Exercise, sex, coffee and even nose blowing may raise risk of stroke: Study

By Dr. Ananya Mandal, MDMay 5 2011

According to researchers in the Netherlands, coffee, sex and nose blowing could increase the risk of a type of stroke. The study on 250 patients identified eight risk factors linked to bleeding on the brain. These factors all increase blood pressure which could result in blood vessels bursting, according to research published in the journal Stroke.

The Stroke Association said more research was needed to see if the triggers caused the rupture. More than 150,000 people in the UK have a stroke each year with nearly 29,000 due to bleeding on the brain. Bleeding can happen when a weakened blood vessel, known as a brain aneurysm, bursts. This can result in brain damage or death say experts.

The researchers at the University Medical Center in Utrecht looked at 250 patients for three years to identify what triggers ruptures. They found that coffee was responsible for more than one in 10 burst brain aneurysms.

While people drinking coffee had only a 1.7 times greater risk, it is more common than other risk factors. Being startled increased the risk by more than 23 times, but was responsible for just 2.7% of cases.

Dr Monique Vlak, a neurologist and the study's lead author, said, “All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture.” About 2% of people have aneurysms, the authors point out, but most never rupture. In the U.S., there are 25,000 to 27,000 ruptures per year; about 40% are fatal, according to the Brain Aneurysm Foundation.

Dr Vlak advised that, “Reducing caffeine consumption or treating constipated patients with un-ruptured intracranial (brain) aneurysms with laxatives may lower the risk of subarachnoid haemorrhage.” Authors add that high blood pressure weakens blood vessels in the first place and can be caused by being overweight, smoking and a lack of exercise.

Dr Sharlin Ahmed, Research Liaison Officer at The Stroke Association said, “A sudden surge in high blood pressure can increase the likelihood of an aneurysm rupturing. However, it's very difficult to determine whether the triggers identified in this study are definitely related to the onset of a stroke as they could simply be put down to coincidence. A lot more research needs to be carried out to assess whether each of the identified triggers could directly cause an aneurysm to rupture.”

Dr. Christopher Wallace, a neurologist at Toronto's University Health Network who specializes in neurovascular conditions, said he's concerned the findings will lead some people to believe that people with aneurysms “don't have a life because no matter what they do they'll die - and that's just not true.” Vlak said the findings aren't meant to scare people away from normal activities or induce worry that they may have an aneurysm that could burst.

And a ruptured aneurysm can be catastrophic if not treated quickly. An estimated 40 to 50 per cent of patients die from the bleeding into the brain, while roughly 20 per cent who survive are left with neurological deficits, some extremely severe. “More than 40 per cent go home in good shape,” Wallace estimated. Wallace said some people with known aneurysms do not need to have surgical repair. Some have malformations that are small and pose little risk of rupture, and for some older patients the procedure may pose a greater risk than the aneurysm itself. “It's important then not to drive fear into those individuals who have discovered an aneurysm and it may have been deemed not reasonable to treat them…I will not be changing my advice to patients based on this article. I don't restrict (their activities) in any way shape or form.”