title: Salivary estradiol and testosterone in Filipino men: Diurnal patterns and relationships with adiposity.
abstract: OBJECTIVE
  We used detailed saliva sampling procedures to test for diurnal changes in men's salivary estradiol (E2) and testosterone (T) and assessed whether greater adiposity predicted higher E2 and T.
  
  
  METHODS
  We drew on a subsample of young adults enrolled in a long-running birth cohort study in Metro Cebu, Philippines. Subjects provided saliva samples at four time points during the day (waking, waking +40 min, early evening, and bedtime), which were assayed for E2 and T. Using these detailed hormonal data, we calculated E2 (n = 29) and T (n = 44) area-under-the-curve values, which provide insights on hormonal production over the study period.
  
  
  RESULTS
  While T declined immediately after waking and reached a nadir in the early evening, E2 did not show significant diurnal change (P ≥ 0.1) but was positively correlated to T at multiple time points (P ≤ 0.05). Subjects with higher adiposity (BMI, waist circumference, skinfolds) had elevated E2 secretion throughout the day (P ≤ 0.01), but adiposity was not related to salivary T.
  
  
  CONCLUSIONS
  Consistent with past research, our results indicate that adipose tissue is a significant site of E2 production in males but differ from a limited number of prior studies of young men in that we did not find lower T with increasing adiposity. Given E2's role in male hypothalamic-pituitary-gonadal function and complex interfaces with the immune system, these results have important implications for models of male life history as rates of overweight and obesity rise in populations around the world.
authors.affiliation: Department of Anthropology, University of Notre Dame, Indiana.
authors.forename: Lee T
authors.initials: LT
authors.lastname: Gettler
authors.forename: Thomas W
authors.initials: TW
authors.lastname: McDade
authors.forename: Alan B
authors.initials: AB
authors.lastname: Feranil
authors.forename: Sonny S
authors.initials: SS
authors.lastname: Agustin
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Kuzawa
mesh_terms: D050154:Adiposity; D000328:Adult; D015992:Body Mass Index; D002940:Circadian Rhythm; D015331:Cohort Studies; D004958:Estradiol / Q000378:metabolism*; D005220:Fathers; D006801:Humans; D008297:Male; D010679:Philippines; D012463:Saliva / Q000737:chemistry; D012885:Skinfold Thickness; D013739:Testosterone / Q000378:metabolism*; D055105:Waist Circumference
chemical_list: D013739:Testosterone; D004958:Estradiol