TORONTO - Rates of diabetes among aboriginals have risen at an alarming rate over the last several decades, especially for women of child-bearing age, a long-term study has found.
The study, led by researchers at the University of Saskatchewan, found the incidence of diabetes is more than four times higher in First Nations women than among non-First Nations women. For men, the rate of new diabetes cases in aboriginals is 2.5 times that of non-aboriginals.
"Most new cases of diabetes in First Nations adults are occurring between the ages of 20 and 50, whereas in non-First Nations people, most cases are occurring much older than that, 60-plus," said lead author Dr. Roland Dyck. "So it's almost like two different diseases."
Of critical concern, said Dyck, is the high prevalence of the disease among aboriginal women, particularly those in their reproductive years.
For one thing, native women have much higher rates of gestational diabetes, he said. While three to four per cent of non-aboriginal women develop pregnancy-related diabetes, "in First Nations women, we're seeing rates of 12, 15, 20 per cent. So it's quite a lot higher."
No matter one's ethnicity, gestational diabetes dramatically increases a woman's risk of developing Type 2 diabetes later on in life -- and also makes her offspring more likely to get the disease.
"This is the intergenerational impact of diabetic pregnancies that we're also very interested in," said Dyck.
The study, published Monday in the Canadian Medical Association Journal, used Saskatchewan's health database to identify 8,275 First Nations and 82,306 non-First Nations diabetes cases from 1980 to 2005.
The surge in diabetes has gone hand-in-hand with an epidemic of obesity within native communities that may be linked to the loss of traditional lifestyles. A 1937 tuberculosis survey of 1,500 Saskatchewan aboriginals found no reported cases of diabetes.
But by 1990, almost 10 per cent of the overall native population had the disease, a rate that hit 20 per cent by 2006, and included a proportion of children, said Dyck.
"By the time First Nations people reach their 60s and older, over 50 per cent of women and over 40 per cent of men had diabetes."
The researchers say programs to prevent diabetes among Canada's aboriginals should target pregnant women, children and young adults, in particular, he said. "In Saskatchewan, and probably it's true in Canada generally, about half of the aboriginal population is under 20."
Dr. Robert Hegele, a diabetes specialist at the University of Western Ontario, welcomed the study's findings. "It's what we've always sort of suspected, but it's important to have the documentation."
Saying diabetes rates among aboriginals across Canada are likely similar to those in Saskatchewan, Hegele pointed out that the causes of Type 2 diabetes are complex -- and trying to reduce the burden of the disease will be equally complicated.
They include culturally appropriate programs to promote healthy eating, physical activity and other lifestyle changes aimed at both children and their families.
"There's not one thing that you could do or recommend that would turn the tide or reverse things," he said.
Anthony Hanley, an epidemiologist at the University of Toronto, said he's been involved with diabetes prevention research in conjunction with residents of the Sandy Lake First Nation, north of Sioux Lookout, Ont., for more than 15 years.
Approaches include studying interventions such as intense exercise and other lifestyle changes among Sandy Lake residents at high risk for developing the disease, as well as school- and community-based diabetes education programs.
"One of the most exciting things in my mind, which was entirely a community initiative, was the construction of a network of walking trails," said Hanley, explaining that dirt roads for vehicles are so dusty that they act as a disincentive to exercise.
"They rehabilitated trails away from the roads. It's safer frankly for the kids to walk and ride bikes" because there aren't the thick clouds of dust thrown up by vehicles.
Hanley said aboriginal communities across Canada are working to develop similar health-promotion programs, often in collaboration with outside experts and researchers but based on cultural needs and traditions.
"The encouraging news is some of these things seem to be working on the level of risk factors that we know are related to diabetes," he said.
Dyck said primary prevention of diabetes needs to be aimed at very young children before they develop risk factors such as obesity and a sedentary lifestyle -- a lesson that applies equally to non-aboriginals.
A Statistics Canada survey on the fitness of Canadians released last week showed nearly two-thirds of adults and a quarter of children are overweight or obese -- representing a three-fold increase in childhood obesity and a 70 per cent jump in adult obesity since 1981.
"First Nations communities are very aware of what's happening," Dyck said. "They're looking for answers just like everybody else is."
