IMPAIRMENT OF GROWTH-HORMONE RESPONSIVENESS TO GROWTH-HORMONE RELEASING HORMONE AND PYRIDOSTIGMINE IN PATIENTS AFFECTED BY PRADER-LABHARDT-WILLI SYNDROME

In order to evaluate the impairment of GH response in patients affecte d by Prader-Labhardt-Willi (PLW) syndrome, in 18 patients we studied G H response to clonidine and to GHRH + pyridostigmine, a cholinergic dr ug which enhances GHRH induced GH responsiveness in obese patients. Af ter clonidine GH response was abnormal in 14/18 subjects (mean GH peak : 4.1 +/- 1.3 mu g/l; area under curve: 208.1 +/- 74.2 mu g/l . h) whi le all but 5 patients showed an inadequate GH response to GHRH + pyrid ostigmine (mean GH peak: 13.4 +/- 2.5 mu g/l; area under curve: 903.4 +/- 171.0 mu g/l . h). However, in the three patients with low adiposi ty index, GH response to GHRH + pyridostigmine was significantly highe r than that observed in fatter subjects, In addition, GH response to G HRH + pyridostigmine was negatively correlated to age and adiposity in dex. In conclusion, our data are consistent with the hypothesis of the existence of a complex derangement of GH neuroendocrine regulation in these subjects. (C) 1996, Editrice Kurtis