Bone mineral density in girls with classical congenital adrenal hyperplasia due to CYP21 deficiency

Abstract

Aim: To verify possible associations among glucocorticoid doses, use of dexamethasone, and bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), in female children with congenital adrenal hyperplasia due to CYP21 deficiency (CAH-CYP21). Classical CAH-CYP21 in females allows the study of the effects of hyperandrogenism and chronic glucocorticoid exposure.

Design: Cross-sectional observational study.

Patients: Sixteen girls (4-19 years) with CAH-CYP21 and 32 age-matched control girls.

Measurements: BMD was the main outcome measure assessed by total body and lumbar spine L1-L4 DXA (DXAtot and DXAIs), lumbar spine L1-L4 bone mineral apparent density (BMAD) and spinal L1-L4 QCT of trabecular (QCTtrab) and cortical (QCTcort) bone. The glucocorticoid dose used by patients with CAH-CYP21 was expressed as hydrocortisone equivalents/m2.

Results: Mean BMD in both groups was similar by any method. In patients, BMD decreased with the increasing mean dose of glucocorticoid, seen in QCTcort (r = -0.55; p = 0.03) and QCTtrab (r = -0.52; p = 0.04). There was also a negative correlation between cumulative glucocorticoid dose and BMD in QCTcort (beta = -0.0016; p = 0.005) and QCTtrab (beta = -0.0009; p = 0.03).

Conclusions: The dose of glucocorticoid used in the treatment of girls with CAH-CYP21 correlated negatively with BMD, and dexamethasone was not selectively harmful.