Compensatory maturational deceleration of growth or "catch-down growth" in patients with congenital adrenal hyperplasia after delayed initiation of therapy.

The growth pattern is reported of 16 patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency in whom therapy was started after the age of 3 years. Treatment was initiated at a mean chronological age (CA) of 4.7 years (range 3.0-7.2) and at a mean bone age (BA) of 10.4 years (range 10.2-13.2). It consisted of hydrocortisone (mean dosage 26 mg/m2) or prednisone (8.7 mg/m2) in all, and of fluorohydrocortisone (0.05-0.1 mg daily) in five patients. At the last examination the mean duration of therapy was 5.2 years, the mean CA 10.0 years, and the mean BA 12.6 years. In 13 of the 16 patients a "catch-down growth" pattern was observed, which was characterised by a decrease in height (expressed as SDS) for CA, a deceleration of bone maturation and increase of height (SDS) for BA, and an improvement in predicted height (Bayley-Pinneau).