Air pollution puts women with diabetes at higher heart risk

WASHINGTON – Air pollution is a major risk factor for cardiovascular disease, and women with diabetes may be more susceptible to its effects than others, a long-term US study said Wednesday.

The study, published in the Journal of the American Heart Association, found that women with diabetes who are exposed to air pollution for long periods may have a much higher risk for cardiovascular disease.

“We didn’t expect diabetes to be the strongest factor in determining susceptibility,” study lead author Jaime Hart, an epidemiologist at the Boston-based Brigham and Women’s Hospital and Harvard T. H. Chan School of Public Health.

“We looked at age, family history of cardiovascular disease, weight, smoking status and region of the country but diabetes was the most consistent across diseases and across different size fractions of particulate matter,” Hart said.

The research team explored data from more than 100,000 participants in a long-term study called the Nurses’ Health Study, looking at rates of cardiovascular disease, specifically incidence of coronary heart disease and stroke.

They assessed long-term exposure to three different sizes of particulate matter (PM) air pollution from 1989 to 2006: Fine particulate pollutant smaller than 2.5 thousandths of a millimeter in diameter (PM2.5), PM10 and PM2.5-10. PM10 includes both PM2.5 and PM2.5-10.

While all women had small increases in risk of cardiovascular events with more air pollution exposure, the increased risk was statistically significant for all cardiovascular outcomes measured and across all sizes of particulate matter among women with diabetes.

According to the team, an increase of 10 micrograms per cubic meter of air pollution in PM2.5, PM2.5-10 and PM 10 will raise a woman’s risk of cardiovascular disease by 44 percent, 17 percent and 19 percent, respectively, if she had type 2 diabetes.

The team found that these effects were greater among women 70 and older and obese women.

Since the study participants were mostly white women of middle- and upper-socioeconomic status, further research will be needed to determine if these patterns are also seen in men and in racially and socioeconomically diverse populations, they added.