The use of hypoglycemic drugs in Parkinson's disease: An updated meta-analysis of randomized controlled trials.

Introduction: Recent studies have demonstrated an association between hypoglycemic medications and neuroprotective action in neurodegenerative diseases, such as Parkinson's disease (PD). Therefore, in this meta-analysis, our objective was to evaluate the efficacy of these medications, compared to placebo, as disease-modifying therapy in patients with PD.

Methods: We systematically searched PubMed, Embase, and Cochrane for studies comparing the use of hypoglycemic drugs and placebo in patients with PD. Statistical analyses were performed using R Studio 4.3.2. Mean difference (MD) with 95 % confidence intervals (CI) were pooled across trials. Outcomes of interest were change in Movement Disorders Society - Unified Parkinson's Disease Rating Scale (MDS-UPDRS) parts I, II, III, IV, and Parkinson's Disease Questionnaire 39 (PDQ-39).

Results: This meta-analysis included six randomized controlled trials (RCT) reporting data on 787 patients. Among them, 480 (61 %) received hypoglycemic drugs. Follow-up ranged from 36 to 61 weeks. At the end of follow-up, improvement in MDS-UPDRS part III score during OFF state occurred when subjects received any hypoglycemic agents at their lowest dose (MD -1.36; 95 % IC -2.78 to -0.47; I2 = 38 %), as well as highest doses (MD -1.58; 95 % IC -3.07 to -0.09; I2 = 50 %). Changes in MDS-UPDRS part III score in patients examined in the ON state who received any dose of any hypoglycemic agents (MD -3.32; 95 % IC -5.28 to -1.36; I2 = 0 %) were significant. There was no significant difference between groups MDS-UPDRS parts I, II, IV, and PDQ-39.

Conclusion: In patients with PD, the use of hypoglycemic agents showed efficacy on symptomatic PD treatment with an improvement in MDS-UPDRS part III.