Plasma Fibroblast Growth Factor 23 as a Predictor for Fosinopril Therapeutic Efficacy in Pediatric Primary Hypertension

BACKGROUND: Plasma fibroblast growth factor 23 (FGF23) has been reported to be a predictive biomarker for therapeutic effectiveness of angiotensin‐converting enzyme inhibitors in heart failure. Higher plasma FGF23 levels have been shown in pediatric primary hypertension, but the predictive value of FGF23 for angiotensin‐converting enzyme inhibitors’ effectiveness in pediatric primary hypertension has not been documented. METHODS AND RESULTS: This is a prospective study. An exploratory study with 139 patients was first conducted to determine the cutoff value of FGF23 for the prediction of treatment responsiveness. After receiving fosinopril for 4 weeks, of all 139 patients, 91 responded, while 48 did not respond to the treatment, and the responders had a significantly higher baseline plasma FGF23 level than nonresponders (P<0.01). Multiple regression analysis revealed a significant impact of baseline plasma FGF23 levels on fosinopril responsiveness (P<0.05). The receiver operating characteristic curve analysis showed that the plasma FGF23 predicted the effectiveness of fosinopril treatment with an area under the curve of 0.784 (95% CI, 0.704–0.863) for a sensitivity and a specificity of 67.0% and 89.6%, respectively, for a cutoff value of 62.08 RU/mL. Subsequently, another group of 40 patients were recruited for validation. The blood pressure control rate in those (n=22) with baseline plasma FGF23 >62.08 RU/mL was significantly higher than that in children (n=18) with FGF23 ≤62.08 RU/mL (P<0.05). CONCLUSIONS: Plasma FGF23 might be a valuable biomarker to guide fosinopril therapy for primary hypertension in children.