Chapter 38: Diabetes in Aboriginal Peoples
Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada
- In Canada, Aboriginal peoples are a heterogeneous population comprised of individuals of First Nations, Inuit, and Métis heritage living in a range of environments from large cities to small, isolated communities.
- National survey data have consistently shown that the national age-adjusted prevalence of diabetes is 3 to 5 times higher in First Nations than in the general population, with rates as high as 26% in some communities.
- The higher rate of adverse health outcomes in Aboriginal peoples is associated with a number of factors, including lifestyle (diet and physical activity), genetic susceptibility, and historic-political and psychosocial factors.
- Barriers to care that are unique to Aboriginal settings also exacerbate the problem with fragmented healthcare, poor chronic disease management, high healthcare staff turnover, and limited or non-existent surveillance.
- Social determinants of health, including low income, lack of education, high unemployment, poor living conditions, lack of social support, negative stereotyping and stigmatization, and poor access to health services compound the problem.
- Among First Nations peoples, over 20% of females are impacted by type 2 diabetes, especially during reproductive years, compared to 16% in males. Prevalence of diabetes has also increased threefold from 1980 to 2005 among children.
- Aboriginal women in Canada also experience gestational diabetes mellitus (GDM) rates 2 to 3 times higher than others, in part related to an interaction of Aboriginal ethnicity with pregravid adiposity.
- Recent research suggests that epigenetic factors play a key role in the interaction between genes and the environment, influencing the development of diabetes complications.
Complications and Mortality Due to Diabetes
- Higher prevalence rates of microvascular disease, including chronic kidney disease (CKD), lower limb amputation, foot abnormalities, and more severe retinopathy, are found in Aboriginal peoples with diabetes than in the general population with diabetes.
- Aboriginal peoples also are burdened by higher rates of macrovascular disease, cardiometabolic risk factors (e.g. smoking, obesity, and hypertension), albuminuria and are more likely than others to progress to end-stage renal disease (ESRD).
- Potentially modifiable risk factors for kidney disease progression include poor glycemic control, systolic hypertension, smoking, and insufficient use of angiotensin-converting-enzyme (ACE) inhibitors as well as periodontal disease.
- The prevalence of metabolic syndrome is elevated among both First Nations adults (especially women) and children. Increased adiposity and dysglycemia are more common components than hypertension, and non-traditional risk factors, such as elevated C-reactive protein are also elevated.
- Aboriginal peoples with metabolic syndrome should be targeted by programs designed to prevent type 2 diabetes since interventions, such as increased physical activity and consumption of long chain omega 3 fatty acids, have been shown to improve glucose tolerance in Aboriginal peoples.
- Healthcare costs for Aboriginal peoples with diabetes have been shown to be considerably higher than costs in the general population with diabetes due to higher use of physician and hospital services. Increased morbidity and mortality among First Nations people are at least partly due to poorer quality of diabetes care.
- Starting in early childhood, Aboriginal people should be evaluated for modifiable risk factors of diabetes (e.g. obesity, lack of physical activity, unhealthy eating habits), prediabetes, or metabolic syndrome [G rade D, Consensus].
- Screening for diabetes in Aboriginal children and adults should follow guidelines for high risk populations (i.e. earlier and at more frequent intervals depending on presence of additional risk factors) [Grade D, Consensus].
- Screening for diabetes with a fasting plasma glucose (FPG) test, an A1C, or an oral glucose tolerance test (OGTT) should be considered every 1 to 2 years in individuals with ≥1 additional risk factor(s).
- Screening every 2 years also should be considered from age 10 or established puberty in Aboriginal children with ≥1 additional risk factor(s), including exposure to diabetes in utero
- Regular screening and follow-up should be done in children who are very obese (BMI ≥99.5 percentile)
- While an OGTT remains the standard for the diagnosis of diabetes, the A1C has a distinct appeal for testing in this population as it is relatively inexpensive and does not require fasting.
- Regular screening, follow-up, and surveillance in individuals with prediabetes (IFG and/or IGT), history of GDM, or polycystic ovary syndrome (PCOS) should be encouraged, as 20 to 50% of high risk individuals with IFG may have a 2-hour plasma glucose ≥11.1 mmol/L. Lifestyle or metformin should be initiated as treatment of prediabetes and ongoing monitoring should be instituted.
- Efforts to prevent diabetes should focus on all diabetes risk factors, including prevention of childhood, adolescent, adult, and pregravid obesity; and prevention and optimal management of diabetes in pregnancies to reduce macrosomia and diabetes risk in offspring.
- Culturally appropriate primary prevention programs for children and adults should be initiated in and by Aboriginal communities with support from the relevant health system(s) and agencies to assess and mitigate the environmental risk factors, such as: geographic and cultural barriers, food insecurity, psychological stress, insufficient infrastructure, or settings that are not conducive to physical activity [Grade D, Consensus].
- Programs to detect pre-gestational and gestational diabetes provide optimal management of diabetes in pregnancy, and timely post-partum follow-up should be instituted for all Aboriginal women to improve perinatal outcomes, manage persistent maternal dysglycemia, and reduce type 2 diabetes rates in their children [Grade D, Level 4].
- Aboriginal women should attempt to reach a healthy body weight prior to conception to reduce their risk for gestational diabetes [Grade D, Level 4].
- Management of prediabetes and diabetes in Aboriginal peoples should follow the same clinical practice guidelines as those for the general population with respect for, and sensitivity to, particular language, cultural history, traditional beliefs and medicines, and geographic issues as they relate to diabetes care and education in Aboriginal communities across Canada. Programs should adopt a holistic approach to health that addresses a broad range of stressors shared by Aboriginal peoples [Grade D, Consensus].
- Lifestyle intervention programs targeted towards Aboriginal people with diabetes show modest results. Targeted programs to improve diet and increase exercise have been effective in improving glycemic control, reducing caloric intake, reducing weight, reducing WC and diastolic blood pressure, and increasing folate intake.
- In Aboriginal communities, where access to physicians is often limited, strategies to improve care should focus on building capacity of existing front-line staff. Working with community healthcare providers and community leaders assures that local resources and challenges, such as access to healthy foods, geographic location, and isolation level, are acknowledged and considered and that programs developed are community-directed.
- Aboriginal peoples in Canada should have access in their communities to a diabetes management program that would include an interprofessional nurse-led team, diabetes registries, and ongoing quality assurance and surveillance programs [Grade D, Level 4].
- Comprehensive management of diabetes in small remote communities remains difficult due to discontinuities in staffing, lack of work-practice support, and services not adapted to individual's needs. Expanding the scope of practice for nurses and allied health professionals in diabetes care is an effective strategy, and particularly important where doctors are scarce.
- The DREAM 3 study used home and community care workers to implement a nurse-led algorithm-driven hypertension management program which produced sustained reductions in blood pressure in a Saskatchewan First Nations community through a randomized controlled trial.
- Algorithm-based screening and management of renal and cardiovascular abnormalities by local health workers supported by nurses and physicians reduced renal failure.
- Algorithm-based, nurse-led management showed improvement in hypertension and cholesterol.
- Nurse case management has shown benefit in urban and rural settings, increasing screening rates and compliance.
- Multidisciplinary teams, occasionally including Aboriginal health workers, also have shown benefit.
- The SANDS study demonstrated that aggressive lipid targets could be safely maintained in Indigenous peoples with diabetes with the help of standardized algorithms, point-of-care lipid testing, and non-physician providers.
- For mitigation of geographic access to diabetes care, mobile screening and treatment units equipped with staff, lab, and diagnostic equipment showed significant improvements in BMI, blood pressure, A1C, and lipid levels.
- Given the multiple barriers to high quality care, multifaceted interventions also have shown benefit. These include: diabetes registries, recall systems, care plans, training for community health workers, and an outreach service. These have been found to be effective in Australia, but it is not clear which elements are key.
- There is an urgent need for systematic and validated surveillance of prevalence, incidence, and morbidity and mortality rates due to type 2 diabetes in First Nations communities. Surveillance systems in other countries that monitor diabetes rates in Aboriginal groups have shown improvements in quality of care. A national surveillance program should be considered in Canada for on- and off-reserve Aboriginal communities.
For definitions of the levels of evidence cited in this chapter, please refer to the Guideline Recommendations: Levels of Evidence.
If you would like more details on this topic, please visit the Canadian Diabetes Association Clinical Practice Guidelines: Chapter 38.