Short-term recombinant human growth hormone therapy does not modify growthhormone, thyrotropin and prolactin responses to thyrotropin-releasing hormone in adult dialysis patients

Background. We recently have reported the first randomized, controlled stud y on the effects of short-term recombinant human growth hormone (rhGH) ther apy on the nutritional status of a group of malnourished adult dialysis pat ients. In order to evaluate whether rhGH administration exerts any influenc e on GH, thyrotropin (TSH) and prolactin (PRL) responses to TSH-releasing h ormone (TRH), we assessed these responses before and after rhGH therapy. Methods. GH, PRL and TSH responses to TRH before and 1 month after rhGH the rapy in a group of adult dialysis patients were evaluated. Seventeen dialys is patients (11 on continuous ambulatory peritoneal dialysis/six on haemodi alysis) were studied (rhGH group, n = 8; control group, n = 9). In the rhCH group, 0.2 IU/kg/day rhGH was administered subcutaneously. Each patient wa s tested with TRH (400 mu g bolus i.v.) on two separate occasions, just bef ore and immediately after the treatment period. Results. rhGH treatment did not modify baseline serum GH concentrations (6. 6+/-2.7 vs 4.1+/-1.1 mu g/l), paradoxical GH responses to TRH (six out of e ight patients), GH peak (11.9+/-4.6 vs 11.2+/-5.3 mu g/l, NS) or area under the secretory curve of GH (GH AUC; 19.1+/-4.5 vs 12.1+/-3.1 mu g/h/l). Bot h basal PRL (35.5+/-7.1 vs 36.7+/-8.6 mu g/l) and TSH (2.3+/-1.1 vs 2.8+/-1 .7 mU/l) concentrations, as well as their responses to TRH stimulation (PRL peak, 59.9+/-16.6 vs 59.5+/-11.8 mu g/l; TSH peak, 6.2+/-2.6 vs 7.1+/-3.9 mU/l), were also unaffected by rhGH therapy. Conclusion. These results suggest that short-term rhGH therapy does not sig nificantly influence the magnitude of the somatotropic, lactotropic or thyr otropic response to TRH in adult dialysis patients. However, this finding h as to be interpreted with caution due to the two different patient groups i ncluded in this study.