Testosterone and growth hormone improve body composition and muscle performance in older men.
BACKGROUND
Impairments in the pituitary-gonadal axis with aging are associated with loss of muscle mass and function and accumulation of upper body fat.


OBJECTIVE
We tested the hypothesis that physiological supplementation with testosterone and GH together improves body composition and muscle performance in older men.


METHODS
One hundred twenty-two community-dwelling men 70.8 +/- 4.2 yr of age with body mass index of 27.4 +/- 3.4 kg/m2, testosterone of 550 ng/dl or less, and IGF-I in lower adult tertile (< or =167 ng/dl) were randomized to receive transdermal testosterone (5 or 10 g/d) during a Leydig cell clamp plus GH (0, 3, or 5 microg/kg . d) for 16 wk.


METHODS
Body composition by dual-energy x-ray absorptiometry, muscle performance, and safety tests were conducted.


RESULTS
Total lean body mass increased (1.0 +/- 1.7 to 3.0 +/- 2.2 kg) as did appendicular lean tissue (0.4 +/- 1.4 to 1.5 +/- 1.3 kg), whereas total fat mass decreased by 0.4 +/- 0.9 to 2.3 +/- 1.7 kg as did trunk fat (0.5 +/- 0.9 to 1.5 +/- 1.0 kg) across the six treatment groups and by dose levels for each parameter (P < or = 0.0004 for linear trend). Composite maximum voluntary strength of upper and lower body muscles increased by 14 +/- 34 to 35 +/- 31% (P < 0.003 in the three highest dose groups) that correlated with changes in appendicular lean mass. Aerobic endurance increased in all six groups (average 96 +/- 137 sec longer). Systolic and diastolic blood pressure increased similarly in each group with mean increases of 12 +/- 14 and 8 +/- 8 mm Hg, respectively. Other predictable adverse events were modest and reversible.


CONCLUSIONS
Supplemental testosterone produced significant gains in total and appendicular lean mass, muscle strength, and aerobic endurance with significant reductions in whole-body and trunk fat. Outcomes appeared to be further enhanced with GH supplementation.
Sattler
Fred R
FR
Departments of Medicine, Division of Biokinesiology, Keck School of Medicine, University of Southern California, 1200 North State Street, Room 6442, Los Angeles, California 90033, USA. fsattler@usc.edu
Castaneda-Sceppa
Carmen
C
Binder
Ellen F
EF
Schroeder
E Todd
ET
Wang
Ying
Y
Bhasin
Shalender
S
Kawakubo
Miwa
M
Stewart
Yolanda
Y
Yarasheski
Kevin E
KE
Ulloor
Jagadish
J
Colletti
Patrick
P
Roubenoff
Ronenn
R
Azen
Stanley P
SP
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001823:Body Composition / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004338:Drug Combinations; D015444:Exercise / Q000502:physiology; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D053580:Muscle Strength / Q000187:drug effects / Q000502:physiology; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects*; D013739:Testosterone / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*
D004338:Drug Combinations; D019382:Human Growth Hormone; D013739:Testosterone; D007334:Insulin-Like Growth Factor I