The prevailing assumption is that strokes can happen to anyone, anytime, anywhere. But there’s some good news: researchers have proven that 90% of all strokes are actually preventable.
High blood pressure, which factors in hypertension, is the single most important risk factor for a stroke. This and nine other risk factors all add up to for 90% of all strokes, according to an INTERSTROKE analysis of about 27,000 people from all over the world.
Although these 10 risk factors were studied to be the most significant, the relative role of some individual risk factors varied by region in the study – something the researchers say should affect the development of strategies to reduce stroke occurrences.
The research, headed by Dr. Martin O’Donnell and Professor Salim Yusuf of McMaster University, collaborated with scientists from 32 other countries and studied the INTERSTROKE data. To calculate the proportion of stroke caused by a specific factor, the researchers came up with PAR, an estimate of the overall risk that could be reduced if a certain factor was removed. What this essentially means is the higher the PAR percentage, the more likely it can decrease the chances of getting a stroke.
The PAR was 47.9% for hypertension, 35.8% for physical inactivity, 23.3% for poor diet, 18.6% for obesity, 12.4% for smoking, 9.1% for cardiac causes, 3.9% for diabetes, 5.8% for alcohol consumption, 5.8% for stress and 26.8% for lipids.
Many of these listed risk factors are also associated with each other, such as obesity and diabetes. Combined together, total PAR for all of these is 90.7%, similar in all regions, age groups and genders.
The researchers noted that the importance of risk factors were different per region. For example, the PAR for hypertension averaged at 38.8% in Western Europe, North America and Australia but jumped to 59.6% in Southeast Asia. The PAR for alcohol intake was at the lowest also in Western Europe, North America and Australia, and highest in South Asia at 10.7% and Africa at 10.4%. The PAR for physical inactivity was at its highest in China.
Yusuf said that the study’s findings will help “inform the development of global population-level interventions to reduce stroke, and how such programmes may be tailored to individual regions.”
These interventions include accessibility to healthy food, better education in health, cheaper medications for hypertension and lessening tobacco and alcohol intake.
Experts from the National Institute for Stroke and Applied Neurosciences said that the three key things to be taken from the study are that stroke can be prevented globally, that prevention programs should be regional ad focused, and that more research is necessary for countries and populations that were not included in the INTERSTROKE survey.
The study was published in The Lancet.
