Women with diabetes who are exposed to ambient air pollution are more likely to have an increased risk of heart disease and stroke, a new study reports.
Researchers at the Brigham and Women’s Hospital and Harvard Medical School, United States, studied 114,537 women for whom data was collected on pollution exposure and health outcomes as part of the Nurses’ Health Study.
Between 1989 and 2006, there were 6,767 cases of cardiovascular disease, 3,295 strokes 3,878 cases of coronary heart disease. The risk of cardiovascular disease rose marginally for all women with diabetes who had increased exposure to long-term particulate matter (PM).
Particle pollution comes from power plants, engine combustion and road dust. For every additional 10 micrograms of pollution particle exposure, women with diabetes had an increased 19 per cent risk of cardiovascular disease and 23 per cent risk of stroke. Roughly 90 per cent of diabetes cases are type 2, but the percentage of type 2 patients used in the trial was not specified.
The finest of these particles are known as PM 2.5. These can enter the bloodstream after being inhaled most easily, and typically come from power plants and vehicle exhaust. When exposed to an extra 10 micrograms of PM 2.5 pollution, the diabetic women had an increased 44 per cent risk of heart disease and 66 per cent stroke risk.
Lead author Jaime E. Hart said: “There is a convincing literature that long-term air pollution is associated with a higher risk of cardiovascular disease. A number of studies of short-term air pollution exposures have suggested that individuals with diabetes are at higher risk of cardiovascular disease.”
People with type 2 and type 1 diabetes have an increased risk of cardiovascular disease, and the link between pollution and diabetes is increasing. Several studies are now starting to illustrate an association between the two.
While the risks were highest for women aged 70 or older, obese women, and those living in the Northeast or South of American, the researchers were uncertain as to why women with diabetes had such higher levels of air pollution compared to women without diabetes.
“There is some evidence to suggest that when women with diabetes are exposed to air pollution that they have higher levels of air pollution and oxidative stress than women without diabetes, but I think this is an area where more research is needed,” Hart told Reuters Health.
“Most of the evidence suggests that the results would be similar in men, but interactions with hormones can’t be ruled out.”
Hart concluded: “Given the vast literature on the adverse health effects of air pollution, I do believe that people should be concerned about air pollution exposures. I think the recommendations for women with diabetes would be similar to advice for all women: don’t smoke cigarettes, eat a healthy diet, get regular exercise and, when practical, avoid being outside in areas of high pollution.”
The findings appear online in the Journal of the American Heart Association.