Effects of 2 wk of GH administration on 24-h indirect calorimetry in young, healthy, lean men.
The present study was designed as a randomized, double-blind placebo (Plc)-controlled study to determine the effect of 2 wk of growth hormone administration (GH-adm.) on energy expenditure (EE) and substrate oxidation in healthy humans. Sixteen young healthy men were divided into two groups. The study consisted of two 24-h measurements (indirect calorimetry), separated by 2 wk of either Plc or GH injections (6 IU/day). At baseline, no significant differences were observed between the two groups in any of the measured anthropometric, hormonal, or metabolic parameters, neither did the parameters change over time in the Plc group. GH-adm. resulted in a 4.4% increase in 24-h EE (P < 0.05) and an increase in fat oxidation by 29% (P < 0.05). However, a decrease in the respiratory quotient was only observed in the postabsorptive phase after an overnight fast (0.84 +/- 0.1 to 0.79 +/- 0.1, P < 0.05). Furthermore, lean body mass (LBM) was increased by GH-adm. only [62.8 +/- 2.5 kg (baseline) vs. 64.7 +/- 2.4 kg (after), P < 0.001]. In conclusion, GH-adm. increases 24-h EE, which may be partly explained by increased LBM. Furthermore, GH-adm. stimulates fat combustion, especially in the postabsorptive state.
Hansen
Mette
M
Institute of Sports Medicine, Copenhagen, Building 8, Bispebjerg Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark. mh19@bbh.hosp.dk
Morthorst
Rikke
R
Larsson
Benny
B
Flyvbjerg
Allan
A
Rasmussen
Michael Højby
MH
Orskov
Hans
H
Astrup
Arne
A
Kjaer
Michael
M
Lange
Kai Henrik Wiborg
KH
D000328:Adult; D001823:Body Composition; D002153:Calorimetry, Indirect; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005452:Fluoresceins; D019382:Human Growth Hormone / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D010042:Ouabain / Q000031:analogs & derivatives; D010919:Placebos; D013997:Time Factors
D005230:Fatty Acids, Nonesterified; D005452:Fluoresceins; D010919:Placebos; C109049:rhodol green-ethylenediamine-ouabain; D019382:Human Growth Hormone; D010042:Ouabain; D007334:Insulin-Like Growth Factor I