Foundation researcher examines stroke risk in new immigrants
Recent immigrants, most of whom are under 50 years of age, may be healthier than long-time residents of a country. This is called the "healthy immigrant effect.” At the same time, these immigrants face changes in employment, housing, relationships and diet that can cause stress that could potentially raise blood pressure or have other negative health effects.
Foundation researcher and director of the stroke research unit at St. Michael’s Hospital in Toronto, Dr. Gustavo Saposnik, is studying how these factors contribute to the stroke risk of new immigrants compared to other Canadians. “Immigrants are usually younger and have less risk factors than the Canadian born,” Dr. Saposnik says. “On the other hand, they are exposed to resettlement stress. They have to adjust to new cultural values and find their place in this new society. That can be stressful.”
Dr. Saposnik and his research team are looking at 965,000 new immigrants (about 65% from Asia and South Asia and the remaining participants from Europe, Africa, Central and South America and other regions) who have been in Canada for less than five years. They are comparing them with 3.27 million long-time residents of Canada who have been living here more than five years.
Participants were separated into three age groups: Younger than 30; 31 to 44; and 45 to 65 to help adjust for the risk of stroke associated with age. While his study is not yet complete, preliminary findings suggest that the new immigrants do have a lower risk of stroke. This is after adjusting for age, socioeconomic status, location, history of blood pressure, diabetes smoking and other risk factors. “We were expecting a new immigrant might have a higher risk of stroke, especially hemorrhagic strokes. But, it appears that the healthy immigrant effect is playing more of a role here than the potential stress, at least in this study completed in Ontario.”
He says that although it appears this group is at a lower risk, that it’s important to keep studying the differences between immigrants and long-time residents. “We should keep an eye on these stroke rates because these people may lose the advantage of the healthy immigrant effect over time.”
The research team (including Dr. Donald Redelmeier, Dr. Hong Lu, Dr. Esme Fuller Thomson, Dr. Eva Lonn and Dr. Joel Ray) is also looking at the rates of heart attack in the new immigrants versus the long-time residents.
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Posted: August 04, 2009
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