GFR Variability, Survival, and Cardiovascular Events in Older Adults

RATIONALE & OBJECTIVE: Variability in estimated glomerular filtration rate (eGFR) over time is often observed, but it is unknown whether this variation is clinically important. We investigated the association between eGFR variability and survival free of dementia or persistent physical disability (disability-free survival) and cardiovascular disease (CVD) events (myocardial infarction, stroke, hospitalization for heart failure, or CVD death). STUDY DESIGN: Post hoc analysis. SETTING & PARTICIPANTS: 12,549 participants of the ASPirin in Reducing Events in the Elderly trial. Participants were without documented dementia, major physical disability, previous CVD, and major life-limiting illness at enrollment. PREDICTORS: eGFR variability. OUTCOMES: Disability-free survival and CVD events. ANALYTICAL APPROACH: eGFR variability was estimated using the standard deviation of eGFR measurements obtained from participants’ baseline, first, and second annual visits. Associations between tertiles of eGFR variability with disability-free survival and CVD events occurring after the eGFR variability estimation period were examined. RESULTS: During median follow-up of 2.7 years after the second annual visit, 838 participants died, developed dementia, or acquired a persistent physical disability; 379 had a CVD event. The highest tertile of eGFR variability had an increased risk of death/dementia/disability (HR, 1.35; 95% CI, 1.14-1.59) and CVD events (HR, 1.37; 95% CI, 1.06-1.77) compared with the lowest tertile after covariate adjustment. These associations were present in patients with and without chronic kidney disease at baseline. LIMITATIONS: Limited representation of diverse demographics. CONCLUSIONS: In older, generally healthy adults, higher variability in eGFR over time predicts increased risk of future death/dementia/disability and CVD events.