Migraines linked to heart disease and stroke
If you have migraines, newspapers have claimed that this will increase your risk of death from heart disease or stroke. Is this scare-mongering or something to take seriously?
The story is based on research published in the BMJ, that found an approximately 50 per cent increased risk for major cardiovascular disease (CVD) (defined as resulting in heart attack, stroke, angina, angioplasty or heart bypass) in women with migraines, and an increased risk of death from CVD.
The researchers now believe that a patient’s history of migraines should be considered as a marker for an increased risk of any CVD event. A statin along with Vitamin D could reduce the risk of migraine, and there should be “urgent” research into whether this medicine could reduce the risk of CVD too, they argued. But it's important to be aware that the number of women with migraines who died of heart problems during the study represented less than 0.2 per cent of all of the participants, and that while migraine may have increased their risk, the overall risk remained small.
If anyone who experiences migraines is concerned they should discuss this further with their GP
The scientists, from Harvard University in America and the Institute of Public Health in Berlin, studied 115,541 American nurses aged 25-42 for more than 20 years, doing questionnaires every two years. However, just 15 per cent of them reported that a doctor had diagnosed them with migraines, so the results were based on a total of 17,531 women. During this time, 223 women died from cardiovascular disease.
The BHF View
Maureen Talbot, Senior Cardiac Nurse at the British Heart Foundation (BHF), said: “This large study of young women shows an association between migraine and an increased risk of developing cardiovascular disease.
“However, further research is needed to establish a possible cause for this and also to determine if the findings apply to men and older age groups. If anyone who experiences migraines is concerned they should discuss this further with their GP who can determine if a heart health check is required.”
The results were similar across different ages, smoking habits, and blood pressure, which suggests a consistent link
Is the research reliable?
The researchers had no information on how often the women had migraines, or which of the three main types of migraine they had.
- Migraine with aura is where there are specific warning signs just before the migraine begins, such as seeing flashing lights.
- Migraine without aura is the most common type, where the migraine occurs without the specific warning signs.
- Silent migraine is where an aura or other migraine symptoms are experienced, but a headache doesn't develop.
The fact that they couldn’t tell the type of migraine is important, as previous studies suggest that migraine with aura is the subgroup carrying the highest risk of CVD.
The research can only show a link, and as it was observational, inflammation or genetic factors “remains an alternative explanation”, the scientists admitted. Moreover, “the mechanisms by which migraine increases stroke risk remains unclear”. The researchers said that “links between migraine and any cardiovascular disease are not easily identifiable”.
Cause of death was deemed to be coronary heart disease (CHD) if it was the underlying cause on the death certificates but there was no prior knowledge of CHD, and medical records concerning the death were unavailable. This means that the death rate for CHD in the study could be inaccurately high.
Strengths of the research included that large number of women were studied over a long period, there was a high participation rate, and women who already had cardiovascular disease were excluded from the study.
The results were similar across the sub-groups of women, such as by age, smoking habits, and by high blood pressure, which suggests a consistent link, and that these are not factors that could ruin the results.
The participants were all women and mostly white, so the results cannot be generalised to men, or women from different backgrounds
However all of the participants were women, and mostly white, so the results cannot be generalised to men, or women from different backgrounds.
The women were asked whether a doctor had diagnosed them as having migraine, so the diagnosis was not self-reported and is more credible. But people with mild migraine symptoms may not have reported their symptoms to a clinician, and therefore not received a diagnosis.
The story was widely covered by the media, for example in the Daily Mail, Express, and The Telegraph.
The researchers did not want to scaremonger and stressed that the 223 women with migraines that died of heart problems during the study represented less than 0.2 per cent of all of the participants, and that while this risk was higher among migraine patients, it is still tiny. But The Express headline warns: “Suffer with migraines? Female sufferers 'more likely' to DIE from heart disease and stroke”. This statement is true but it is not until the last paragraph (paragraph 19) that the background information is made clear.