The study included 71 patient with ischemic coronary disease (ICD) with type II diabetes mellitus (DM) treated by oral hypoglycemic agents undergoing off-pump coronary artery bypass grafting (CABG). The mean age was 59 (56-64) years. Before the surgery the patients were randomized to continuing of oral hypoglycemic agents (n = 34) or to switching to rapid-acting insulin (n = 37). In the studied groups we compared glycemic parameters, markers of myocardial necrosis (troponin T and creatinine phosphokinase-MB (CPK-MB)) and acid-base balance, as well as their dynamics during the perioperative period. The relationships of myocardial necrosis markers dynamics with glucose metabolism and acid-base balance parameters were investigated. Before the surgery in switched to rapid-acting insulin patients serum glucose, its daily variability and the proportion of blood glucose values less than recommended perioperative range (6,1-10,0 mmol/l) were higher than in those at oral hypoglycemic agents. The myocardial necrosis markers at the day before and 24 h after surgery as well as lactate level and blood acidity during and at 24 hours after surgery were higher in the insulin-group. The insulin-group was characterized by greater increase of troponin T during 24 h after surgery (0,36 [0,25-0,40] vs 0,2 [0,1-0,25] ng/ml; p < 0,001) and CPK-MB (14 [8,0-17,0] vs 7,3 [1,5-8,7] U/L; p < 0,001). Troponin T and CPK-MB dynamics correlated with serum glucose during surgery (r = +0,81 and r = +0,66 respectively), daily serum glucose variability at the day before surgery (r = +0,71 and r = +0,63) and the first day of admission to hospital (r = +0,37 and r = +0,31).