Predictors of Rapid Progression of Glomerular and Nonglomerular Kidney Disease in Children and Adolescents: The Chronic Kidney Disease in Children (CKiD) Cohort

Abstract

Background Few studies have prospectively evaluated the progression of chronic kidney disease (CKD) in children and factors associated with progression. Study Design Prospective assessment of risk factors for the composite event of renal replacement therapy (RRT) or 50% glomerular filtration rate (GFR) decline. Setting and Participants 496 children with CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study. Outcomes Parametric failure time models were used to characterize adjusted associations between baseline levels and changes of predictors and the time to composite event. Results The cohort consisted of 398 children with non-glomerular and 98 children with glomerular disease, of whom 29% and 41%, respectively progressed to the composite event after a median follow-up of 5.2 and 3.7 years. Demographic, clinical characteristics and outcomes differed substantially according to underlying diagnosis, hence risk factors for progression were assessed in stratified analyses and formal interactions by diagnosis were performed. Among non-glomerular patients and after adjusting for baseline GFR, times to the composite event were significantly reduced with Up/c > 2 mg/mg, hypoalbuminemia, elevated blood pressure, dyslipidemia, male gender and anemia by 79%, 69%, 38%, 40%, 38% and 45%, respectively. Among patients with glomerular disease, Up/c > 0.5 mg/mg, hypoalbuminemia and elevated blood pressure significantly reduced times to the composite event by 94%, 71% and 67%, respectively. Variables expressing change in patient clinical status over the initial year of the study contributed significantly to the model which was cross validated internally. Limitations small number of events in glomerular patients and use of internal cross validation. Conclusions Characterization and modeling of risk factors for CKD progression can be used to predict the extent to which these factors, either alone or in combination, would shorten the time to RRT/50% decline of GFR in children with CKD.