B‐type natriuretic peptide is a useful biomarker for the estimation of volume overload in children with hypertension on peritoneal dialysis

AIM: The aim of the present study was to evaluate the usefulness of serum B-type natriuretic peptide (BNP) as a biomarker of fluid retention in hypertensive children on peritoneal dialysis (PD). METHODS: Hypertensive children on PD were included. The changes (∆) of body weight (BWt), blood pressure (BP) and serum BNP at initial and follow-up periods were reviewed. Data are presented as mean ± standard deviation (median, minimum - maximum). Wilcoxon signed-rank test was used to evaluate the changes in BWt, BP, and BNP. Linear regression analysis was applied for the correlation between the changes of BNP and BP. RESULTS: A total of 56 hypertensive events were evaluated in 30 patients. Initial findings were BWt 30.5 ± 22.4 (26.5, 3.0-93.5) kg, systolic BP (SBP) 153.3 ± 21.5 (150, 110-241) mmHg, diastolic BP (DBP) 100.1 ± 22.3, (99.5, 49-181) mmHg, BNP 3579.3 ± 6328.9 (1198.5, 305-22 028) pg/mL. Follow-up results were BWt 29.1 ± 21.3 (25.0, 3.12-86) kg, SBP 116.4 ± 17.8 (117.5, 82-150) mmHg, DBP 73.3 ± 14.2 (75.0, 42.0-101.0) mmHg, BNP 63.5 ± 49.2 (60.5, 2-261) pg/mL. ∆SBP (-23.1 ± 13.8, -22.8, -46.9 - 22.5%, P < 0.001), ∆DBP (-24.1 ± 19.2, -24.7, -55.6 - 23.2%, P < 0.001) and ∆BNP (-93.5 ± 8.1, -96.7, -99.9 - -61.0%, P < 0.001) dropped significantly after reduction of ∆BWt (-4.8 ± 4.7, -4.8, -18.7 - 5.6%, P < 0.001). The ∆BNP were significantly correlated with ∆SBP (adjusted R square = 0.221, P < 0.001) and ∆DBP (adjusted R square = 0.203, P < 0.001). CONCLUSIONS: Serum B-type natriuretic peptide should be measured in hypertensive patients on PD to evaluate the volume status.