Top 5 Risk Factors for Stroke can be Controlled with Simple Measures
Findings from the INTERSTROKE study, presented at the World Congress of Cardiology (WCC) 2010, show that 5 risk factors for stroke could be controlled with simple measures. Topping the list of risk factors for stroke that can be controlled is high blood pressure.
According to Dr Martin O'Donnell from McMaster University, Hamilton, ON, "The important message is that these identified risk factors are important for reducing the risk of stroke, and some appear to be more important than anticipated." Dr. O'Donnell who led the INTERSTROKE study says even though heart disease and stroke are closely linked, "the relative importance of the risk factors is different."
The findings show that stroke is predictable and simple measures that include controlling blood pressure can reduce the impact of stroke. Hypertension accounts for most occurrences of brain hemorrhage that can result in permanent disability.
Dr. O’Donnell also says it’s easy to measure blood pressure and tell someone they are at risk for stroke. It also takes little expertise. He adds, High blood pressure can be controlled “with generic medications, and it can also be modified at the population level by implementing such policies as those aimed at reducing salt intake”
The study shows that low income countries are the most affected by stroke- 81 percent were from Southeast Asia, India, or Africa among 3000 first strokes studies and 3000 controls from 22 countries. Only 14 percent were from high income countries. High blood pressure more than doubles the chances of having a stroke.
The four other top risk factors for stroke identified included current smoking, abdominal obesity, diet, and lack of physical activity, accounting for 80 percent of ischemic strokes and 90 percent of hemorrhagic stroke. The highest risk for hemorrhagic stroke was found from hypertension, smoking, abdominal obesity, diet, and alcohol intake. Other risk factors included in the study were diabetes mellitus, alcohol intake, psychosocial factors, and the ratio of apolipoprotein B to A1, heart irregularities, previous heart attack and heart valve disease.
Dr. O’Donnell says, "Before INTERHEART was done, there was the belief that 30% to 40% of the risk of myocardial infarction was unexplained. Similarly, some people believe that about 30% of stroke isn't explained and have been pursuing all sorts of other markers, genetics, and so on. Here, we show that these risk factors, known or proposed to be important, have now been quantified and can be extended to other regions of the world." He also notes that studies have failed to show a link between high cholesterol and stroke, but the study did find a reduced risk of ischemic stroke from higher apolipoprotein A1 - a protein contained in “good” HDL cholesterol -and HDL cholesterol.
O’Donnell says the most important message for physicians is to help patients keep their blood pressure in the recommended range. Normal blood pressure for otherwise healthy individuals should be 120/80 or lower according to the National Institutes of Health. He also suggests policies that target larger populations to lower blood pressure can also aid in stroke prevention that has become a global burden.
Five risk factors were identified in the INTERSTROKE study that can be controlled to prevent stroke. Reducing high blood pressure by cutting salt intake and taking inexpensive medication when needed, weight loss, smoking cessation, consuming a healthy diet that includes limiting alcohol intake and exercise are simple measures that can control the top 5 risk factors for stroke identified in the study. According to O’Donnell, “everything that your mom told you to do” can help prevent stroke.
Lancet 2010; DOI:10.1016/S0140-6736(10)60834