Abstract
BACKGROUND: Currently, the cognitive impact of Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) remains unclear in non-diabetic patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI), despite their widespread use for type 2 diabetes. This meta-analysis summarized cognitive outcomes from randomized controlled trials (RCTs) of GLP-1 RAs in non-diabetic patients with AD or MCI.
METHODS: PubMed, Cochrane Library, and Embase were searched for studies through October 27, 2024. Pooled standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated using random-effects models. Sensitivity analyses addressed variations in cognitive assessment methodologies. Between-study heterogeneity was evaluated using the I² index.
RESULTS: Four RCTs comprising 112 patients (61 placebo, 51 treatment) were included. For cognitive tests where higher scores indicate better outcomes, no significant difference was observed between GLP-1 RA and placebo groups (pooled SMD: -0.10, 95% CI: -0.53, 0.34; I² = 23.9%). Sensitivity analyses yielded consistent results. Analysis of the Alzheimer's Disease Assessment Scale-Cognitive subscale from two studies, where lower scores indicate better outcomes, similarly showed no significant treatment effect (SMD: 0.07, 95% CI: -0.47, 0.62; I² = 0%).
CONCLUSION: There was no evidence that GLP-1 RAs improved cognitive outcomes compared to placebo in non-diabetic patients with AD or MCI. Further research is needed to clarify their neuroprotective potential and explore alternative therapeutic strategies for cognitive decline.