Review consolidating the biomarker evidence for repurposing antidiabetic medications in Parkinson’s disease, linking proposed mechanisms (metabolic, inflammatory, mitochondrial) to clinical trial outcomes and identifying gaps in biomarker strategies.

By cataloguing biomarkers and mechanistic rationales for antidiabetic agents in PD, the paper helps prioritize measurable endpoints for disease‑modification trials and highlights methodological gaps whose resolution could accelerate repurposing efforts.

Parkinson's disease (PD) is a progressive neurodegenerative disorder. It shares many pathophysiologic similarities with type 2 diabetes mellitus (T2DM). Numerous studies have explored the repurposing of antidiabetic medications for their potential neuroprotective effects in PD. There has not been a consolidated review of the biochemical biomarkers that have been evaluated across antidiabetic medications. This review aims to assess the current landscape of biomarker research in evaluating the efficacy of these antidiabetic agents as disease-modifying therapies in PD. We examine the molecular mechanisms targeted by these drugs, the biomarkers used to assess their effects, and the outcomes of clinical trials. This review hopes to identify gaps in current research and enhance the evaluation of antidiabetic medications in PD.