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

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.

Cross-sectional observational study.

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

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.

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).

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