Urinary concentrations of bisphenol A and phthalate metabolites and weight change: a prospective investigation in US women.
OBJECTIVE
Both bisphenol A (BPA) and phthalates are known endocrine-disrupting chemicals for which there is widespread general population exposure. Human exposure occurs through dietary and non-dietary routes. Although animal studies have suggested a potential role of these chemicals in obesity, evidence from human studies is sparse and inconsistent, and prospective evidence is lacking. This study evaluated urinary concentrations of BPA and major phthalate metabolites in relation to prospective weight change.


METHODS
The study population was from the controls in a prospective case-control study of type 2 diabetes in the Nurses' Health Study (NHS) and NHSII. A total of 977 participants provided first-morning-void urine samples in 1996-2002. Urinary concentrations of BPA and nine phthalate metabolites were measured using liquid chromatography-mass spectrometry. Body weights were self-reported at baseline and updated biennially thereafter for 10 years.


RESULTS
On average, the women gained 2.09 kg (95% confidence interval (CI), -2.27 to 6.80 kg) during the 10-year follow-up. In multivariate analysis with adjustment of lifestyle and dietary factors, in comparison with women in the lowest quartile of BPA concentration, those in the highest quartile had 0.23 kg per year (95% CI, 0.07-0.38 kg per year) greater weight gain during the 10-year follow-up (P-trend=0.02). Several phthalate metabolites, including phthalic acid, MBzP and monobutyl phthalate, were also associated with faster prospective weight gain in a dose-response fashion (P-trend<0.01), whereas other phthalates metabolites, including MEP and monoethylhexyl phthalate, were not monotonically associated with body weight change.


CONCLUSIONS
These data suggest urinary concentrations of BPA and certain individual phthalate metabolites that were associated with modestly greater weight gain in a dose-response fashion. These data are consistent with a potential role of BPA and phthalates in obesity, although more prospective data are needed to corroborate these observations.
1] Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, USA [2] Department of Epidemiology, School of Public Health, Brown University, Providence, RI, USA.
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Song
1] Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA [2] Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
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Hauser
1] Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA [2] Department of Nutrition, Harvard School of Public Health, Boston, MA, USA [3] Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Hu
Natural Products and Experimental Therapeutics Program, University of Hawaii Cancer Center, Honolulu, Hawaii.
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Franke
1] Department of Epidemiology, School of Public Health, Brown University, Providence, RI, USA [2] Department of Medicine, Alpert School of Medicine, Brown University, Providence, RI, USA [3] Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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Liu
1] Department of Nutrition, Harvard School of Public Health, Boston, MA, USA [2] Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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D000328:Adult; D001559:Benzhydryl Compounds / Q000009:adverse effects / Q000652:urine*; D015992:Body Mass Index; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000737:chemistry / Q000652:urine; D005260:Female; D006801:Humans; D008875:Middle Aged; D009726:Nurses; D009765:Obesity / Q000139:chemically induced / Q000453:epidemiology*; D010636:Phenols / Q000009:adverse effects / Q000652:urine*; D010795:Phthalic Acids / Q000009:adverse effects / Q000652:urine*; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D015430:Weight Gain; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D004785:Environmental Pollutants; D010636:Phenols; D010795:Phthalic Acids; C032279:phthalic acid; C006780:bisphenol A; D000098826:Bisphenol A Compounds