Stroke risk reduced among recent immigrants
MedWire News: Recent immigrants to Canada have a lower risk for stroke than do long-term residents, report researchers.
Health screens on country entry and the need for people to be in good health to cope with the stresses of immigrating create what is known as the “healthy immigrant effect.” Thus, immigrants are known to have reduced rates of conditions such as hypertension.
Against this, however, “new immigrants are exposed to persistent stressors as they adapt to changes in diet, employment, housing, and social relationships,” say Gustavo Saposnik (University of Toronto, Ontario) and colleagues. This could potentially raise their risk for cardiovascular diseases.
But in the current study, which appears in the journal Neurology, stroke risk was almost a third lower among people who arrived in the country between 1995 and 2006 than among long-term residents.
The team identified 965,829 recent immigrants and matched them by year of birth, gender, and location to 3,272,393 people who had lived there for at least 5 years. In this cohort, there were 6216 strokes during 6 years of follow-up. The incidence rates were 1.69 versus 2.56 per 10,000 person-years among recent immigrants compared with long-term residents, respectively.
This equated to a 31% reduction in stroke risk among the immigrants, after accounting for age, demographic factors, hypertension, diabetes, smoking status, and number of health insurance claims. The risk reductions were similar for ischemic, hemorrhagic, and undetermined stroke, at 29%, 31%, and 35%, respectively.
In a related editorial, Bradley Jacobs (Wright Sates University, Dayton, Ohio, USA) said that the presence or absence of certain vascular risk factors in a person’s country of origin may influence their stroke risk after immigrating.
“Perhaps environmental triggers at a certain age may predispose to the development of stroke at a later age,” he suggested.
“Further investigation to determine whether the risk for stroke in immigrants ‘normalizes’ to the levels seem in longer-term residents may help to shed light on perhaps yet undiscovered risk factors for stroke.”
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By Eleanor McDermid