Obesity and type 2 diabetes prevalence in adults from two remote first nations communities in northwestern ontario, Canada

Assessing the Contribution of Traditional Foods to Food Security for the Wapekeka First Nation of Canada

The food security crisis and disproportionately high burden of dietary related disease amongst northern Indigenous populations in Canada continues to be a troubling reality with little sign of improvement. The Government of Canada is responding by developing programs to support local food initiatives for northern isolated communities. While such investments appear commendable, the impact of local food harvesting to improve food security has yet to be determined. While there are clear nutritional and cultural benefits to traditional food sources, communities face considerable barriers acquiring it in sufficient amounts because of historically imposed lifestyle changes that have increased food insecurity rates. This study responds by providing a novel multidisciplinary approach that draws from firsthand experiences working with First Nations community members in a remote subarctic region in northwestern, Ontario to estimate their community's total food requirement and the amount of wild animal food sources needed to sustain yearly food intake. This transferrable energy demand approach will be critical for policy makers to put into perspective the amount of wild food needed to have an impact on food security rates and ultimately improve dietary related diseases. Novelty: • It will provide government policy makers information about current harvest yields in a remote northern First Nation to understand the potential contribution of traditional food to improve local food security • Provides Indigenous communities a means to assess local food resources to measure the caloric contributions of traditional foods toward household food security.

Metabolic outcomes after bariatric surgery for Indigenous patients in Ontario

BACKGROUND

In 2013, 18% of Canadian adults had obesity (body mass index [BMI] >30 kg/m²), compared with 25.7% of Canada's Indigenous population. Bariatric surgery is an effective treatment for obesity, but has not been studied in Canadian Indigenous populations.

OBJECTIVES

To determine the effects of bariatric surgery in the Indigenous Ontario population.

SETTING

Multicenter data from the publicly funded Ontario bariatric program and registry.

METHODS

Prospectively collected data using all surgical patients between March 2010 and 2018 was included in initial analysis and included the following postoperative outcomes: diabetes, hypertension, and gastroesophageal reflux disease. Demographic characteristics, baseline characteristics, and univariate outcomes were assessed using Pearson Χ² or t tests. Multivariable regression for BMI change was used with complete case analysis and multiple imputation.

RESULTS

Of 16,629 individuals initially identified, 338 self-identified as Indigenous, 13,502 as Non-Indigenous, and 2789 omitted ethnicity and were excluded. Baseline demographic characteristics were not statistically different; rates of hypertension (P = .03) and diabetes (P < .001) were higher in the Indigenous population. Univariable analysis showed similar 1-year BMI change (Indigenous: 15.8 ± 6.0 kg/m²; Non-Indigenous: 16.1 ± 5.6 kg/m², P = .362). After adjustment, BMI change was not different between groups at 6 months (effect size = .07, 95% confidence interval -.45 to .58, P = .803) and 1 year (effect size = -.24, 95% confidence interval -.93 to .45, P = .489). Rates of co-morbidities were similar at 1 year between the 2 populations, despite differences at baseline. Six-month and 1-year follow-up rates were higher in the Non-Indigenous population (P < .001, P = .005, respectively).

CONCLUSIONS

Weight loss and resolution of obesity-related co-morbidities are similar in Indigenous and Non-Indigenous patients. Access to surgery, patient selection, and long-term results merit further investigation.

A Scoping Review of Obesity among Indigenous Peoples in Canada

Indigenous populations in Canada are heavily affected by the burden of obesity, and certain communities, such as First Nations on reserve, are not included in the sampling framework of large national health surveys. A scoping review of ever published original research reporting obesity rates (body mass index ≥ 30), among adult Indigenous peoples in Canada, was conducted to identify studies that help close the Canadian Community Health Survey (CCHS) data gap for obesity prevalence in Indigenous populations in Canada and to make comparisons based on ethnicity, sex, time, and geography. First Nations on reserve with self-reported height and weight had higher rates of obesity (30%-51%) than First Nations off reserve (21%-42%) and non-Indigenous populations (12%-31%) in their respective province or territory, with the exception of Alberta, where rates in First Nations on reserve (30% and 36%) were lower or similar to those reported in First Nations off reserve (38%). First Nations on reserve with predominantly measured height and weight (42%-66%) had higher rates of obesity compared to Inuit in Quebec (28%), Nunavut (33%), and Newfoundland and Labrador (41%), while the rates were similar to those in Inuit in Northwest Territories (49%). Obesity in these large studies conducted among Inuit was based solely on measured height and weight. Studies in First Nations and Inuit alike showed higher prevalence of obesity in women, as well as an increase with time. No recent studies measured the obesity rates for First Nations in Yukon and Northwest Territories and for Métis living in settlements of Northern Alberta. Researchers are encouraged to conduct total diet studies in these regions, and to use existing data to analyze the associations between obesity, road access, latitude, food environment, and traditional food intake, to further inform community planning and development.

National pattern of grain products consumption among Canadians in association with body weight status

Background

Obesity in Canadian adults is showing upward trends. Consumption of whole-grains is one recommendation for the prevention of obesity. Despite the apparent nutritional and energy content differences between whole and refined grains, knowledge relating refined grains to weight gain in Canadian adults is scarce. The aim of this study was to assess the consumption of specific grain-based foods at the regional and national levels, and to evaluate the association between grain consumption with overweight or obesity in Canadian adults.

Methods

We used the 2004 Canadian Community Health Survey data. The association between type of grain product consumed and Body Mass Index (BMI) in adults aged ≥19y was evaluated by logistic regression.

Results

The mean daily intake of whole grains (86 ± 1.9 g/day) was significantly less than refined grains (276.6 ± 3.8 g/day), which was different across provinces. After adjustment for caloric needs, male consumers showed significantly lower intake of whole grains than females. Accordingly, the incidence of overweight or obesity was higher in males than in females. Also, in comparison to whole grains, the consumption of refined grains was associated with a higher risk of overweight or obesity among adults.

Conclusion

Canadians’ preference was refined grain products consumption, based on 2004 Health Survey, which was significantly associated with overweight/obesity. Hence, consumption of whole grains should be more effectively promoted rather than refined grain products to prevent obesity and its complications such as cardiovascular diseases and type 2 diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s40795-017-0183-x) contains supplementary material, which is available to authorized users.

Nonalcoholic Fatty Liver Disease in Canadian First Nations and Non-First Nations Patients

Background. Features of nonalcoholic fatty liver disease (NAFLD) have yet to be described in the Canadian First Nations (FN) population. The aim of this study was to compare the prevalence, severity, and outcome of NAFLD in FN versus non-FN patients at an urban, tertiary care centre. Methods. Adults with NAFLD and no additional liver disease were identified in a prospectively derived database at the University of Manitoba. Demographic, clinical, laboratory, imaging, and histologic data were analyzed. Results. 482 subjects fulfilled diagnostic criteria for NAFLD, including 33 (7%) FN. Aside from rural residence, diabetes and cholestasis being more common in FN patients, the ages, gender distributions, clinical and radiologic features, and liver enzyme/function test results were similar in the two cohorts. Noninvasive tests of fibrosis (APRI and NAFLD fibrosis scores) were also similar in the two cohorts. There were no significant differences in liver enzyme or function tests in either cohort after approximately three years of follow-up. Conclusion. Compared to the prevalence of FN persons in the general population of this study site (10-15%), FN patients were underrepresented in this NAFLD population. The severity and progression of liver disease in FN patients appear to be similar to those in non-FN patients.

Molecular and cellular mechanisms linking inflammation to insulin resistance and β-cell dysfunction

Obesity is a major public health problem worldwide, and it is associated with an increased risk of developing type 2 diabetes. It is now commonly accepted that chronic inflammation associated with obesity induces insulin resistance and β-cell dysfunction in diabetic patients. Obesity-associated inflammation is characterized by increased abundance of macrophages and enhanced production of inflammatory cytokines in adipose tissue. Adipose tissue macrophages are suggested to be the major source of local and systemic inflammatory mediators such as tumor necrosis factor α, interleukin (IL)-1β, and IL-6. These cytokines induce insulin resistance in insulin target tissues by activating the suppressors of cytokine signaling proteins, several kinases such as c-Jun N-terminal kinase, IκB kinase β, and protein kinase C, inducible nitric oxide synthase, extracellular signal-regulated kinase, and protein tyrosine phosphatases such as protein tyrosine phosphatase 1B. These activated factors impair the insulin signaling at the insulin receptor and the insulin receptor substrates levels. The same process most likely occurs in the pancreas as it contains a pool of tissue-resident macrophages. High concentrations of glucose or palmitate via the chemokine production promote further immune cell migration and infiltration into the islets. These events ultimately induce inflammatory responses leading to the apoptosis of the pancreatic β cells. In this review, the cellular and molecular players that participate in the regulation of obesity-induced inflammation are discussed, with particular attention being placed on the roles of the molecular players linking inflammation to insulin resistance and β-cell dysfunction.

Elevated contaminants contrasted with potential benefits of ω-3 fatty acids in wild food consumers of two remote first nations communities in northern Ontario, Canada

Indigenous communities in Boreal environments rely on locally-harvested wild foods for sustenance. These foods provide many nutritional benefits including higher levels of polyunsaturated fatty acids (PUFAs; such as ω-3) than what is commonly found in store-bought foods. However, wild foods can be a route of exposure to dietary mercury and persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs). Here, we show a strong association between the frequency of wild food consumption in adults (N = 72) from two remote First Nations communities of Northern Ontario and environmental contaminants in blood (POPs) and hair (mercury). We observed that POPs and mercury were on average 3.5 times higher among those consuming wild foods more often, with many frequent wild food consumers exceeding Canadian and international health guidelines for PCB and mercury exposures. Contaminants in locally-harvested fish and game from these communities were sufficiently high that many participants exceeded the monthly consumption limits for methylmercury and PCBs. Those consuming more wild foods also had higher proportions of potentially beneficial ω-3 fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These results show that the benefits of traditional dietary choices in Boreal regions of Canada must be weighed against the inherent risks of contaminant exposure from these foods.

Dietary practices in isolated First Nations communities of northern Canada: combined isotopic and lipid markers provide a good qualitative assessment of store-bought vs locally harvested foods consumption

OBJECTIVE:

In First Nations communities of northwestern Ontario, where rates of type 2 diabetes mellitus are some of the highest in the world, ascertaining wild food dietary practices is extremely challenging owing to seasonal availability, environmental factors, life circumstances and language/cultural barriers. The purpose of this study was to determine whether analysis of isotopic and fatty acid (FA) profiles could provide more comprehensive information to discriminate between three categories of wild food consumption (that is, plants and animals) in two isolated First Nations communities of northwestern Ontario. In addition, this analysis also highlights whether wild food consumption as practiced in these two communities can increase circulating levels of polyunsaturated FAs (PUFAs), which provide a number of important metabolic benefits that could impact the prevention/treatment of T2DM.

RESULTS:

¹³C enrichment (in expired CO₂, plasma and hair), ¹⁵N enrichment (in hair) and FA profiles in plasma phospholipids (phospholipid fatty acid (PL-FA)) were quantified in men and in women consuming various amounts of wild food. ¹³C/¹²C ratios were lower and ¹⁵N/¹⁴N ratios were higher in participants consuming wild food at least once a week. In addition, FA results indicated that the relative contributions of 20:4 Ω-6 and 22:6 Ω-3 to total PL-FAs were higher and 18:2 Ω-6 lower in wild food consumers.

CONCLUSION:

Together, these findings confirm that isotopic and lipid markers discriminate between the different wild food categories in these two First Nations communities. Knowing the close relationship between dietary intake and the potential role of PUFA in the prevention/treatment of obesity and obesity-related diseases, it is critical to accurately measure the composition of diet for individuals in their specific environments.

Anthropometric measurements in Canadian children: a scoping review

OBJECTIVE

The objective of the current study was to identify what forms of anthropometric measurement are currently being utilized with Canadian children and youth and what are the gaps in the literature on this topic.

METHODS

The current study utilized a scoping review methodology in order to achieve the study objectives. Online databases Medline and PubMed and CINAHL were used to search articles from the last decade (2002-2012) that addressed Canadian children aged 2-18 years.

SYNTHESIS

50 studies were included in this review. A variety of anthropometric measurements were identified, including body mass index, waist circumference, hip-to-waist ratio, among others. Six of the included studies (12%) utilized nationally representative data from large-scale studies. BMI was the most reported form of measurement with 88% of studies collecting it. Waist circumference was a distant second with 20% of studies reporting it. Several gaps in the literature exist with regards to First Nations (FN) research; many of the measurement methods were not used. Additionally, FN accounted for only 2.5% of the study's sample. The majority of studies took place in Quebec (29%) and Ontario (27%).

CONCLUSION

Body mass index is the most reported method of anthropometric measurement used for children. Efforts should be taken by health care practitioners and researchers to collect other forms of measurement in order to assist in understanding the validity of other measures and their value when used with children. Furthermore, attention needs to be focused on utilizing and studying various forms of anthropometric measurement across all Canadian regions and populations.

The association of type 2 diabetes and insulin resistance/secretion with persistent organic pollutants in two First Nations communities in northern Ontario

AIMS

Recent evidence suggests an association between persistent organic pollutants (POPs) and type 2 diabetes. In two First Nations communities where wild food is consumed by a large portion of the population, we compared pollutants in plasma between diabetic and non-diabetic individuals, and investigated the strength of association between pollutants and insulin resistance/secretion in non-diabetic individuals.

METHODS

The study population consisted of 72 participants. Oral Glucose Tolerance Tests were used to assess diabetes status. Plasma was used to determine POP concentrations and mercury concentrations were determined from hair samples.

RESULTS

Age-adjusted plasma concentrations of some pollutants were significantly higher in diabetic than in non-diabetic individuals. When taking into account age, adiposity levels, and smoking status, POP levels were not associated with insulin resistance nor with insulin secretion in non-diabetic individuals.

CONCLUSIONS

These findings confirm that POP concentrations in plasma may be higher in diabetic than in non-diabetic individuals. No association was however seen between POP concentrations and markers of insulin resistance/secretion in non-diabetic individuals.

Obesity and insulin resistance: an abridged molecular correlation

A relationship between obesity and type 2 diabetes is now generally well accepted. This relationship represents several major health hazards including morbid obesity and cardiovascular complications worldwide. Diabetes mellitus is a complex metabolic disorder characterized by impaired insulin release and insulin resistance. Lipids play an important physiological role in skeletal muscle, heart, liver and pancreas. Deregulation of fatty acid metabolism is the main culprit for developing insulin resistance and type 2 diabetes. A predominant predisposing factor to developing obesity, insulin resistance and type 2 diabetes is the permanent elevation of free fatty acids in plasma followed by impaired utilization of lipids by muscle. Diabetes-induced inflammation and oxidative stress have also vital role for development of insulin resistance in diabetic patients. The present review is intended to describe the correlation between lipids, obesity and insulin resistance based on current literature, in order to elucidate involved molecular mechanisms in depth.

Dysregulation of cytokine response in Canadian First Nations communities: is there an association with persistent organic pollutant levels?

In vitro and animal studies report that some persistent organic pollutants (POPs) trigger the secretion of proinflammatory cytokines. Whether POP exposure is associated with a dysregulation of cytokine response remains to be investigated in humans. We studied the strength of association between plasma POP levels and circulating cytokines as immune activation markers. Plasma levels of fourteen POPs and thirteen cytokines were measured in 39 Caucasians from a comparator sample in Québec City (Canada) and 72 First Nations individuals from two northern communities of Ontario (Canada). Caucasians showed significantly higher levels of organochlorine insecticides (β-HCH, p,p'-DDE and HCB) compared to First Nations. Conversely, First Nations showed higher levels of Mirex, Aroclor 1260, PCB 153, PCB 170, PCB 180 and PCB 187 compared to Caucasians. While there was no difference in cytokine levels of IL-4, IL-6, IL-10 and IL-22 between groups, First Nations had significantly greater average levels of IFNγ, IL-1β, IL-2, IL-5, IL-8, IL-12p70, IL-17A, TNFα and TNFβ levels compared to Caucasians. Among candidate predictor variables (age, body mass index, insulin resistance and POP levels), high levels of PCBs were the only predictor accounting for a small but significant effect of observed variance (∼7%) in cytokine levels. Overall, a weak but significant association is detected between persistent organochlorine pollutant exposure and elevated cytokine levels. This finding augments the already existing information that environmental pollution is related to inflammation, a common feature of several metabolic disorders that are known to be especially prevalent in Canada's remote First Nations communities.

Association of adiposity trajectories with insulin sensitivity and glycemic deterioration: a longitudinal study of rural Chinese twin adults

OBJECTIVE

To evaluate associations between adiposity trajectories over time and insulin sensitivity and glucose deterioration in a Chinese twin cohort.

RESEARCH DESIGN AND METHODS

This study focused on 341 males and 292 females aged 20-50 years at baseline who had physical clinical examinations and oral glucose tolerance test at two time points with an average of 6 years apart. BMI, waist circumference, percent body fat (PBF), and percent trunk fat (PTF) trajectories were classified into five track groups based on age- and sex-specific tertiles at each visit. We calculated the odds of the insulin sensitivity index((0,120)) [ISI((0,120))] or glycemic deterioration at follow-up among five defined trajectories (tertile(baseline) → tertile(follow-up)) using generalized estimate equation models. Additionally, we applied structural equation models to examine genetic and environmental influences on adiposity, adiposity change over time (ACO), ISI((0,120)), and the interrelationships among them.

RESULTS

Participants with stable adiposity (BMI, waist circumference, PBF, and PTF) in the highest tertile or shifting to the highest tertile tended to have the lowest ISI((0,120)) at follow-up or experience glycemic deterioration. Genetic factors exerted the major influence on adiposity, but environmental factors unique to each twin contributed more strongly to ISI and ACO. Correlations between adiposity/ACO and insulin sensitivity were mainly due to environmental influences.

CONCLUSIONS

When adiposity stays or becomes high, insulin sensitivity falls and risk of glycemic deterioration rises. Additionally, we found that genetic factors exerted the major influence on adiposity, while environmental factors played the principal role for ACO and insulin sensitivity.