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Perfluoroalkyls (PFAS) and obesity | Blog | County Pathology Ltd

Perfluoroalkyls (PFAS) and obesity

PFAS

Childhood Obesity Link to Prenatal Exposure to Perfluoroalkyls
Children had greater risk of obesity and a more rapid increase in body mass index z-scores (BMIz) in early childhood if their mothers had been exposed to higher concentrations of perfluorooctanoic acid (PFOA), according to a study published online November 11 in Obesity.

"Perfluoroalkyl substances [PFAS], which have been used in oil and water-resistant textile coatings, nonstick cookware, food-container coatings, floor polish, firefighting foam, and industrial surfactants, are a class of suspected obesogens that are persistent in the environment and humans," write Joseph M Braun, MSPH, PhD, RN, of Brown University School of Public Health in Providence, Rhode Island, and colleagues.

"Some experimental rodent and in vitro studies show that PFAS exposure may cause impaired glucose control, increased body weight, and altered adipocyte differentiation while others do not," they write.

In this research they demonstrate a dose-response relationship between exposure to PFAS and obesogenic influences, which "is consistent with a threshold effect," they note.

Was Cincinnati Drinking Water Contaminated?

The researchers measured PFOA and perfluorooctane sulfonic (PFOS), perfluorononanoic (PFNA), and perfluorohexane sulfonic (PFHxS) acids in prenatal serum samples of 468 women who were 16 to 26 weeks pregnant at nine prenatal clinics in Cincinnati, Ohio, between March 2003 and January 2006. The majority (87%) of the samples were collected at 16 weeks' gestation.

After researchers excluded multiples, stillbirths, and study dropouts, 309 singleton children remained. The researchers compared the PFAS concentrations and the BMIz scores, waist circumference, and body fat in 285 of the children (73% of original cohort) between ages 2 and 8 and in 204 (52%) of the children at age 8 years.

Data came from a total of 1021 study visits that included 243 children at age 2 years, 219 children at age 3 years, 167 children at age 4 years, 188 children at age 5 years, and 204 children at age 8 years.

The researchers adjusted for both sociodemographic covariates (maternal race, age, education, marital status, employment, and household income) and perinatal variables (maternal depressive symptoms, maternal BMI at 16 weeks' gestation, parity, and cotinine serum levels for tobacco-smoke exposure). They also accounted for prenatal vitamin use and frequency of fruit, vegetable, and fish consumption during pregnancy.

In their serum analysis of PFAS concentrations, the scientists also adjusted their findings for prenatal urinary bisphenol A (BPA) concentrations, since BPA is also a suspected obesogen.

Median PFOA concentrations in the cohort were more than double compared with data from pregnant women in the 2003–2004 and 2005–2006 US National Health and Nutrition Examination Surveys (NHANES).

"The higher serum PFOA concentrations among women in our cohort could be due to ingestion of drinking water contaminated with PFOA released by the DuPont Washington Works plant in Parkersburg, West Virginia," about 250 miles upstream of Cincinnati along the Ohio River, the researchers write.

The plant was emitting over 80,000 pounds of PFOA annually into the environment as recently as 2000, they report. "This contamination may affect other communities along the Ohio River, including the city of Cincinnati, because they draw their drinking-water supplies from the river," they observe.

Children of mothers with high levels of PFAS were 84% more likely to be overweight or obese at age 8 years compared with children whose mothers who had low levels of PFAS.

Similarly, median waist circumference of high risk children was 4.3 cm greater than the low risk children.