Link Between Commonly Used Chemicals, Gestational Diabetes

Kaiser Permanente researchers find phenols associated with pregnancy blood sugar disorder

By Jan Greene

Pregnant people may have increased risk of gestational diabetes if they have higher exposure to phenols, common chemicals used in food packaging and many consumer products, according to Kaiser Permanente research.

A study published October 13 in the journal Diabetes found a higher risk of gestational diabetes among patients with higher exposure to bisphenol S, a chemical that was introduced as an alternative to bisphenol A, which was linked to hormonal changes in humans. The study also found higher gestational diabetes risk among certain patients with first-trimester exposure to triclosan, an antiseptic found in hand sanitizer and wipes.

The study of 333 pregnant people is the first and largest analysis in the U.S. including people of diverse backgrounds to show a connection between these chemicals in early to mid-pregnancy and gestational diabetes, said lead author Yeyi Zhu, PhD, a research scientist with the Kaiser Permanente Division of Research. “Given how ubiquitous phenols are in the environment and in daily life, these findings could have important implications for the health of pregnant patients,” Zhu said.

The study included 111 pregnant patients with gestational diabetes and 222 pregnant people without gestational diabetes, matched for factors such as age, race or ethnicity, gestational weeks at first visit, and facility. The patients were all participants in the Pregnancy Environment and Lifestyle Study (PETALS), a long-term study tracking lifestyle and environmental factors and health status of 3,346 pregnant people of Kaiser Permanente Northern California.

“The prevalence of gestational diabetes continues to increase, and we wanted to find out whether the parallel increase in exposure to environmental contaminants might be a factor,” explained senior author Assiamira Ferrara, MD, PhD, senior research scientist with the Division of Research and principal investigator of the PETALS study.

The researchers analyzed all the patients as a group, and then carried out additional analysis of Asian and Pacific Islander patients separately because they generally have higher prevalence of gestational diabetes than other ethnic/racial groups. The Asian and Pacific Islander patients in the study also had lower levels of phenols exposure than the other ethnic or racial groups, possibly because they generally used fewer prepackaged foods in plastics or cans.

The study linked exposure to bisphenol S with gestational diabetes risk in all patients, finding twice the risk of those without bisphenol in urine samples taken during pregnancy. The analysis also found — in non-Asian and non-Pacific Islander patients — a link between first-trimester exposure to bisphenol A (4.6 times higher risk) and triclosan (2.88 times higher risk) and gestational diabetes.

Phenols are chemicals used in many common products that may degrade in the body within a day or 2. However, frequent use of products containing phenols — such as pre-packaged foods, beverages, and personal care products — exposes people regularly to phenols. Pregnant people who want to avoid exposing themselves to bisphenols and triclosan could seek out alternatives during pregnancy, the researchers said. These include alcohol-based alternatives to hand sanitizer that contains triclosan.

Phenols are considered endocrine disrupting chemicals, which have been linked to obesity and altered glucose metabolism. Previous research focused on the widespread use of bisphenol A, which was banned by the Food and Drug Administration in certain children’s products in 2012 and 2013. Other types of bisphenol, such as BPS and BPF, have been introduced as alternatives.

It’s very hard to avoid these consumer products, which are a part of our daily life.

—Yeyi Zhu, PhD

Gestational diabetes develops in pregnancy and can increase risk of complications to the mother — such as preeclampsia and early birth — as well as long-term metabolic and cardiovascular problems.

Zhu said future research could explore whether pregnant patients could reduce the impact of environmental exposures on risk of gestational diabetes by adjusting other lifestyle factors, such as diet, physical activity, and stress. “It’s very hard to avoid these consumer products, which are a part of our daily life,” Zhu said. “Maybe we could explore whether there is anything we could do to modify the factors that are in our control, such as focusing on healthy diet and physical activity.”

Meanwhile, the research team is continuing its work studying the PETALS participants for chemical exposures in pregnancy and risk of gestational diabetes as well childhood health outcomes through the Environmental Influences on Child Health Outcomes (ECHO) program, a National Institutes of Health initiative.

The research was funded by the National Institute of Environmental Health Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Office of the Director, and National Institute of Diabetes and Digestive and Kidney Diseases.

Additional co-authors of the study were Monique Hedderson, PhD, Stacey Alexeeff, PhD, Juanran Feng, and Charles Quesenberry, PhD, of the Division of Research, and Antonia M. Calafat, PhD, of the Centers for Disease Control and Prevention.

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About the Kaiser Permanente Division of Research

The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.