2026-05-12

Tirzepatide beats dulaglutide on kidney outcomes in type 2 diabetics with heart disease

Tirzepatide is a dual incretin agonist—GLP-1 and GIP. Dulaglutide is GLP-1 only. Both are FDA-approved for type 2 diabetes. SURPASS-CVOT enrolled 13,165 people with type 2 diabetes and cardiovascular disease, randomized them to tirzepatide (up to 15 mg weekly) or dulaglutide (1.5 mg weekly), and followed them for four years. The trial was designed to compare heart outcomes. Kidney outcomes were exploratory.

What the paper found. Tirzepatide reduced the risk of major kidney events by 23% compared to dulaglutide. Hazard ratio 0.77 (95% CI 0.68–0.88). 396 events in the tirzepatide group versus 498 in the dulaglutide group. The composite outcome: persistent protein in urine, 50% or greater drop in kidney filtration, end-stage kidney disease, or death from kidney disease.

The benefit held across risk groups. In low-to-moderate-risk chronic kidney disease (about 77% of participants), tirzepatide cut events 30%. In high-risk chronic kidney disease (about 23%), it cut events 21%. The mechanism varied by risk group. Low-risk patients saw less new-onset heavy protein spillage (macroalbuminuria). High-risk patients saw slower decline in kidney filtration—0.93 mL/min per 1.73 m² less decline per year.

What's missing. This was an exploratory analysis. Not the primary endpoint. The trial wasn't powered to detect kidney differences in subgroups. High-risk participants had only four years of follow-up. Chronic kidney disease progresses slowly. Five, ten years would tell a fuller story.

Side effects: nausea, vomiting, diarrhea—more common with tirzepatide. Same incretin profile we've seen before.

What it means. If you're on dulaglutide for diabetes and have kidney risk, tirzepatide may slow progression. The paper is Zoungas et al., Lancet Diabetes & Endocrinology, May 2026. The data exist. Most clinicians won't read them.

Bukowski did.