title: A closed literature-based discovery technique finds a mechanistic link between hypogonadism and diminished sleep quality in aging men.
abstract: OBJECTIVE
  Sleep quality commonly diminishes with age, and, further, aging men often exhibit a wider range of sleep pathologies than women. We used a freely available, web-based discovery technique (Semantic MEDLINE) supported by semantic relationships to automatically extract information from MEDLINE titles and abstracts.
  
  
  METHODS
  We assumed that testosterone is associated with sleep (the A-C relationship in the paradigm) and looked for a mechanism to explain this association (B explanatory link) as a potential or partial mechanism underpinning the etiology of eroded sleep quality in aging men.
  
  
  RESULTS
  Review of full-text papers in critical nodes discovered in this manner resulted in the proposal that testosterone enhances sleep by inhibiting cortisol. Using this discovery method, we posit, and could confirm as a novel hypothesis, cortisol as part of a mechanistic link elucidating the observed correlation between decreased testosterone in aging men and diminished sleep quality.
  
  
  CONCLUSIONS
  This approach is publically available and useful not only in this manner but also to generate from the literature alternative explanatory models for observed experimental results.
authors.affiliation: National Institutes of Health, National Library of Medicine, Cognitive Science Branch, Bethesda, MD 20894, USA. millercm@mail.nih.gov
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Miller
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Rindflesch
authors.forename: Marcelo
authors.initials: M
authors.lastname: Fiszman
authors.forename: Dimitar
authors.initials: D
authors.lastname: Hristovski
authors.forename: Dongwook
authors.initials: D
authors.lastname: Shin
authors.forename: Graciela
authors.initials: G
authors.lastname: Rosemblat
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Kingman P
authors.initials: KP
authors.lastname: Strohl
mesh_terms: D000375:Aging / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007006:Hypogonadism / Q000097:blood* / Q000150:complications*; D016239:MEDLINE; D008297:Male; D008875:Middle Aged; D007319:Sleep Initiation and Maintenance Disorders / Q000097:blood / Q000150:complications*; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D006854:Hydrocortisone