Intensity of peri-operative glycemic control and postoperative outcomes in patients with diabetes: a meta-analysis

Peri-operative hyperglycemia is a risk factor for postoperative morbidity and mortality. However, the role of specific glycemic targets in reducing this risk has not been defined, particularly among patients with diabetes. Thus, our objective was to conduct a meta-analysis relating distinct peri-operative glycemic targets and postoperative outcomes in patients with diabetes.

A systematic review was performed by two authors utilizing pre-specified terms: "diabetes mellitus" and "perioperative" and "mortality" and "blood glucose" or "strict glucose control" or "intensive insulin therapy" in PUBMED, CENTRAL and EMBASE. Glycemic control was considered strict when perioperative targets ranged between 100 and 150mg/dL (5.6-8.3mmol/l), moderate when the targets ranged between 150 and 200mg/dL 8.3-11.1mmol/l), and liberal when the target was >200mg/dL (11.1mmol/l). The data were combined utilizing the Dersimoan-Laird random-effects method. The primary endpoint was postoperative mortality with secondary endpoints of postoperative atrial fibrillation, wound infection, and stroke.

The literature search yielded 760 studies, of which only 6 met inclusion criteria. When compared with a liberal target, pooled data showed that a moderate glycemic target was associated with reduced postoperative mortality (OR=0.48, 95% CI 0.24-0.76) and stroke (OR=0.61, 95% CI 0.38-0.98), but no differences in atrial fibrillation or wound infection were found. There were no significant differences in postoperative outcomes between moderate versus strict perioperative glycemic target.

Pooled results suggest that in patients with diabetes, a moderate peri-operative glycemic target (150-200mg/dl [5.6-8.3mmol/l]) is associated with reduction in postoperative mortality and stroke compared with a liberal target (>200mg/dl [11.1mmol/l]), whereas no significant additional benefit was found with more strict glycemic control (<150mg/dl [5.6mmol/l]).