TUESDAY, July 18, 2006 (HealthDay News) -- The authors of a new study linking migraines with aura to an increased risk for heart woes came under attack Tuesday by the editor of the medical journal that published their research the same day.
The editor-in-chief of the Journal of the American Medical Association criticized six researchers, led by a Harvard professor, for not disclosing that they have done consulting work or received research funding from makers of treatments for migraines or heart-related problems, the Associated Press reported.
The research, published in the July 19 issue of the journal, came a week after the journal announced a crackdown on researchers who don't reveal industry ties.
Dr. Catherine DeAngelis, JAMA editor-in-chief, said hereditors did not know about the ties until the APbrought it to their attention.
"We'll get killed," the wire service quotes her as saying, referring to the potential damage to the journal's reputation.
During the past two months, there have been two cases of JAMA authors not disclosing their consulting relationships with drug companies, one involving antidepressants and the other arthritis drugs.
DeAngelis told the AP that she would have added the authors' financial association with the pharmaceutical companies if she had known about them, especially in the latest incident.
Dr. Tobias Kurth, the study's lead author and an assistant professor of medicine at Harvard School of Public Health in Boston, said the researchers were not trying to mislead the journal because they believed theirfinancial ties were irrelevant. The study does not promotedrug treatment, he added.
The research found specifically that women aged 45 and older who have migraines with aura are at an increased risk for heart attacks, strokes, angina and death due to cardiovascular disease but that there was no increased risk for women with a history of migraine without aura.
"This study confirmed an association between migraine with aura and stroke that was previously identified, and also demonstrated that migraine was a risk factor for ischemic heart disease as well," said Dr. Richard B. Lipton, co-author of an editorial accompanying the study and director of the Montefiore Headache Center in New York City.
"We expanded it beyond ischemic stroke," added Kurth. "The heart part is new, but it's not a different mechanism. It just shows a higher risk of overall cardiovascular disease."
About 18 percent of women and 6 percent of men have migraine in any given year, with some 28 million Americans suffering from the condition.
Migraine headaches are especially severe and can involve nausea, vomiting, sensitivity to light and sound. In some cases, the event also involves an aura -- visual and sensory "warning signs" just before the attack.
Migraines with auras, which comprise the minority of migraine attacks, have already been linked to an increased risk of ischemic stroke. Their association with other cardiovascular problems has not been established.
To evaluate the link between migraine (with and without aura) and vascular events, the authors looked at data on nearly 28,000 women aged 45 and older who were participating in the Women's Health Study.
Women who reported having active migraine with aura had about double the risk of major cardiovascular disease and heart attacks, almost double the risk for ischemic stroke and a 70 percent higher risk for ischemic cardiovascular death.
This translated into 18 additional major cardiovascular disease events attributable to migraine with aura per 10,000 women per year.
Women who had migraines without aura did not face increased risk in any of these areas. That's good news, since most migraine sufferers do not experience aura.
"It's important to understand that, for most migraine patients, this is not an issue," Kurth said. "Migraine without aura was not associated with any increased risk of vascular events, and this is the vast majority of migraine sufferers."
The biological mechanisms linking aura and cardiovascular risk remain unclear.
"There's pretty good evidence that migraine with or without aura have separate genetic risk factors," Lipton explained. "One of the migraine-with-aura genes is associated with elevated levels of high blood pressure and other risk factors. So, one possibility is that there's a genetic link between migraine with aura and heart disease."
For women who do experience aura with their migraines, there are some common-sense strategies.
"Over the last 20 years, there has been an enormous emphasis on knowing your risk factors for heart disease and reducing them," Lipton said. "This study suggests that migraine with aura should be added to that list of risk factors, at least in women over 45."
Scientists don't know, however, if treating the migraine itself will decrease the risk.
While researchers search for that answer, women should pay attention to known risk factors.
"Women with migraine with aura should be especially careful about addressing those risk factors that they can modify for heart disease, such as cholesterol and high blood pressure," Lipton said.
"Patients and treating physicians should be particularly cautious about other modifiable risk factors for cardiovascular disease, in particular smoking," Kurth added.
And research needs to confirm the findings in men and in younger women to see if they, too, should heed heightened precautions.
The National Institute of Neurological Disorders and Stroke can tell you more about migraine.