Mild to moderate decrease in eGFR and cognitive decline in older adults.

BACKGROUND AND OBJECTIVES: Whether mild to moderately low eGFR is associated with cognitive decline in older adults is not clear. We evaluated changes in cognition in relation to baseline eGFR in older adults participating in the Alzheimer's Disease Neuroimaging Initiative (ADNI).

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: This is a longitudinal secondary analysis of an established observational cohort. We used data from ADNI, an NIH funded, multicenter longitudinal observational study, which includes participants with and without cognitive impairment who were administered a comprehensive battery of neuropsychological tests every six months. We related the chronic kidney disease Epidemiology Collaboration eGFR with previously validated cognition composite scores for memory (ADNI-Mem) and executive function (ADNI-EF) in multivariable linear regression analysis adjusted for age, sex, race and level of education.

RESULTS: 1127 ADNI participants with a mean age of 74±7 years, 57% men, 97% Caucasian, and mean follow up for 6±2.6 years were included in the analysis. Mean baseline eGFR was 76±19 ml/min/1.73 m2, with 6% with eGFR <45, 22% with eGFR 45 to < 60, 51% with eGFR 60 to 90, and 21% with eGFR >90 ml/min/1.73 m2 at baseline. Both ADNI- Mem and ADNI-EF scores declined over time. In the multivariable linear regression model, older age (β= -0.117, p = 0.01), female sex (β = 0.312, p < 0.001) and lower education (β = 0.079, p < 0.001) were associated with decline in ADNI-Mem scores, whereas baseline eGFR (each 10 ml/min/1.73 m2 change) was not (β= -0.03, CI -0.06 to 0.001, p = 0.11). Similarly, older age (β= -0.278, p < 0.001) and lower education (β = 0.099, p < 0.001) were associated with decline in ADNI-EF scores whereas baseline eGFR was not (β = 0.004, CI -0.04 to 0.04, p = 0.84).

CONCLUSIONS: In this cohort from the ADNI study, there was no association between baseline eGFR and cognitive decline in older adults with mild-moderately low eGFR.