While some evidence exists of increased dementia risk from anemia, it is unclear if this association persists among adults with CKD. Anemia may be a key marker for dementia among adults with CKD. We therefore evaluated if anemia is associated with an increased risk of dementia among adults with CKD.
Retrospective cohort study.
The study included 620,095 veterans aged ≥45 years with incident stage 3 CKD (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m) between January 2005 and December 2016 in the US Veterans Health Administration system and followed through December 31, 2018 for incident dementia, kidney failure or death.
Anemia was assessed based on the average of hemoglobin levels (g/L) during the two years prior to the date of incident CKD and categorized as normal, mild and moderate/severe anemia (≥12.0, 11.0-11.9, <11.0 g/dL, respectively for women and ≥13.0, 11.0-12.9, <11.0 g/dL for men).
Dementia and the composite outcome of kidney failure or death.
Adjusted cause-specific hazard ratios were estimated for each outcome.
At the time of incident CKD, mean age was 72 years, 97% were male, and mean eGFR was 51 mL/min per 1.73 m. Over a median 4.1 years of follow-up, 92,306 (15%) veterans developed dementia before kidney failure or death. Compared to veterans with CKD without anemia, multivariable-adjusted models showed a 16% (95% confidence interval [CI] 14% to 17%) significantly higher risk of dementia for those with mild anemia and a 27% (95% CI 23% to 31%) higher risk with moderate/severe anemia. Combined risk of kidney failure or death was higher at 39% (95% CI 37% to 40%) and 115% (95% CI 112% to 119%) for mild and moderate/severe anemia, respectively, compared to no anemia.
Residual confounding from the observational study design. Findings may not be generalizable to the broader U.S.
Anemia was significantly associated with increased risk of dementia among veterans with incident CKD, underscoring the role of anemia as a predictor of dementia risk.

Copyright © 2023. Published by Elsevier Inc.