Effects of testosterone supplementation on body composition and lower-body muscle function during severe exercise- and diet-induced energy deficit: A proof-of-concept, single centre, randomised, double-blind, controlled trialResearch in context
Stefan M. Pasiakos,
Claire E. Berryman,
J. Philip Karl,
Harris R. Lieberman,
Jeb S. Orr,
Lee M. Margolis,
John A. Caldwell,
Andrew J. Young,
Monty A. Montano,
William J. Evans,
Oshin Vartanian,
Owen T. Carmichael,
Kishore M. Gadde,
Neil M. Johannsen,
Robbie A. Beyl,
Melissa N. Harris,
Jennifer C. Rood
Affiliations
Stefan M. Pasiakos
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Corresponding author at: 10 General Greene Ave., Bldg. 42, Natick, MA 01760, USA.
Claire E. Berryman
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA; Department of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, FL, USA
J. Philip Karl
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
Harris R. Lieberman
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
Jeb S. Orr
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA
Lee M. Margolis
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA
John A. Caldwell
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA
Andrew J. Young
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA; Oak Ridge Institute for Science and Education, Belcamp, MD, USA
Monty A. Montano
MyoSyntax Corporation, Worcester, MA, USA; Harvard Medical School, Boston, MA, USA; Brigham and Women's Hospital, Boston, MA, USA
William J. Evans
University of California at Berkeley, Berkeley, CA, USA; Duke University, Durham, NC, USA
Oshin Vartanian
Defence Research and Development Canada, University of Toronto, Canada
Owen T. Carmichael
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Kishore M. Gadde
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Neil M. Johannsen
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Robbie A. Beyl
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Melissa N. Harris
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Jennifer C. Rood
Louisiana State University's Pennington Biomedical Research Centre, Baton Rouge, LA, USA
Background: Severe energy deficits during military operations, produced by significant increases in exercise and limited dietary intake, result in conditions that degrade lean body mass and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. Methods: We conducted a three-phase, proof-of-concept, single centre, randomised, double-blind, placebo-controlled trial (CinicalTrials.gov, NCT02734238) of non-obese men: 14-d run-in, free-living, eucaloric diet phase; 28-d live-in, 55% exercise- and diet-induced energy deficit phase with (200 mg testosterone enanthate per week, Testosterone, n = 24) or without (Placebo, n = 26) exogenous testosterone; and 14-d recovery, free-living, ad libitum diet phase. Body composition was the primary end point; secondary endpoints included lower-body muscle function and health-related biomarkers. Findings: Following energy deficit, lean body mass increased in Testosterone and remained stable in Placebo, such that lean body mass significantly differed between groups [mean difference between groups (95% CI), 2.5 kg (3.3, 1.6); P < .0001]. Fat mass decreased similarly in both treatment groups [0.2 (−0.4, 0.7), P = 1]. Change in lean body mass was associated with change in total testosterone (r = 0.71, P < .0001). Supplemental testosterone had no effect on lower-body muscle function or health-related biomarkers. Interpretation: Findings suggest that supplemental testosterone may increase lean body mass during short-term severe energy deficit in non-obese, young men, but it does not appear to attenuate lower-body functional decline. Funding: Collaborative Research to Optimize Warfighter Nutrition projects I and II, Joint Program Committee-5, funded by the US Department of Defence. Keywords: Hypothalamic-pituitary-gonadal axis, Hypogonadism, Military operational stress, Semi-starvation, Anabolism, Muscle mass, Lower-body muscle function
