RESUMEN
BACKGROUND & OBJECTIVE: Numerous studies have identified hyperhomocysteinemia as an independent risk factor for coronary artery disease (CAD). Furthermore, influences of polymorphysim of methylenetetrahydrofolate reductase (MTHFR) on homocysteine levels are documented. However, the relationship between severity of CAD and polymorphism of MTHFR has not been systematically evaluated. The present study was undertaken to evaluate this relationship in patients undergoing coronary artery bypass surgery. METHODS: Serum homocysteine and MTHFR polymorphism in relation to severity of CAD was examined in 113 male patients, who all underwent coronary artery bypass surgery. The prevalences of 677 C-->T transition of the MTHFR gene were determined in these patients. Two groups were compared according to GENSINI coronary score : mild atherosclerosis (CAD stenosis < 30) and severe atherosclerosis (CAD stenosis > 30). RESULTS: Patients with CAD showed a significantly higher serum concentration of homocysteine than control subjects (P < 0.01). The serum homocysteine level was significantly higher in patients with increased scores than in patients with mild CAD (Gensini score < 30) both with and without the MTHFR polymorphism. INTERPRETATION & CONCLUSION: The findings of our study showed that hyperhomocysteinemia was significantly related to the severity of CAD independent on MTHFR polymorphism.