Growth analysis in patients with 21-hydroxylase deficiency influence of glucocorticoid dosage, age at diagnosis, phenotype and genotype on growth and height outcome.

Objective: To evaluate the impact of hydrocortisone dosage, age at diagnosis, compliance, genotype and phenotype on growth and height outcome in 21-hydroxylase-deficient patients.

Methods: We analyzed 37 patients with 21-hydroxylase deficiency (17 had completed growth, 20 still growing). Final (FH)/predicted final height (pFH) and loss of height potential related to target height (TH) were calculated and the impact of 4 hydrocortisone (HC) dosage regimens on height outcome and growth velocities was evaluated. Mean FH SDS and pFH SDS were analyzed in accordance to age at diagnosis, compliance, genotype and phenotype.

Results: Mean (FH SDS, pFH SDS) was -1.8+/-1.06 SD, with 35.1% of all 37 patients exhibiting short stature. Doses >20 mg/m2/day during the first year and >15 mg/m2/day during age 1-5 and at puberty resulted in significantly lower FH SDS, pFH SDS and greater height losses. Age at diagnosis, compliance, genotype and phenotype played only a minor role in growth development.

Conclusions: Hydrocortisone substitution in 21-hydroxylase-deficient patients should be kept at the lowest efficient level, if possible <20 during the first year and <15 mg/m2/day until age 5 and during puberty. Normal growth and not complete androgen suppression should be aimed for.