Homocysteine and methylenetetrahydrofolate reductase in subjects undergoing coronary angiography.

OBJECTIVE To determine plasma homocysteine levels and the incidence of methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism in a group of subjects who underwent coronary angiography, in an attempt to establish a correlation between these parameters and the severity of coronary artery disease (CAD), as well as investigate the correlation between hyperhomocysteinemia and the presence of polymorphism. METHODS Twenty subjects with no coronary atheromatosis (controls), fourteen subjects with mild/moderate atheromatosis, and twenty-nine subjects with severe atheromatosis were evaluated. RESULTS Significant differences were observed in mean homocysteine levels between the control and the severe atheromatosis groups (p < 0.001). No significant differences were observed among the other groups. The severe atheromatosis group showed rates of 62.0% and 6.9% for the C677T MTHFR gene polymorphism, in heterozygous and homozygous subjects, respectively. However, there was no correlation between the presence of mutation and hyperhomocysteinemia. A positive correlation of 41.91% (p < 0.001) was found between hyperhomocysteinemia and CAD. CONCLUSION The most important finding of this study was the association between hyperhomocysteinemia and coronary stenosis > 70%; yet, whether elevated plasma homocysteine worsens atherosclerosis or is a consequence remains to be established.