title: Hypogonadal symptoms in young men are associated with a serum total testosterone threshold of 400 ng/dL.
abstract: OBJECTIVE
  To investigate the association between hypogonadal symptoms and serum total testosterone (TT) levels in young men (aged <40 years), in an attempt to determine whether there exists a clear-cut discriminatory threshold of TT below which hypogonadal symptoms become more prevalent.
  
  
  METHODS
  We retrospectively reviewed the charts of 352 men who presented to an outpatient Men's Health Clinic with chief complaint of 'low testosterone'. Sexual, psychological and physical symptoms were evaluated using the Androgen deficiency in Aging Male (ADAM) questionnaire. Serum levels of TT were collected on the same day that men completed their ADAM questionnaires. We subsequently performed univariate (t-test, chi-square) and multivariate analyses (ordinal logistic regression) to evaluate factors that predicted a low TT level.
  
  
  RESULTS
  The probability of hypogonadal symptoms increased at a serum TT level of 400 ng/dL. A cluster of symptoms: two psychological ('decreased energy', 'sadness'), and three physical ('decreased strength and endurance', 'decreased ability to play sports', and 'deterioration in work performance') were most strongly associated with serum TT levels of <400 ng/dL. On multivariable analysis, only 'lack of energy' predicted a TT level of <400 ng/dL.
  
  
  CONCLUSIONS
  Hypogonadal symptoms in men aged <40 years can be associated with a TT level of <400 ng/dL. Of the hypogonadal symptoms evaluated with the ADAM questionnaire, 'lack of energy' appears to be the most important symptom that predicts a TT level of <400 ng/dL.
authors.affiliation: Department of Urology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Scovell
authors.affiliation: Department of Urology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Ranjith
authors.initials: R
authors.lastname: Ramasamy
authors.affiliation: Department of Urology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Wilken
authors.affiliation: Department of Urology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Kovac
authors.affiliation: Department of Urology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Larry I
authors.initials: LI
authors.lastname: Lipshultz
mesh_terms: D000328:Adult; D006801:Humans; D007006:Hypogonadism / Q000097:blood*; D008297:Male; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone
keywords: ADAM; ageing male; androgen deficiency; erectile dysfunction; libido