Newcomers to Canada have a significantly higher risk than long-term residents of developing diabetes, new research shows.
This reflects the reality that in the developing world, where most immigrants and refugees to Canada originate, rates of Type 2 diabetes are soaring.
The data provide an opportunity to intervene early and prevent the devastating impact of the disease, said Marisa Creatore, an epidemiologist at the Centre for Research on Inner City Health of St. Michael's Hospital in Toronto.
"We know which groups of immigrants are at high risk, so we can use this data to target them and nip the problem in the bud," she said. "Ultimately, diabetes is preventable."
The research, published in the Canadian Medical Association Journal, examined diabetes rates among 1.1 million immigrants to Ontario.
Diabetes rates were highest among immigrants from South Asia - four times that of long-term residents for men and 3.2 times higher for women.
Immigrants from Latin America and the Caribbean, and those from Africa, also had rates of diabetes more than double those in the general population.
Immigrants from East Asia and Eastern Europe had about the same rates as long-term residents.
The study also shows that immigrants tend to develop diabetes - a chronic, degenerative disease if untreated - about a decade earlier than long-term residents, which suggests treatment costs are likely much higher.
About 250,000 immigrants and refugees settle in Canada each year, with the majority coming from Asia, Africa and the Middle East, regions where diabetes is rising rapidly.
There is a genetic component to diabetes (with risk lowest in those of European descent, who make up the majority of Canada's population), but lifestyle and socio-economic factors also play a large part in developing the disease.
Ms. Creatore, who is also a PhD candidate at the Institute for Clinical Evaluative Sciences, noted that the longer immigrants live in Canada, the higher their rates of diabetes.
"The risk increases over time, which points to acculturation, to lifestyle changes that contribute to risk," she said.
While overall diabetes rates tend to be higher in men than women, the new research shows this is not true among immigrants. In fact, their pattern of disease is similar to that of aboriginals, with women at higher risk.
About 2.5 million Canadians have diabetes, a disease characterized by high levels of blood glucose that can cause circulatory, heart and kidney problems and is the leading cause of amputations and blindness.
There are three distinct forms: Gestational diabetes is a temporary condition that occurs during pregnancy; Type 1 diabetes, usually diagnosed in children, occurs when the pancreas is unable to produce insulin; Type 2 diabetes occurs when the pancreas doesn't produce enough insulin or the body doesn't effectively use the insulin it produces.
About 90 per cent of diabetics have Type 2, which is usually a consequence of obesity, inactivity, poor diet and aging.