Canadian living takes toll on immigrant hearts: Study

September 1, 2015

By Nicholas Keung, Toronto Star

Is living in Canada bad for your heart?

A groundbreaking new study has found that recent immigrants have a 30 per cent lower rate of major heart problems, such as heart attacks and strokes, than long-term residents, but that gap shrinks the longer they spend in Canada.

While newcomers are known to have better health than the general population because they must pass rigid health screening, Dr. Jack Tu, lead author of the study, says “part of it can be explained by most immigrant groups having lower rates of smoking and obesity than Canadian-born individuals.”

But after 10 years in Canada, and some of the negative impacts of Western culture, like fast-food and cigarettes, that “healthy immigrant effect” diminishes, the study shows.

While recent East Asian immigrants, predominantly Chinese, had the lowest incidence of major heart problems overall (2.4 in men and 1.1 in women per 1,000 person-years), South Asian immigrants from India, Pakistan, Bangladesh, Sri Lanka and Guyana had the highest rates, at 8.9 in men and 3.6 in women.

However, after 10 years in Canada, the rates among East Asians increased by 40 per cent for men and 60 per cent for women, said the study released by the Institute for Clinical Evaluative Sciences in the American Heart Association journal Circulation on Monday.

“East Asians — Chinese from China, Hong Kong and Taiwan — are the most sensitive to the acculturation of Western culture. The overall incidence rate of the other (ethnic) groups is only up by 10 per cent after 10 years,” said Tu, a cardiologist at the Sunnybrook Schulich Heart Centre.

Tu said the study identified a “strong association” between the overall prevalence of traditional cardiac risk factors such as smoking, hypertension, diabetes and high cholesterol in the various ethnic groups and incidence of heart disease and other conditions.

“There’s a fair amount of differences in their individual risks but not all,” said Tu, who is also the Canada Research Chair in Health Services Research at the University of Toronto.

Using information from nine population-based health databases, researchers examined the 10-year incidence of major cardiovascular events, such as heart attack, stroke, angioplasty, bypass surgery and cardiovascular death, of more than 800,000 first-generation immigrant adults who settled in Ontario in 1985 or later.

The study is the biggest and most ethnically diverse look at heart disease in immigrants to Canada to date.

It examined the health trends and patterns across age groups, sex and major ethnic groups of people from more than 200 countries and compared the results to a group of more than 5 million long-term Ontario residents, who were predominantly white and born in Canada.

“This is the first time it has been possible for us to study the frequency of heart attacks and strokes with this level of detail in our immigrant population,” Tu said.

Other key findings of the study:

  • The rate of heart attacks and strokes varies drastically among the eight ethnic communities studied, but the differences diminish the more time they spend in Canada.
  • While 5.6 per 1,000 immigrant adult males and 2.4 of females had major heart problems, long-term Ontarians had a rate of 8.1 for men and 3.4 for women.
  • Among immigrant men, East Asians had the lowest rate of heart disease, followed by black, white-Western European, Southeast Asian, Latin American, West Asian/Arab, white-Eastern European and South Asian.
  • Among immigrant women, the order was somewhat different, though East Asian females still shared the best cardiovascular health. They were followed by white-Western European, Southeast Asian, white-Eastern European, black, Latin American, West Asian/Arab and South Asian.

The study’s findings speak to the need for health professionals to more accurately assess their patients’ risks of heart disease by taking ethnic backgrounds into consideration, Tu said.

“Our study provides new information that shows the importance of creating culturally tailored prevention strategies and early detection programs so that we can ensure we are providing the best care for all patients and the health advantages of this healthy immigrant effect do not diminish over time.”

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