Researchers from the Harvard School of Public Health and colleagues assessed the effect of high air pollution levels, specifically emissions from coal-burning power plants and diesel vehicles, on Boston-area adults with diabetes.
Their study found that on days when air pollution levels were high, adults with diabetes were at higher risk for cardiovascular problems due to impairments in blood vessel function. These results show a biological mechanism linking particulate pollution and impaired cardiovascular function. The findings appear in the June 7, 2005 issue of Circulation: Journal of the American Heart Association.
The study compared the effect of pollution on 270 greater Boston residents divided into two groups; one positively diagnosed with either type I or type II diabetes and the other comprised of non-diabetic individuals but with a family history of diabetes. To assess blood vessel functioning, an ultrasound device was used to measure how well the participants' arteries were able to expand in response to increased blood flow through the arm.
Impaired blood vessel function is associated with an increased risk for atherosclerosis, heart attacks, stroke, other serious cardiovascular problems and death. On days with either high levels of sulfate particles from power plants or black carbon particles from automobile traffic, the arteries of the diabetics in the study were less able to expand in response to blood flow.
Specifically, on days when sulfate pollution was elevated the researchers found an 11 percent decrease in vascular reactivity among diabetic participants. On days when black carbon concentrations were elevated, diabetic study participants had a 13 percent decrease in vascular reactivity. In comparison, non-diabetics were not affected.