Duration of chronic kidney disease reduces attention and executive function in pediatric patients

Chronic kidney disease (CKD) in childhood is associated with neurocognitive deficits. Affected children show worse performance on tests of intelligence than their unaffected siblings and skew toward the lower end of the normal range. Here we further assessed this association in 340 pediatric patients (ages 6-21) with mild-moderate CKD in the Chronic Kidney Disease in Childhood cohort from 48 pediatric centers in North America. Participants underwent a battery of age-appropriate tests including Conners' Continuous Performance Test-II (CPT-II), Delis-Kaplan Executive Function System Tower task, and the Digit Span Backward task from the age-appropriate Wechsler Intelligence Scale. Test performance was compared across the range of estimated glomerular filtration rate and duration of CKD with relevant covariates including maternal education, household income, IQ, blood pressure, and preterm birth. Among the 340 patients, 35% had poor performance (below the mean by 1.5 or more standard deviations) on at least one test of executive function. By univariate nonparametric comparison and multiple logistic regression, longer duration of CKD was associated with increased odds ratio for poor performance on the CPT-II Errors of Commission, a test of attention regulation and inhibitory control. Thus, in a population with mild-to-moderate CKD, the duration of disease rather than estimated glomerular filtration rate was associated with impaired attention regulation and inhibitory control.