In a study published Wednesday in the European Society of Cardiology’s “European Heart Journal,” a team of international researchers looked at more than 13,000 stroke patients in 32 countries as part of the INTERSTROKE study.
Using a “case-crossover approach,” the team determined whether a trigger within one hour of symptom onset was associated with acute stroke, versus the same time period on the previous day.
“Stroke prevention is a priority for physicians, and despite advances it remains difficult to predict when a stroke will occur. Many studies have focused on medium to long-term exposures, such as hypertension, obesity or smoking. Our study aimed to look at acute exposures that may act as triggers,” lead researcher and National University of Ireland Galway professor Andrew Smyth said in a statement.
The research analyzed patterns in patients who suffered an ischemic stroke and the less common intracerebral hemorrhage.
One in 11 survivors experienced a period of anger or upset in the one hour leading up to it, and the global INTERSTROKE study found that one in 20 patients had engaged in heavy physical exertion.
The paper, co-led by the National University of Ireland Galway, suggested that anger or emotional upset was linked to around a 30% increase in the risk of stroke during one hour after an episode – with a greater increase if the patient did not have a history of depression and larger odds for those with a lower level of education.
Heavy physical exertion was linked to around a 60% increase in the risk of intracerebral hemorrhage (ICH) – a rare form of stroke that causes bleeding in the brain – during that same period after heavy exertion, but not with all strokes or ischemic strokes.
There was a greater increase for women and less risk for those with a normal body mass index (BMI).
“Acute anger or emotional upset was associated with the onset of all stroke, ischemic stroke, and ICH, while acute heavy physical exertion was associated with ICH only,” the authors wrote.
“The study also concluded that there was no increase with exposure to both triggers of anger and heavy physical exertion,” Smythe said.
The study pointed out that there was no modifying effect by region, prior cardiovascular disease, risk factors, cardiovascular medications, time or day of symptom onset.
“Compared with exposure to neither trigger during the control period, the odds of stroke associated with exposure to both triggers were not additive,” the study noted.
Co-author and Galway University Hospitals consultant stroke physician Dr. Michelle Canavan said that people should practice mental and physical wellness at all ages, but added that it is “also important for some people to avoid heavy physical exertion, particularly if they are high-risk of cardiovascular, while also adopting a healthy lifestyle of regular exercise.”
In the U.S., the Centers for Disease Control and Prevention (CDC) says that someone has a stroke every 40 seconds and someone dies of stroke every four minutes.
Nearly 800,000 people in America have a stroke every year. About 87% of all strokes are ischemic strokes, in which blood flow to the brain is blocked.
“Some of the best ways to prevent stroke are to maintain a healthy lifestyle, treat high blood pressure and not to smoke, but our research also shows other events such as an episode of anger or upset or a period of heavy physical exertion independently increase the short-term risk.” study co-leader and National University of Ireland Galway Professor Martin O’Donnell said.
“We would emphasize that a brief episode of heavy physical exertion is different to getting regular physical activity, which reduces the long-term risk of stroke,” he explained.
The Associated Press contributed to this report.