Migraine, Smoking--and Stroking
What it all boils down to: smoking is a risk factor for stroke--no matter your age or your migraine status.
©Smailhodzic/shutterstock.com
The risk of stroke is higher in people with migraines. That’s a known fact. That risk is especially significant in younger women if they smoke, and it is even worse if they take birth control pills. But what happens as women age? Does their stroke risk remain the same or does it typically decrease, like their migraines do? And is their risk affected by their smoking status?
In the latest issue of Neurology, I read an article entitled “Migraine and Risk of Stroke in Older Adults”.1 What the authors found was both interesting and different from what I expected.
Let’s review what’s known about the relationship of migraine and stroke. Women (ages 20-45) who have migraines without aura have the same annual risk of stroke as women who don’t have migraines. If a woman either category is taking an estrogen-containing oral contraceptive pill (eOCP), her annual risk of stroke is increased by 7 to 10 times. If she has migraine with aura, this alone increases her annual risk of stroke three-fold.
If she has migraines and she smokes, her risk of stroke is 10 times higher. If she has migraine with aura, smokes, and is also taking eOCP, her annual risk of stroke increases, in some reports, by up to 20 times. In 2009, in the British Medical Journal, a systematic review and meta-analysis confirmed that men and women with migraine with aura had double the risk of stroke of non-migraineurs. There was also a higher risk of stroke in women with migraine, in men and women who smoked, and in women on eOCP.2
In a 2013 abstract from the Women’s Health Study, it was reported that a higher risk of stroke was found for women who had migraine with aura. That risk for stroke was as high as if they had diabetes, uncontrolled high blood pressure, or were smokers.3 In 2014, the Northern Manhattan Study (NOMAS) using a mixed race and gender population, reported that there was twice the burden of “subclinical brain infarction” found by MRI in older patients with past history of migraine after adjusting for sociodemographic and vascular risk factors.4
In effect, the implication is that migraine-especially with aura-placed patients at higher risk for stroke or for findings that suggested “subclinical strokes” in cerebral imaging studies done later in life. Therefore, it would not have surprised me me if in their most recent study, Monteith and colleagues1 had confirmed an association between migraine and stroke in older patients.
But their findings were not in line with this expectation.
This group’s new article was an 11-year prospective, population-based cohort study. In contrast to their 2014 study, they did not find a correlation between migraine and stroke or other vascular events. There was a three-times higher stroke hazard ratio for current smokers versus nonsmokers. This was similar to the risk reported in other mixed population studies of smoking and stroke.5
An Unexpected Take-Away
For me the take-away was unexpected. In your older migraine patients, smoking status makes more of a difference than their migraine status.
Yet, I have questions. Are these findings because older patients have lower migraine frequency? (Their migraine frequency was not reported). What if you control migraines, both with and without aura, in younger populations: does this lower their stroke risk? At this time, there are no answers.
Nevertheless, the well known conclusion remains: smoking is a risk factor for stroke, no matter your age or your migraine status.
References:
1. Monteith T Gardener H, Rundek T, et al. Migraine and risk of stroke in older adults.Neurology. 2015;85:1-7.
2. Schurks M, Rist PM, Bigal ME, et al. Migraine and cardiovascular disease: systematic review and meta-analysis. BMJ. 2009;339:b3914.
3. Kurth T, Bubes V, Buring J. Relative contribution of migraine with aura to cardiovascular disease occurrence in women. In: Program and abstracts of the American Academy of Neurology’s 65th Annual Meeting; March 16-23, 2013; San Diego. Abstract S40.001.
4. Monteith T, Gardener H, Rundek T, et al. Migraine, white matter hyperintensities, and subclinical brain infarction in a diverse community. Stroke. 2014;45:1830-1832.
5. Shah RS, Cole JW. Smoking and stroke: the more you smoke the more you stroke. Expert Rev Cardiovasc Ther. 2010;8(7):917-932.
