title: Predictors and long-term reproducibility of urinary phthalate metabolites in middle-aged men and women living in urban Shanghai.
abstract: Phthalate esters are man-made chemicals commonly used as plasticizers and solvents, and humans may be exposed through ingestion, inhalation, and dermal absorption. Little is known about predictors of phthalate exposure, particularly in Asian countries. Because phthalates are rapidly metabolized and excreted from the body following exposure, it is important to evaluate whether phthalate metabolites measured at a single point in time can reliably rank exposures to phthalates over a period of time. We examined the concentrations and predictors of phthalate metabolite concentrations among 50 middle-aged women and 50 men from two Shanghai cohorts, enrolled in 1997-2000 and 2002-2006, respectively. We assessed the reproducibility of urinary concentrations of phthalate metabolites in three spot samples per participant taken several years apart (mean interval between first and third sample was 7.5 years [women] or 2.9 years [men]), using Spearman's rank correlation coefficients and intra-class correlation coefficients. We detected ten phthalate metabolites in at least 50% of individuals for two or more samples. Participant sex, age, menopausal status, education, income, body mass index, consumption of bottled water, recent intake of medication, and time of day of collection of the urine sample were associated with concentrations of certain phthalate metabolites. The reproducibility of an individual's urinary concentration of phthalate metabolites across several years was low, with all intra-class correlation coefficients and most Spearman rank correlation coefficients ≤0.3. Only mono(2-ethylhexyl) phthalate, a metabolite of di(2-ethylhexyl) phthalate, had a Spearman rank correlation coefficient ≥0.4 among men, suggesting moderate reproducibility. These findings suggest that a single spot urine sample is not sufficient to rank exposures to phthalates over several years in an adult urban Chinese population.
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA. Electronic address: Anne.Starling@ucdenver.edu.
authors.forename: Anne P
authors.initials: AP
authors.lastname: Starling
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Engel
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Stella
authors.initials: S
authors.lastname: Koutros
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Jaya M
authors.initials: JM
authors.lastname: Satagopan
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Gong
authors.initials: G
authors.lastname: Yang
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Matthews
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Qiuyin
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Jessie P
authors.initials: JP
authors.lastname: Buckley
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Bu-Tian
authors.initials: BT
authors.lastname: Ji
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Cai
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Wong-Ho
authors.initials: WH
authors.lastname: Chow
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology, Shanghai Cancer Institute, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Rothman
authors.affiliation: Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Yong-Bing
authors.initials: YB
authors.lastname: Xiang
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN, USA.
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Shu
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002681:China; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010795:Phthalic Acids / Q000652:urine*; D010968:Plasticizers / Q000378:metabolism; D015203:Reproducibility of Results; D012308:Risk Management; D014505:Urban Population
chemical_list: D010795:Phthalic Acids; D010968:Plasticizers; C032279:phthalic acid; D003404:Creatinine
keywords: Food contaminants; Personal care products; Phthalates; Predictors; Reproducibility