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.