title: Methyl mercury, but not inorganic mercury, associated with higher blood pressure during pregnancy.
abstract: Prior studies addressing associations between mercury and blood pressure have produced inconsistent findings; some of this may result from measuring total instead of speciated mercury. This cross-sectional study of 263 pregnant women assessed total mercury, speciated mercury, selenium, and n-3 polyunsaturated fatty acids in umbilical cord blood and blood pressure during labor and delivery. Models with a) total mercury or b) methyl and inorganic mercury were evaluated. Regression models adjusted for maternal age, race/ethnicity, prepregnancy body mass index, neighborhood income, parity, smoking, n-3 fatty acids and selenium. Geometric mean total, methyl, and inorganic mercury concentrations were 1.40µg/L (95% confidence interval: 1.29, 1.52); 0.95µg/L (0.84, 1.07); and 0.13µg/L (0.10, 0.17), respectively. Elevated systolic BP, diastolic BP, and pulse pressure were found, respectively, in 11.4%, 6.8%, and 19.8% of mothers. In adjusted multivariable models, a one-tertile increase of methyl mercury was associated with 2.83mmHg (0.17, 5.50) higher systolic blood pressure and 2.99mmHg (0.91, 5.08) higher pulse pressure. In the same models, an increase of one tertile of inorganic mercury was associated with -1.18mmHg (-3.72, 1.35) lower systolic blood pressure and -2.51mmHg (-4.49, -0.53) lower pulse pressure. No associations were observed with diastolic pressure. There was a non-significant trend of higher total mercury with higher systolic blood pressure. We observed a significant association of higher methyl mercury with higher systolic and pulse pressure, yet higher inorganic mercury was significantly associated with lower pulse pressure. These results should be confirmed with larger, longitudinal studies.
authors.affiliation: School of Health Sciences, Purdue University, West Lafayette, IN, USA. Electronic address: wells54@purdue.edu.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Wells
authors.affiliation: Columbia Center for Children's Environmental Health, Columbia University Mailman School of Public Health, New York, NY, USA.
authors.forename: Julie B
authors.initials: JB
authors.lastname: Herbstman
authors.affiliation: National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA.
authors.forename: Yu Hong
authors.initials: YH
authors.lastname: Lin
authors.affiliation: National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Hibbeln
authors.affiliation: Center for Environmental Security, Biodesign Institute, Arizona State University, Tempe, AZ, USA.
authors.forename: Rolf U
authors.initials: RU
authors.lastname: Halden
authors.affiliation: Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Witter
authors.affiliation: Milken Institute School of Public Health, George Washington University, Washington, DC, USA.
authors.forename: Lynn R
authors.initials: LR
authors.lastname: Goldman
mesh_terms: D000328:Adult; D015142:Baltimore; D001794:Blood Pressure / Q000187:drug effects*; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D015525:Fatty Acids, Omega-3 / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008628:Mercury / Q000097:blood* / Q000633:toxicity*; D008767:Methylmercury Compounds / Q000097:blood* / Q000633:toxicity*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000209:etiology*; D012643:Selenium / Q000097:blood
chemical_list: D015525:Fatty Acids, Omega-3; D008767:Methylmercury Compounds; D008628:Mercury; D012643:Selenium
keywords: Blood pressure; Inorganic mercury compounds; Mercury; Methylmercury compounds; Pregnancy