For Release: March 26, 2007 4 p.m. ET
Contact: DMS Communications 603-650-1492
New Aspirin Study Results Questioned
HANOVER, NH—Sorting through the evidence about aspirin's benefits for women can be confounding, according to a Dartmouth Medical School physician.
New findings that women who take low to moderate doses of aspirin have a reduced risk of death, and especially heart disease-related deaths, are provocative. However, they contrast sharply with prior research that found no benefits of aspirin use in healthy women, leaving confusion about aspirin's role, says Dr. John A. Baron, professor of medicine and of community and family medicine.
He comments on the association between aspirin and reduced cardiovascular mortality reported in the March 26 Archives of Internal Medicine in an accompanying editorial. "Is aspirin really that good or is there some other explanation for the findings that differ so much?" he asks.
Researchers at Massachusetts General Hospital and Harvard Medical School and colleagues examined the association between aspirin use and death in 79,439 women enrolled in the Nurses' Health Study (NHS), a large group of female nurses who have been followed since 1976. Beginning in 1980 and again every two years through 2004, the women were asked if they used aspirin regularly and if so, how many tablets typically per week. At the beginning of the study, the women had no history of cardiovascular disease or cancer.
According to the study, women who reported using aspirin currently had a 25 percent lower risk of death from any cause than women who never used aspirin regularly. The association was stronger for death from cardiovascular disease (women who used aspirin had a 38 percent lower risk) than for death from cancer (women who used aspirin had a 12 percent lower risk).
"The NHS findings for cardiovascular mortality are provocative, contrasting sharply with the patterns seen in primary prevention clinical trials," Baron writes. In an earlier trial, the Women's Health Study (WHS), researchers followed almost 40,000 women for 11 years and in 2005 reported no reduced risk of cardiovascular or other death associated with aspirin therapy, Baron points out.
"The difference between the NHS and the aggregated data from the WHS and other trials is too large to be explained by potential weaknesses in the randomized studies," Baron says. "At the same time, one has to consider that the observational NHS may not have been able to deal with the differences between aspirin users and non-users. These new findings ... cannot overcome the accumulated evidence that aspirin is not particularly effective for the primary prevention of death from cardiovascular disease in women," he concludes.