For the millions of Americans who suffer from migraines, the risk of throbbing pain that can last for days is plenty to worry about. But studies have shown that having a propensity for these severe and sometimes disabling headaches can also increase the risk for cardiovascular events such as stroke and heart attack.
In new report published this week in Neurology, researchers using data from the Women’s Health Study suggest that only those women with a specific genetic variation and whose migraines include aura, a type of visual disturbance characterized by flashing lights and patterns, are at increased risk for cardiovascular disease (CVD).
Previous studies have attempted to link both migraines and CVD with a variation referred to as the D/I polymorphism in ACE, a gene that encodes a blood vessel-constricting protein. Drugs that inhibit the ACE protein are used to treat migraines and CVD.
In a study that included 25,000 women with European ancestry, about 3,200 of whom had migraines, Schürks et al. found no association of the D/I polymorphism with the headaches. Over 12 years of follow-up, there were 625 cardiovascular events (mainly strokes and heart attacks) in the group, but again, no association with the D/I polymorphism.
When the researchers took genetics out of the equation, they found that a woman with a history of any type of migraine was about 30% more likely to have CVD. But when they added genetics back in and also divided the migraneurs (people who get migraines) up based on the presence or absence of aura, they found that only those women who had migraine with aura and also had the DD or DI genotype at the ACE polymorphism were at about two-fold increased risk for CVD.
(23andMe customers can check their data using SNP rs1799752 in the Browse Raw Data feature. Data for this SNP is available only to those customers who received their data after 9/1/08, or upgraded their accounts since that date.)
Although these results may eventually help scientists understand the exactly how migraine and CVD are related to ACE, a lot of work remains to be done. The authors themselves warn that larger studies will be needed and that their research did not take into account environmental or other genetic risk factors. They also note that their study sample was restricted to Caucasian women 45 years old and older, which may mean that their results are not applicable to the population as a whole. Finally, in both women with and without migraine, the proportion of the different genotypes (DD/DI/II) differed from what would be expected in the population, suggesting that there may have been flaws in the study.
