Higher White Blood Cell Count May Boost Death Risk

FRIDAY, May 4 (HealthDay News) -- Men and women with above-normal white blood cell counts could face an increased risk of death at an earlier age, particularly from cardiovascular disease, a new study suggests.

People with normal white cell counts may not be out of danger, either, since individuals on the high end of the normal range were also at increased risk of illness and death, the team of Italian and American researchers said.

"The risk of cardiovascular mortality increased progressively with increasing white blood cell counts," noted study lead author Dr. Carmelinda Ruggiero from the U.S. National Institute on Aging. And, "the increased risk of mortality associated with high white blood cell (counts) was maintained over 40 years of follow-up," she added.

But the researchers stressed that they have not yet confirmed a cause-and-effect link between higher white blood cell counts and illness risk. It remains unclear whether an elevated count helps trigger serious disease, or whether these cell counts rise naturally after illness.

And one expert said it's too early to make any changes to practice based on the findings.

"The findings are interesting and help to bolster that inflammation status is involved in the biology of many chronic diseases, but the findings do not suggest specific screening or treatment would be advisable," said Dr. Mary Cushman, director of the thrombosis and hemostasis program at the University of Vermont and Fletcher Allen Health Care in Colchester, Vt.

The findings are published in the May 8 issue of theJournal of the American College of Cardiology.

Generated by the bone marrow and spread throughout the body, white blood cells (WBC) -- also called leukocytes -- are the immune's system key weapon against infectious disease. In the absence of disease, they normally make up just one percent of a person's blood.

According to the U.S. National Institutes of Health, a simple blood test can easily determine whether a patient's WBC count falls within the normal range of 4,500 to 10,000 cells per microliter of blood.

While a below-normal WBC count may indicate bone marrow failure and/or liver and spleen disease, illness or invasion by a foreign body typically provokes a rise in white blood cells. Physical or emotional stress and certain chronic medications can also prompt an increase.

In their study, Ruggiero and colleagues examined data collected during a multi-decade study on aging. They tracked the medical histories of more than 2,800 men and women from the Baltimore and Washington, D.C., area.

Participants were healthy at the time of their entry into the study. WBC counts, body mass indexes, and cholesterol and blood pressure levels were tallied during biannual medical evaluations.