Bone mineral density and bone turnover in Romanian children and young adults with classical 21-hydroxylase deficiency are influenced by glucocorticoid replacement therapy

Objective It remains controversial if glucocorticoid replacement therapy impairs bone mineral density (BMD) in young patients with 21‐hydroxylase deficiency. We aimed to analyze the impact of treatment variables, phenotype and genotype on BMD and bone metabolism in these patients. Design Cross‐sectional study. Measurements Twenty‐eight Caucasian patients with classical 21‐hydroxylase deficiency (5–39 years). Clinical parameters, hormonal status, osteocalcin (OC), C‐terminal telopeptide of type I collagen (CTX), genotype and lumbar BMD (Z‐scores) were assessed. Cumulative and mean hydrocortisone equivalent doses were calculated for the entire treatment period. Results Patients with severely reduced BMD Z‐scores (≤–2·5 SD) had significantly higher mean/cumulative glucocorticoid doses compared to patients with moderately reduced (P = 0·003/P = 0·026) and normal Z‐scores (> –1 SD) (P = 0·005/P = 0·011). Mean hydrocortisone equivalent doses > 20 mg/m²/day led to significantly lower lumbar BMD Z‐scores (–2·16 ± 1·4 SD) vs. doses ≤ 20 mg/m²/day (–0·59 ± 1·25 SD) (P = 0·008). BMD correlated negatively with mean/cumulative glucocorticoid doses and treatment duration. OC (86·45 ± 37·45 ng/ml) and CTX (1·45 ± 0·43 ng/ml) were significantly increased compared to an age‐ and sex‐matched control group in patients with active growth; only CTX was slightly increased in patients who completed growth. Conclusions High cumulative and mean glucocorticoid doses negatively impact on BMD in children and young adults with classical 21‐hydroxylase deficiency. Substitution therapy should be adapted particularly at this life period to prevent bone loss.