Measurements

A day before CABG surgery, venous blood samples were obtained from all patients for the measurement of serum cobalamin, folate, and homocysteine. Homocysteine levels were measured using enzyme immunoassay (EIA) method (Axis-Shield Diagnostics, Scotland). Hyperhomocysteinemia was classified into moderate (15–30 µmol/L), intermediate (30– 100 µmol/L), and severe (greater than 100 µmol/L) types based on the level of Homocysteine.¹⁸ Serum folate was determined via EIA method (Roche Diagnostic, USA) and values less than 3 ng/mL were considered as indicative of folic acid deficiency.¹⁹ Serum cobalamin was estimated utilizing the EIA method (Roche Diagnostic, USA), and values less than 200 pg/mL were considered as indicative of cobalamin deficiency, and amounts between 200 and 300 pg/mL were considered as borderline.¹⁹