Cardiovascular and lung researchers at The Ohio State University Medical Center are the first to report a direct link between air pollution and diabetes. If the ongoing research continues to confirm this association, scientists fear human health in both industrialized and developing countries could be impacted.
“We now have even more compelling evidence of the strong relationship between air pollution and obesity and type 2 diabetes,” said Dr. Sanjay Rajagopalan, principal investigator of the study.
The latest study builds upon previous research from Rajagopalan’s team implicating air pollution as a major adverse risk factor for cardiovascular effects, high blood pressure and acute coronary syndromes.
Researchers found that exposure to air pollution, over a period of 24 weeks, exaggerates insulin resistance and fat inflammation.
“The prevalence of obesity has reached epidemic proportions with 34 percent of adults in the U.S., ages 20 and over, meeting the criteria for obesity,” said Rajagopalan. “Obesity and diabetes are very prevalent in urban areas and there have been no studies evaluating the impact of poor air quality on these related conditions until now.”
Type 2 diabetes, a consequence of obesity, has soared worldwide with a projected 221 million people expected to suffer from this disease in 2010, a 46 percent increase compared to 1995.
In the Ohio State research, scientists fed male mice a diet high in fat over a 10-week period to induce obesity and then exposed them to either filtered air or air with particulate matter for six hours a day, five days a week, over a 24-week period. Researchers monitored measures of obesity, fat content, vascular responses and diabetic state.
The air pollution level inside the chamber containing particulate matter was comparable to levels a commuter may be exposed to in urban including many metropolitan areas in the U.S.
According to the U.S. Environmental Protection Agency, the four most common pollutants emitted into the air are particulate matter, ozone, nitrogen dioxide and sulfur dioxide. Air pollution is commonly the result of industrial emissions, power plants and automobile exhaust.
“This study provides additional guidance for the EPA to review air pollution standards,” says Rajagopalan. “Our study also confirmed a need for a broader based approach, from the entire world, to influence policy development.”
Dr. Qinghua Sun, first author of the study, is leading an international effort to understand the effects of urban air pollution in Beijing, where the impact of recent stringent measures on air quality during the Olympics is being monitored in another controlled experiment.