Profile of FGF23 and NTproBNP levels and their association with left ventricular hypertrophy in children and adolescents with CKD.

BACKGROUND: While N-terminal pro-B-type natriuretic peptide (NTproBNP) and fibroblast growth factor 23 (FGF23) have independently been evaluated for identification of left ventricular hypertrophy (LVH) in adults, their utility in children is underexplored. METHODS: This cross-sectional study was conducted in children and adolescents (5-18 years) with CKD; those with severe anemia, congestive heart failure or congenital heart disease were excluded. Clinical assessment, hemogram, kidney function tests, and bone mineral metabolism parameters were recorded. Serum FGF23 was measured by ELISA and NTproBNP by chemiluminescence-based kits. Echocardiography was done in children (CKD stages 3-5) within 2 weeks of blood investigations. RESULTS: Of 60 patients with median (IQR) age 10 (7;12) years enrolled, hypertension was present in 28 (46.6%). NTproBNP was elevated in 40% and FGF23 in 60%. LVH was found in 12 (33.3%) out of the total 36 subjects in CKD stage 3-5. NTproBNP had a significant correlation with hypertension (p < 0.01). The sensitivity and specificity of NTproBNP, eGFR-adjusted NTproBNP and FGF23 to predict LVH were 91.7% and 65.2% (AUC 0.69), 91.7% and 52.2% (AUC 0.53), and 41.7% and 82.6% (AUC 0.51), respectively. Combined FGF23 and NTproBNP achieved sensitivity of 55% and specificity of 100% which was unchanged after eGFR adjustment. CONCLUSIONS: NTproBNP showed a high sensitivity for predicting LVH, and the specificity nearly reached 100% when combining NTproBNP with FGF23, indicating its potential as a screening tool where availability of echocardiography is limited.