November 15, 2017
University of Illinois at
Unequal exposure to environmental
pollutants acting as endocrine-disrupting chemicals is an under-recognized risk
factor that may play a key role in driving the higher rates of diabetes among
minority and low-income populations, according to a new article.
Unequal exposure to
environmental pollutants acting as endocrine-disrupting chemicals is an
under-recognized risk factor that may play a key role in driving the higher
rates of diabetes among minority and low-income populations, according to a new
article in the journal Diabetes Care.
chemicals interfere with the body’s ability to produce or respond to hormones.
Many of these chemicals can hinder the production or use of insulin — a
hormone produced by the pancreas that allows the body to use sugar from food
for fuel. An inability to produce or properly use insulin causes diabetes,
which affects approximately 24 million Americans.
Compared to whites, the
risk for developing diabetes is estimated to be 66 percent higher for Latinos
and 77 percent higher for blacks. Approximately 18 percent of blacks and 20
percent of Latinos have diabetes, compared with 9 percent of whites.
While studies have
examined disparities in exposure to endocrine-disrupting chemicals across
diverse populations — and implicated these same chemicals in helping to
promote the development of diabetes — none have made the connection that
overexposure to these chemicals among minority and low-income populations may
contribute to their increased burden of diabetes.
“The burden of
diabetes isn’t borne uniformly by society,” said Dr. Robert Sargis,
assistant professor of endocrinology, diabetes and metabolism in the UIC
College of Medicine and one of the lead authors on the paper. “In order to
address this disparity, we need to know all the contributing factors.”
Black, Latino and
low-income populations historically have carried the heaviest burden of
diabetes. Studies are now looking at the role of disproportionate environmental
exposures in diabetes among these groups, said Daniel Ruiz, a graduate student
at the University of Chicago and a co-lead author on the paper.
Minority and low-income
populations are much more likely to live in neighborhoods with a manufacturing
plant, or near major sources of air pollution like highways or agricultural
fields, Sargis said. “Many social and cultural factors have combined to
contribute to the fact that these groups have traditionally lived in degraded
areas where toxic exposures are more likely to occur,” he said.
Sargis and colleagues
searched the medical literature from 1966 through 2016 for papers documenting
associations between endocrine-disrupting chemicals and diabetes, and papers
that reported on racial, ethnic, and/or socioeconomic disparities in exposures
to endocrine-disrupting chemicals known to contribute to metabolic diseases,
They identified 36 studies
that looked at five types of endocrine-disrupting chemicals (polychlorinated
biphenyls, or PCBs; organochloride pesticides; chemicals in air pollution
related to traffic; bisphenol A, or BPA; and phthalates) and diabetes risk, and
33 that had data on disparities in exposure to these chemicals.
“The majority of the
studies we reviewed on exposures to endocrine-disrupting chemicals reported
that low-income people of color were disproportionately exposed,” said
“We need to change
how we think about what is driving these disparities to include the
contribution of environmental pollution,” Sargis said. “Knowing that
these risk factors exist presents an opportunity to mitigate them and focus on
policies that reduce the risk.”
The researchers also
looked at interventional studies that focused on lowering levels of
endocrine-disrupting chemicals in humans. Based on these studies, they created
a list of sources for each of the five chemicals they studied — along with
specific exposure reduction strategies for each — with the goal of sharing it
with healthcare workers.
providers need to not only become more aware of the impact of environmental
exposures on their patients’ health, they should also have the resources to
help their patients reduce their exposures through patient education,”