The graded effect of hyperhomocysteinemia on the severity and extent of coronary atherosclerosis

It is not clear to what extent methylenetetrahydrofolate reductase (MTHFR) gene and hyperhomocysteinemia effect the severity and extent of coronary at herosclerosis in Asian populations. We examined the MTHFR genotypes and pla sma homocysteine (HCY) concentrations in 192 Taiwanese and investigated the ir relationship with coronary artery disease (CAD), and the severity and ex tent of coronary atherosclerosis. The distribution of MTHFR genotypes was s imilar in 116 CAD patients and 76 non-CAD subjects. Homozygosity was noted in 8% of CAD patients and 13% of non-CAD subjects (P = 0.33; 95% CI, 0.2-1. 6). The geometric mean of HCY values was higher in CAD patients (11.10 +/- 1.51 mu mol/l) than in non-CAD subjects (9.21 +/- 1.55 mu mol/l) (P = 0.003 ). HCY levels were higher in patients with multi-vessel disease (P < 0.05) or in patients with greater than or equal to 90% stenotic lesions (P = 0.00 5), compared with non-CAD subjects. The CAD risks in the top two I-ICY quar tiles (greater than or equal to 14.0 and 10.1-13.9 mu mol/l) were 4.0 (95% CI, 1.7-9.2) and 3.2 (95% CI, 1.4-7.4) times higher than in the lowest quar tile (less than or equal to 7.9 mu mol/l) (P = 0.001 and 0.007, respectivel y). Linear regression analysis showed significant correlations between HCY concentrations and the severity and extent of atherosclerosis (P = 0.0001 f or both). In conclusion, hyperhomocysteinemia appears to have a graded effe ct on the risk of CAD as well as the severity and extent of coronary athero sclerosis. Our findings do not support the homozygous genotype of MTHFR as a genetic risk factor for CAD in this Taiwanese population. Perhaps a furth er study including assessment of vitamin status is needed to better clarify the relationship between MTHFR genotypes and CAD. (C) 1999 Elsevier Scienc e Ireland Ltd. All rights reserved.