disease were investigated. Red blood cell
5-methyltetrahydrofolate concentrations were significantly decreased with the increasing number of diseased vessels (analysis of variance, P < 0.001). Red blood cell
5-methyltetrahydrofolate was also inversely and significantly correlated with the number of diseased vessels (r = -0.36, P < 0.001). Stepwise multiple regression analysis showed that red cell
5-methyltetrahydrofolate was a strong predictor of number of diseased vessels independent of plasma total
homocysteine, 5,10-methyltetrahyrofolate
reductase C677T genotype, and all other coronary artery risk factors (beta = -0.002, P < 0.001, r2 = 0.128). The results of this study suggest that low red blood cell
5-methyltetrahydrofolate is associated with the severity of
coronary artery disease independent from plasma
homocysteine and other cardiovascular risk factors.