Mean Arterial Pressure and Chronic Kidney Disease Progression in the CKiD Cohort

Consensus blood pressure guidelines vary in their recommended ambulatory blood pressure targets for children with chronic kidney disease (CKD) because of limited research in this area. We analyzed longitudinal ambulatory blood pressure monitoring data from 679 children with moderate CKD enrolled in the observational CKiD (Chronic Kidney Disease in Children) cohort by time-varying mean arterial pressure (MAP) percentile categories based on the highest wake or sleep MAP percentile. Analyses were stratified by nonglomerular and glomerular diagnoses, with 3 models constructed: unadjusted, adjusted for age, sex, and race, and additional adjustment for proteinuria. The outcome of interest was time to renal replacement therapy or 50% decline in baseline renal function. We found that among children with nonglomerular CKD, MAP percentile was not associated with accelerated disease progression risk until after 4 years of follow-up at which point a high MAP (>90th percentile) was associated with a higher risk of progression to the composite end point (HR, 1.88 [CI, 1.03-3.44]). Among those with glomerular CKD, differential risk for progression began from baseline with the highest risk in those with MAP >90th percentile (HR, 3.23 [CI, 1.34-7.79]). These relationships were attenuated somewhat after adjustment for level of proteinuria, but the trend for higher MAP being associated with higher risk of progression remained significant. Thus, in children with CKD, having ambulatory wake or sleep MAP >90th percentile was associated with higher risk of kidney disease progression with the highest levels of MAP associated with the greatest risk of progression. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00327860.