title: Cortisol and testosterone in Filipino young adult men: evidence for co-regulation of both hormones by fatherhood and relationship status.
abstract: OBJECTIVE
  Although cortisol (CORT) may suppress testosterone (T) production under stress, in many species males' T and CORT are co-elevated during mate acquisition or conspecific competition. It is presently unknown how CORT co-varies with T in relation to fatherhood/relationship status in men. Here we evaluate associations between waking (AM) and pre-bed (PM) salivary CORT and T, and with plasma total T and luteinizing hormone. We also test whether co-elevationor co-downregulation of CORT and T are present in men who are mating-oriented (non-pairbonded, non-fathers) and parenting-oriented (pairbonded and/or fathers), respectively.
  
  
  METHODS
  Data come from 630 of young adult Filipino males (21-23 years) enrolled in the Cebu Longitudinal Health and Nutrition Survey, a population-based birth cohort study in Cebu City, Philippines.
  
  
  RESULTS
  T and CORT were positively related in AM (r = 0.37) and PM (r = 0.30) saliva samples (both P < 0.001). The positive relationship between AM measures was strengthened as caloric intake improved (interaction P < 0.05). Mating-oriented men were more likely to have co-elevated PM CORT and T (P < 0.05), defined as being in the highest tertile for both hormones, while parenting-oriented men were more likely to have co-downregulated (lowest tertile for both hormones) AM (P < 0.05) and PM (P < 0.001) CORT and T.
  
  
  CONCLUSIONS
  CORT and T are positively related upon waking and before bed and are more likely to be co-elevated in mating-oriented men and co-downregulated in parenting-oriented men. Our findings support the interpretation that CORT and T serve complementary roles in facilitating men's mating effort.
authors.affiliation: Department of Anthropology, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Lee T
authors.initials: LT
authors.lastname: Gettler
authors.forename: Thomas W
authors.initials: TW
authors.lastname: McDade
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Kuzawa
mesh_terms: D002940:Circadian Rhythm; D015331:Cohort Studies; D002149:Energy Intake; D005219:Father-Child Relations; D005220:Fathers; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D010679:Philippines; D012044:Regression Analysis; D043762:Reproductive Behavior; D012463:Saliva / Q000737:chemistry; D013739:Testosterone / Q000032:analysis* / Q000097:blood*; D055815:Young Adult
chemical_list: D013739:Testosterone; D007986:Luteinizing Hormone; D006854:Hydrocortisone