title: [Reference ranges of total serum and free testosterone in Japanese male adults].
abstract: OBJECTIVE
  To establish reference range of serum Total Testosterone (T-T) and Free Testosterone (F-T) in Japanese male adults.
  
  
  METHODS
  Among 1,172 male adults, who daily lived their healthy life, 1,143 subjects in the year range from 20 to 77 years old, who had serum LH concentration within its reference range (For 20-70 years old: 1.1-25.9 mIU/mL), were selected. As diurnal rhythm of both T-T and F-T was observed, blood samples were collected in the morning when T-T and F-T concentration were relatively stable at their high concentration levels. The collected samples were stored at -20 degree C until they were used for assays.
  
  
  RESULTS
  Reference range for T-T has decided to express by the mean +/- 2SD calculated from the entire test results, because influence of aging on the results was negligible, Reference range of T-T has established as 2.01-7.50 ng/mL. The other hand, reference ranges of F-T classified for every decade have decided to express by the mean +/- 2SD of each decade subgroup, because great influence of aging on F-T was observed. For each decade from 20 years on and > 70 years, reference ranges of F-T have established as: 8.5-27.9 pg/mL, 7.6-23.1 pg/mL, 7.7-21.6 pg/mL, 6.9-18.4 pg/mL, 5.4-16.7 pg/mL, and 4.5-13.8 pg/ mL, respectively.
  
  
  CONCLUSIONS
  Reference ranges of serum T-T and F-T in Japanese male adults have established. And the value of Young Adult Mean (YAM) of F-T calculated for a group of the ages between 20 and 39 years have been proposed as a guideline of requirement for the Androgen Replacement Therapy (HRT). The value of 80% and 70% of YAM were 12.4 pg/mL and 10.9 pg/mL, respectively.
authors.affiliation: Department of Urology, Center for Reproductive Medicine, ST Marianna University School of Medicine.
authors.forename: Teruaki
authors.initials: T
authors.lastname: Iwamoto
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yanase
authors.forename: Eitetsu
authors.initials: E
authors.lastname: Koh
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Horie
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Baba
authors.forename: Mikio
authors.initials: M
authors.lastname: Namiki
authors.forename: Hajime
authors.initials: H
authors.lastname: Nawata
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood; D000728:Androgens / Q000627:therapeutic use; D044466:Asian People; D002940:Circadian Rhythm; D020249:Hormone Replacement Therapy / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013739:Testosterone / Q000097:blood*
chemical_list: D000728:Androgens; D013739:Testosterone