# The Importance of Disease-specific Growth Charts for Children with Congenital Adrenal Hyperplasia

## TL;DR

This study shows that children with congenital adrenal hyperplasia (CAH) have unique growth patterns, so special growth charts are needed to better track and manage their development.

## Contribution

The study introduces CAH-specific growth charts using specialized statistical modeling to better evaluate growth patterns in children with CAH.

## Key findings

- CAH patients have significantly different growth trajectories compared to the general population, including a diminished pubertal growth spurt.
- Adiposity rebound occurs earlier in CAH children (around 3.3-3.9 years) compared to normative data (5-8 years).
- Growth patterns differ across age groups, emphasizing the need for CAH-specific charts for accurate clinical evaluation.

## Abstract

Children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency typically have height, weight, and body mass index (BMI) growth patterns that differ from the general population due to increased androgen and/or glucocorticoid exposures. With the recent surge in the development of new therapies, CAH-specific growth charts are needed to evaluate the effectiveness of these new treatments.

Retrospective data from patients aged 0 to 20 years with classic CAH, confirmed by hormonal testing and/or CYP21A2 genotyping, from 2 large clinical databases were analyzed. Specialized charts were developed using the lamda-mu-sigma semiparametric modeling method to generate CAH-specific percentile curves from 0 to 20 years. Nodal-point analyses were conducted to assess differences in incremental growth at 4, 8, 12, 16, and 20 years of age relative to Centers for Disease Control and Prevention (CDC) 2000 normative charts using 1-sided quantile tests and age of adiposity rebound estimated with curve derivative solutions.

A total sample of 8692 visits from 515 patients was used. Growth (height-, weight-, BMI-for-age) channels of CAH patients were significantly different over the entire growing period and characterized by diminished pubertal spurt relative to the CDC reference. Onset of adiposity rebound based on BMI-for-age occurred earlier for CAH patients (females 3.3 years, males 3.9 years) compared to their normative counterparts (5-8 years).

Our study showed that at incremental time points throughout childhood, children with CAH collectively follow specific differences in growth trajectories as compared to unaffected children. These variations highlight the need for CAH-specific charts to assist in clinical management, appraisal of growth trajectories, and assessment of the impact of new therapies.