Extensive exposure to air pollutants like nitrogen dioxide and fine particulate matter could feed the development of type 2 diabetes (T2D), Chinese researchers reported in a meta-analysis published this month in the European Journal of Endocrinology.
“In recent years, several major epidemiological studies have shown that air pollution is obviously associated with increased risks of cardiovascular disease, lung cancer and natural-cause mortality,” corresponding author Yangang Wang, of the Affiliated Hospital of Medical College at Qingdao University in Qingdao, China, and colleagues wrote. “However, the effect of air pollution on type 2 diabetes risk has not been clearly described.”
It’s a relatively new space, Wang and co-authors said, since much research surrounding T2D has centered around modifiable lifestyle factors like diet and weight. Scientists have proposed non-metabolic factors, like air pollution, as contributors to T2D, but studies have come back with conflicting results.
To assess the effect of long-term exposure to air pollution—in the form of 2.5-micrometer and 10-micrometer particulate matter (PM) and nitrogen dioxide (NO2)—the authors identified 808 related research articles through Pubmed, Embase and Web of Science. Ten cohort studies were eventually selected, which involved a total of 2.37 million patients with 21,095 incident cases of T2D.
Results were clear—incident type 2 diabetes was most pronounced in populations with long-term exposure to high levels of PM2.5, PM10 and NO2. Women appeared more susceptible to T2D than men when exposed to PM2.5 and NO2, but not PM10. Even when using standardized risk estimates, Wang and colleagues said the overall relative risks of T2D were “significant.”
“The study provides a strong evidence for the adverse effect of air pollution on type 2 diabetes risk, and long-term exposure to high levels of main air pollutants is significantly associated with elevated risk of type 2 diabetes mellitus,” the authors wrote. “In addition, more prospective cohort studies with large numbers of participants, especially those from developing countries, are needed to provide a more precise assessment of the adverse effects of long-term exposure to air pollution on type 2 diabetes risk.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.