The effects of testosterone on body composition in obese men are not sustained after cessation of testosterone treatment.
Ключови думи
Резюме
BACKGROUND
Testosterone treatment in obese dieting men augments the diet-associated loss of fat mass, but protects against loss of lean mass. We assessed whether body composition changes are maintained following withdrawal of testosterone treatment.
METHODS
We conducted a prespecified double-blind randomized placebo-controlled observational follow-up study of a randomized controlled trial (RCT). Participants were men with baseline obesity (body mass index >30 kg/m2 ) and a repeated total testosterone level <12 nmol/L, previously enrolled in a 56-week testosterone treatment trial combined with a weight loss programme. Main outcome measures were mean adjusted differences (MAD) (95% confidence interval), in body composition between testosterone- and placebo-treated men at the end of the observation period.
RESULTS
Of the 100 randomized men, 82 completed the RCT and 64 the subsequent observational study. Median [IQR] observation time after completion of the RCT was 82 weeks [74; 90] in men previously receiving testosterone (cases) and 81 weeks [67;91] in men previously receiving placebo (controls), P=.51. At the end of the RCT, while losing similar amounts of weight, cases had, compared to controls, lost more fat mass, MAD -2.9 kg (-5.7, -0.2), P=.04, but had lost less lean mass MAD 3.4 kg (1.3, 5.5), P=.002. At the end of the observation period, the former between-group differences in fat mass, MAD -0.8 kg (-3.6, 2.0), P=1.0, in lean mass, MAD -1.3 kg (-3.0, 0.5), P=.39, and in appendicular lean mass, MAD -0.1 kg/m2 (-0.3, 0.1), P=.45, were no longer apparent. During observation, cases lost more lean mass, MAD -3.7 kg (-5.5, -1.9), P=.0005, and appendicular lean mass, MAD -0.5 kg/m2 (-0.8, -0.3), P<.0001 compared to controls.
CONCLUSIONS
The favourable effects of testosterone on body composition in men subjected to a concomitant weight loss programme were not maintained at 82 weeks after testosterone treatment cessation.
