Urinary phthalate metabolite concentrations and blood glucose levels during pregnancy.
OBJECTIVE
To examine associations between phthalate metabolite urinary concentrations during early pregnancy and blood glucose levels obtained at the time of screening for gestational diabetes mellitus (GDM).


METHODS
Upon initiation of prenatal care, women with a mean gestational age of 12.8 weeks were recruited for a study of environmental chemical exposures (n = 110) and provided a spot urinary specimen. Blood glucose concentrations (mg/dl) were obtained from the electronic medical record for those patients who did not experience a pregnancy loss and did not transfer care to another facility prior to glucose screening (n = 72). Urinary concentrations of nine phthalate metabolites and creatinine were measured at the US Centers for Disease Control and Prevention. Associations between tertiles of phthalate metabolites concentrations and blood glucose levels were estimated using linear regression.


RESULTS
Compared to pregnant women in the lowest concentration tertile, women with the highest urinary concentrations (≥ 3 rd tertile) of mono-iso-butyl phthalate (tertile: ≥ 15.3 μg/l, β = -18.3, 95% CI: -35.4, -1.2) and monobenzyl phthalate (tertile: ≥ 30.3 μg/l, β = -17.3, 95% CI: -34.1, -0.4) had lower blood glucose levels at the time of GDM screening after adjustment for urinary creatinine and demographic covariates.


CONCLUSIONS
Because maternal glucose levels increase during pregnancy to provide adequate nutrition for fetal growth and development, these findings may have implications for fetal health. However, given the limitations of our study, findings should be interpreted cautiously.
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, 801 NE 13th St., Room 309, Oklahoma City, OK 73104, USA. Electronic address: candace.robledo@unthsc.edu.
Candace A
CA
Robledo
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, 801 NE 13th St., Room 309, Oklahoma City, OK 73104, USA. Electronic address: jennifer-peck@ouhsc.edu.
Jennifer D
JD
Peck
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, 801 NE 13th St., Room 309, Oklahoma City, OK 73104, USA. Electronic address: julie-stoner@ouhsc.edu.
Julie
J
Stoner
Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention (CDC), 4770 Buford Hwy, Atlanta, GA 30341, USA. Electronic address: acalafat@cdc.gov.
Antonia M
AM
Calafat
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, 801 NE 13th St., Room 309, Oklahoma City, OK 73104, USA. Electronic address: helene-carabin@ouhsc.edu.
Hélène
H
Carabin
Department of Biostatistics & Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, 801 NE 13th St., Room 309, Oklahoma City, OK 73104, USA. Electronic address: linda-cowan@ouhsc.edu.
Linda
L
Cowan
Department of Obstetrics and Gynecology, Maternal-Fetal Medicine, Stritch School of Medicine, Loyola University Health System, 2160 South First Avenue, Building 103, Maywood, IL 60153, USA. Electronic address: jrgoodman@lumc.edu.
Jean R
JR
Goodman
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D003404:Creatinine / Q000652:urine; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000652:urine; D005260:Female; D006801:Humans; D016014:Linear Models; D018811:Maternal Exposure / Q000009:adverse effects*; D010795:Phthalic Acids / Q000009:adverse effects* / Q000652:urine; D011247:Pregnancy; D055815:Young Adult
D001786:Blood Glucose; D004785:Environmental Pollutants; D010795:Phthalic Acids; C575690:mono-isobutyl phthalate; C103325:mono-benzyl phthalate; C032279:phthalic acid; D003404:Creatinine
Blood glucose; Mono-2-ethyl-5-carboxypentyl phthalate (PubChem CID: 148386); Mono-2-ethyl-5-hydroxyhexyl phthalate (PubChem CID: 53437104); Mono-2-ethyl-5-oxohexyl phthalate (PubChem CID: 12080048); Mono-2-ethylhexyl phthalate (PubChem CID: 20393); Mono-3-carboxypropyl phthalate (PubChem CID: 53435015); Mono-iso-butyl phthalate (PubChem CID: 92272); Mono-n-butyl phthalate (PubChem CID: 8575); Monobenzyl phthalate (PubChem CID: 31736); Monoethyl phthalate (PubChem CID: 75318); Phthalate; Pregnancy