Endocrine Abstracts

Introduction: Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive condition that causes reduced cortisol, reduced aldosterone, and increased testosterone production. Hydrocortisone is used to manage CAH in children. Current literature suggests children with CAH often have abnormal growth patterns.

Aims and Methods: Data from 103 children was extracted from our centre. We investigated the effects of age, sex, ethnicity, Index of Multiple Deprivation (IMD), and type of CAH on hydrocortisone dosing using regression modelling. Individual height velocity (HV) standard deviation scores (SDS) and BMI SDS were calculated for age groups 5-8.5yrs, 8.5-12, and post-12yrs to create cohort means. Pearson’s Correlation was performed to assess the effects of hydrocortisone dosing on HV and BMI. Bone age X-rays and 17 OHP results were recorded.

Results: Hydrocortisone dose per surface area increased with age (P = 0.044) and type of CAH (P < 0.001). There was no significant effect of sex, ethnicity, or IMD on hydrocortisone dose. The average hydrocortisone dose for 5-8.5yrs = 11.6 mg/m², 8.5-12yrs = 11.7 mg/m², and post-12yrs = 13 mg/m². Average BMI SDS for 5-8.5yrs = 1.12 (Range: -1.48- 3.69), 8.5-12yrs = 1.30 (Range: -0.73- 3.20), and post-12yrs = 1.20 (Range: -0.28- 3.07). Pearson’s Correlation showed no significant association between hydrocortisone dose and HV or BMI. Average HV SDS demonstrated above-normal linear growth in the 5-8.5yrs cohort (HV SDS= +1.28), normal HV in the 8.5-12yrs cohort (HV SDS= -0.13), and significantly reduced HV in the post-12yrs cohort (HV SDS= -3.61) in contrast to normal growth patterns. 17-hydroxyprogesterone (17 OHP) levels were elevated in 79% of 5-year-olds and 92% of 12-year-olds. Of the 28 patients with bone age X-rays, 22 (71%) had an advanced bone age (mean bone age advancement was +1.7yrs).

Conclusion: Monitoring HV to identify children deviating from the population mean is important in CAH. Accelerated HV at 5-8.5yrs is likely driven by suboptimal disease control and may lead to reduced HV in older patients, and advancement of bone age. Hydrocortisone doses ~13 mg/m² are not associated with significant excess weight. Hence, higher hydrocortisone doses may be required to manage accelerating HV in younger children to prevent the significantly reduced HV post-12yrs.