Association of impaired kidney function with dementia and brain pathologies: A community‐based cohort study

Abstract Introduction The relationship between impaired kidney function (KF), dementia, and brain pathologies remains unclear. Methods A total of 1354 dementia‐ and kidney disease‐free participants including 895 with normal and 459 with impaired KF were followed from 2002 until 2020 (median [interquartile range]: 5 [2–9]) to detect incident dementia. KF was assessed at baseline and categorized as normal or impaired. Over the follow‐up, 453 participants died and underwent autopsies for neuropathological assessment. Results Compared to those with normal KF, the hazard ratios (95% confidence intervals [CIs]) of those with impaired KF was 1.48 (1.15, 1.90)/1.44 (1.10, 1.88) for dementia/Alzheimer's dementia. Furthermore, impaired KF was related to a significantly higher burden of cerebral amyloid angiopathy (CAA; odds ratio = 1.96, 95% CI: 1.17, 3.30), but not to other brain pathologies. Discussion Impaired KF is associated with an increased risk of dementia and Alzheimer's dementia. CAA may underlie, in part, this association. Highlights Impaired kidney function (KF) was associated with higher dementia and Alzheimer's dementia risk. Impaired KF anticipated dementia and Alzheimer's dementia onset by more than 1.5 years. Impaired KF was significantly related to a higher burden of cerebral amyloid angiopathy (CAA) but not to other brain pathologies.