Cumulative burden of estimated glomerular filtration rate and the risk of intracranial atherosclerosis: a prospective cohort study

Intracranial atherosclerosis (ICAS) is a major cause of ischemic stroke. The longitudinal associations of estimated glomerular filtration rate (eGFR) with ICAS are unclear. This study aimed to investigate the association of cumulative eGFR burden with incident ICAS. In this prospective cohort study, 4032 participants underwent baseline examinations in 2010-2011, 2012-2013, and 2014-2015 and were followed through 31 December 2021. Cumulative eGFR was calculated based on three consecutive measurements obtained from 2010 to 2015. The eGFR slope was calculated by eGFR versus time through linear mixed model from 2010 to 2015. The outcome was defined as the incident ICAS during 2016-2021. The average follow-up time was 3.96 years, and there were 374 (9.28%) incident cases of ICAS. In fully adjusted model, single-time-point eGFR < 90 mL/min/1.73 m2 ;(OR: 1.817, 95%CI:1.343, 2.459), cumulative eGFR burden > 0 (OR: 1.366, 95%CI:1.041, 1.791), eGFR slope < -10 mL/min/1.73 m2/year (OR: 2.086, 95%CI:1.480, 2.944), and reduced kidney function exposure duration of (3,6] years (OR: 1.867, 95%CI:1.329, 2.622) were significantly associated with ICAS risk. Cumulative eGFR burden had a higher net reclassification improvement and integrated discrimination improvement than single-time-point eGFR for predicting ICAS. Single-time-point eGFR, cumulative eGFR burden, eGFR slope and reduced kidney function exposure duration were associated with increased risk of ICAS in this cohort study. Cumulative eGFR burden had a higher predictive value than single-time-point eGFR for ICAS. Our study emphasized that cumulative eGFR burden which combined both duration and magnitude of eGFR could better reflect the risk for ICAS.