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Body composition reverts after testosterone therapy cessation in men with obesity
After cessation of a weight-loss program combined with testosterone therapy, men with obesity did not retain favorable changes in body composition, according to findings published in Clinical Endocrinology.
Mathis Grossmann, PhD, professor in the department of medicine, Austin Health, the University of Melbourne, and colleagues conducted a follow-up observational study on 64 men with obesity (BMI > 30 kg/m2) who completed a randomized controlled study in which they were assigned 1,000 mg intramuscular testosterone treatment (cases) or matching placebo (controls) for 56 weeks. During randomization, participants also completed a weight-loss program. Researchers sought to determine whether changes in body composition after testosterone therapy are maintained after treatment cessation. The median observation time was 82 weeks for cases and 81 weeks for controls.
During the randomized controlled study phase, testosterone level increased in cases, and luteinizing hormone levels were suppressed; however, at the end of the observation period, levels were similar to those at baseline.
Both cases and controls lost significant amounts of body weight with no significant differences between the groups during the randomized controlled study. Lean mass and fat mass were lost by controls, whereas cases almost exclusively lost fat mass. Body weight was regained by both cases and controls at the end of the observation period.
“The beneficial effects of 56 weeks of testosterone treatment on body composition in dieting obese men did not persist 82 weeks after cessation of testosterone treatment,” the researchers wrote. “Given that testosterone treatment may need to be maintained for longer durations, and possibly indefinitely, to maintain treatment-associated benefits, longer-term controlled studies will be necessary to more precisely define the benefits and potential risks of testosterone treatment.” – by Amber Cox
Disclosure: Grossmann reports financial ties with Bayer Pharma, Besins Healthcare, Lilly, Novartis and Weight Watchers. Please see the full study for a list of all other authors’ relevant financial disclosures.
Perspective
Back to TopFindings from several studies provide a rationale for investigating the therapeutic potential of testosterone for managing obesity in men. Obesity is causally associated with low serum testosterone. Testosterone treatment increases skeletal muscle mass, irrespective of starting muscle mass, in a dose-dependent manner, and the effect is augmented by muscle strength training. Even low-dose testosterone treatment decreases fat mass and increases lean body mass. In accordance with these observations, the researchers on this study have reported that men enrolled in a 56-week weight-loss regimen and treated with three monthly intramuscular testosterone injections lost more fat mass and less lean mass than the placebo group. These investigators subsequently followed a group of the men for 81 to 82 weeks after discontinuation of testosterone or placebo and now report that, by at least 12 months, the men previously treated with testosterone gained fat and lost muscle such that the differences in fat mass and lean appendicular mass between the groups were no longer apparent. The extent to which this may have been due to suppression of the hypothalamic–pituitary–gonadal axis cannot be determined from the current study in which recovery of the axis was apparent at the single timepoint studied.
A further observation from this study is that the increase in testosterone that occurred due to weight loss in the placebo-treated men was not maintained as weight was regained suggesting that an increase in endogenous testosterone, at least of that magnitude, is insufficient to break the interdependent interaction between obesity and testosterone.
Where does this leave the use of testosterone for weight management? There is a general principle that the benefit of weight-management pharmacotherapy is apparent while the medication is taken. The same applies to testosterone. There are currently insufficient efficacy or safety data to make any recommendation for the use of testosterone for weight management outside of current guidelines for prescribing testosterone.
Moderate weight loss (5% to 7%) can be achieved, sustainably, with lifestyle interventions, provided there is ongoing engagement in a management program. Weight loss of this magnitude increases serum testosterone and can be achieved with preservation of lean body mass by the inclusion of adequate protein intake and resistance exercise.
It is important to point out that eating less of a nutritionally insufficient diet to achieve weight loss may not lead to better health outcomes, whereas either nutritionally optimal diets or a combination of aerobic and resistance activity improve health outcomes even if weight is not lost.