Perioperative hyperglycemia is common in patients with type 2 diabetes undergoing cardiac surgery and is linked to adverse outcomes. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) offer glucose-dependent insulinotropic effects and potential cardiac benefits, but their perioperative role remains uncertain. This review evaluated the efficacy and safety of GLP-1 RA therapy as an adjunct to insulin in this setting. Three electronic databases (PubMed, Cochrane, and Google Scholar) were searched for relevant articles up to October 2025. The primary endpoint was blood glucose levels during the perioperative period, while secondary endpoints included hypoglycemia incidence, total insulin requirement, time in target glucose range, and postoperative complications. Three randomized controlled trials (RCTs) including 168 patients with type 2 diabetes undergoing cardiac surgery were assessed. Perioperative use of liraglutide (subcutaneously in doses of 0.6-1.8 mg/day) was associated with preliminary evidence of improved glycemic control across preoperative, intraoperative, and early postoperative periods, including lower glucose levels, reduced glycemic variability, and fewer insulin adjustments, with a low incidence of hypoglycemia. However, heterogeneity in dosing, timing, and monitoring protocols across studies limits direct comparisons. Mild gastrointestinal adverse events, such as nausea and vomiting, were more frequent with liraglutide. One study reported exploratory immunometabolic effects in adipose tissue. Preliminary evidence from these heterogeneous studies suggests that adding liraglutide to insulin may improve perioperative glycemic control compared to insulin or placebo in patients with type 2 diabetes undergoing cardiac surgery. However, findings are limited by the small number of studies, methodological variability, and lack of long-term outcomes, necessitating larger, standardized trials.
