title: Menstrual function among women exposed to polybrominated biphenyls: a follow-up prevalence study.
abstract: BACKGROUND
  Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs) and structurally similar polychlorinated biphenyls (PCBs). The feedback system for menstrual cycle function potentially allows multiple pathways for disruption directly through the hypothalamic-pituitary-ovarian axis and indirectly through alternative neuroendocrine axes.
  
  
  METHODS
  The Michigan Female Health Study was conducted during 1997-1998 among women in a cohort exposed to PBBs in 1973. This study included 337 women with self-reported menstrual cycles of 20-35 days (age range: 24-56 years). Current PBB levels were estimated by exponential decay modeling of serum PBB levels collected from 1976-1987 during enrollment in the Michigan PBB cohort. Linear regression models for menstrual cycle length and the logarithm of bleed length used estimated current PBB exposure or enrollment PBB exposure categorized in tertiles, and for the upper decile. All models were adjusted for serum PCB levels, age, body mass index, history of at least 10% weight loss in the past year, physical activity, smoking, education, and household income.
  
  
  RESULTS
  Higher levels of physical activity were associated with shorter bleed length, and increasing age was associated with shorter cycle length. Although no overall association was found between PBB exposure and menstrual cycle characteristics, a significant interaction between PBB exposures with past year weight loss was found. Longer bleed length and shorter cycle length were associated with higher PBB exposure among women with past year weight loss.
  
  
  CONCLUSIONS
  This study suggests that PBB exposure may impact ovarian function as indicated by menstrual cycle length and bleed length. However, these associations were found among the small number of women with recent weight loss suggesting either a chance finding or that mobilization of PBBs from lipid stores may be important. These results should be replicated with larger numbers of women exposed to similar lipophilic compounds.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Road, Alanta, GA 30322, USA. sidavis@cdc.gov
authors.forename: Stephanie I
authors.initials: SI
authors.lastname: Davis
authors.forename: Heidi Michels
authors.initials: HM
authors.lastname: Blanck
authors.forename: Vicki S
authors.initials: VS
authors.lastname: Hertzberg
authors.forename: Paige E
authors.initials: PE
authors.lastname: Tolbert
authors.forename: Carol
authors.initials: C
authors.lastname: Rubin
authors.forename: Lorraine L
authors.initials: LL
authors.lastname: Cameron
authors.forename: Alden K
authors.initials: AK
authors.lastname: Henderson
authors.forename: Michele
authors.initials: M
authors.lastname: Marcus
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004703:Endocrine System / Q000187:drug effects; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D004785:Environmental Pollutants / Q000097:blood / Q000493:pharmacokinetics / Q000633:toxicity*; D005260:Female; D005411:Flame Retardants / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D020387:Food Chain; D006801:Humans; D016015:Logistic Models; D008597:Menstrual Cycle / Q000187:drug effects*; D008824:Michigan; D008875:Middle Aged; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000493:pharmacokinetics / Q000633:toxicity*; D015995:Prevalence; D015431:Weight Loss / Q000187:drug effects
chemical_list: D004785:Environmental Pollutants; D005411:Flame Retardants; D011078:Polychlorinated Biphenyls