title: Plasma adrenal, gonadal, and conjugated steroids following long-term exercise-induced negative energy balance in identical twins.
abstract: There are few reports of the change in sex hormone levels accompanying a weight change in men, although an excessive decline in testosterone (TESTO) has been described as an associate of stress-induced weight loss. Plasma levels of cortisol, TESTO, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), androsterone glucuronide (ADT-G), and androstane-3alpha, 17beta-diol glucuronide (3alphaDIOL-G) were measured in seven pairs of sedentary male monozygotic twins (age, 21.0 +/- 0.8 years; body mass index [BMI], 26.2 +/- 5.5 kg/m2) before and after 93 days of standardized submaximal (50% to 55% maximum oxygen consumption) cycle-ergometer exercise. A total energy deficit of 244 +/- 9.7 MJ induced significant changes (P < .0001) in body weight ([BW] -5.0 +/- 2.2 kg) and body fatness measures. Plasma TESTO and DHEA-S increased and 3alphaDIOL-G decreased. The increase in TESTO was a significant inverse correlate of loss in all measures of body fat, particularly central adiposity (r = -.58 to -.86, P < .001, fat loss-adjusted). Lower postexercise levels of 3alphaDIOL-G correlated positively with decreased body composition measures (r = .65 to .68, P < .01). The increase in plasma TESTO accompanying the loss of abdominal visceral fat (AVF) was greater in men with lower fasting insulin levels (P < .0001). The baseline within-twin-pair resemblance in TESTO and 3alphaDIOL-G (intraclass correlation coefficients [ICC] = .83 and .78, respectively, P < .01) was lost with intervention. Cortisol, DHEA-S, and ADT-G developed within-twin-pair similarity (ICC adjusted for fat loss: cortisol, .72; ADT-G, .62, P < .05; DHEA-S, .85, P < .002). We conclude that a steroid profile characterized by high TESTO and low androgen metabolite levels accompanied the changes in body composition and body fat distribution generated by the exercise-induced negative energy balance. Furthermore, these changes were characterized by a significant resemblance within identical-twin pairs.
authors.affiliation: Department of Physiology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Pritchard
authors.forename: J P
authors.initials: JP
authors.lastname: Després
authors.forename: J
authors.initials: J
authors.lastname: Gagnon
authors.forename: A
authors.initials: A
authors.lastname: Tchernof
authors.forename: A
authors.initials: A
authors.lastname: Nadeau
authors.forename: A
authors.initials: A
authors.lastname: Tremblay
authors.forename: C
authors.initials: C
authors.lastname: Bouchard
mesh_terms: D000328:Adult; D015113:Androstane-3,17-diol / Q000031:analogs & derivatives / Q000097:blood; D000738:Androsterone / Q000031:analogs & derivatives / Q000097:blood; D001823:Body Composition; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D013196:Dihydrotestosterone / Q000097:blood; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D008297:Male; D013256:Steroids / Q000097:blood*; D013739:Testosterone / Q000097:blood; D014430:Twins, Monozygotic / Q000235:genetics*; D015431:Weight Loss
chemical_list: D007328:Insulin; D013256:Steroids; D013196:Dihydrotestosterone; C027927:androsterone glucuronide; D015113:Androstane-3,17-diol; C028895:androstane-3,17-diol glucuronide; D013739:Testosterone; D019314:Dehydroepiandrosterone Sulfate; D000738:Androsterone; D006854:Hydrocortisone