The patients with blood sugar >180 mg/dl were randomly assigned to the study group (insulin infusion) and control group (subcutaneous insulin injection). The earlier blood sugar control medications (metformin, pioglitazone etc.) of all patients were stopped before the study began. Insulin infusion was prescribed for the subjects based on East Jefferson protocol in the study, and subcutaneous insulin injection in the control group was administered by a cardiologist. For patients in the study group, a venous infusion solution made from 100 units human regular insulin and 100 ml normal saline (0.9%) at a ratio of 1:1 was administered. Insulin infusion was started from column 5 of the East Jefferson protocol.[16] Patients’ blood sugar was checked each hour using the glucometer, and the protocol of insulin infusion level (units per hour) was changed based on the last measurement value of blood sugar based on the measured blood sugar level. In case of no reduction observed in the blood sugar level, compared to the latest measurement, the column was changed by one to right (e.g. from column 5 to column 6), and if blood sugar was less than 140 mg/dl, the column was changed by one to left (e.g. from column 5 to column 4), and infusion level was regulated based on the new column. When patients’ blood sugar level was in the range of target value (140–180 mg/dl) and/or the blood sugar titer was less than the former one, insulin infusion was continued based on the same column. When patients’ blood sugar was not in the target level (140–180 mg/dl) for at least 4 h, insulin infusion was changed to subcutaneous insulin injection two times a day or other blood sugar control methods. If the blood sugar was not in the target level for 24 h, insulin infusion was stopped and the patient was excluded from the study. The patients in the control group were on regular insulin sliding scale.[17] Blood sugar was checked four times a day in this group (three times before meals and one time before sleep). Based on patients’ nutrition timetable in the hospital, patients’ blood sugar was checked at 06:00 h, 12:00 h, 18:00 h, and 24:00 h for 48 h, and human regular insulin was injected to patients in this group through subcutaneous method based on their blood sugar level.