CHICAGO — A simple and inexpensive test for elevated white-blood-cell counts could help predict which postmenopausal women are at greater risk for heart attacks or strokes, a national team of researchers reported yesterday.

A high white-blood-cell count is an indicator of inflammation, which has been linked to the buildup of fatty deposits in arteries feeding the heart and brain, the hallmark of cardiovascular disease. Expert theorize that inflammation plays a role in strokes and heart attacks, perhaps by weakening blood vessels and causing fatty buildups inside them to break loose and create a blockage.

Reporting in the Archives of Internal Medicine, the researchers found that women who had the highest white-blood-cell counts had a 40 percent higher risk of heart attack than women with the lowest counts. Women in the highest bracket also had a 46 percent greater risk of stroke and a 50 percent greater risk of death during the large, six-year study.

"This confirms the finding that there is a role of inflammation in the prediction of cardiovascular disease and that the white-blood-cell count is another potential test that could be used to help identify which people are at higher risk," said Dr. Philip Greenland, chief of preventive medicine at the Northwestern University Feinberg School of Medicine and a member of the study team.

White blood cells are the body's germ fighters. Their levels rise when the body is fighting infection from viruses and bacteria, and doctors routinely take a white-blood-cell count to diagnose various illnesses.

The white-blood-cell count could be used in conjunction with assessment of other risk factors such as cholesterol, diabetes, high blood pressure, weight, smoking and physical activity, Greenland said.

Many doctors measure inflammation in patients using another test called the C-reactive protein, or CRP. CRP is a byproduct of the inflammatory process.

The CRP test costs about $70, whereas the routine blood test, which includes the white-blood-cell count and red-cell and platelet counts, runs $25-$30, Greenland said.

The researchers reported, "This offers a stable, well-standardized, widely available and inexpensive measure of systemic inflammation."

Since the cheaper blood test is such a routine part of physical exams, it could serve as an additional early predictor of cardiovascular disease in women who have not received a CRP test, he said.

Cleveland Clinic cardiologist Dr. Steven Nissen, who was not involved in the study but who has done similar research, said the new findings might not change medical guidelines but should get doctors' attention.

"It's really a wake-up call for the profession," he said. "Heart disease was not created by cholesterol alone."

Which comes first, inflammation or damaged blood vessels, is unknown. It is also unclear whether lowering white-blood-cell counts can lower the risk of heart attacks and strokes, said study leader Dr. Karen Margolis of the Berman Center for Clinical Research in Minneapolis.

The study involved a six-year follow-up of 72,242 postmenopausal women aged 50 to 79 years who participated in the Women's Health Initiative (WHI). Seattle's Fred Hutchinson Cancer Research Center serves as the WHI Clinical Coordinating Center for data collection, management and analysis. Other WHI studies have uncovered the risks of taking hormones.

Material from The Associated Press is included in this report.