Plasma insulin-like growth factor I levels during treatment of congenital adrenal hyperplasia

We tested the hypotheses that the levels of insulin-like growth factor I (IGF-I) reflect the degree of control during the treatment of patients with congenital adrenal hyperplasia (CAH), and that suppressed IGF-I levels during puberty contribute to decreased adult height. We measured serial IGF-I levels in 26 CAH patients followed over 6 months to 5 years. The control of CAH was variable, with several cases of overtreatment in infancy, and frequent undertreatment in childhood and adolescence. IGF-I levels were quite variable and inconsistent with the control of CAH. Our results suggest that IGF-I levels are not helpful in monitoring CAH patients; IGF-I does not seem to play a role in the growth failure during CAH therapy.