title: Genetic and environmental effects on diurnal dehydroepiandrosterone sulfate concentrations in middle-aged men.
abstract: BACKGROUND
  Dehydroepiandrosterone sulfate (DHEAS) is important for its association with immune system function and health outcomes. The characterization of the genetic and environmental contributions to daily DHEAS concentrations is thus important for understanding the genetics of health and aging.
  
  
  METHODS
  Saliva was collected from 783 middle-aged men (389 complete pairs and 5 unpaired twins) as part of the Vietnam Era Twin Study of Aging. Samples were taken at multiple specified time points across two non-consecutive days in the home and one day at the study sites. A twin modeling approach was used to estimate genetic and environmental contributions for time-specific and average DHEAS concentrations.
  
  
  RESULTS
  There was a consistent diurnal pattern for DHEAS concentrations in both at-home and day-of-testing (DOT) measures, which was the highest at awakening and decreased slightly throughout the day. Heritability estimates were significant for measures at 10 am, 3 pm and bedtime for the in-home days and at 10 am and 3 pm on the DOT, ranging between 0.37 and 0.46.
  
  
  CONCLUSIONS
  The significant heritability estimates later in the day reflect time-specific genetic effects for DHEAS, compared with prior twin and family designs studies which frequently used averaged morning-only measures. Additive genetic influences on DHEAS concentrations were consistent between at-home and DOT measures.
authors.affiliation: Virginia Institute for Behavioral and Psychiatric Genetics, Virginia Commonwealth University, Richmond, VA 23298-0126, United States. ecpromwormle@vcu.edu
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Prom-Wormley
authors.forename: Timothy P
authors.initials: TP
authors.lastname: York
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Jacobson
authors.forename: Lindon J
authors.initials: LJ
authors.lastname: Eaves
authors.forename: Sally P
authors.initials: SP
authors.lastname: Mendoza
authors.forename: Dirk
authors.initials: D
authors.lastname: Hellhammer
authors.forename: Nicole
authors.initials: N
authors.lastname: Maninger
authors.forename: Seymour
authors.initials: S
authors.lastname: Levine
authors.forename: Sonia
authors.initials: S
authors.lastname: Lupien
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lyons
authors.forename: Richard
authors.initials: R
authors.lastname: Hauger
authors.forename: Hong
authors.initials: H
authors.lastname: Xian
authors.forename: Carol E
authors.initials: CE
authors.lastname: Franz
authors.forename: William S
authors.initials: WS
authors.lastname: Kremen
mesh_terms: D002940:Circadian Rhythm / Q000235:genetics; D019314:Dehydroepiandrosterone Sulfate / Q000032:analysis* / Q000378:metabolism; D004777:Environment; D059647:Gene-Environment Interaction; D005796:Genes / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D014427:Twins; D047829:Vietnam Conflict; D014851:Wakefulness / Q000502:physiology
chemical_list: D019314:Dehydroepiandrosterone Sulfate