Table 3.
Studies of GH therapy in healthy older men
| First author, year (Ref.) | Study protocol, active treatment, duration, no. of subjects | Main subject characteristics | Main findings and remarks |
|---|---|---|---|
| Papadakis, 1996 (94) | Parallel groups | Healthy older men | LBM increased and BF decreased; no changes in muscle function, VO2max |
| GH, 30 μg/kg 3 times/wk; doses adjusted according to IGF-I levels | Age, 70–85 yr | ||
| Duration, 6 months | IGF-I, <161 ng/ml | ||
| Act, n = 26; PL, n = 29 (dropouts, Act, n = 2; PL, n = 2) | Baseline IGF-I, 75.2 ± 4.5 ng/ml | ||
| Munzer, 2001 (576); Blackman, 2002 (49); Christmas, 2002 (583); Huang, 2005 (598); Münzer, 2009 (645) | Parallel groups | Community-dwelling healthy older men | Increased LBM and decreased total and sc fat; no changes in BMD, VO2max, protein kinetics, or muscle function |
| GH starting dose, 30 reduced to 20 μg/kg, 3 times/wk | Age, 65–88 yr | ||
| Duration, 6 months | IGF-I, <230 ng/ml | ||
| Act, n = 17 to 21; PL, n = 17 (dropouts, Act, n = 1) | Baseline IGF-I, 146 ± 10 ng/ml | ||
| Giannoulis, 2006 (48, 646); 2008 (597) | Parallel groups | Community-dwelling healthy older men | LBM and whole body protein turnover increased |
| GH starting dose, 0.1 mg/d; increased gradually to a mean of 0.54 mg/d | Age, 65–85 yr | No changes in BF, muscle function, VO2max, lipid profile, VLDL metabolism | |
| Target IGF-I, 250 ng/ml | IGF-I, <145 ng/ml | No changes in insulin levels; no glucose intolerance, diabetes, or other adverse events | |
| Duration, 6 months | Baseline IGF-I, 102 ± 5.3 ng/dl | ||
| Act, n = 18; PL, n = 20 (dropouts, Act, n = 2; PL, n = 4) | |||
| Lange, 2001 (595) | Parallel groups | Healthy older men | LBM increased, BF decreased |
| GH increased gradually over 3 wk to 12 μg/kg · d | Age, 74 ± 1 yr | ||
| Duration, 12 wk | Baseline IGF-I, 162 ± 22 ng/ml | ||
| Act, n = 8; PL, n = 8 (dropouts, Act, n = 2) | |||
| Rudman, 1990 (20) | No placebo control study | Healthy older men | Increased LBM, decreased BF, marginal improvement in BMD |
| GH, 30 μg/kg 3 times/wk | Age, 61–81 yr | ||
| Duration, 6 months | IGF-I, <189 ng/ml (350 U/liter) | ||
| Act, n = 12; controls, n = 9 (no treatment was given) | Baseline IGF-I, 162 ± 11.9 ng/ml | ||
| Cohn, 1993 (593) | No placebo control study | Community-dwelling healthy older men | High incidence of adverse events observed when IGF-I levels were above the 75%ile for the young age-specific normal range |
| GH, 30 μg/kg 3 times/wk | Age, >60 yr | ||
| Duration, 6 months | IGF-I, <189 ng/ml | ||
| Act, n = 50; controls, n = 18 (no treatment was given) (dropouts, Act, n = 27; PL, n = 2) | Baseline IGF-I, 165 ± 12.6 ng/dl | ||
| Lange, 2002 (594) | Parallel groups | Community-dwelling healthy older men | Changes in body composition, but muscle strength, power, muscle CSA, fiber size did not change |
| GH ± Ex | Age, 70–82 yr | No additional improvement in muscle strength was observed when GH was co-prescribed with Ex | |
| GH increased gradually over 3wk to 12 μg/kg · d | Baseline IGF-I, 145 ± 14 ng/dl | ||
| Duration, 12 wk | |||
| Act GH, n = 8; Act GH+Ex, n = 8; Ex, n = 8; PL, n = 7 | |||
| Taaffe, 1996 (461); 1994 (607) | Parallel groups | Healthy older men | GH failed to further improve the muscle function, muscle CSA, and fiber size observed after Ex alone |
| 14-wk Ex program followed by 10-wk treatment period | Age, 65–82 yr | ||
| GH, 20 μg/kg · d | Baseline IGF-I, 113 ± 10 ng/ml | ||
| Duration, 10 wk | |||
| Act GH+Ex, n = 10; Ex+PL, n = 8 (dropouts, Act, n = 2) | |||
| Yarasheski, 1995 (512); 1997 (589) | GH ± resistance Ex | Healthy older men | High doses of GH were used, hampered by high incidence of adverse events |
| GH, 12.5–24 μg/kg · d | Age, 67 ± 1 yr | Short-term GH administration in conjunction with Ex program did not confer any additional benefits on muscle function outcomes | |
| Duration, 16 wk | Baseline IGF-I, 106 ± 13 ng/ml | ||
| Act GH+Ex, n = 12–8; PL+Ex, n = 15 to 11 (dropouts, Act GH+Ex, n = 5) |
All studies included are randomized, placebo-controlled and double blind unless otherwise stated. Nine trials were identified where GH was administered in healthy subjects and not in older men (aged >60 yr) who were frail or had other associated comorbidities that were reported on outcome measurements related to physical function. From the 309 subjects included, 169 received GH. Act, Active treatment; PL, placebo; Ex, exercise.