title: Testosterone concentrations in hair of hypogonadal men with and without testosterone replacement therapy.
abstract: BACKGROUND
  The measurement of testosterone (T) is essential for the diagnosis of male hypogonadism and for monitoring treatment. Samples need to be obtained at specific times in relation to the diurnal rhythm and therapeutic T injections. In this study, we explored the measurement of T in hair as an alternative method to assess gonadal status and long-term T exposure in men.
  
  
  METHODS
  Thirty-six male subjects comprising 17 healthy volunteers, 10 untreated hypogonadal men, and nine hypogonadal men receiving T injections were studied. T was measured in serum and in hair. T in hair was measured using a commercially available salivary T enzyme immunoassay kit adapted for this use.
  
  
  RESULTS
  The T concentration in the hair of hypogonadal men receiving T injections was significantly higher than that in untreated hypogonadal volunteers, but not eugonadal men. Median T concentrations were 3.66 (range, 0.82-15.00), 0.94 (range, 0.33-3.68), and 1.85 (range, 0.58-3.06) pg/g hair, respectively.
  
  
  CONCLUSIONS
  T in hair reflects gonadal status in men and may be useful for monitoring T therapy over several weeks to months in hypogonadal men.
authors.affiliation: Department of Physiology & Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Thomson
authors.forename: Gideon
authors.initials: G
authors.lastname: Koren
authors.forename: Veronique
authors.initials: V
authors.lastname: Van Steen
authors.forename: Michael
authors.initials: M
authors.lastname: Rieder
authors.forename: Stan H M
authors.initials: SH
authors.lastname: Van Uum
mesh_terms: D000328:Adult; D000728:Androgens / Q000172:deficiency; D016903:Drug Monitoring / Q000379:methods; D006197:Hair / Q000737:chemistry*; D020249:Hormone Replacement Therapy; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy*; D007124:Immunoenzyme Techniques / Q000379:methods; D008297:Male; D008875:Middle Aged; D013739:Testosterone / Q000032:analysis* / Q000097:blood / Q000627:therapeutic use*
chemical_list: D000728:Androgens; D013739:Testosterone