Identifying the link between diabetes, environmental exposures

Certain populations that include African Americans, Latinos and low-income Americans may be at higher risk of diabetes, partially due to their increased exposure to potentially harmful endocrine-disrupting chemicals (EDCs) in the environment. That's the determination of a new study published in Diabetes Care.

According to the National Diabetes Statistics Report, 2017, overall, diabetes prevalence was higher among American Indians/Alaska Natives (15.1%), non-Hispanic blacks (12.7%) and people of Hispanic ethnicity (12.1%) than among non-Hispanic whites (7.4%) and Asians (8.0%).

The environmental study authors looked at nearly 70 articles addressing the connection between chemical exposures and metabolic disease, published from 1966 to December 2016. They found "significantly higher exposures" to diabetogenic EDCs that include:

• Polychlorinated biphenyls: A class of 209 synthetic chemicals introduced in the United States in the 1930s. They were used in electrical, heat transfer and hydraulic equipment, along with other industrial applications, but remain in the environment even though banned in 1977.

• Organochlorine pesticides: This class was an early generation of synthetic pesticides used extensively in the U.S. for agriculture and mosquito control. They're still measurable in the U.S. population.

• Multiple chemical constituents of air pollution: This includes fine particles, noxious gases, ground level ozone, tobacco smoke and more.

• Bisphenol A: It is a common synthetic chemical used in the production of polycarbonate and other plastics commonly found in consumer products, including the lining of food and beverage cans.

• Phthalates: These are synthetic compounds used to enhance the flexibility of plastics, including those composed of polyvinyl chloride (PVC). They are also used in a variety of personal care products, including fragrances, cosmetics, shampoos and lotions, as well as in other applications.

It's known that EDCs disrupt the body's normal hormonal processes and that some can actually reduce the way the body produces or responds to insulin.

Next: The role of chemicals

Not acting alone

"We’re not saying chemicals are the only cause of diabetes, but they may play a role," corresponding author Robert Sargis, MD, PhD, told Medical Economics.

"Those at-risk populations also historically haven't had access to enough fresh fruits and vegetables, easy access to parks for safe recreation and may be 'trapped' into being exposed due to their occupations or areas of residence,” says Sargis, an assistant professor in the Division of Endocrinology, Diabetes and Metabolism in the University of Illinois at Chicago Department of Medicine. “There can also be a 'knowledge gap' when it comes to education understanding the risks."

He encourages physicians, other providers and policymakers to use the study's data to affect change. "Let's not just bang the drum, but let's really pay attention to these issues, and use the data to help determine how to lower exposure among people who are at risk. We need more studies on ways to reduce exposure."

From the "what you don't know can hurt you" category, Sargis says everyone may be exposed to chemicals that may be associated with obesity and diabetes-that are not shown on the labels of products that we use.

"We don't know exactly what's in plastics used to store our food, because manufacturers are not required to disclose that information,” he says. “It often feels like a giant experiment on people who are exposed to things they don't know about. We can't take action to lower exposure if we don't know where these substances are coming from."

When people know what the hazards are, they can make informed decisions, he says. "We need testing to show something is safe, which it is generally 'assumed to be' until proven to be harmful. That can be a recipe for disaster."

What to do

Overall, Sargis recommends the following specific measures to help reduce harmful exposure:

• Disparities in environmental exposures are an under-recognized potential contributor to diabetes risk, and there needs to be recognition and rectification of the factors that lead to disproportionate exposures to environmental toxicants among vulnerable populations.

• Development of better ways to address these exposures at the level of an individual, which requires vastly improved information about chemicals exposed to, such as improved product labeling.

• Improved policy efforts focused on identifying and eliminating chemical hazards to endocrine and metabolic health.

• Additional science to understand how the chemicals to which individuals are exposed to adversely affect human health, including metabolic health-obesity and diabetes risk.

• As an interconnected world, demand that the chemical industry unleash their innovative brilliance to move away from toxics to green chemicals that are safe for all life.

Next: The role of education

Educate and discuss

Sargis is also a proponent of more education for clinicians on environmental exposure that may increase disease risk, he says. That includes considering and discussing the ways that at-risk populations are put in harm's way.

Whether individuals live in rural or urban locations, they face inherent risks, Sargis says. For example, they may live in an industrial area, near major thoroughfares or near fields where pesticides are used.

The study authors actually developed a Supplemental Healthcare Provider Guide that accompanies the study. It contains more detailed explanations of environmental exposures, and a comprehensive bibliography of data sources and further reading.

"Current evidence suggests that improvements in environmental health could reduce diabetes risk and disparities," the authors conclude. "More data will mean the practicing diabetologist and endocrinologist will be uniquely positioned to address exposure to diabetogenic environmental toxicants as part of individualized diabetes care plans to reduce disease risk and to improve diabetes outcomes across the population."