Effect of cyproterone acetate (CA) on growth and endocrine function in precocious puberty

16 girls with precocious puberty have been studied. Following low dosage cyproterone acetate (CA) therapy (mean daily dosage 65 mg/m2BSA) a beneficial effect on growth and skeletal maturation was observed. During high dosage therapy (150 mg/m2 per day) endocrinological studies were performed in 10 of these patients. There was no significant difference in HGH levels (insulin- and arginine-test), T3 and TSH values (TRH-test) between patients and controls, T4 concentration was significantly increased. Basal prolactin levels and prolactin response to TRH was definitely elevated. Oral glucose load and arginine infusion resulted in a significantly enhanced insulin release. There was a significant reduction in basal LH levels and an increase in FSH response to LH-RH. Basal and diurnal plasma cortisol values were markedly reduced and the cortisol release due to corticotrophin injection, lysinevasopressin (LVP) injection and insulin-hypoglycemia as well. A definite increase in basal ACTH levels was observed, during LVP- and insulin-hypoglycemia test ACTH concentrations were within or significantly above normal range. In our patients a primary adrenocortical insufficiency due to CA treatment was evident.