A systematic review of three small randomized trials found that adding liraglutide (a GLP-1 receptor agonist) to insulin during cardiac surgery in type 2 diabetes patients showed preliminary benefits for blood glucose control, though the evidence base remains limited and larger studies are needed to establish clinical significance.
Perioperative hyperglycemia, the elevated blood glucose that occurs around the time of surgery, is common in cardiac surgery patients with type 2 diabetes and has been associated with worse postoperative outcomes. Current practice typically relies on insulin alone to manage glucose during this critical window. This systematic review examined whether GLP-1 receptor agonists, a class of drugs that work through glucose-dependent mechanisms, could improve glucose management when added to standard insulin protocols.
The review identified only three randomized controlled trials involving 168 total patients with type 2 diabetes undergoing cardiac surgery. All three trials examined liraglutide, a GLP-1 receptor agonist administered subcutaneously at doses ranging from 0.6 to 1.8 mg per day. Across the preoperative, intraoperative, and early postoperative periods, patients receiving liraglutide plus insulin showed lower average blood glucose levels compared to insulin or placebo alone. The liraglutide groups also demonstrated reduced glycemic variability, meaning their blood glucose fluctuated less dramatically throughout the perioperative period. Additionally, patients in the liraglutide groups required fewer insulin dose adjustments during this time.
The hypoglycemia rates (dangerously low blood glucose events) were low across all treatment groups, suggesting that the combination approach did not introduce unexpected safety concerns related to low glucose episodes. One notable finding involved time in target glucose range: liraglutide-treated patients spent more time within their prescribed glucose targets during the perioperative window. One study reported exploratory findings of immunometabolic changes in adipose tissue among liraglutide-treated patients, though the clinical relevance of these biochemical changes remains unclear. Gastrointestinal side effects, particularly nausea and vomiting, occurred more frequently with liraglutide, which is consistent with the known side effect profile of GLP-1 receptor agonists.
However, the review's authors emphasized significant limitations that substantially weaken the conclusions. Study designs differed in their dosing schedules, monitoring protocols, and timing of liraglutide initiation relative to surgery. This heterogeneity makes it difficult to determine which aspects of the approach actually drove the improvements. The three studies included only 168 patients total, a modest sample size for drawing firm clinical recommendations. No study examined longer-term outcomes beyond the immediate postoperative period, leaving questions about whether the perioperative glucose benefits translate to reduced rates of infection, cardiac events, or other clinically meaningful outcomes. The authors concluded that while findings are "preliminary," they warrant larger, more standardized trials to establish whether this combination approach improves patient outcomes in cardiac surgery.
If you have type 2 diabetes and are facing cardiac surgery, this research does not yet establish that adding a GLP-1 receptor agonist to your perioperative insulin regimen is standard practice. The evidence remains preliminary and comes from small, heterogeneous studies. Your perioperative glucose management plan should remain a conversation between you and your surgical and anesthesia teams, who understand your individual medical history and risk factors.
That said, the consistent direction of findings across three independent trials suggests this is a promising area for future research. If your healthcare team is considering an experimental perioperative glucose management approach as part of a clinical trial, understanding that small-scale evidence exists for this specific strategy may be relevant context for your decision-making.
For the general diabetes population not facing surgery, this research has no direct implications. GLP-1 receptor agonists are already established treatments for type 2 diabetes management in outpatient settings, but this review specifically addresses their use during the acute perioperative period in cardiac surgery, which is a distinct clinical context.
| Attribute | Details |
|---|---|
| Study Type | Systematic review of randomized controlled trials |
| Total Participants | 168 patients with type 2 diabetes |
| Number of Included Trials | 3 RCTs |
| Primary Intervention | Liraglutide (0.6-1.8 mg/day subcutaneously) plus insulin |
| Comparison | Insulin alone or placebo plus insulin |
| Primary Outcome | Blood glucose levels during perioperative period |
| Secondary Outcomes | Hypoglycemia incidence, insulin requirements, time in target glucose range, postoperative complications |
| Key Findings | Lower glucose levels, reduced glycemic variability, fewer insulin adjustments with liraglutide; higher nausea/vomiting rates |
| Limitations | Small number of studies, heterogeneous protocols, no long-term outcomes assessed, lack of standardization |
| Evidence Quality | B tier (limited RCT evidence, small sample, methodological variability) |
| Journal | Annals of Cardiac Anaesthesia |
| Published |
Pubmed: https://pubmed.ncbi.nlm.nih.gov/42862661/
Study databases searched: PubMed, Cochrane Library, Google Scholar (through October 2025)
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