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

Abstract

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. Graphical abstract.

Keywords: Adolescents; Children; Chronic kidney disease; Cohort study; Glomerular filtration rate; Hypertension.

Conflict of interest statement

Conflicts of Interest

Joseph Flynn reports grants from the American Heart Association, personal fees from Silvergate Phamaceuticals, Ultragenyx, Springer, and Up To Date outside the published work. No other conflicts of interest to report.

Figures

Figure 1.

Time to kidney replacement therapy or 30% decline in GFR by CKD diagnosis (n = 679 person-visits from n = 194 participants. (G) and n = 2403 person-visits from n = 560 participants (NG))

Figure 2.

Unadjusted and adjusted hazard ratios and 95% confidence intervals comparing the risk of stage 5 chronic kidney disease or a 30% decline in GFR for different blood pressure percentile categories with blood pressure ≥ 90th percentile as the reference. Adjustment models included race (black race vs. non-black race), income, maternal education, baseline age, baseline proteinuria and baseline GFR as covariates. Circles and triangles represent the estimated hazard ratios relative to BP >90th percentile for unadjusted and adjusted models, respectively. Whiskers depict the 95% confidence intervals of the hazard ratio estimates.