title: Salivary progesterone levels and rate of ovulation are significantly lower in poorer than in better-off urban-dwelling Bolivian women.
abstract: BACKGROUND
  Agriculturalists in less-developed countries (LDC) have lower progesterone levels than urban industrialized populations. However, it is unknown if urban LDC populations are also relatively lower. We tested whether urban Bolivia samples-poorer (Bol-p) and better-off (Bol-b)-have lower progesterone than a Chicago (USA) sample, and whether progesterone and rate of ovulation are lower in Bol-p than in Bol-b.
  
  
  METHODS
  Serial salivary samples collected from Bolivians, screened according to strict exclusion criteria during two complete menstrual cycles, were radioimmunoassayed for progesterone; anthropometrics were collected at mid-follicular and mid-luteal phases.
  
  
  RESULTS
  Progesterone levels are lower in the Bolivia samples, and higher in the Bol-b than Bol-p; ovulation rate is greater in Bol-b than Bol-p. For only ovulatory cycles, mean-follicular-P (pmol/l), mean-luteal-P (pmol/l), and mean-peak-P (pmol/l) are respectively 65, 142 and 208 in Bol-p; 76, 167 and 232 in Bol-b; and 96, 240 and 330 in Chicago. Principal components representing body-size and progesterone level are positively correlated (r = 0.404, P = 0.005).
  
  
  CONCLUSIONS
  Progesterone levels appear to be influenced by chronic and acute ecological conditions, evidenced by the association with body-size and the probability of ovulation respectively. These findings have implications for understanding cancer aetiology, developing population-appropriate hormonal contraceptives, and modelling the evolution and functioning of the reproductive system.
authors.affiliation: Institute for Primary and Preventative Health Care, and Department of Anthropology, Binghamton University (SUNY), Binghamton, NY 13901, USA. vvitzthu@nsf.gov
authors.forename: Virginia J
authors.initials: VJ
authors.lastname: Vitzthum
authors.forename: Gillian R
authors.initials: GR
authors.lastname: Bentley
authors.forename: Hilde
authors.initials: H
authors.lastname: Spielvogel
authors.forename: Esperanza
authors.initials: E
authors.lastname: Caceres
authors.forename: Jonathan
authors.initials: J
authors.lastname: Thornburg
authors.forename: Lary
authors.initials: L
authors.lastname: Jones
authors.forename: Sarah
authors.initials: S
authors.lastname: Shore
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Hodges
authors.forename: Robert T
authors.initials: RT
authors.lastname: Chatterton
mesh_terms: D000328:Adult; D000858:Anovulation / Q000453:epidemiology; D001823:Body Composition; D001824:Body Constitution; D001838:Bolivia / Q000453:epidemiology; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D010060:Ovulation / Q000502:physiology; D011203:Poverty; D015995:Prevalence; D011374:Progesterone / Q000378:metabolism*; D012463:Saliva / Q000378:metabolism*; D014505:Urban Population
chemical_list: D011374:Progesterone