Research Summary

Do Semaglutide and Tirzepatide Reduce Neurocognitive Risk?

Miranda Manier, BA

Key Highlights

  • GLP-1 receptor agonist (GLP-1RA) use (semaglutide or tirzepatide) was associated with lower risks of dementia (HR, 0.63; 95% CI, 0.50–0.81), stroke (HR, 0.81; 95% CI, 0.70–0.93), and all-cause mortality (HR, 0.70; 95% CI, 0.63–0.78) versus other antidiabetic drugs.
  • No significant differences were observed for Parkinson disease, mild cognitive impairment, or intracerebral hemorrhage.
  • Subgroup analyses suggested greater benefit in adults aged 60 years or older, women, and patients with BMI 30–40.

In a large, matched electronic health record (EHR) cohort of adults with type 2 diabetes and obesity, treatment with semaglutide or tirzepatide was associated with reduced risks of dementia, stroke, and all-cause mortality compared with other antidiabetic therapies, with no differences in Parkinson disease or intracerebral hemorrhage.

Glucagon-like peptide 1 receptor agonists provide cardiometabolic benefits in type 2 diabetes and obesity, but their effects on neurodegenerative and cerebrovascular outcomes remain insufficiently defined. Given the elevated baseline risks of dementia and stroke in this population, clarifying associations between newer GLP-1RAs such as semaglutide and tirzepatide and brain or vascular outcomes is clinically relevant.

This retrospective cohort study used TriNetX US network data (December 1, 2017–June 30, 2024). Adults aged 40 years or older with type 2 diabetes and obesity initiating semaglutide or tirzepatide were compared with patients starting other antidiabetic drugs (biguanides, sulfonylureas, dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, thiazolidinediones, and α-glucosidase inhibitors). Patients with prior neurodegenerative or cerebrovascular disease were excluded. Propensity score matching (1:1) balanced baseline characteristics, yielding 60 860 patients (30 430 per group). Primary outcomes were incident dementia, Parkinson disease, mild cognitive impairment, ischemic stroke, and intracerebral hemorrhage; the secondary outcome was all-cause mortality. Cox proportional hazards models estimated hazard ratios (HRs) with 95% confidence intervals (CIs).

Over follow-up (mean [SD], 1.77 [1.35] years; cumulative probabilities reported through 7 years), GLP-1RA users had a lower risk of dementia (HR, 0.63; 95% CI, 0.50–0.81) and stroke (HR, 0.81; 95% CI, 0.70–0.93) relative to users of other antidiabetic drugs. All-cause mortality was also lower with GLP-1RAs (HR, 0.70; 95% CI, 0.63–0.78). There were no significant differences for Parkinson disease or intracerebral hemorrhage, and mild cognitive impairment did not differ between groups. Kaplan–Meier curves for the composite of neurodegenerative and cerebrovascular outcomes diverged over time, with lower cumulative incidence in the GLP-1RA group. Subgroup analyses indicated stronger associations among adults aged 60 years or older, women, and those with BMI 30–40.

The authors note limitations inherent to observational EHR research, including potential residual confounding despite extensive propensity matching; lack of biomarker, genetic, or neuroimaging data; reliance on prescriptions rather than confirmed medication adherence or dosing; and inability to perform traditional competing-risks modeling on the platform (addressed in part via supplementary composite end points). These issues warrant cautious interpretation of associations and underscore the need for randomized trials.

“In this cohort study, the use of GLP-1RAs, particularly semaglutide and tirzepatide, is associated with a lower incidence of dementia, stroke, and all-cause mortality in patients with both type 2 diabetes and obesity, suggesting potential neuroprotective and cerebrovascular benefits,” Huan-Tang Lin, MD, PhD, and colleagues concluded.

Reference:
Lin HT, Tsai YF, Liao PL, Wei JC. Neurodegeneration and stroke after semaglutide and tirzepatide in patients with diabetes and obesity. JAMA Netw Open. 2025;8(7):e2521016. doi:10.1001/jamanetworkopen.2025.21016