Menstrual function among women exposed to polybrominated biphenyls: A follow-up prevalence study

Stephanie I Davis,Heidi Michels Blanck,Carol Rubin,Vicki S Hertzberg,Lorraine L Cameron,Alden K Henderson,Paige E Tolbert,Michele Marcus

doi:10.1186/1476-069x-4-15

Abstract

BackgroundAlteration 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.MethodsThe 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.ResultsHigher 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.ConclusionThis 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.

Highlights

Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs) and structurally similar polychlorinated biphenyls (PCBs)
We found no overall association between current estimated PBBs and either menstrual cycle length or bleed length; the associations between PBB exposure and menstrual cycle length or bleed length differed for women based on their history of weight loss in the past year
We further examined the cumulative distribution functions (CDF) for PBB distributions among the 44 women with past year weight loss by menstrual cycle length and bleed length categories (Figure 4)

Summary

Introduction

Alteration in menstrual cycle function is suggested among rhesus monkeys and humans exposed to polybrominated biphenyls (PBBs) and structurally similar polychlorinated biphenyls (PCBs). From 1997–1998, the Michigan Female Health Study (MFHS) was conducted to assess whether PBB exposure disrupted endocrine function among cohort women. One rhesus monkey study was found, suggesting that PBBs may be associated with longer menstrual cycles [3]. Animal studies of structurally similar polychlorinated biphenyls (PCBs) have found that menstrual cycle length was either not different [4,5,6,7] or longer [8] with Aroclor 1248 [4,8] or Aroclor 1254 [5,6,7] dosing. Cooper et al reported that bleed length was not associated with PCBs [10], but Yucheng women, with cooking oil exposure to PCBs, reported abnormal bleeding more often than controls [12]

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