Background: Chronic kidney disease (CKD) is associated with incident cognitive impairment (ICI) and disproportionately affects older adults and Black persons.
Objective: To determine (1) whether age or race differences exist in the association of CKD and ICI and (2) whether cognitive trajectories differ in people with and without CKD.
Design: Nationwide cohort study.
Participants: A total of 22,435 Black and White adults age ≥ 45 years without baseline cognitive impairment.
Measurements: Creatinine-cystatin C-based eGFR and albumin-to-creatinine ratio (ACR). Six-item screener (SIS) of global cognition every 6 months, three cognitive domain tests (memory, semantic, and letter fluencies) every 2 years for 10 years. Logistic regression for risk of CI and latent growth curve models for trajectory analysis.
Results: Participants were 56% female, 37% Black, 56% hypertensive, and 19% had diabetes. Overall, 13% (n = 2959) developed ICI over 10 years. In mid-life (age 45- < 65), the OR (95% CI) of ICI for eGFR < 45 vs eGFR ≥ 90 was 1.9 (1.2, 3.0); in late-life (≥ 65), the OR was 0.9 (0.7, 1.1), p interaction < 0.001. For ACR > 300 vs ACR < 10, in mid-life and late-life, the ORs were 1.6 (1.0, 2.6) and 1.0 (0.7, 1.4), p interaction 0.02. Compared to those with eGFR ≥ 60, eGFR < 60 was associated with lower initial cognitive domains scores, worse in mid-life than late-life, but the slopes did not differ. Compared to ACR < 30, ACR ≥ 30 had lower initial cognitive domain scores, which were similar in mid and late-life, and a steeper decline for memory scores. No differences by race were observed.
Conclusions: Kidney disease was more strongly linked to cognitive impairment in mid-life than in late-life. Albuminuria was associated with steeper decline in memory function, especially in mid-life.
Primary funding source: NIGMS.
© 2025. The Author(s), under exclusive licence to Society of General Internal Medicine.