Cabergoline therapy of growth hormone & growth hormone/prolactin secreting pituitary tumors.

Dopamine agonists have been used as adjunctive therapy for acromegaly for many years, but relatively few studies have assessed the efficacy of a newer agonist, cabergoline. Some data suggest that cabergoline may be more effective than bromocriptine, in particular for those patients whose tumors secrete both growth hormone and prolactin. In order to assess this possibility further, we have evaluated the biochemical response to cabergoline therapy in patients with acromegaly at our center.

Basal and glucose-suppressed GH levels less than 1 microg/L in newly diagnosed acromegaly.

The development of highly sensitive and specific GH assays has necessitated a critical re-evaluation of the biochemical criteria needed for the diagnosis of acromegaly. Use of these assays has revealed that GH levels after oral glucose in healthy subjects and postoperative patients with active acromegaly can be significantly less than previously recognized with older GH assays. In order to assess GH criteria for newly diagnosed acromegaly with a modern assay we have evaluated GH levels in 25 patients referred to our Neuroendocrine Unit for evaluation of untreated acromegaly.

Significance of "abnormal" nadir growth hormone levels after oral glucose in postoperative patients with acromegaly in remission with normal insulin-like growth factor-I levels.

Our initial study in postoperative patients with acromegaly identified a group of patients in remission, as defined by normal IGF-I levels, but who had a subtle abnormality of GH suppression after oral glucose. To investigate the significance of this abnormality, we have undertaken further detailed testing of GH secretion and a longitudinal follow-up of some of these patients. Of the 110 postoperative patients with acromegaly evaluated by oral glucose tolerance test, 76 were in remission (i.