MONDAY, June 25, 2012 (HealthDay News) -- The cholesterol-lowering drugs known as statins may be less effective for preventing death and recurrent strokes in women than in men, a new study suggests.
A review of 11 trials found that statins such as Lipitor and Crestor prevent recurrent heart attacks in men and women, but it showed no benefit for women in terms of second stroke or death from all causes.
However, experts who weren't involved with the study said it was flawed -- women comprised only a fraction of participants, for example -- and they contend the drugs are life-savers for both sexes.
The report was published June 25 in the Archives of Internal Medicine.
For the study, researchers led by Dr. Jose Gutierrez, of the vascular neurology program at the Neurological Institute of Columbia University Medical Center in New York City, pooled data on more than 43,000 participants from studies published prior to September 2010.
All patients had previous cardiovascular disease, such as a prior heart attack or stroke, angina, or peripheral artery disease.
"Statin therapy reduces the recurrence of cardiovascular events rate in both men and women," said Gutierrez.
"For women, the reduction in the recurrence rate of stroke and all-cause mortality is less robust than in men," he added.
In this type of study, called a meta-analysis, researchers try to glean common patterns from similar, but different studies. The results of any meta-analysis are limited by the selection of studies, the power of their conclusions and the number of participants.
In this case, each study looked at whether statins, which are taken by millions of Americans, were better than placebo in preventing new strokes and heart attacks or death among men and women with a history of heart problems.
The researchers found that among men, statins did reduce the odds of suffering a new heart attack or stroke or of dying from any cause. For women, although statins reduced the risk of a second heart attack, they did not appear to reduce the risk of a second stroke or death from any cause.
Several possible explanations for the discrepancy exist, Gutierrez said.
For one thing, women made up only one-fifth of study participants. Also, the women had worse cardiovascular profiles, and fewer women than men took daily aspirin, even if they met the criteria for it, he said.
"Other factors, such as differences in hormonal profiles or sex-specific characteristics, are not ruled out, but these issues cannot be addressed with the result of this meta-analysis," Gutierrez added.
Since their introduction more than 20 years ago, statins have been studied primarily in men. And results concerning the benefits for women have been mixed, the researchers noted.
Dr. Tara Narula, a cardiologist at Lenox Hill Hospital in New York City, said the study's limitations led the researchers to a false conclusion.
"Statins are beneficial for men and women; they work equally in men and women," she said.
Narula said the researchers included studies that dealt with older, sicker women, which could have swayed the results. Also, other important trials were omitted, she said.
Doctors should not change their treatment of women based on the results of this study, she added.
Given the benefit of statins in preventing second heart attacks and strokes, she said, "doctors should be as aggressive in treating women as they are for men."
Another expert, Dr. Bruce Rutkin, a cardiologist at North Shore University Hospital in Manhasset, N.Y., said that "it's pretty tough to draw definitive conclusions from a meta-analysis."
Based on this study, there is insufficient evidence to say statins are less effective in women, he said.
"We know that statins reduce the risk of having recurrent cardiovascular events in both sexes, and we see that every day," Rutkin said.
For more information on statins, visit the U.S. National Library of Medicine.