Nephrotic range proteinuria is strongly associated with poor blood pressure control in pediatric chronic kidney disease

Despite the importance of blood pressure (BP) control in chronic kidney disease (CKD), few longitudinal studies on its trends exist for pediatric patients with CKD. Here we longitudinally analyzed casual data in 578 children with CKD and annual BP measurements standardized for age, gender and height. At baseline, 124 children were normotensive, 211 had elevated BP and 243 had controlled hypertension. Linear mixed effects models accounting for informative dropout determined factors associated with BP changes over time and relative sub-hazards (RSH) identified factors associated with the achievement of controlled BP in children with baseline elevated BP. Younger age, black children, higher body mass index, and higher proteinuria at baseline were associated with higher standardized BP levels. Overall average BP decreased during follow-up, but nephrotic range proteinuria, and increased proteinuria and body mass index were risk factors for increasing BP over time. Only 46% of hypertensive patients achieved controlled BP during follow-up; least likely were those with nephrotic range proteinuria (RSH 0.19), black children (RSH 0.42) and children with baseline GFR under 40 ml/min/1.73m(2) (RSH 0.58). Thus, of many coexisting factors, nephrotic range proteinuria was most strongly associated with poor BP control and worsening BP over time. Future research should focus on strategies to reduce proteinuria, as this may improve BP control and slow the progression of CKD.