Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. People with diabetes face additional challenges when they need treatments, such as surgery, for other conditions. In the August 2023 update to the Cochrane review, reviewers examined whether perioperative glycaemic control might help with this, and we asked joint lead author, Dídac Mauricio from the CIBER of Diabetes and Associated Metabolic Disease in Barcelona Spain to tell us more in this podcast.

Dídac: Compared to people without diabetes, people with diabetes having surgery are more likely to develop complications. These include infections and cardiovascular problems during or after the operation. This leads to longer stays in hospital, higher healthcare resource use, and even an increased risk of death. One way that has been suggested to reduce these risks is to seek more intensive blood glucose control during the perioperative period, but there is uncertainty about whether this is better than targeting conventional blood glucose control. We hoped to resolve this in our review, where we define the perioperative period as the time surrounding an individual's surgical procedure, covering the preoperative (before operation), intraoperative (during operation) and postoperative (after operation) periods.
We found eight new randomised trials for the update, which we added to the previous 12 studies, giving us a total of nearly 2700 participants randomised to perioperative intensive glucose control or conventional management.
This evidence shows that despite the lower blood sugar concentrations attained, intensive glucose control led to little or no reduction in postoperative outcomes such as infection, kidney problems, length of stay in hospital or intensive care, and all-cause mortality. However, we found that intensive glucose control may reduce the risk of cardiovascular problems, but may slightly increase the risk of hypoglycaemia, including severe episodes. We should underline, though, that although we have high confidence in the findings for mortality, the confidence is low for other results.
In summary, our review shows that intensive perioperative glucose control does lead to lower glucose concentrations in people with diabetes mellitus undergoing surgery but it does not reduce mortality, and has little or no effect in reducing other complications, except for cardiovascular problems. While, on the negative side, intensive glucose lowering is associated with increased risk of hypoglycaemia.

Mike: If you'd like to find out more about these findings, you can find the review at Cochrane Library dot com with a search for 'perioperative glycaemic control and diabetes'.