The growth hormone responses to L-dopa and TRH in acromegaly

The GH responses to TRH and L-dopa were investigated in 14 Indian and African patients with untreated acromegaly. A positive response to L-dopa (greater than 50% change from basal) was obtained in 6 of the 14 patients tested while a positive response to TRH (greater than 100% change from basal) was found in 5 of 12 patients tested. While 9 patients responded to at least one agent, only 2 had a positive response to both agents. Positive responders appeared to be hyper-prolactinemic and have evidence of abnormal glucose tolerance as compared to nonresponders.