Insulin glargine improves glycaemic control after coronary surgery in patients with diabetes or pre-diabetes

Objectives. Determine if pre-emptive daily insulin glargine surpasses regular insulin when needed for glycaemic control after cardiac surgery. Design. Prospective, randomized study of 43 patients (scheduled for coronary artery bypass grafting) with preoperatively diagnosed diabetes (DM) or pre-DM. Lantus group received insulin glargine daily from start of surgery while Actrapid group received regular insulin (sliding scale) when needed (plasma glucose (P-glu) > 10 mmol/l). Primary endpoint was percent of pre- and post-prandial P-glu values within Target Intervals: Pre-prandial P-glu: 4.5-7 mmol/l; post-prandial P-glu: 4.5-9 mmol/l. Study period 1-4 days after surgery. Tissue glucose was also measured continuously. Results. More than twice as many P-glu values were within Target Interval for Lantus patients as compared with Actrapid patients (p < 0.001). One of 504 timed measurements was 4 mmol/l. Area under the curve for glucose >7 mmol/l was reduced by 61% by Lantus (p < 0.001). Conclusion. The routine protocol with pre-emptive glargine insulin studied here provides a major improvement in glycaemic control with a minimal incidence of hypoglycaemia and without an excessive increase in nursing burden.