GLP-1 drugs cut CV risk in type 2 diabetes

A new network meta-analysis published in Diabetes, Obesity and Metabolism on 31 May 2026 pooled data from cardiovascular-outcomes trials of GLP-1-based therapies in people with type 2 diabetes and found that, as a class, these drugs significantly reduce all-cause mortality, cardiovascular mortality and major adverse cardiovascular events (MACE)^[1]. Among individual agents, efpeglenatide, albiglutide and injectable semaglutide showed the most favourable comparative profiles for MACE reduction.

What the analysis found

Chuang and colleagues conducted a systematic review and network meta-analysis of placebo-controlled randomised trials evaluating GLP-1 receptor agonists on five cardiovascular endpoints: all-cause mortality, cardiovascular mortality, MACE, non-fatal myocardial infarction and non-fatal stroke^[1]. In the pooled placebo-controlled comparisons, GLP-1-based therapies significantly reduced the first three endpoints. Albiglutide also reduced non-fatal myocardial infarction versus placebo, though stroke estimates across the class lacked statistical precision.

The network ranking placed efpeglenatide, albiglutide and injectable semaglutide at the top for MACE. That ranking aligns with what the individual landmark trials reported. SUSTAIN-6 (Marso et al., NEJM 2016) showed a 26% relative MACE reduction with semaglutide in type 2 diabetes at high cardiovascular risk (HR 0.74, 95% CI 0.58 to 0.95)^[2]. Harmony Outcomes (Hernandez et al., Lancet 2018) reported a 22% reduction with albiglutide (HR 0.78, 95% CI 0.68 to 0.90)^[3]. The LEADER trial (Marso et al., NEJM 2016) found a 13% reduction with liraglutide in 9,340 patients with type 2 diabetes and high cardiovascular risk (HR 0.87, 95% CI 0.78 to 0.97, P=0.01 for superiority), with cardiovascular mortality also significantly lower at 4.7% versus 6.0%^[4].

Beyond diabetes: the SELECT signal

The network meta-analysis focused on trials in type 2 diabetes, but the cardiovascular story does not stop there. The SELECT trial (Lincoff et al., NEJM 2023) tested semaglutide 2.4 mg in 17,604 adults aged 45 and older with overweight or obesity and established cardiovascular disease, none of whom had diabetes^[5]. Over a mean follow-up of 39.8 months, SELECT reported a 20% MACE reduction (HR 0.80, 95% CI 0.72 to 0.90, P<0.001). The primary endpoint occurred in 6.5% of the semaglutide group versus 8.0% on placebo.

That trial was the first to show a hard cardiovascular benefit for a weight-loss medication in an obesity-only population. It moved semaglutide from the diabetes cardiology playbook into the broader conversation about cardiovascular prevention in people with obesity, and it is one reason GLP-1 prescribing has expanded into cardiology clinics since 2024.

For tirzepatide, the dual GIP and GLP-1 receptor agonist, cardiovascular-outcomes evidence is still emerging. The SUMMIT trial (Packer et al., NEJM 2025) reported a 38% reduction in cardiovascular death or worsening heart-failure events in obesity-related heart failure with preserved ejection fraction (HFpEF) over a median 104 weeks (HR 0.62, 95% CI 0.41 to 0.95). That is a different endpoint and population from the MACE trials in the network meta-analysis. A dedicated MACE trial matching the scope of SELECT has not yet read out. Whether tirzepatide's dual-agonist mechanism translates into a larger cardiovascular benefit than single-agonist GLP-1 drugs remains an open question.

What is not settled

The meta-analysis could not confirm a class-wide stroke reduction, and the confidence intervals for several individual agents overlapped. Network meta-analyses also carry structural limitations: they depend on the assumption that trial populations are comparable across studies, and the included trials used different comparators, follow-up durations and definitions of high cardiovascular risk. The authors note that head-to-head cardiovascular-outcomes trials between GLP-1 agents remain scarce, so the between-drug rankings should be read as signals rather than settled rankings.

Also absent from the analysis is the newer generation of dual and triple agonists. Tirzepatide and retatrutide are not yet represented in completed cardiovascular-outcomes trials large enough for inclusion in a network meta-analysis of this kind. As those trials report, the competitive landscape will shift. Meanwhile, the current generation of GLP-1 agents faces a practical constraint: albiglutide, which ranked highly in the analysis, was withdrawn from the market by GlaxoSmithKline in 2018 for commercial reasons, leaving semaglutide as the highest-ranked agent still available to prescribers.

Where this lands

For clinicians and patients weighing GLP-1 therapy options in type 2 diabetes, this meta-analysis reinforces a class-level cardiovascular benefit that extends beyond glycaemic control. The practical question is which agent, and the data so far favour semaglutide and albiglutide on the MACE endpoint, though albiglutide was withdrawn from the market in 2018 for commercial reasons. Readers can explore the evidence for individual agents on the semaglutide and tirzepatide peptide pages.