title: Changes in sex hormone-binding globulin and testosterone during weight loss and weight maintenance in abdominally obese men with the metabolic syndrome.
abstract: BACKGROUND
  Mild hypoandrogenism in men, usually defined by low levels of testosterone, is a peculiar feature of abdominal obesity that independently predicts the development of insulin resistance and diabetes mellitus. Little is known about the short- and long-term effects of weight loss on sex steroids in abdominally obese men, however.
  
  
  OBJECTIVE
  We assessed the effect of rapid weight loss and sustained weight maintenance on the plasma concentrations of testosterone and other sex hormones in 58 abdominally obese men (age, 46.3 +/- 7.5 years; body mass index, 36.1 +/- 3.8 kg/m(2); waist girth, 121 +/- 10 cm) with the metabolic syndrome.
  
  
  RESULTS
  The men lost on average 16.3 +/- 4.5 kg during a 9-week very low-calorie diet (VLCD) and maintained 14.3 +/- 9.1 kg weight loss after a 12-month maintenance period (vs. baseline, p < 0.001). Sex hormone-binding globulin (SHBG) increased from 27.6 +/- 11.9 to 48.1 +/- 23.5 nmol/l during the VLCD but decreased to 32.6 +/- 12.9 nmol/l during weight maintenance, which was still higher than at baseline (p < 0.001). Free testosterone (fT) increased from 185 +/- 66 to 208 +/- 70 pmol/l (p = 0.002) during the VLCD and remained high after 1 year of weight maintenance (212 +/- 84 pmol/l, p = 0.002). Total testosterone levels followed a pattern intermediate between fT and SHBG. Plasma estradiol and dehydroepiandrosterone sulphate concentrations changed only transiently or not at all.
  
  
  CONCLUSIONS
  Rapid weight loss with successful weight maintenance in abdominally obese men with the metabolic syndrome brings about a sustained increase in fT levels. The dramatic increase in SHBG attenuated initially during weight maintenance but remained elevated. These findings may be important with regard to prevention of progressive metabolic decompensation and cardiovascular disease associated with obesity and the metabolic syndrome.
authors.affiliation: Department of Medicine, Kuopio University Hospital, Kuopio, Finland. leo.niskanen@kuh.fi
authors.forename: L
authors.initials: L
authors.lastname: Niskanen
authors.forename: D E
authors.initials: DE
authors.lastname: Laaksonen
authors.forename: K
authors.initials: K
authors.lastname: Punnonen
authors.forename: P
authors.initials: P
authors.lastname: Mustajoki
authors.forename: J
authors.initials: J
authors.lastname: Kaukua
authors.forename: A
authors.initials: A
authors.lastname: Rissanen
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D008076:Cholesterol, HDL / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D004038:Diet, Reducing / Q000379:methods; D004958:Estradiol / Q000097:blood; D006801:Humans; D007328:Insulin / Q000378:metabolism; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000150:complications; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000178:diet therapy; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013739:Testosterone / Q000097:blood*; D014280:Triglycerides / Q000097:blood; D015431:Weight Loss / Q000502:physiology
chemical_list: D008076:Cholesterol, HDL; D007328:Insulin; D012738:Sex Hormone-Binding Globulin; D014280:Triglycerides; D013739:Testosterone; D004958:Estradiol; D019314:Dehydroepiandrosterone Sulfate