Growth in children with nephrotic syndrome: a post hoc analysis of the NEPTUNE study

Background: Steroids, the mainstay of treatment for nephrotic syndrome in children, have multiple adverse effects including growth suppression. Methods: Anthropometric measurements in children < 18 years enrolled in the Nephrotic Syndrome Study Network (NEPTUNE) were collected. The longitudinal association of medication exposure and nephrotic syndrome characteristics with height z-score and growth velocity was determined using adjusted Generalized Estimating Equation regression and linear regression. Results: A total of 318 children (57.2% males) with a baseline age of 7.64 ± 5.04 years were analyzed. The cumulative steroid dose was 216.4 (IQR 61.5, 652.7) mg/kg (N = 233). Overall, height z-scores were not significantly different at the last follow-up compared to baseline (− 0.13 ± 1.21 vs. − 0.23 ± 1.71, p = 0.21). In models adjusted for age, sex, and eGFR, greater cumulative steroid exposure (β − 7.5 × 10⁻⁶, CI − 1.2 × 10⁻⁵, − 3 × 10⁻⁶, p = 0.001) and incident cases of NS (vs. prevalent) (β − 1.1, CI − 2.22, − 0.11, p = 0.03) were significantly associated with lower height z-scores over time. Rituximab exposure was associated with higher height z-scores (β 0.16, CI 0.04, 0.29, p = 0.01) over time. Conclusion: Steroid dose was associated with lower height z-score, while rituximab use was associated with higher height z-score. Graphical abstract: (Figure presented.)