May 4, 2007 (Boston) — The well-established association
between migraine — particularly migraine with aura — and
ischemic stroke cannot be explained by elevated biomarkers of
cardiovascular disease (CVD), according to a study presented
here at the American Academy of Neurology 59th Annual Meeting.
"Migraine with aura has been associated
with ischemic stroke in several studies," said lead author
Tobias Kurth, MD, ScD, from the division of preventive
medicine at Harvard Medical School, in Boston, Massachusetts.
"Recently, data from the Women's Health Study showed that
migraine is not only associated with ischemic stroke but with
any cardiovascular events," he told meeting attendees.
To investigate whether the observed
association between migraine and ischemic vascular events
might be due to adverse levels of CVD biomarkers, such as high
total cholesterol, low high-density lipoprotein cholesterol (HDL-C),
and elevated C-reactive protein (CRP), Dr. Kurth and
colleagues analyzed data from the Women's Health Study — a
large, randomized, placebo-controlled trial of aspirin and
vitamin E in the primary prevention of CVD and cancer among
apparently healthy women over 45 years of age.
A total of 39,876 female health
professionals were included in the study, 27,626 of whom
answered questions related to their migraine history and
provided blood samples that could be analyzed for all
evaluated biomarkers. The investigators measured blood levels
of the following biomarkers: total cholesterol, low- and
high-density lipoprotein cholesterol (LDL-C and HDL-C), non-HDL-C,
apolipoprotein A-1 and B 100, lipoprotein (a), CRP,
fibrinogen, soluble intracellular-adhesion molecule 1
(ICAM-1), homocysteine, and creatinine.
Of the subjects, 5087 (18.4%) reported any
history of migraine at study entry. Of these, 3585 women had
active migraine (ie, experienced migraine attacks in the
previous year), and 1422 (39.7%) reported migraine with aura.
Large Sample Size
An analysis of the results revealed a
modest but statistically significant association between
migraine and some of the biomarkers of CVD, Dr. Kurth said.
"We found statistically significantly increased prevalence
odds ratios for total cholesterol, non-HDL cholesterol, apo B
100, and CRP for women who reported any history of
migraine."
Dr. Kurth cautioned, however, that these
results are based on a very large sample, so the fact that
they are statistically significant does not necessarily mean
that they are also clinically significant. "The differences in
the median values are quite small," he said.
Dr. Kurth also noted that, after adjustment
for traditional cardiovascular risk factors, migraine with
aura was not associated with any of the elevated biomarkers.
"Thus, the elevated biomarkers are an unlikely explanation of
why women with migraine with aura are at increased risk for
cardiovascular disease in this particular cohort," he
concluded.
Risk for Adverse Risk Factor Levels in
Women With a History of Migraine vs No Migraine Adjusted for
CVD Risk Factors
|
Biomarker
|
Odds Ratio
|
95% CI
|
|
Total cholesterol
|
1.09
|
1.01 – 1.18
|
|
Non-HDL-C
|
1.14
|
1.05 – 1.23
|
|
Apolipoprotein B 100
|
1.09
|
1.01 – 1.18
|
|
CRP
|
1.13
|
1.05 – 1.22
|
Interestingly, the association between
migraine and certain biomarkers of CVD was strongest for
women who reported a history of migraine but not active
migraine, Dr. Kurth said. One possible explanation for this
finding is that the migraine pain may go away because the
vasculature becomes unhealthier and loses its elasticity as
the women age, he said. He emphasized, however, that this is
just a hypothesis, and the reason why migraine with aura is
associated with an increased risk for CVD remains to be
explained.
The study was supported by grants from
the National Institutes of Health, the Donald W. Reynolds
Foundation, Leducq Foundation, and the Doris Duke Charitable
Foundation. Dr. Kurth disclosed he has received personal
compensation for activities with the i3 Drug Safety and
Organon. He has received research support from the National
Institutes of Health, Bayer Pharmaceuticals Corporation,
McNeil Consumer & Specialty Pharmaceuticals, and Wyeth.
Disclosures for coauthors appear in the published abstract.
American Academy of Neurology 59th Annual
Meeting: Session S05.001. Presented May 1, 2007.
