Objective: Despite published guidelines no unified approach to hormone replacement
in congenital adrenal hyperplasia (CAH) exists. We aimed to explore geographical and
temporal variations in the treatment with glucocorticoids and mineralocorticoids in
CAH. Design: This retrospective multi-center study, including 31 centers (16 countries),
analyzed data from the International-CAH Registry. Methods: Data were collected from
461 patients aged 0-18 years with classic 21-hydroxylase deficiency (54.9% females)
under follow-up between 1982 and 2018. Type, dose and timing of glucocorticoid and
mineralocorticoid replacement were analyzed from 4174 patient visits. Results: The
most frequently used glucocorticoid was hydrocortisone (87.6%). Overall, there were
significant differences between age groups with regards to daily hydrocortisone-equivalent
dose for body surface, with the lowest dose (median with interquartile range) of 12.0
(10.0-14.5) mg/m2/day at age 1-8 years and the highest dose of 14.0 (11.6-17.4) mg/m2/day
at age 12-18 years. Glucocorticoid doses decreased after 2010 in patients 0-8 years
(P < 0.001) and remained unchanged in patients aged 8-18 years. Fludrocortisone was
used in 92% of patients, with relative doses decreasing with age. A wide variation
was observed among countries with regards to all aspects of steroid hormone replacement.
Conclusions: Data from the I-CAH Registry suggests international variations in hormone
replacement therapy, with a tendency to treatment with high doses in children.
