Mid- and Late-Life Chronic Kidney Disease Is Associated with Parkinson's Disease, Not with an Increased Risk of Alzheimer's Disease.

Chronic kidney disease (CKD) is strongly associated with dementia. However, its independent association with Alzheimer's or Parkinson's disease remains unclear. This study investigated the prospective association of patients with CKD aged ≥55 years with an increased risk of Alzheimer's or Parkinson's disease. We conducted a retrospective cohort analysis using a national cohort sample of approximately one million patients. Primary outcome indicators measured included incidence of all-cause dementia, Alzheimer's disease, and Parkinson's disease events using person-years at risk. The hazard ratio was adjusted using the Cox proportional hazards model. We included 952 patients without CKD and 476 with CKD over 55 years using propensity score matching. The CKD group exhibited higher incidences of all-cause dementia, Parkinson's disease, and Alzheimer's disease than the non-CKD group. Furthermore, the CKD group had an elevated risk of all-cause dementia and a significantly increased risk of Parkinson's disease, especially among older women. Notably, the risk of Parkinson's disease was higher within the first 3 years of CKD diagnosis. These findings emphasize the link between CKD in mid- and late-life individuals and a higher incidence of all-cause dementia and Parkinson's disease rather than Alzheimer's disease.