In a randomized trial of 38 patients with diabetes and coronary disease, pre-operative liraglutide significantly altered epicardial fat microRNA profiles and improved intra-operative blood glucose control during bypass surgery.
146 vs 160 mg/dL intra-operative glucoseLiraglutide-treated patients had significantly better blood sugar control during bypass surgery compared to placebo, independent of weight loss — a clinically meaningful benefit during a high-risk procedure.
What the researchers found
In all patients, miR16, miR155, and miR181a were significantly higher in coronary epicardial fat (CORO-EAT) and left atrial epicardial fat (LA-EAT) compared to subcutaneous fat (SAT). In the liraglutide group specifically, miR16 and miR181a were significantly higher in CORO-EAT vs. SAT, and miR155 and miR181a were higher in LA-EAT vs. SAT. Liraglutide-treated patients had significantly better intra-operative glucose control (146 ± 21 vs 160 ± 21 mg/dL, p<0.01) independent of weight loss.
Why it matters
Epicardial fat is increasingly recognized as an active contributor to heart disease — not just passive storage tissue. Understanding how GLP-1 agonists change the molecular profile of heart fat could reveal new mechanisms of cardiovascular protection. The finding that liraglutide improves surgical glucose control is immediately clinically useful for managing diabetic patients undergoing cardiac surgery.
How the study worked
Randomized, double-blind, placebo-controlled trial of 38 patients with type 2 diabetes and coronary artery disease scheduled for coronary artery bypass grafting (CABG). Patients received liraglutide or placebo for 4-12 weeks pre-operatively. During CABG, fat samples were collected from three locations: coronary epicardial fat, left atrial epicardial fat, and subcutaneous fat. MicroRNA expression (miR16, miR155, miR181a) was analyzed across locations and treatment groups.
What this study cannot tell us
Small sample size (38 patients) limits statistical power and the ability to adjust for multiple comparisons. The microRNA differences between fat depots are described but their functional significance is not tested. The 4-12 week treatment window varied, introducing heterogeneity. The study measured miRNA expression but did not connect it to clinical cardiovascular outcomes. Only three miRNAs were analyzed, and a broader unbiased profiling might reveal additional changes.
How to read the evidence
This is a small but well-designed randomized, double-blind, placebo-controlled trial with a unique translational approach (sampling fat during surgery). The RCT design is strong, but the small sample size and descriptive microRNA analysis limit the conclusiveness of the molecular findings.
When this study was published
Published in 2025, this study reflects current interest in how GLP-1 agonists affect cardiac fat biology — a mechanistic frontier in understanding their cardiovascular benefits.
The bigger picture
GLP-1 agonists reduce cardiovascular events, but the mechanisms aren't fully understood. This study adds a new piece: liraglutide modifies the microRNA profile of heart fat, which could influence local inflammatory and metabolic signaling to coronary arteries. The regional differences in epicardial fat gene expression also suggest that heart fat should be studied location by location, not as a uniform tissue.
Questions still open
- Do the microRNA changes in epicardial fat translate into measurable differences in coronary inflammation or atherosclerosis progression?
- Which specific targets of miR16, miR155, and miR181a in epicardial fat are most relevant to cardiovascular protection?
- Would longer pre-operative GLP-1 agonist treatment produce greater changes in epicardial fat biology?
Common questions
What is epicardial fat and why does it matter for heart disease?
Should diabetic patients take liraglutide before heart surgery?
Read the original research
Liraglutide effects on epicardial adipose tissue micro-RNAs and intra-operative glucose control.
Nutrition, metabolism, and cardiovascular diseases : NMCD, 35(2), 103726
Citation
Iacobellis, Gianluca; Goldberger, Jeffrey J; Lamelas, Joseph; Martinez, Claudia A; Sterling, Carlos Munoz; Bodenstab, Monica; Frasca, Daniela. (2025). Liraglutide effects on epicardial adipose tissue micro-RNAs and intra-operative glucose control.. Nutrition, metabolism, and cardiovascular diseases : NMCD, 35(2), 103726. https://doi.org/10.1016/j.numecd.2024.08.019