THE EFFECTS OF 2 DOSES OF REPLACEMENT GROWTH-HORMONE ON THE BIOCHEMICAL, BODY-COMPOSITION AND PSYCHOLOGICAL PROFILES OF GROWTH HORMONE-DEFICIENT ADULTS

This study examined the effects of growth hormone (GH) replacement on the insulin-like growth factor-I (IGF-I), body composition and psychol ogical profiles of GH-deficient adults. We assessed whether two doses of GH produced different effects on these variables and whether patien ts who, at the end of the study chose to remain on long-term GH replac ement responded differently to these who chose to abandon therapy. For ty-two adults ( aged 42.9 +/- 1.9 years (mean +/- S.E.M.)) with docume nted GH deficiency entered two studies (24 in study 1, 18 in study 2), Biochemical, body composition and psychological profiles were assesse d at baseline, and after 6 months and 1 year, Psychological assessment s were performed using well-established, independent, validated 'Quali ty of Life' questionnaires (Nottingham Health Profile (NHP) and the Ps ychological General Well-Being Schedule (PGWB)). The study protocols d iffered only in the doses of growth hormone (0.024 mg/kg per day and 0 .012 mg/kg per day respectively). Comparison between studies and betwe en patients eventually continuing and abandoning GH therapy was perfor med. GH replacement was associated with significant changes in IGF-I l evels (P<0.001), body composition (P<0.01) and self-perceived well-bei ng (NHP, P<0.01; PGWB, P<0.01). The higher dose of GH produced a great er IGF-I response than the lower dosage (44.6 +/- 7.3 vs 26.2 +/- 3.6 nmol/l, P<0.05, but no better psychological response (NHP, P=0.22; PGW B, P=0.23), Those deciding to continue replacement therapy did not res pond differently to those choosing to abandon therapy with respect to IGF-I (P=0.72), body composition (P=0.38) and psychological assessment (NHP, P=0.29; PGWB, P=0.24). GH replacement in GH-deficient adults wa s associated with significant improvements in self-perceived well-bein g as well as changes in body composition and other variables, This imp rovement was similar at two different doses of replacement GPI. Those patients electing to continue on long-term replacement did not achieve a demonstrably different psychological, body composition or biochemic al benefit to those patients deciding to discontinue replacement.