Air Pollution May Contribute to Diabetes, Particularly Among African Americans, Study Finds
Published July 27, 2021
Diabetes is a public health issue affecting more than 34 million people in the United States. According to the National Institutes of Health, nearly twice as many African American adults are likely to develop type 2 diabetes—a more common type found in older adults—than white adults. Left uncontrolled, the disease can cause heart disease, eye problems, nerve damage and kidney disease as well as death.
Scientists are investigating the causes for the health disparities among African Americans to better understand why the disease is more prevalent among this population. Epidemiologists are studying possible risk factors including biology, behavior, and socioeconomic status. At EPA, one epidemiologist has explored another potential contributing risk factor—air pollution. Multiple studies have suggested a link between air pollution and Type 2 diabetes, though more research is needed, and many studies show that African Americans are exposed to more air pollution than whites. However, this is one of the first studies that explores the association between air pollution and higher rates of diabetes in African Americans living in the southern United States.
Anne Weaver, a population health data scientist at EPA, began the research during her postdoctoral studies at Indiana University-Purdue University Indianapolis (IUPUI). She completed the study after she joined EPA’s Office of Research and Development in 2017 and published the findings in the June 2021 issue of Environmental Epidemiology. Weaver has a strong interest in pursuing research on populations that may be impacted by air pollution but have not been well represented in environmental epidemiology studies.
“We need to do more to understand the association between air pollution exposure and diabetes, particularly among African Americans,” she explains. “There is some data suggesting an association between air pollution and diabetes in African Americans, but we need to do more research to understand the issue.”
Weaver’s research indicates air pollution may play a role in the development of diabetes in African Americans, with some evidence showing an association between long-term exposure to ozone and fine particulate matter (PM2.5) and those who have diabetes.
To conduct her study, Weaver used health data of 5,301 African Americans, ages 21-94, living in and near Jackson, Mississippi, collected in the Jackson Heart Study. This large study, led by the University of Mississippi Medical Center, began 20 years ago to investigate environmental and genetic factors associated with cardiovascular disease among African Americans. It is funded by the National Heart, Lung, and Blood Institute, the National Institute on Minority Health and Health Disparities and the National Institutes of Health.
Using EPA’s atmospheric model, called CMAQ, the researchers estimated exposure to ozone and PM2.5 by zip code for all study participants, including those who had diabetes at the start of the Jackson Heart Study, those who developed the disease later, and those who did not develop diabetes. Since there are other risk factors for diabetes such as age, sex, body mass index and smoking status, scientists controlled for those factors in order to focus on air pollution’s potential impact.
Additional research is needed, but results showed air pollution, especially ozone, may be a contributing factor to the higher incidence of diabetes in this population, Weaver says. Ultimately, this line of research will help inform environmental justice efforts, help doctors better treat patients with diabetes, and help people make more informed decisions to protect their health.
Weaver’s latest research is focused on another underserved population, Native Americans, who have a high prevalence of high blood pressure (hypertension). For the research, Weaver is collaborating with the University of Oklahoma, which has collected data for the Strong Heart Study in North and South Dakota and Arizona, and colleagues at the University of North Carolina in Chapel Hill, NC.
The two main goals, she says, are to assess study participants’ exposure to air pollution and then determine if there is an association between the pollutants and hypertension.
The study contributes to a larger research focus by EPA to investigate the cardiovascular impacts of air pollution on populations that may be more susceptible or live in areas where air pollution exposure is higher.