Bone Health Index in Children and Adolescents with Congenital Adrenal Hyperplasia

Hussain Alsaffar; Rosie Davies; John Reed; Urmi Das; Senthil Senniappan; Mohammed Didi; Jo Blair

Introduction: Patients with congenital adrenal hyperplasia (CAH) require life long glucocorticoid (GC) therapy. In CAH, the adverse effect of GC on bone health (BH) may be counteracted by the effect of modest elevations in adrenal androgens.

Aim: To examine relationships between BH index (BHI) SDS, calculated by BoneXpert on bone age (BA) x-rays, BA, hydrocortisone (HC) dose (mg/m² per day), and mean 17-hydroxyprogesterone (17-OHP) concentration on 24 h blood spot profile.

Methods: Retrospective study of data collected during annual review. Data were analysed in two age groups: <10 years and ≥10 years. BA was reported according to Tanner Whitehouse II reference data.

Results: Data were available for 22 (11M) patients, age 10.7±3.4 years. Results are reported in Table 1. BA was advanced in both age groups. BHI-SDS was <−1.5 in four subjects (18%). BHI-SDS was not related to either HC dose or 17OHP concentrations. BHI-SDS correlated positively with chronological age and BA advance (BA – chronological age) in age <10 years, r=0.48 and r=0.35 respectively, and with BA for all patients (r=0.55, P<0.0001).

**Table 1.** (for abstract P2-P51)
Age range	Patients (gender) (episodes)	Age (years)	BA (TWII score)	BA-chronological age (years)	BHI SDS	Mean 17OHP (nmol/l)	Hydrocortisone (mg/m² per day)
<10 years	12 (7M:5F)(20)	6.9 (3.15–9.93)	11.1 (6.39–14.3)	3.47 (−1.9 to +6.82)	−0.65 (−4 to +2.3)	30.2 (4–147.2)	10.4 (7.5–16.6)
≥10 years	15 (8M,7F)(31)	12.75 (10.2–17.5)	14.9 (9.22–18.1)	2.06 (−1.6 to +5.14)	−0.3 (−2.9 to 2.5)	23.9 (0−230.3)	10.0 (5.8–17.3)
Data are reported as median (range).

Conclusion: As anticipated, we observed modest BA advance, consistent with modestly elevated 17OHP concentrations. BHI SDS was <−1.5 SDS in 18% of patients, suggesting a negative effect of HC persists despite the protective effect of elevated androgens. These relationships may be more evident in a larger cohort of patients. The clinical significance of this observation, if any, is unknown. However, osteoporosis in adult patients with CAH is reported (1) and this observation deserves further evaluation in a larger cohort, studied prospectively.

Reference: 1. Paula et al. 2008 Eur J Endocrinol 158 879–887.

ESPE Abstracts

P2-P51