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HERO ID
2215422
Reference Type
Journal Article
Title
Within-person reproducibility of urinary bisphenol A and phthalate metabolites over a 1 to 3 year period among women in the Nurses' Health Studies: A prospective cohort study
Author(s)
Townsend, MK; Franke, AA; Li, X; Hu, FB; Eliassen, AH
Year
2013
Is Peer Reviewed?
1
Journal
Environmental Health
EISSN:
1476-069X
Volume
12
Issue
1
Page Numbers
80
Language
English
PMID
24034517
DOI
10.1186/1476-069X-12-80
Web of Science Id
WOS:000324520700001
Abstract
Background: Associations of bisphenol A and phthalates with chronic disease health outcomes are increasingly being investigated in epidemiologic studies. The majority of previous studies of within-person variability in urinary bisphenol A and phthalate metabolite concentrations have focused on reproducibility over short time periods. Long-term reproducibility data are needed to assess the potential usefulness of these biomarkers for prospective studies, particularly those examining risk of diseases with long latency periods. Low within-person reproducibility may attenuate relative risk estimates and reduce statistical power to detect associations with disease. Therefore, we assessed within-person reproducibility of bisphenol A, eight phthalate metabolites, and phthalic acid in spot urine samples over 1 to 3 years among women enrolled in two large cohort studies.
Methods: Women in the Nurses' Health Study and Nurses' Health Study II provided two spot urine samples, 1 to 3 years apart (n = 80 women for analyses of bisphenol A; n = 40 women for analyses of phthalate metabolites; n = 34 women for analyses of phthalic acid). To measure within-person reproducibility, we calculated Spearman rank correlation coefficients and intraclass correlation coefficients for creatinine-adjusted concentrations of bisphenol A, phthalate metabolites, and phthalic acid.
Results: Over 1 to 3 years, within-person variability of bisphenol A was high relative to total variability (intraclass correlation coefficient = 0.14) and rankings of bisphenol A levels between time-points were weakly correlated (Spearman correlation = 0.19). Seven of the eight phthalate metabolites and phthalic acid demonstrated moderate within-person stability over time (Spearman correlation or intraclass correlation coefficient = 0.39-0.55). Restricting analyses to first-morning urine samples did not alter results.
Conclusions: Single measurements of bisphenol A in spot urine samples were highly variable within women over 1 to 3 years, indicating that investigation of associations between a single urinary bisphenol A measurement and disease risk may be challenging in epidemiologic studies. The majority of urinary phthalate metabolites and phthalic acid appeared moderately reproducible within women over time, suggesting single measurements may be useful in epidemiologic studies, although observed relative risks can be substantially attenuated.
Keywords
Adult; Biological markers/urine; Bisphenol a; Phthalate metabolites; Reproducibility
Tags
IRIS
•
BBP (Butyl benzyl phthalate)
•
Dibutyl Phthalate (DBP)
•
Diisobutyl Phthalate (DIBP) Final
Additional Search Strategies
References obtained during assessment process
Studies with Supporting Data
Toxicokinetics
No Primary Data on Toxic Effects
Exposure levels
Cited in September 2014 DIBP Preliminary Materials
•
Phthalates – Targeted Search for Epidemiological Studies
Source – all searches
Pubmed
WOS
Excluded
Source - Dec 2013 Update (Private)
Pubmed
WOS
Source - Jun 2014 Update (Private)
WOS
Source – Dec 2014 Update (Private)
Pubmed
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