Discrimination could hurt the heart, new research shows.

In a study of 181 middle-aged black women, those reporting the most chronic discrimination had the highest buildup of calcium in blood vessels of the heart. Calcium deposits in blood vessel walls are associated with atherosclerosis (hardening of the arteries).

The results were presented in Washington, D.C., at the American Heart Association's 45th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

"These findings suggest that chronic exposure to discrimination may be an important risk factor for cardiovascular disease in African-American women," says Tené Lewis, PhD, in a news release.

Heart Disease, Women, and Race

Heart disease is a leading cause of death for men and women in the U.S.

Last December, the CDC reported that in 1995 heart disease death rates for black women were 2.6 times higher than those of Asian and Pacific Islander women; 2.1 times higher than those of Hispanic, Native American, and Native Alaskan women; and 1.4 times higher than the rates for white women.

Among black women, approximately 22 percent of heart disease deaths from 1991-1995 were premature (before age 65), says the CDC.

In comparison, 23 percent of heart disease deaths during that period were premature in Native American and Native Alaskan women. For white women, the figure was 7.7 percent.

There may have been some misreporting of race and ethnicity on death certificates, which may have made heart disease death rates too low for Native Americans, Native Alaskans, and Asian and Pacific Islanders compared with blacks and whites, says the CDC.

Tracking Discrimination

Lewis' study included 181 black women who were 45-58 years old. The women lived in Chicago and Pittsburgh.

Once a year for four years, the women filled out a questionnaire on everyday discrimination. The questionnaire focused on feelings of discrimination, such as feeling ignored or treated disrespectfully.

"The women reported discrimination in the form of having poorer service in stores or restaurants, being treated as if they were less smart, or being treated as if they were dishonest," says Lewis, a health psychologist in preventive medicine at Chicago's Rush University Medical Center.

Checking the Coronary Artery

In the study's fourth year, the women were tested to see how much calcium buildup was found in the wall of heart vessels (coronary arteries). Nearly 60 percent (108 women) had some amount of coronary artery calcification.

Chronic discrimination went hand in hand with finding calcium deposits in vessel walls, the study shows.

"Chronic discrimination was associated with a 2.8-fold higher rate of coronary artery calcification," write the researchers.

Little Change After Considering Other Risk Factors

What about high blood pressure, high cholesterol, smoking, body mass index (BMI -- an indirect measure of body fat) and age? Those heart disease risk factors didn't change the results much, says the study.

After considering all of those factors -- except BMI -- the women's odds of having calcium in blood vessel walls were still 2.6 times higher with chronic discrimination.

Adjusting for BMI put the odds of coronary artery calcification at 2.5 times higher with chronic discrimination. Those factors are still important to health, but they didn't explain the pattern in Lewis' study.

"The more discrimination African-American women experience, the more calcium buildup they have," says Lewis in a news release.

Discrimination = Stress

"We know from other studies in this area that stressful life experiences can have an effect on cardiovascular outcomes," says Lewis. "Discrimination appears to be a stressor that has particular relevance for the health of African-American women."

Prejudice is ugly and pervasive. "This is an unavoidable stressor for African-American women," says Lewis.

"Because we can't change society, we need to focus on helping African-American women cope more effectively with these encounters," she says. "We really need to come up with some specific strategies in dealing with discrimination."

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: American Heart Association 45th Annual Conference on Cardiovascular Disease Epidemiology and Prevention, Washington, D.C., April 29-May 2, 2005. News release, American Heart Association. CDC.