T. Kue Young

Indigenous health in the Arctic: an overview of the circumpolar Inuit population.

The health of the Inuit has undergone substantial changes over the past five centuries, as a result of social, cultural, and economic changes brought about by interactions with Europeans. This process was accelerated considerably in the second half of the twentieth century. The incidence of infectious diseases has declined considerably but is still high compared with Western societies. Chronic diseases such as diabetes and cardiovascular disease are on the increase, while accidents, suicides, violence, and substance abuse are of major importance for the pattern of ill health in most Inuit communities. Lifestyle changes, social change, and changes in society and the environment are major determinants of health among the Inuit.

Obesity and Lowered Cognitive Performance in a Canadian First Nations Population

The association between obesity, other cardiovascular risk factors, and cognitive function in a Canadian First Nations population was investigated using a cross‐sectional design. Eligible individuals were aged ≥18 years, without a history of stroke, nonpregnant, with First Nations status, and who had undergone cognitive function assessment by the Clock Drawing Test (CDT) and Trail Making Test Parts A and B. Parts A and B were combined into an Executive Function Score (TMT‐exec). Hypertension, a previous history of cardiovascular disease, dyslipidemia, metabolic syndrome, insulin resistance, and the presence and duration of diabetes were examined in addition to obesity. In the case of TMT‐exec only, obese individuals were at an approximately fourfold increased risk for lowered cognitive performance compared to those who were not obese in multivariable models (odds ratio (OR): 3.77, 95% confidence interval (CI): 1.46–9.72) whereas there was no effect for overweight individuals compared to those with a normal weight in unadjusted analysis. Those having an increased waist circumference also had 5 times the risk compared to those without an increased waist circumference (OR: 5.41, 95% CI: 1.83–15.99). Adjusted for age, sex, and insulin resistance, individuals having the metabolic syndrome were at an approximately fourfold increased risk compared to those without the metabolic syndrome (OR: 3.67, 95% CI: 1.34–10.07). No other cardiovascular risk factors were associated. Obesity and metabolic syndrome were associated with lowered cognitive performance. These results highlight the importance of studying the health effects of obesity beyond traditional disease endpoints, even in a relatively youthful population.

Low incidence of cardiovascular disease among the Inuit*/what is the evidence?

BACKGROUND The notion that the incidence of ischemic heart disease (IHD) is low among the Inuit subsisting on a traditional marine diet has attained axiomatic status. The scientific evidence for this is weak and rests on early clinical evidence and uncertain mortality statistics. METHODS We reviewed the literature and performed new analyses of the mortality statistics from Greenland, Canada, and Alaska. FINDINGS The evidence for a low mortality from IHD among the Inuit is fragile and rests on unreliable mortality statistics. Mortality from stroke, however, is higher among the Inuit than among other western populations. Based on the examination of 15 candidate gene polymorphisms, the Inuit genetic architecture does not obviously explain putative differences in cardiovascular disease prevalence. INTERPRETATION The mortality from all cardiovascular diseases combined is not lower among the Inuit than in white comparison populations. If the mortality from IHD is low, it seems not to be associated with a low prevalence of general atherosclerosis. A decreasing trend in mortality from IHD in Inuit populations undergoing rapid westernization supports the need for a critical rethinking of cardiovascular epidemiology among the Inuit and the role of a marine diet in this population.

Association between the FTO rs9939609 polymorphism and the metabolic syndrome in a non-Caucasian multi-ethnic sample

BackgroundThe rs9939609 T>A single-nucleotide polymorphism (SNP) in the FTO gene has previously been found to be associated with obesity in European Caucasian samples. The objective of this study is to examine whether this association extends to metabolic syndrome (MetS) and applies in non-Caucasian samples.MethodsThe FTO rs9939609 SNP was genotyped in 2121 subjects from four different non-Caucasian geographical ancestries. Subjects were classified for the presence or absence of MetS according to the International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel (NCEP ATP) III definitions.ResultsCarriers of ≥ 1 copy of the rs9939609 A allele were significantly more likely to have IDF-defined MetS (35.8%) than non-carriers (31.2%), corresponding to a carrier odds ratio (OR) of 1.23 (95% confidence interval [CI] 1.01 to 1.50), with a similar trend for the NCEP ATP III-defined MetS. Subgroup analysis showed that the association was particularly strong in men. The association was related to a higher proportion of rs9939609 A allele carriers meeting the waist circumference criterion; a higher proportion also met the HDL cholesterol criterion compared with wild-type homozygotes.ConclusionThus, the FTO rs9939609 SNP was associated with an increased risk for MetS in this multi-ethnic sample, confirming that the association extends to non-Caucasian population samples.

Prevalence of Obesity and Its Metabolic Correlates Among the Circumpolar Inuit in 3 Countries

OBJECTIVES We investigated the prevalence of obesity and the metabolic correlates of different levels of body mass index (BMI) and waist circumference among the Inuit in 3 countries. METHODS Data from 4 surveys of Inuit in Canada, Greenland, and Alaska conducted during 1990-2001 were pooled, with a total sample size of 2545 participants. These data were compared with data from a Canadian population of predominantly European origin. RESULTS Using the World Health Organization criteria for overweight and obesity, we found that the crude prevalence of overweight among Inuit men and women was 36.6% and 32.5%, respectively, and obesity was 15.8% and 25.5%, respectively. Inuit prevalences were similar to those of the highly developed countries of Europe and North America. As levels of obesity increased, as measured by BMI or waist circumference, the mean values of various metabolic indicators-lipid, glucose, and insulin levels and blood pressure-also increased. However, at each level of BMI or waist circumference, the Inuit had lower blood pressure and lipid levels than did Euro-Canadians. CONCLUSIONS Our data indicate that universal criteria for obesity may not reflect the same degree of metabolic risk for populations such as the Inuit and suggest that ethnic-specific criteria are needed.

Lifestyle Variables, Non-traditional Cardiovascular Risk Factors, and the Metabolic Syndrome in an Aboriginal Canadian Population

Objective: To examine lifestyle factors associated with metabolic syndrome (MetS) and to explore the relationships between MetS and non‐traditional cardiovascular disease risk factors [adiponectin, leptin, C‐reactive protein (CRP), interleukin‐6 (IL‐6), and serum amyloid A (SAA)] in an isolated Aboriginal Canadian community.

Prevalence and Risk Factors for Neuropathy in a Canadian First Nation Community

OBJECTIVE—The purpose of this study was to determine the prevalence of and risk factors for diabetic neuropathy in a Canadian First Nation population. RESEARCH DESIGN AND METHODS—This was a community-based screening study of 483 adults. Measures included glucose, A1C, cholesterol, triglycerides, homocysteine, hypertension, waist circumference, height, weight, and foot examinations. Neuropathy was defined as loss of protective sensation determined through application of a 10-g monofilament. RESULTS—Twenty-two percent of participants had a previous diagnosis of diabetes, and 14% had new diabetes or impaired fasting glucose (IFG). The prevalence of neuropathy increased by glucose level: 5% among those with normal glucose levels, 8% among those with new IFG and diabetes, and 15% among those with established diabetes (P < 0.01). Those with neuropathy were more likely to have foot deformities (P < 0.01) and callus (P < 0.001) than those without neuropathy. Among those with dysglycemia (≥6.1 mmol/l), the mean number of foot problems for those with insensate feet was 3 compared with 0.3 among those with sensation (P < 0.001). In multivariate logistic regression female sex, low education, A1C, smoking, and homocysteine were independently associated with neuropathy, after controls for age. CONCLUSIONS—Neuropathy prevalence is high, given the young age of our participants (mean 40 years) and was present among those with undiagnosed diabetes. The high number and type of foot problems places this population at increased risk for ulceration; the low level of foot care in the community increases the risk. Homocysteine is a risk factor that may be related to lifestyle and requires further investigation.

An overview of Aboriginal health research in the social sciences: current trends and future directions

OBJECTIVES: To examine if Aboriginal health research conducted within the field of social sciences reflects the population and geographic diversity of the Aboriginal population. STUDY DESIGN: Review. METHODS: We searched the Web of Science Social Science Citation Index, the Arts and Humanities Citation Index and Scholars Portal for the time period 1995–2005 using search terms to reflect different names used to refer to Canada’s Aboriginal peoples. Citations that did not focus on health or Canada were eliminated. Each paper was coded according to 7 broad categories: Aboriginal identity group; geography; age; health status; health determinants; health services; and methods. RESULTS: Based on the 96 papers reviewed, the results show an under-representation of Metis and urban Aboriginal peoples. Most of the papers are on health status and non-medical determinants of health, with a particular focus on chronic conditions and life-style behaviours. Only 6 papers examined traditional approaches to healing and/or access to traditional healers/medicines. A small number involved the use of community-based research methods. CONCLUSIONS: Further research is required to address gaps in the current body of literature. Community-based research studies are necessary to address gaps that are most relevant to Aboriginal peoples.

Emerging obesity among preschool-aged Canadian Inuit children: results from the Nunavut Inuit Child Health Survey.

Objectives. The study goal was to evaluate the growth status of preschool-age Canadian Inuit children. Study design. As part of a larger study of population health across the Canadian High Arctic, the International Polar Year Inuit Health Survey collected growth and nutrition data on 388 children aged 3 to 5 years. Methods. Data collection included anthropometric measures, health history, food frequency and 24-hour recall. Height and BMI were compared with the 2000 Centers for Disease Control and Prevention (CDC) growth reference (1); 24-hour recall and FFQ results were tabulated to produce daily and monthly frequencies of consumption of market and country foods. Results. Mean height-for-age z-scores were comparable, but body mass index z-scores were significantly greater than the U.S. standard reference population for all age and sex categories. The overall prevalence of overweight was 50.8%. There were significantly more boys (57.1%) than girls (45.2%) in the overweight category. An examination of biological, socio-economic and dietary factors, including birth weight, breastfeeding, day care attendance, traditional and market food consumption and sweetened beverage consumption revealed no significant associations that could explain the development of obesity risk in this population. Conclusions. Stature in preschool-age Inuit children is comparable to the U.S. reference, indicating that the previously reported secular trend toward increasing height has continued. Overweight prevalence is higher than that previously reported in Inuit children and may be occurring at an earlier age. The gender difference in child overweight prevalence runs counter to that reported in adults, leading to concern that contemporary growth patterns may result in significant increases in obesity-related illness for young Inuit men.

Association between the -455T>C promoter polymorphism of the APOC3 gene and the metabolic syndrome in a multi-ethnic sample

BackgroundCommon polymorphisms in the promoter of the APOC3 gene have been associated with hypertriglyceridemia and may impact on phenotypic expression of the metabolic syndrome (MetS). The rs7566605 marker, located near the INSIG2 gene, has been found to be associated with obesity, making it also a potential genetic determinant for MetS. The objective of this study is to examine the APOC3 -455T>C and the INSIG2 rs7566605 polymorphisms as potential genetic determinants for MetS in a multi-ethnic sample.MethodsSubjects were genotyped for both the APOC3 -455T>C and INSIG2 rs7566605 polymorphisms, and classified for the presence or absence of MetS (NCEP ATP III and IDF definitions). The total study population included 2675 subjects (≥18 years of age) from six different geographical ancestries.ResultsFor the overall study population, the prevalence of MetS was 22.6% (NCEP ATP III definition). Carriers of ≥1 copy of APOC3 -455C were more likely to have MetS (NCEP ATP III definition) than noncarriers (carrier odds ratio 1.73, 95% CI 1.40 to 2.14, adjusting for age and study group). The basis of the association was related not only to a higher proportion of -455C carriers meeting the triglyceride and high-density lipoprotein cholesterol criteria, but also the blood pressure criteria compared with wild-type homozygotes. Plasma apo C-III concentrations were not associated with APOC3 -455T>C genotype. The INSIG2 rs7566605 polymorphism was not associated with MetS or measures of obesity.ConclusionMeta-analysis of the sample of multiple geographic ancestries indicated that the functional -455T>C promoter polymorphism in APOC3 was associated with an approximately 2-fold increased risk of MetS, whereas the INSIG2 rs7566605 polymorphism was not associated with MetS.