Hypopituitarism in Cushing's disease

Impaired GH secretion usually accompanies Cushing's syndrome and a variable proportion of patients reportedly fail to recover normal GH secretion after successful treatment. We prospectively studied 34 patients (27 females and 7 males, age range 21- 68 yr) formerly affected by Cushing's disease. Patients were studied 2 to 20 yr (median 3.3 yr) following remission of hypercortisolism. All patients had undergone transsphenoidal surgery with the removal of an ACTH-secreting adenoma. None of the patients had undergone radiation therapy. In all subjects, the GH response to GHRH+arginine stimulation was evaluated. Twenty-two patients (65%) in long-term surgical remission presented subnormal GH secretion: partial GHD was found in 11 patients and severe GHD in another 11 patients. Our experience has demonstrated a GHD in a high percentage of patients with Cushing's disease even after long-term remission of hypercortisolism obtained by surgery alone. This finding is significant as it highlights that even the most favorable therapeutical course, i.e. remission achieved by surgery, is often accompanied by impaired GH release. Assessment of GH secretion is therefore recommended in all patients cured from Cushing's disease, even if not submitted to radiotherapy.