Endocrine Abstracts

OBJECTIVE: To investigate the association between APD, treated Cushing's disease and severe hypopituitarism.

METHODS: Fifty-seven patients (42 female), in remission after treatment for Cushing's disease, were studied. The cohort comprised 13 patients with, and 44 without APD. APD was defined as a serum prolactin persistently below the detection limit of the assay. Age and gender did not significantly differ between sub-groups.

RESULTS: Deficiencies of GH, TSH, LH/FSH (p<0.0001) and ADH (p=0.006) status were present more frequently in the APD sub-group. After pituitary surgery, a significant correlation between peak GH response and interval since remission of Cushing's syndrome was found in the sub-group without APD (r = 0.4, p = 0.04). In contrast, no patient with APD demonstrated a detectable GH response at any time-point after pituitary surgery. No patient with APD showed recovery of prolactin secretion by the time of the most recent measurement (mean; 57 months).

Operative details were available for 11 of 12 surgically treated patients with APD, and all underwent a radical operation. In contrast, of 28 patients with Cushing's disease who did not develop APD, only 3 underwent radical surgery (p < 0.0001). Six of 14 patients (42.9%) who underwent a radical operation and 2 of 20 treated by selective adenomectomy (10%) required additional treatment to achieve control of Cushing's syndrome (p = 0.04).

CONCLUSION: APD occurring after pituitary surgery for Cushing's disease occurs only after a radical operation. In this context patients do not experience recovery of GH secretion, even after the effects of glucocorticoid excess subside. In the absence of APD, GH status may normalise after surgical treatment. When a selective adenomectomy is not possible, control of Cushing's disease by operation is less frequent and when achieved, is more often at the cost of hypopituitarism. The optimal management of such patients requires further study.