title: Determinants of the rate and extent of spermatogenic suppression during hormonal male contraception: an integrated analysis.
abstract: BACKGROUND
  Male hormonal contraceptive methods require effective suppression of sperm output.
  
  
  OBJECTIVE
  The objective of the study was to define the covariables that influence the rate and extent of suppression of spermatogenesis to a level shown in previous World Health Organization-sponsored studies to be sufficient for contraceptive purposes (< or =1 million/ml).
  
  
  METHODS
  This was an integrated analysis of all published male hormonal contraceptive studies of at least 3 months' treatment duration.
  
  
  METHODS
  Deidentified individual subject data were provided by investigators of 30 studies published between 1990 and 2006.
  
  
  METHODS
  A total of 1756 healthy men (by physical, blood, and semen exam) aged 18-51 yr of predominantly Caucasian (two thirds) or Asian (one third) descent were studied. This represents about 85% of all the published data.
  
  
  METHODS
  Men were treated with different preparations of testosterone, with or without various progestins.
  
  
  METHODS
  Semen analysis was the main measure.
  
  
  RESULTS
  Progestin coadministration increased both the rate and extent of suppression. Caucasian men suppressed sperm output faster initially but ultimately to a less complete extent than did non-Caucasians. Younger age and lower initial blood testosterone or sperm concentration were also associated with faster suppression, but the independent effect sizes for age and baseline testicular function were relatively small.
  
  
  CONCLUSIONS
  Male hormonal contraceptives can be practically applied to a wide range of men but require coadministration of an androgen with a second agent (i.e. progestin) for earlier and more complete suppression of sperm output. Whereas considerable progress has been made toward defining clinically effective combinations, further optimization of androgen-progestin treatment regimens is still required.
authors.affiliation: Department of Andrology, ANZAC Research Institute, University of Sydney and Concord Hospital, Concord, New South Wales 2139, Australia. pliu@mail.usyd.edu.au
authors.forename: Peter Y
authors.initials: PY
authors.lastname: Liu
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Swerdloff
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Anawalt
authors.forename: Richard A
authors.initials: RA
authors.lastname: Anderson
authors.forename: William J
authors.initials: WJ
authors.lastname: Bremner
authors.forename: Joerg
authors.initials: J
authors.lastname: Elliesen
authors.forename: Yi-Qun
authors.initials: YQ
authors.lastname: Gu
authors.forename: Wendy M
authors.initials: WM
authors.lastname: Kersemaekers
authors.forename: Robert I
authors.initials: RI
authors.lastname: McLachlan
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Meriggiola
authors.forename: Eberhard
authors.initials: E
authors.lastname: Nieschlag
authors.forename: Regine
authors.initials: R
authors.lastname: Sitruk-Ware
authors.forename: Kirsten
authors.initials: K
authors.lastname: Vogelsong
authors.forename: Xing-Hai
authors.initials: XH
authors.lastname: Wang
authors.forename: Frederick C W
authors.initials: FC
authors.lastname: Wu
authors.forename: Michael
authors.initials: M
authors.lastname: Zitzmann
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
authors.forename: Christina
authors.initials: C
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D003272:Contraceptive Agents, Male / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011372:Progestins / Q000008:administration & dosage*; D013091:Spermatogenesis / Q000187:drug effects*; D013739:Testosterone / Q000008:administration & dosage*; D044465:White People
chemical_list: D003272:Contraceptive Agents, Male; D011372:Progestins; D013739:Testosterone