New immigrants to Ontario have lower risk of stroke
February 3, 2010
Debra Black
Recent immigrants to Ontario have a 30 per cent lower risk of having a stroke than long-term residents, according to
study published Wednesday in the American Academy of Neurology medical journal.
The study is the first of its kind to look at strokes in an immigrant population – especially younger immigrants, according to Dr. Gustavo Saposnik, a neurologist at St. Michael’s Hospital and a scientist at the Institute of Clinical Evaluative Sciences.
Researchers identified all new immigrants to Ontario over a 12 year period and then matched them with residents of the province who had lived here for at least five years. Both sets of participants ranged in age from 16 to 65, with the average age of 34. Data from about 4.2 million Ontario residents were used in the study.
The study, which was conducted by researchers at St. Michael’s Hospital and the Institute of Clinical Evaluative Sciences, followed participants over a six year period. According to the study there were 933 strokes among the new immigrants and 5,283 among long term residents. The study also found that new immigrants had a rate of 1.7 strokes per person per year compared to 2.6 strokes per person per year with long-term residents.
New immigrants also showed a lower rate of hypertension – 14 per cent of the new immigrants suffered from hypertension as compared to 18 per cent of long term residents.
The motivation for the study was to examine which factors had more of an effect on strokes – the psychosocial factors such as the stress of moving to a new country as compared to what Saposnik calls “a competing force” - the fact that new immigrants are usually younger and have lower incidents of chronic conditions such as hypertension, diabetes and obesity.
Saposnik said he and his team of five other scientists were surprised by the study’s result. “We expected that because of the stress associated with immigrating to a new country, new environment, new house, new shops that it might increase risk of stroke, especially hemorrhagic stroke, which is more directly associated with hypertension.
“We were expecting immigrants might have a higher risk (for stroke) associated with stress and stress would pump blood pressure up especially in the first period when they immigrate. But that wasn’t the case.”
Saposnik and his team aren’t sure why new immigrants have fewer strokes. Although there is speculation that dietary habits and genetic factors might be at the root of it. Another potential explanation for the study’s results may be that as a new immigrant one has to pass several physical exams and barriers before acceptance to Canada, he said. And so recent immigrants may just be healthier.
Saposnik believes the study could translate into a plan for long-term health benefits for the whole population. “We need to do further research but the study points to the need for policies that aim to preserve the healthier state of new immigrants while continuing to focus on lowering stroke risk among all adults,” Saposnik said.
He also added that the study shows that, at least initially, members of the immigrant population “don’t appear to be a big burden for the health care system.”
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