Achieved clinic blood pressure level and chronic kidney disease progression in children: a report from the Chronic Kidney Disease in Children cohort

Background: Control of hypertension delays progression of pediatric chronic kidney disease (CKD), yet few data are available regarding what clinic blood pressure (BP) levels may slow progression. Methods: Longitudinal BP data from children in the Chronic Kidney Disease in Children cohort study who had hypertension or an auscultatory BP ≥ 90th percentile were studied. BP categories were defined as the maximum systolic or diastolic BP percentile (< 50th, 50th to 75th, 75th to 90th, and ≥ 90th percentile) with time-updated classifications corresponding to annual study visits. The primary outcome was time to kidney replacement therapy or a 30% decline in estimated glomerular filtration rate. Cox proportional hazard models described the effect of each BP category compared to BP ≥ 90th percentile. Results: Seven hundred fifty-four participants (median age 9.9 years at study entry) met inclusion criteria; 65% were male and 26% had glomerular CKD. Any BP < 90th percentile was associated with a decreased risk of progression for those with glomerular CKD (hazard ratio (HR), 0.63; 95% CI, 0.28–1.39 (< 50th); HR, 0.59; 95% CI, 0.28–1.26 (50th–75th); HR, 0.40; 95% CI, 0.18–0.93 (75th–90th)). Similar results were found for those with non-glomerular CKD: any BP < 90th percentile was associated with decreased risk of progression (HR, 0.78; 90% CI, 0.49–1.25 (< 50th); HR, 0.53; 95% CI, 0.33–0.84 (50th–75th); HR, 0.71; 95% CI, 0.46–1.08 (75th–90th)). Conclusions: Achieved clinic BP < 90th percentile was associated with slower CKD progression in children with glomerular or non-glomerular CKD. These data provide guidance for management of children with CKD in the office setting. [Figure not available: see fulltext.]