title: Efficacy and tolerability of an individualized dosing regimen for adult growth hormone replacement therapy in comparison with fixed body weight-based dosing.
abstract: To determine whether an individualized dose titration regimen (ID) for adult GH replacement therapy would have similar efficacy and better tolerability than a fixed body weight-based dosing regimen (FD), 387 adults with GH deficiency were randomized to FD (n = 200) or ID (n = 187) for 32 wk. In FD, subjects received sequentially 4, 8, and 12 microg/kg.d GH. ID was started at 0.2 mg/d and increased by 0.2-mg/d increments, based on clinical and serum IGF-I responses, to a maximum of 0.8 mg/d. Increases (mean +/- sd) in serum IGF-I were similar in both groups (FD, 110.2 +/- 87.8 vs. ID, 99.6 +/- 77.7 microg/liter, P = 0.20) despite higher final GH doses in FD (0.70 +/- 0.32 vs. 0.54 +/- 0.22 mg/d, P < 0.001). Favorable changes in several efficacy measures were observed with no significant differences between the FD and ID groups: lean body mass increased; health-related quality of life improved; and abdominal fat mass, hip circumference, sum of skinfolds, and total and low-density lipoprotein cholesterol decreased. The decrease in fat mass was greater with FD than ID for men (-2.7 +/- 2.7 kg vs. -1.8 +/- 2.5 kg, P = 0.04) but not for women (-2.1 +/- 2.4 vs. -2.0 +/- 3.8 kg). The change in waist circumference was greater with FD than ID for women but not for men. There was a significant reduction of systolic blood pressure in ID but not in FD. The adverse event profile was similar between FD and ID except that ID had a lower occurrence of peripheral edema (9.1% vs. 16.5%, P = 0.03) and rash (1.1% vs. 5.5%, P = 0.02) than FD. In summary, the use of ID resulted in improved tolerability and similar efficacy compared with FD. We conclude that GH replacement therapy should be initiated at a low dose and titrated to a dose producing maximal benefits without adverse side effects and an IGF-I level within the age- and sex-adjusted normal range.
authors.affiliation: Medical Service, Veterans Affairs Palo Alto Health Care System and Stanford University, 3801 Miranda Avenue, Palo Alto, CA 94304, USA. arhoffman@stanford.edu
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Hoffman
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Strasburger
authors.forename: Anthony
authors.initials: A
authors.lastname: Zagar
authors.forename: Werner F
authors.initials: WF
authors.lastname: Blum
authors.forename: Anne
authors.initials: A
authors.lastname: Kehely
authors.forename: Mark L
authors.initials: ML
authors.lastname: Hartman
mesh_terms: D000328:Adult; D001835:Body Weight; D004305:Dose-Response Relationship, Drug; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D019382:Human Growth Hormone / Q000008:administration & dosage* / Q000009:adverse effects* / Q000172:deficiency; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008661:Metabolism, Inborn Errors / Q000188:drug therapy / Q000503:physiopathology; D008875:Middle Aged; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I