Title: Association between Graves’ disease and Parkinson’s disease: A systematic review and meta-analysis
Authors: Jamir Pitton Rissardo, Ana Leticia Fornari Caprara
Conference: 7th WPC, Phoenyx, AZ
Objective
To evaluate the bidirectional association between Graves’ disease (GD) and Parkinson’s disease (PD) using data from population-based studies.
Background
Emerging evidence suggests autoimmune thyroid disorders may influence neurodegenerative processes. Graves’ disease, characterized by hyperthyroidism and autoimmunity, could share pathogenic mechanisms with PD, including immune dysregulation and oxidative stress. However, the strength and direction of this association remain unclear.
Design/Methods
A systematic review was conducted using PubMed to identify observational studies assessing the relationship between GD and PD. Studies reporting incidence or prevalence of GD in PD patients or PD in GD patients were included. Data were pooled using Mantel–Haenszel odds ratios (OR) under fixed and random-effects models. Heterogeneity was assessed with I2 and Cochran’s Q. Publication bias was evaluated using fail-safe N methods.
Results
Three studies met inclusion criteria (Rugbjerg et al., 2009; Li et al., 2012; Cho et al., 2022), encompassing 392,280 participants and 1,398 events. For PD→GD (two studies), the fixed-effect pooled OR was 12.36 (95% CI: 9.79–15.61; p < 0.0001), indicating a significantly increased risk of GD among PD patients. Random-effects analysis showed OR 3.38 (95% CI: 0.30 to 10.49; p = 0.35) with high heterogeneity (I2 = 99.2%). For GD→PD (one study), the OR was 1.37 (95% CI: 1.21–1.56; p < 0.0001). Fail-safe N analyses suggested robustness against publication bias.
Conclusions
Our findings support a bidirectional association between GD and PD, with PD patients exhibiting a higher risk of GD and GD patients showing a modestly increased risk of PD. Shared autoimmune and neuroinflammatory pathways may underlie this link. Further longitudinal studies are warranted to clarify causality and mechanisms.
Citation
Rissardo JP, Caprara ALF. Association between Graves’ disease and Parkinson’s disease: A systematic review and meta-analysis. J Parkinsons Dis 2026;16(1_suppl):68. doi: 10.1177/1877718X261451755.
Figure 1. Forest plots show bidirectional PD–GD risk with pooled ORs; Baujat plot identifies study contributions to heterogeneity and overall effect.