Potential Protective Link Between Type I Diabetes and Parkinson's Disease Risk and Progression

Abstract Background Epidemiological studies suggested an association between Parkinson's disease (PD) and type 2 diabetes, but less is known about type 1 diabetes (T1D) and PD. Objective This study sought to explore the association between T1D and PD. Methods We used Mendelian randomization, linkage disequilibrium score regression, and multi‐tissue transcriptome‐wide analysis to examine the association between PD and T1D. Results Mendelian randomization showed a potentially protective role of T1D for PD risk (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.94–0.99; P = 0.039), as well as motor (OR, 0.94; 95% CI, 0.88–0.99; P = 0.044) and cognitive progression (OR, 1.50; 95% CI, 1.08–2.09; P = 0.015). We further found a negative genetic correlation between T1D and PD (rg = −0.17; P = 0.016), and we identified eight genes in cross‐tissue transcriptome‐wide analysis that were associated with both traits. Conclusions Our results suggest a potential genetic link between T1D and PD risk and progression. Larger comprehensive epidemiological and genetic studies are required to validate our findings. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.