Growth hormone replacement in healthy older men improves body composition but not functional ability.
OBJECTIVE
To determine whether growth hormone replacement in older men improves functional ability.


METHODS
Randomized, controlled, double-blind trial.


METHODS
General community.


METHODS
52 healthy men older than 69 years of age with well-preserved functional ability but low baseline insulin-like growth factor 1 levels.


METHODS
Growth hormone (0.03 mg/kg of body weight) or placebo given three times a week for 6 months.


METHODS
Body composition, knee and hand grip muscle strength, systemic endurance, and cognitive function.


RESULTS
The participants' mean age was 75.0 years (range, 70 to 85 years). At 6 months, lean mass had increased on average by 4.3% in the growth hormone group and had decreased by 0.1% in the placebo group, a difference of 4.4 percentage points (95% CI, 2.1 to 6.8 percentage points). Fat mass decreased by an average of 13.1% in the growth hormone group and by 0.3% in the placebo group, a difference of 12.8 percentage points (CI, 8.6 to 17.0 percentage points). No statistically or clinically significant differences were seen between the groups in knee or hand grip strength or in systemic endurance. The mean Trails B score in the growth hormone group improved by 8.5 seconds, whereas scores in the placebo group deteriorated by 5.0 seconds, a difference of 13.5 seconds (CI, 3.1 seconds to 23.9 seconds; P = 0.01). However, the growth hormone group's score on the Mini-Mental Status Examination deteriorated by 0.4, whereas the placebo group's score improved by 0.2, a difference of 0.6 (P = 0.11). The two treatment groups had almost identical scores on the Digit Symbol Substitution Test (P > 0.2). Twenty-six men in the growth hormone group had 48 incidents of side effects, and 26 placebo recipients had 14 incidents of side effects (P = 0.002). Dose reduction was required in 26% of the growth hormone recipients and in none of the placebo recipients (P < 0.001).


CONCLUSIONS
Physiologic doses of growth hormone given for 6 months to healthy older men with well-preserved functional abilities increased lean tissue mass and decreased fat mass. Although body composition improved with growth hormone use, functional ability did not improve. Side effects occurred frequently.
Papadakis
M A
MA
University of California, San Francisco, California, USA.
Grady
D
D
Black
D
D
Tierney
M J
MJ
Gooding
G A
GA
Schambelan
M
M
Grunfeld
C
C
D000339:Affect / Q000187:drug effects; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism / Q000502:physiology*; D001823:Body Composition / Q000187:drug effects*; D003071:Cognition / Q000187:drug effects; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D009132:Muscles / Q000187:drug effects* / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use
D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I