9 in 10 Indigenous Young Women in Canada Will Develop Diabetes

Troy Brown, RN

October 05, 2016

Approximately eight in 10 young First Nations people in Canada will eventually develop type 2 diabetes in their lifetime, as will five in 10 non–First Nations people, according to estimates of lifetime risk from a new population-based cohort study.

Tanvir Chowdhury Turin, MBBS, PhD, department of family medicine, department of community health sciences, and the Institute of Public Health, University of Calgary, Alberta, and colleagues reported their findings online September 19 in CMAJ.

"Diabetes is an emergency in Canada," Dr Turin told Medscape Medical News.

"Our results [are] certainly not the first wake-up call.…There have been works around diabetes prevention, but it looks like somehow the snooze button on this issue…has been pressed. Our estimates…definitely serve as a follow-up alarm," he added.

The findings among First Nations men and women in particular are "really dramatic," Jan Hux, MD, chief science officer, Canadian Diabetes Association, told Medscape Medical News.

The figures in the general population are "also strikingly bad. One in two young people in their 20s in Canada will develop diabetes at some point in their lifetimes if we don't do something to stem the tide of the epidemic."

Numbers Were Worse for 20-Year Olds

The researchers studied data on almost three million individuals without a history of diabetes. Of those, 70,631 (2.5%) had First Nations status. Participants were followed up for a mean of 8.7 years. Those with First Nations status were younger, had a higher prevalence of comorbid conditions in general, and almost half (42.5%) were in the lowest-income quintile.

The lifetime risk for diabetes after adjustment for competing risk of death was calculated in 5-year bands. The researchers did not differentiate between type 1, type 2, and gestational diabetes, but they note that type 2 diabetes accounts for 90% to 95% of all cases in Canada.

Among men aged 20 years, the lifetime risk was 75.6% in the First Nation group and 55.6% in the non–First Nations group. The risk rose steadily over longer time horizons for all index ages in both groups. For example, among First Nations men aged 20 years, the risk for diabetes was 1.4%, 6.0%, 15.4%, 31.5%, 51.7% and 68.6% over the 10-, 20-, 30-, 40-, 50-, and 60-year time horizons, respectively.

Among women aged 20 years, the adjusted lifetime risk was 87.3% in the First Nations and 46.5% in the non–First Nations groups, respectively. Risk for diabetes also rose steadily in both groups of women over longer time horizons.

In First Nations women aged 20 years, the diabetes risk was 2.8%, 9.2%, 19.4%, 38.6%, 60.8%, and 79.2% over the 10-, 20-, 30-, 40-, 50-, and 60-year time horizons, respectively.

"Although in cumulative risk analysis the numbers were the worst for 20-year-olds, it's still the case that the majority of diabetes will occur in older people, and it doesn't mean that we should change our screening criteria and start screening all 20-year-olds — it's still a risk-based screening — but it's a reminder [of] just how severe the diabetes epidemic is," Dr Hux told Medscape Medical News.

In the non–First Nations group, the lifetime risk for diabetes was lower among women compared with men in all index age categories. In the First Nations group, however, the lifetime risk was higher among women compared with men in all index age categories.

Rural vs Urban Residence

In First Nations men and women, the lifetime diabetes risk was markedly higher among those residing in rural areas compared with those living in towns and cities, and this difference was particularly noticeable among women.

First Nations women aged 20 years had a lifetime risk of developing diabetes of 94.2% if they lived in a rural area compared with 80.4% among those in urban areas.

"This difference was striking among First Nations women. Access to care and geographic factors, which have been identified as important determinants of health for indigenous people, may be contributing to the higher observed risk," the authors write.

In contrast, among non–First Nations men and women, the lifetime diabetes risk was "slightly higher" among those residing in urban areas compared with those residing in rural areas, the researchers report.

Risk-Factor Reduction Critical

The higher incidence of diabetes forecast to occur among First Nations women compared with First Nations men can be partly explained by the fact that women in this group are more likely to be overweight or obese compared with men and at a younger age.

In addition, rates of gestational diabetes are high among pregnant aboriginal women, who are then at extremely high risk of developing type 2 diabetes.

The First Nations group overall reached a higher risk of diabetes at a much younger age than the non–First Nations group.

"These findings, coupled with the observations that younger people had a higher lifetime risk of diabetes than their older counterparts, indicate the importance of early mobilization of preventive measures against the development of diabetes among First Nations people," the researchers write.

Possible reasons for these differences include genetic susceptibility, dietary acculturation, adoption of sedentary lifestyle, and increasing prevalence of obesity and metabolic syndrome.

"Healthcare providers and workers, including clinicians, need to emphasize…the preventive activities at the population level that will lower the risk of diabetes. This is important especially because even relatively modest lifestyle changes can reduce diabetes risk significantly," Dr Turin stressed.

Diabetes Among Aboriginals a Worldwide Public-Health Issue

First Nations populations in Canada are not alone among indigenous populations worldwide in being vulnerable to developing diabetes, the researchers write.

It is likely that a number of factors "play major roles in the diabetes epidemic in indigenous populations," including inequities in the social, cultural, historical, economic, and political determinants of health, inadequate access to nutritionally adequate food, and barriers to proper healthcare, they note.

The aboriginal communities in the United States "are similarly affected," Dr Hux said. "Pima Indians in the Southwest US have higher rates [of diabetes] than we have in our First Nations communities in Canada, and certainly I can't imagine that the general population situation is any better in America than it is in Canada."

The findings are also a reminder of the global problem of diabetes among all people, the researchers note.

"Diabetes is a major public-health problem in the developed world as well as developing countries, where the Westernization of the lifestyle is occurring at a much faster pace. Our estimates, although not directly applicable to the other countries, should bring attention to the diabetes problem worldwide," Dr Turin emphasized.

And he continued: "It's important to understand and disseminate disease burdens in a comprehensible way to the general public and to the policy makers as a part of knowledge translation to have their buy-in in the fight against diabetes."

The severity of the problem makes it an urgent public-health issue and is a reminder of the importance of appropriately screening for type 2 diabetes and helping patients make good lifestyle choices, Dr Hux concluded.

The authors and Dr Hux have disclosed no relevant financial relationships.

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CMAJ. Published online September 19, 2016. Article


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