Parkinson’s disease and chronic kidney disease trends and disparities in the US population aged over 25 years (1999–2023)

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neuronal loss and α-synuclein aggregation, resulting in motor dysfunction and increasing mortality. Chronic kidney disease (CKD), affecting nearly 700 million people worldwide, is associated with systemic inflammation, vascular dysfunction, and excess mortality. Emerging evidence suggests a bidirectional relationship between CKD and PD, with renal impairment potentially accelerating neurodegeneration and worsening clinical outcomes. This study examined national mortality trends among individuals with coexisting PD and CKD in the United States from 1999 to 2023. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Mortality data were obtained from the CDC WONDER database. Deaths listing both PD (International Classification of Diseases, Tenth Revision [ICD-10]: G20) and CKD (ICD-10: N18) were identified. Age-adjusted mortality rates (AAMRs) per 1,00,000 population were standardized to the 2000 US population and stratified by year, sex, region, and urban-rural status. Joinpoint regression estimated Annual percent change (APC), with P < .05 considered statistically significant. Between 1999 and 2023, 20,437 deaths were attributed to coexisting PD and CKD. National AAMR increased more than 4-fold, from 0.1 to 0.5 per 1,00,000 (APC = 5.23; 95% CI: 3.92-6.55). Mortality increased in females (0.1-0.3; APC = 5.15; 95% CI: 3.35-6.99) and males (0.2-0.8; APC = 4.79; 95% CI: 3.57-6.02). All census regions demonstrated significant increases, with the greatest rise in the West (APC = 5.92; 95% CI: 4.22-7.64). Mortality also increased in both urban (APC = 5.01) and rural (APC = 4.78) populations. Mortality among individuals with coexisting PD and CKD has risen substantially across demographic and geographic groups in the United States over the past 2 decades. These findings highlight the need for integrated neurology-nephrology care, early recognition of renal dysfunction, and targeted risk-factor management. Further research is warranted to clarify underlying mechanisms and develop strategies to reduce mortality in this high-risk population.