title: Testosterone, sex hormone-binding globulin, and the development of type 2 diabetes in middle-aged men: prospective results from the Massachusetts male aging study.
abstract: OBJECTIVE
  The objective was to examine prospectively the association between low testosterone and sex hormone-binding globulin (SHBG) levels and the subsequent development of type 2 diabetes in men.
  
  
  METHODS
  Analyses were conducted on the cohort of the Massachusetts Male Aging Study, a population-based random sample of men aged 40-70. Of the 1,709 men enrolled in 1987-1989 (T1), 1,156 were followed up 7-10 years later (T2). Testosterone and SHBG levels at T1 were used to predict new cases of diabetes between T1 and T2.
  
  
  RESULTS
  After controlling for potential confounders, diabetes at follow-up was predicted jointly and independently by lower baseline levels of free testosterone and SHBG. The odds ratio for future diabetes was 1.58 for a decrease of 1SD in free testosterone (4 ng/dl) and 1.89 for a 1SD decrease in SHBG (16 nmol/l), both significant at P < 0.02.
  
  
  CONCLUSIONS
  Our prospective findings are consistent with previous, mainly cross-sectional reports, suggesting that low levels of testosterone and SHBG play some role in the development of insulin resistance and subsequent type 2 diabetes.
authors.affiliation: New England Research Institutes, Watertown, Massachusetts, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Stellato
authors.forename: H A
authors.initials: HA
authors.lastname: Feldman
authors.forename: O
authors.initials: O
authors.lastname: Hamdy
authors.forename: E S
authors.initials: ES
authors.lastname: Horton
authors.forename: J B
authors.initials: JB
authors.lastname: McKinlay
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D015438:Health Behavior; D006331:Heart Diseases / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011237:Predictive Value of Tests; D044469:Racial Groups; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013739:Testosterone / Q000097:blood*; D013997:Time Factors
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone