Air pollution poses risk to diabetics
Jim Ritter / Chicago Sun-Times 1oct01

[Abstract below]

A study of hospital admissions in Cook County has found a new group of people, diabetics, who are vulnerable to air pollution.

Researchers found that when microscopic soot pollution goes up, there is a 2 percent increase in admissions for heart disease among diabetics. By comparison, there was a less than 1 percent increase in heart disease admissions among non-diabetics.

The study by researchers from the Harvard School of Public Health is published in the American Journal of Respiratory and Critical Care Medicine.

Prior studies have shown that children, the elderly and people with heart and lung diseases are more susceptible than the general population to air pollution.

Researchers analyzed a form of pollution called particulates, which are particles of soot, dust and acid droplets that are small enough to lodge in lungs. Particulates come from such sources as diesel trucks and buses and coal-burning power plants.

Particulate levels have been declining in the Chicago area during the past 30 years, but not as rapidly as other forms of air pollution, said Ron Burke of the American Lung Association of Metropolitan Chicago.

"Even though air quality is considerably better today, it remains a health risk for a large percentage of the population, and now we know diabetics are at risk," Burke said.

Harvard researchers picked Cook County because it is the most populous county in the United States with daily monitoring of particulates. They looked at what effect fluctuating particulate levels had on the number of Medicare patients admitted to hospitals for heart and lung diseases.

Diabetics were no more likely than other people to be admitted for lung disease on days when particulate levels were high. But they were more than twice as likely to be admitted for heart disease when there was an increase of 10 micrograms of particulates per cubic meter of air. (A microgram is one-millionth of a gram.) Particulate levels in Chicago usually range from 25 to 150 micrograms per cubic meter.

An estimated 16 million people in the United States have diabetes, but 5 million don't know it, the American Diabetes Association said. Diabetics are at increased risk for heart attacks, strokes and other health problems.

Are Diabetics More Susceptible to the Health Effects of Airborne Particles?
Am. J. Respir. Crit. Care Med. v.164, n. 5, 2001; 164: 831-833. 5sep01

Antonella Zanobetti and Joel Schwartz
Environmental Epidemiology Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts

Convincing evidence now exists that particulate air pollution exacerbates heart and lung disease, leading to increased morbidity and mortality. The populations particularly susceptible to these exposures are still unclear. Recent work on potential mechanisms of action of particulate air pollution point to pathways also influenced by diabetes. We examined whether diabetes modified the effect of airborne particles by looking at the association of PM10 with hospital admissions for heart and lung disease in persons with or without diabetes as a comorbidity. In addition we stratified by age within persons with and without diabetes. We used Medicare data for Cook County, Illinois for the years 1988-1994, and found that a 10 µg/m3 increase in PM10 was associated with a 2.01% (95% CI 1.40-2.62%) increase in admissions for heart disease with diabetes, but only a 0.94% (95% CI 0.61-1.28%) increase in persons without diabetes. Similar effect modification was not seen for lung diseases. When analyzing by age we found twice the PM10-associated risk for heart disease in diabetics than nondiabetics in both age groups. We found for pneumonia admissions that diabetes is an effect modifier in the younger age group, and for COPD in the older age group. We conclude that persons with diabetes are a susceptible population.

Keywords: particles; diabetes; air pollution; heart disease; PM₁₀