Preventing Cardiovascular and Renal Disease in Canada's Aboriginal Populations

The Impact of Chronic Disease on the Corrected QT (QTc) Value in Women in a British Columbia First Nations Population

BACKGROUND

Indigenous women have higher rates of chronic disease than Indigenous men and non-Indigenous women. Long QT syndrome (LQTS) can be inherited or acquired; the latter may occur with chronic disease. A prolonged corrected QT value (QTc) is an independent risk factor for ventricular arrhythmias and sudden death, but few studies have quantified the impact of chronic disease on the QTc. We assessed the association between chronic disease and QTc prolongation in a population of First Nations women previously ascertained to study a high rate of inherited LQTS due to a unique genetic (founder) variant in their community.

METHODS

This substudy focusing on women expands on the original research where patients with clinical features of LQTS and their relatives were assessed for genetic variants discovered to affect the QTc. Medical records were retrospectively reviewed and chronic diseases documented. Using multivariate linear regression, adjusting for the effect of genetic variants, age, and QTc-prolonging medications, we evaluated the association between chronic disease and the QTc.

RESULTS

In total, 275 women were included. After adjustments, a prolonged QTc was associated with coronary artery disease (26.5 ms, 95% confidence interval [CI] 9.0-44.1 ms; P = 0.003), conduction system disease (26.8 ms, 95% CI 2.2-51.4 ms; P = 0.033), rheumatoid arthritis (28.9 ms, 95% CI 12.7-45.1 ms; P = 0.001), and type 2 diabetes mellitus (17.9 ms, 95% CI 3.6-32.3 ms; P = 0.015).

CONCLUSIONS

This quantification of the association between chronic disease and QTc prolongation in an Indigenous cohort provides insight into the nongenetic determinants of QTc prolongation. Corroboration in other populations will provide evidence for generalisability of these results.

Industrialization and food safety for the Tsleil-Waututh Nation: An analysis of chemical levels in shellfish in Burrard Inlet

While Indigenous food systems remain critical for community well-being, traditionally harvested foods are a potential source of toxic exposures. The Tsleil-Waututh Nation (TWN) is seeking to restore shellfish harvesting in Burrard Inlet (British Columbia [BC], Canada), where the cumulative effects of industrial activity have nearly eliminated safe harvesting. The Trans Mountain Expansion project would triple the capacity to transport oil through the inlet, threatening TWN's progress to restore shellfish harvesting. To inform ongoing efforts we assessed contamination by heavy metals (arsenic, cadmium, lead, and mercury) and 48 polycyclic aromatic hydrocarbons (PAHs) congeners in different shellfish species (Softshell clams, Varnish clams, and Dungeness crab) in three areas. We compared our results against local screening values (SVs) established by the TWN and BC Ministry of Environment and Climate Change Strategy, as well as provincial and national benchmarks. In total, we analyzed 18 composite samples of Softshell clams and Varnish clams (5 individuals per sample), as well as 17 individual crabs. We found chemical contamination in all species at all sites. PAHs were most frequently detected in Softshell clams, highest in the site closest to the pipeline terminus. Clams presented higher levels of contamination than crabs for PAHs, but not for heavy metals. For Softshell and Varnish clams, all heavy metals across study sites exceeded at least one of the population-specific SVs. Of the 14 PAHs detected, benzo(a)pyrene presented a median concentration in Softshell clams of 3.25 μ/kg, exceeding local SV for subsistence fisher. Our results call for further assessment of human health impacts related to food harvesting within Burrard Inlet and establishing a long-term coordinated program co-led by the TWN to monitor contamination and inform future harvesting programs. The study draws attention to the need to consider locally-relevant toxicity benchmarks, and include potential health impacts of food contamination in appraising development project proposals.

Social determinants and spatio-temporal variation of Ischemic Heart Disease in Manitoba

Introduction

The aim was to study any spatial and/or temporal patterns of ischemic heart disease (IHD) prevalence and measure the effects of selected social determinants on these spatial and space-time patterns.

Methods

Data were obtained from the Population Research Data Repository housed at the Manitoba Centre for Health Policy to identify persons who were diagnosed with IHD between 1995 and 2018. These persons were geocoded to 96 geographic regions of Manitoba. An area-level socioeconomic factor index (SEFI-2) and the proportion of the population who was Indigenous were calculated for each geographic region using the 2016 Canadian Census data. Associations between these factors and IHD prevalence were measured using Bayesian spatial Poisson regression models. Temporal trends and spatio-temporal trends were measured using Bayesian spatio-temporal Poisson regression models.

Results

Univariable models showed a significant association with increased regional Indigenous population proportion associated with a higher prevalence of IHD (RR: 0.07, 95% CredInt: (0.05, 0.10)) and for SEFI-2 (RR: 0.17, 95% CredInt: (0.11, 0.23)). Using a multivariable model, after accounting for the proportion of the population that was Indigenous, there was no evidence of an association between IHD prevalence and area-level socioeconomic factor. Spatio-temporal models showed no significant overall temporal trend in IHD prevalence, but there were significant spatially varying temporal trends within the 96 regions.

Conclusions

Association between Indigenous population proportion and IHD is consistent with previous research. No significant overall temporal trend was measured. However, regions with significantly increasing trends and significantly decreasing trends in IHD prevalence were identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12369-1.

Reported sources of health inequities in Indigenous Peoples with chronic kidney disease: a systematic review of quantitative studies

BACKGROUND

To summarise the evidentiary basis related to causes of inequities in chronic kidney disease among Indigenous Peoples.

METHODS

We conducted a Kaupapa Māori meta-synthesis evaluating the epidemiology of chronic kidney diseases in Indigenous Peoples. Systematic searching of MEDLINE, Google Scholar, OVID Nursing, CENTRAL and Embase was conducted to 31 December 2019. Eligible studies were quantitative analyses (case series, case-control, cross-sectional or cohort study) including the following Indigenous Peoples: Māori, Aboriginal and Torres Strait Islander, Métis, First Nations Peoples of Canada, First Nations Peoples of the United States of America, Native Hawaiian and Indigenous Peoples of Taiwan. In the first cycle of coding, a descriptive synthesis of the study research aims, methods and outcomes was used to categorise findings inductively based on similarity in meaning using the David R Williams framework headings and subheadings. In the second cycle of analysis, the numbers of studies contributing to each category were summarised by frequency analysis. Completeness of reporting related to health research involving Indigenous Peoples was evaluated using the CONSIDER checklist.

RESULTS

Four thousand three hundred seventy-two unique study reports were screened and 180 studies proved eligible. The key finding was that epidemiological investigators most frequently reported biological processes of chronic kidney disease, particularly type 2 diabetes and cardiovascular disease as the principal causes of inequities in the burden of chronic kidney disease for colonised Indigenous Peoples. Social and basic causes of unequal health including the influences of economic, political and legal structures on chronic kidney disease burden were infrequently reported or absent in existing literature.

CONCLUSIONS

In this systematic review with meta-synthesis, a Kaupapa Māori methodology and the David R Williams framework was used to evaluate reported causes of health differences in chronic kidney disease in Indigenous Peoples. Current epidemiological practice is focussed on biological processes and surface causes of inequity, with limited reporting of the basic and social causes of disparities such as racism, economic and political/legal structures and socioeconomic status as sources of inequities.

"That's What the Program Is All about… Building Relationships": Exploring Experiences in an Urban Offering of the Indigenous Youth Mentorship Program in Canada

Peer mentorship is an effective approach for delivering health promotion programs that may be particularly useful among underrepresented populations. Advancing the peer-led approach, the Indigenous Youth Mentorship Program (IYMP) is a communal-led program rooted in Indigenous values aimed at the promotion of healthy lifestyles in children and youth. The program includes layers of multi-age mentoring (i.e., elementary students, high school student mentors, and young adult health leaders [YAHLs]) and incorporates three core components: physical activity, healthy eating, and cultural teachings. The purpose of this study was to qualitatively explore elementary student, mentor, and YAHL experiences in an urban IYMP offering. Eleven sharing circles were conducted; six with elementary students (n = 23; grade 4 and 5 students), two with mentors (n = 3; students enrolled in a grade 10 wellness girls class), and three with YAHLs (n = 6; undergraduate university students). Focus groups were also held with respective school teachers and principals. An inductive content analysis generated three themes that represent the perceived impacts of this urban IYMP offering: (1) Fostering Wellness, (2) Strengthening Meaningful Connections, and (3) Exploring Leadership. Findings are positioned within a communal mentorship framework that is circular and multi-directional. By bringing together Indigenous and non-Indigenous peoples, this program offering supports Indigenous cultural relevance in an urban-based wellness program.

Primary and Secondary Cardiovascular Prevention Among First Nations Peoples With Type 2 Diabetes in Canada: Findings From the FORGE AHEAD Program

Background

First Nations (FN) peoples in Canada face spiraling rates of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Data on the extent of CVD risk-factor management in FN peoples with T2DM in Canada are scarce.

Methods

A T2DM registry with data from 7 FN communities in Canada was utilized to identify individuals eligible for primary and secondary CVD prevention. Proportions of individuals meeting clinical practice guideline-specified targets (hemoglobin A1c ≤7.0%; blood pressure ≤130/80 mm Hg; low-density lipoprotein ≤2 mmol/L) were calculated. Prescription of recommended cardioprotective medications (antithrombotic medication, lipid-lowering agents, renin-angiotensin-aldosterone system inhibitors, and beta-blockers) among those with CVD was assessed. χ² tests were employed to evaluate differences between CVD prevention groups and sexes.

Results

Of the 2098 individuals in the registry, 18% had documented CVD (female: male = 1.12). Overall, <10% met all 3 clinical practice guideline targets. Attainment of hemoglobin A1c and blood pressure targets was comparable between primary and secondary CVD prevention groups, with<50% achieving targets. A greater proportion of the secondary prevention group met low-density lipoprotein targets compared to those without CVD (61.6% vs 40.9%, P < 0.01). In the secondary prevention group, beta-blockers were prescribed to only 20%, and <60% were prescribed antithrombotics, lipid-lowering medications, or agents targeting the renin-angiotensin-aldosterone system; <2% were prescribed medications from all 4 classes of cardioprotective medications.

Conclusions

Primary and secondary CVD prevention recommendations for individuals with T2DM are not being met for an alarmingly high proportion of FN peoples. These findings serve as an urgent call for proactive measures to reduce CVD events and related mortality in this high-risk population.

Approaches to Studying Determinants of Racial-Ethnic Disparities in Stroke and Its Sequelae

Disparities are differences in health outcomes among groups that originate from sources including historically experienced social injustice and broadly defined environmental exposures. Large health disparities exist, defined by many factors including race/ethnicity, sex, age, geography, and socioeconomic status. Studying disparities relies on measures of disease burden. Traditional measures, such as mortality, may be less applicable to neurological disorders, which often lead to substantial morbidity and lower quality of life, without necessarily causing death. Measures such as disability-adjusted life-years or healthy life expectancy may be more appropriate for assessing neurological disease and permit comparisons across diseases and communities. There are many approaches that can be used to study disparities. Analyses of population-based observational studies, patient registries, and administrative data all contribute to the understanding of disparities in humans. Animal and other experimental designs, including clinical trials, may be used to identify mechanisms and strategies to reduce disparities. All of these approaches have strengths and weaknesses. Ultimately, understanding and mitigating disparities will require use of all of these methods. Crucially, a focus on not only improving outcomes among all individuals in society but minimizing or eliminating differences between those with better outcomes and those who have historically been disadvantaged should drive the ongoing investigations into disparities. This review is focused on epidemiological approaches to examining the depth and determinants of racial-ethnic disparities in the United States related to stroke, stroke care, and stroke outcomes.

Differences in coronary artery disease complexity and associations with mortality and hospital admissions among First Nations and non-First Nations patients undergoing angiography: a comparative retrospective matched cohort study

BACKGROUND

First Nations people are more likely than the general population to experience long-term adverse health outcomes after coronary angiography. Our aim was to quantify the extent of coronary artery disease among First Nations and non-First Nations patients undergoing angiography to investigate differences in coronary artery disease and related health disparities.

METHODS

We conducted a retrospective matched cohort study to compare health outcomes of First Nations and non-First Nations adult patients (> 18 yr) who underwent index angiography between Apr. 1, 2008, and Mar. 31, 2012, in Manitoba, Canada. The SYNTAX Score was used to measure and compare severity of coronary artery disease between groups. Primary outcomes of all-cause and cardiovascular mortality were compared between groups using Cox proportional hazard models adjusted by SYNTAX Score results and weighted by the inverse probability of being First Nations. Secondary outcomes included all-cause and cardiovascular-related hospital admissions.

RESULTS

The cohort consisted of 277 matched pairs of First Nations and non-First Nations patients undergoing angiography; the average age of patients was 56.0 (standard deviation 11.7) years. The median SYNTAX Score results and patient distributions across categories in the matched paired cohort groups were not significantly different. Although proportionally First Nations patients showed worse health outcomes, mortality risks were similar in the weighted sample, even after controlling for revascularization and SYNTAX Score results. Secondary outcomes showed that adjusted risks for hospital admission for acute myocardial infarction (adjusted hazard ratio [HR] 3.03, 95% confidence interval [CI] 1.40-6.55) and for congestive heart failure (adjusted HR 3.84, 95% CI 1.37-10.78) were significantly higher among First Nations patients in the weighted sample.

INTERPRETATION

The extent of coronary artery disease among matched cohort groups of First Nations and non-First Nations patients appears similar, and controlling for baseline sociodemographic characteristics, coronary artery disease risk factors and SYNTAX Score results explained higher mortality risk and most hospital admissions among First Nations patients. Although there is a need to decrease risk factors for coronary artery disease among First Nations populations, addressing individuals' behaviour without considering root causes underlying risk factors for coronary artery disease will fail to decrease health outcome disparities among First Nations patients undergoing angiography.

Geothermal Energy for Sustainable Food Production in Canada’s Remote Northern Communities

The cold, remote, northern regions of Canada constitute a challenging environment for the provision of reliable energy and food supply to communities. A transition from fossil fuels to renewables-based sources of energy is one positive step in reducing the greenhouse gases from the energy supply system, which currently requires long-distance transport of diesel for electricity and heating needs. Geothermal energy can not only displace diesel for part of this energy need, it can provide a base-load source of local energy to support food production and mitigate adverse impacts of food insecurity on communities. In this proof-of-concept study, we highlight some potential benefits of using geothermal energy to serve Canada’s northern communities. Specifically, we focus on food security and evaluate the technical and economic feasibility of producing vegetables in a “controlled environment”, using ground sources of heat for energy requirements at three remote locations—Resolute Bay, Nunavut, as well as Moosonee and Pagwa in Ontario. The system is designed for geothermal district heating combined with efficient use of nutrients, water, and heat to yield a diverse crop of vegetables at an average cost up to 50% lower than the current cost of these vegetables delivered to Resolute Bay. The estimates of thermal energy requirements vary by location (e.g., they are in the range of 41 to 44 kW of thermal energy for a single greenhouse in Resolute Bay). To attain adequate system size to support the operation of such greenhouses, it is expected that up to 15% of the annually recommended servings of vegetables can be provided. Our comparative analysis of geothermal system capital costs shows significantly lower capital costs in Southern Ontario compared to Northern Canada—lower by one-third. Notwithstanding high capital costs, our study demonstrates the technical and economic feasibility of producing vegetables cost-effectively in the cold northern climate. This suggests that geothermal energy systems can supply the heat needed for greenhouse applications in remote northern regions, supplying a reliable and robust source of cost-competitive sustainable energy over the long-term and providing a basis for improved food security and economic empowerment of communities.

Cardiovascular Medication Use and Long-Term Outcomes of First Nations and Non-First Nations Patients Following Diagnostic Angiography: A Retrospective Cohort Study

Background

In Canada, First Nations (FN) people are at greater risk of mortality than the general population following index angiography. This disparity has not been investigated while considering guideline‐recommended cardiovascular medication use.

Methods and Results

Retrospective analysis of administrative health data investigated patterns of medication dispensation during the first year after index angiography among patients in Manitoba, Canada. Medication possession ratios (MPRs) reflecting the percentage of days in which medications were supplied were calculated separately for β‐blockers, angiotensin‐converting enzyme inhibitors, statins, and antiplatelets (clopidogrel). Patients were assigned to 1 of 4 categories: (1) not dispensed (0% MPR), (2) low (1–39% MPR), (3) intermediate (40–79% MPR), (4) high (≥80% MPR). Cox regression models that adjusted for MPR categories were used to explore the association between FN patients and both 5‐year all‐cause mortality and cardiovascular mortality. FN patients were less likely to have an intermediate MPR (odds ratio: 0.75; 95% CI, 0.57–0.99) or a high MPR (odds ratio: 0.64; 95% CI, 0.50–0.81) for statin medications than non‐FN patients. FN patients also had higher adjusted risks of all‐cause and cardiovascular mortality than non‐FN patients (hazard ratio, all‐cause: 1.54 [95% CI, 1.25–1.89]; cardiovascular: 1.62 [95% CI, 1.16–2.25]).

Conclusions

FN status was independently associated with intermediate and high MPRs for statins during the first year following index angiography among patients with known ischemic heart disease. Differences in MPR categories did not explain the disparity in all‐cause and cardiovascular mortality between the 2 populations. Reduction of cardiovascular disparities may be best addressed using primary prevention strategies that include decolonizing policies and practices.

Diagnosing hypertension in Indigenous Canadians (DREAM-GLOBAL): A randomized controlled trial to compare the effectiveness of short message service messaging for management of hypertension: Main results

Hypertension, the leading cause of cardiovascular morbidity and mortality, affects more than 1 billion people globally. The rise in mobile health in particular the use of mobile phones and short message service (SMS) to support disease management provides an opportunity to improve hypertension awareness, treatment, and control, in remote and vulnerable patient populations. The primary objective of this randomized controlled study was to assess the effect of active (with hypertension specific management SMS) or passive (health behaviors SMS alone) on the difference in blood pressure (BP) reduction between the active and passive SMS groups in hypertensive Canadian First Nations people from six rural and remote communities. Pragmatic features of the study included shifting of BP measures to non-medical health workers. Despite an overall reduction in BP over the study, there was no difference in the BP change between groups from baseline to final for systolic 0.8 (95% CI -4.2 to 5.8 mm Hg) or diastolic -1.0 (95% CI -3.7 to 1.8 mm Hg, P = 0.5) BP. Achieved BP control was 37.5% (25.6%-49.4%, 95% CI) in the active group and 32.8% (20.6%-44.8%, 95% CI) in the passive group (difference in proportions -4.74% (-21.7% to 12.2%, 95% CI, P = 0.6). The study looked at changes in health services delivery, mobile health technologies, and patient engagement to support better management of hypertension in Canadian First Nations communities. The active hypertension specific SMS did not lead to improvements in BP control.

Health Outcome and Follow-up Care Differences Between First Nation and Non-First Nation Coronary Angiogram Patients: A Retrospective Cohort Study

BACKGROUND

First Nations (FN) people experience high rates of ischemic heart disease (IHD) morbidity and mortality. Increasing access to angiography may lead to improved outcomes. We compared various outcomes and follow-up care post-index angiography between FN and non-FN patients.

METHODS

All index angiography patients in Manitoba were identified between April 1, 2000 and March 31, 2009 and categorized into acute myocardial infarction (AMI) or non-AMI groups based on whether their angiogram occurred within 7 days of an AMI. Cox proportional hazard models estimated associations between FN status and outcomes related to mortality, subsequent hospitalizations, revascularizations, and physician visits.

RESULTS

Cardiovascular mortality was higher among FN patients in the non-AMI group (hazard ratio [HR] = 1.50, 95% confidence interval [CI], 1.17-1.94) and in the AMI group (HR = 1.57, 95% CI, 1.05-2.35). FN patients were also more likely to have a subsequent hospitalization for AMI (HR = 2.26, 95% CI, 1.79-2.85) in the non-AMI group. FN patients in the non-AMI group were less likely to receive percutaneous coronary intervention (HR = 0.85, 95% CI, 0.73-0.99) and more likely to undergo coronary artery bypass graft (HR = 1.26, 95% CI, 1.10-1.45). FN patients in both groups were less likely to visit a cardiologist/cardiac surgeon, internal medicine specialist, or family physician within 3 months and 1 year of angiography.

CONCLUSIONS

Cardiovascular health and follow-up care outcomes of FN and non-FN patients who undergo angiography are not the same. Addressing Indigenous determinants of health are necessary to improve cardiovascular outcomes.

The Effectiveness of Text Messaging for Detection and Management of Hypertension in Indigenous People in Canada: Protocol for a Randomized Controlled Trial

Background

Hypertension, the leading cause of morbidity and mortality, affects more than 1 billion people and is responsible globally for 10 million deaths annually. Hypertension can be controlled on a national level; in Canada, for example, awareness, treatment, and control improved dramatically from only 16% in 1990 to 66% currently. The ongoing development, dissemination, and implementation of Hypertension Canada’s clinical practice guidelines is considered to be responsible, in part, for achieving these high levels of control and the associated improvements in cardiovascular outcomes. A gap still exists between the evidence and the implementation of hypertension guidelines in Indigenous communities in Canada, as well as in low- and middle-income countries (LMICs). The rapid rise in the ownership and use of mobile phones globally and the potential for texting (short message service, SMS) to improve health literacy and to link the health team together with the patient served as a rationale for the Dream-Global study in both Canada and Tanzania.

Objective

The primary objective of the Dream-Global study is to assess the effect of innovative technologies and changes in health services delivery on blood pressure (BP) control of Indigenous people in Canada and rural Tanzanians with hypertension using SMS messages and community BP measurement through task shifting with transfer of the measures electronically to the patient and the health care team members.

Methods

This prospective, randomized blinded allocation study enrolls both adults with uncontrolled hypertension (medicated or unmedicated) and those without hypertension but at high risk of developing this condition who participate in a BP screening study. Participants will be followed for at least 12 months.

Results

The primary efficacy endpoint in this study will be assessed by analysis of variance. Descriptive data will be given with the mean and standard deviation for continuous data and proportions for ordinal data. Exploratory subgroup analyses will include analysis by community, sex, mobile phone ownership at baseline, and age. The knowledge gained from the text messages will be assessed using a questionnaire at study completion, and results will be compared between the groups.

Conclusions

This study is expected to provide insights into the implementation of an innovative system of guidelines- and community-based treatment and follow-up for hypertension in Indigenous communities in Canada and in Tanzania, an example of an LMIC. These insights are expected to provide the information needed to plan scalable and sustainable interventions to control BP virtually anywhere in the world.

Trial Registration

Clinicaltrials.gov NCT02111226; https://clinicaltrials.gov/ct2/show/NCT02111226 (Archived by WebCite at http://www.webcitation.org/6v7IdYzZh)

Do physical activity interventions in Indigenous people in Australia and New Zealand improve activity levels and health outcomes? A systematic review

BACKGROUND

Indigenous Australians and New Zealanders have a significantly shorter life expectancy than non-Indigenous people, mainly due to differences in prevalence of chronic diseases. Physical activity helps in the prevention and management of chronic diseases, however, activity levels are lower in Indigenous than in non-Indigenous people.

OBJECTIVE

To synthesise the literature on the effects of physical activity interventions for Indigenous people in Australia and New Zealand on activity levels and health outcomes.

METHODS

The Cochrane Library, MEDLINE, SPORTSDiscus and PsycINFO were searched for peer-reviewed articles and grey literature was searched. Interventions targeted Indigenous people in Australia or New Zealand aged 18+ years and their primary or secondary aim was to increase activity levels. Data were extracted by one author and verified by another. Risk of bias was assessed independently by two authors. Data were synthesised narratively.

RESULTS

407 records were screened and 13 studies included. Interventions included individual and group based exercise programs and community lifestyle interventions of four weeks to two years. Six studies assessed physical activity via subjective (n = 4) or objective (n = 2) measures, with significant improvements in one study. Weight and BMI were assessed in all but one study, with significant reductions reported in seven of 12 studies. All five studies that used fitness tests reported improvements, as did four out of eight measuring blood pressure and seven out of nine in clinical markers.

CONCLUSIONS

There was no clear evidence for an effect of physical activity interventions on activity levels, however, there were positive effects on activity related fitness and health outcomes.

TRIAL REGISTRATION

The review protocol was registered with PROSPERO (registration number: CRD42015016915 ).