Why having high blood pressure can quadruple the risk of developing a brain tumour
People with highest blood pressure twice as likely to develop brain tumourRisk increases fourfold for those with meningioma and high blood pressure
People with high blood pressure may be at increased risk of developing brain tumours, according to a new study.
The overall risk doubles for people with the highest blood pressure levels, compared to those with the lowest.
But it increases up to fourfold for some people diagnosed with meningioma who had high blood pressure, claim researchers from Austria, Norway and Sweden.
At risk: People with the highest blood pressure levels are twice as likely to develop a brain tumour, according to researchers
The scientists took the blood pressure measurements of 580,000 people and then waited to see if they went on to develop a benign or malignant brain tumour over the next ten years.
Around one-third of those taking part were diagnosed with hypertension, the medical name for high blood pressure.
A total of 1,312 people were diagnosed with a brain tumour during the follow-up period, including one-third with high-grade tumours which are more likely to spread.
The findings show that the 20 per cent of participants with the highest blood pressure readings were twice as likely to be diagnosed with meningioma or malignant glioma, types of brain tumour accounting for most cases.
The extra risk was compared to the risk affecting 20 per cent with the lowest readings.
For people with meningioma, which are tumours of the protective membrane around the brain, the risk was as high as fourfold.
The study was published in the Journal of Hypertension, and the researchers were funded by the World Cancer Research Fund (WCRF).
About 9,000 cases of brain tumours are diagnosed in Britain each year, but scientists warn that little is known about the causes.
Lead researcher Michael Edlinger, epidemiologist at the Medical Statistics Department in Innsbruck in Austria said: ‘These results are interesting because the large number of people in this study and the fact that more than 1,000 of them developed brain tumours mean it is unlikely that the findings are down to chance.
“The fact that more than 1,000 people in this study developed brain tumours means it is unlikely the findings are down to chance”
‘But this does not mean we can be confident that it is the high blood pressure that has caused the increase in brain tumour risk, as there are some limitations to our study.
‘For example, we did not have data on whether the participants were using any medication, such as treatment for high blood pressure, which could have affected the results.
‘And just like with the more speculative claims of mobile phone risks, we do not exactly know how such risks could work to cause the occurrence of these tumours.
‘This is why more research is needed into whether high blood pressure increases risk of brain tumour.’
Dr Rachel Thompson, Deputy Head of Science for WCRF, said: ‘Because this is a single study, the jury is still out on whether the high blood pressure is what caused the increased brain tumour risk among the people in this study or whether there is another unexplained reason for it.
‘We would want to see this finding repeated by other studies before we could be confident that blood pressure really is a risk factor for brain tumours.
‘But regardless of whether the findings of this study are confirmed or disproved by further research, there are very good reasons why having high blood pressure is a bad thing.
‘While the possible link between blood pressure and cancer needs more research, it is already well-established that having high blood pressure increases risk of strokes and heart disease.
‘There is strong evidence that having too much salt in your diet and being overweight, which both increase risk of high blood pressure, also increase the risk of cancer.’