Summary
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been shown to decrease blood glucose levels, promote weight loss, and prevent cardiovascular events. However, evidence is limited regarding their effect on dementia, although emerging observational studies, some with serious methodological limitations, have suggested large reductions in dementia associated with GLP-1RAs that may not be entirely causally related.
From 2016 to December 2020, authors conducted a trial emulation to compare the effect of GLP-1RAs versus dipeptidyl peptidase-4 inhibitors (DPP4is) as second-line therapy for type 2 diabetes on risk for dementia among older adults. Participants were Medicare fee-for-service beneficiaries aged 66 years or older with diabetes who used metformin and did not have dementia at baseline and initiated GLP-1RAs or DPP4is between January 2017 and December 2018.
Findings: Among older adults with diabetes, no clear evidence was found that the incidence of dementia differed overall between patients using GLP-1RAs versus DPP4is. Under conventional statistical criteria, an effect of GLP-1RAs between a 39% decrease and a 5% increase in risk for dementia was highly compatible with the data, although estimates differed by age. Randomized trials are needed to quantify the effect of GLP-1RAs on dementia.