FGF23 and Left Ventricular Hypertrophy in Children with CKD

Background and Objectives High plasma concentration of fibroblast growth factor 23(FGF23) is a risk factor for left ventricular hypertrophy (LVH) in adults with CKD, and induces myocardial hypertrophy in experimental CKD. We hypothesized that high FGF23 levels associate with a higher prevalence of LVH in children with CKD. Design, setting, participants, & measurements We performed echocardiograms and measured plasma C-terminal FGF23 concentrations in 587 children with mild-to-moderate CKD enrolled in the Chronic Kidney Disease in Children (CKiD) study. We used linear and logistic regression to analyze the association of plasma FGF23 with left ventricular mass index(LVMI) and LVH (LVMI ≥95th percentile), adjusted for demographics, body mass index, eGFR, and CKD-specific factors. We also examined the relationship between FGF23 and LVH by eGFR level. Results Median age was 12 years ( interquartile range, 8–15) and eGFR was 50 ml/min per 1.73 m 2 ( interquartile range, 38–64). Overall prevalence of LVH was 11%. After adjustment for demographics and body mass index, the odds of having LVH was higher by 2.53 (95% confidence interval, 1.28 to 4.97; P 2 , the prevalence of LVH was 5.4%, 11.2%, and 15.3% for those with FGF23 P trend =0.01). When eGFR was ≥45 ml/min per 1.73 m 2 , higher FGF23 concentrations were independently associated with LVH (fully adjusted odds ratio, 3.08 in the highest versus lowest FGF23 category; 95% confidence interval, 1.02 to 9.24; P P 2 , FGF23 did not associate with LVH. Conclusions Plasma FGF23 concentration ≥170 RU/ml is an independent predictor of LVH in children with eGFR≥45 ml/min per 1.73 m 2 .