Introduction:In this trial, effects of glargine on hyperglycemia in patients with diabetes mellitus type II who were undergoing off-pump coronary artery bypass graft (CAGB), were examined.Methods:Seventy diabetic patients who were candidate for off-pump CABG were randomly divided into the following two groups (1) Control group who were treated with normal saline+regular insulin and (2) Glargine group who received glargine+regular insulin. Normal saline and glargine were administered subcutaneously 2 hours before surgery, and regular insulin was injected before, during and after the surgery in the intensive care unit (ICU) in both groups. Finally, levels of blood sugar before, 2 hours after starting the surgery and at the end of the surgery, were recorded. Blood sugar levels during ICU stay were also measured every 4 hours for 36 hours.Results:There were no significant differences in blood sugar levels between the groups at the three time points (i.e. before, 2 hours after starting the surgery and at the end of the surgery). In addition, during 36 hours of ICU stay, blood sugar levels did not show significant variations between the groups; however, 20 hours after ICU admission, blood sugar level was significantly higher in the glargine group (P=0.04).Conclusion:The results indicated that both glargine and regular insulin effectively control the blood glucose in diabetic patients undergoing CABG. However, the blood sugar fluctuation was less in the glargine group than control group.