Scientists find diabetes link in Oji-Cree

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Scientists at the John P. Robarts Research Institute and spokesmen for the Sandy Lake First Nation announced a genetic discovery last month that may lead to better prediction and control of diabetes in Aboriginal people.

The doctors have discovered a genetic mutation in the Oji-Cree of Sandy Lake, Man. that may hold the answer to that population's diabetes epidemic. The new gene has so far only been seen in Sandy Lake people, although other Native groups have been tested. The Cree in the Sandy Lake area do not seem to have the genetic abnormality.

Dr. Robert Hegele, director of the Blackburn Cardiovascular Genetics Laboratory at Robarts, discovered the mutation. Other principal researchers were Dr. Stewart Harris from the Centre for Studies in Family Medicine at the University of Western Ontario, and Dr. Bernard Zinman from the Samuel Lunenfield Research Institute, Mount Sinai Hospital and University of Toronto. Also delivering presentations were former chief of Sandy Lake, Jonas Fiddler, who holds the band's health portfolio; Deputy Chief Harry Meekis; Dr. Mark Pozansky, president and scientific director of Robarts; and Robarts scientist Dr. Tom McDonald, past chairman of the Canadian Diabetes Association National Research Council.

Dr. Hegele hailed the discovery as "the strongest genetic effect on diabetes that I have seen in 15 years of research. I am unaware of any other diabetic population in the world that is so strongly affected by a single gene variant," he said.

The Oji-Cree of Sandy Lake have the third highest rate of Type 2 diabetes in the world. A 1992 survey showed that 25 to 30 per cent of the population has diabetes; at least another 10 per cent have impaired glucose tolerance, which means they are at greater risk of developing the disease. Complications of diabetes include blindness, heart disease and stroke, kidney failure and gangrene, which results in amputations.

"Until 80 years ago," Dr. Hegele said, "few Aboriginal people in the Sioux Lookout zone had diabetes. In the last 10 to 20 years, diabetes started to be expressed at an epidemic rate. A gene or tendency was always thought to be there, but we think that the change in food and lowering of physical activity - plus the gene - results in diabetes."

In 1990, the people of Sandy Lake were so alarmed at the high incidence of the disease among their population that they asked their chief and council to approach Dr. Harris in Sioux Lookout to investigate the problem. Dr. Harris contacted Dr. Zinman and they undertook the survey, which confirmed the Sandy Lake people have five times more diabetes cases than the national average. Setting up protocols and methodology for their study took them three to four years.

At that point, they asked Dr. Hegele to get involved in testing for a genetic link. Dr. Hegele thought the problem was in the people's DNA, so he tested one blood sample from each of the 728 band members who agreed to participate in the study.

The results were startling. Dr. Hegele's group found that a person who inherited one copy of the mutated gene from their parents was more than twice as likely to have diabetes as a person who did not inherit the mutation. If a person inherited two copies of the mutation, however, he was up to 15 times more likely to have diabetes.

They also found that people with one copy of the mutated gene tended to develop diabetes in their thirties. On average, people with two copies of the mutation developed diabetes in their twenties. The findings were published in the March issue of the Journal of Clinical Endocrinology and Metabolism.

The researchers don't claim to have all the answers. They want to know why some people who do not have diabetes have the variant gene, which could indicate they are predisposed to developing diabetes, Dr. Hegele said.

They also found that 50 per cent of the people in Sandy Lake who have diabetes don't have the genetic mutation. Doctors suspect there could be yet another gene conected to the puzzle.

Finally, they say that two additional studies showed more than 100 people had a variant form of the gene, raising still more questions. And no one can say why eight Inuit communities or the Ojibway of Manitoulin Island they tested do not have the gene, although a high rate of diabetes exists in these places too.

"This discovery is a major contribution to further our ongoing research," Dr. Harris said. "Diabetes is emerging as a major epidemic among First Nations . . . and there is an urgent need to develop (prevention) strategies."

Drs. Harris and Zinman and the people of Sandy Lake decided they needed to do more than conduct laboratory research to get this urgent problem under control. They consulted with anthropologists and nutritionists and, starting in 1995, they set up a prevention program, which is ongoing.

One thing they did was to start diabetes education for Grades 3 through 5. They also aired a "Dr. Diabetes" show on the radio. Even the community's Northern Store assisted the project by agreeing to identify healthy food choices through the use of icons, colors and syllabics on their products. Health workers also undertook home visits to treat and educate those with diabetes.

Dr. Zinman said of the gene mutation discovery that it is important "but not earth-shattering." While he sees it as "an important advance" in doctors' understanding of diabetes, he believes the emphasis will have to remain on prevention through education for a considerable time yet.

All the doctors agree that it could be years before an effective new treatment for diabetes is found. Right now, even the test for the aberrant gene is not available outside the research lab and it is not covered by any health care plan.

"This announcement today confirms the importance of committing research dollars to finding new solutions," Harry Meekis said.