Evaluating the Clinical Effects of GLP-1 Receptor Agonists for Alzheimer's and Parkinson's Diseases Using Minimal Clinically Important Difference: Systematic Review and Meta-Analysis

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are promising candidates for Alzheimer’s disease (AD) and Parkinson’s disease (PD). However, their effects in non-diabetic populations, independent of metabolic confounding, remain unclear. We evaluated the effects of GLP-1RAs on cognition, clinical outcomes, biomarkers, and safety in non-diabetic individuals with PD, AD, and mild cognitive impairment. We assessed the clinical meaningfulness of these effects using minimal clinically important difference thresholds. Relevant studies were retrieved from PubMed, Embase, and Web of Science from inception to November 2025. A random-effects meta-analysis was applied to calculate standardized mean differences (SMDs), mean differences (MDs), and risk ratios with 95