Diabetes mellitus in Alaskan Yup'ik Eskimos and Athabascan Indians after 25 yr

Alaska Native Traditional Food and Harvesting Activity Patterns over 10 Years of Follow-Up

BACKGROUND

Alaska Native (AN) traditional foods and associated harvesting activities are beneficial to human health.

OBJECTIVE

This study assessed longitudinal self-reported traditional food use and harvesting activities among Alaska Native and American Indian (AN/AI) participants in the Alaska Education and Research Towards Health (EARTH) study.

METHODS

In 2004-2006, southcentral Alaska EARTH study participants (n = 1320) completed diet and activity questionnaires which were repeated in 2015-2017; results were compared between participants who completed both questionnaires (n = 388).

RESULTS

In the follow-up questionnaire, >93% of participants reported eating ≥1 traditional food in the past year. The top 3 traditional foods were fish (75%), moose (42%), and shellfish (41%). Women were more likely than men to consume traditional foods, especially fish, gathered berries, shellfish, and seal oil (P < 0.05). Participants aged ≥60 y in the original cohort were significantly more likely to consume fish and shellfish at follow-up, whereas those aged 40-59 y were the most likely of the 3 age groups to consume seal oil (P < 0.05). Between the original cohort and follow-up, there was a significant decline in the mean number of traditional foods eaten from 6.3 to 5.5, as well as reduced consumption of multiple traditional foods (P < 0.001). Over 59% of participants reported ≥1 traditional harvesting activity in the past year; this proportion did not significantly change between baseline and follow-up. Picking berries/greens (44%), cutting/smoking fish or meat (33%), and fishing (30%) were the most common activities. Participation in traditional harvesting activities was greater among women than men (P < 0.05), but did not differ by age.

CONCLUSIONS

Longitudinal follow-up demonstrated that AN/AI people maintained participation in traditional harvesting activities, but the variety of traditional foods declined significantly among both men and women. Promotion of traditional foods and harvesting activities that serve as protective factors against chronic diseases may benefit this population.

Proximate determinants of tuberculosis in Indigenous peoples worldwide: a systematic review

BACKGROUND

Indigenous peoples worldwide carry a disproportionate tuberculosis burden. There is an increasing awareness of the effect of social determinants and proximate determinants such as alcohol use, overcrowding, type 1 and type 2 diabetes, substance misuse, HIV, food insecurity and malnutrition, and smoking on the burden of tuberculosis. We aimed to understand the potential contribution of such determinants to tuberculosis in Indigenous peoples and to document steps taken to address them.

METHODS

We did a systematic review using seven databases (MEDLINE, Embase, CINAHL, Global Health, BIOSIS Previews, Web of Science, and the Cochrane Library). We identified English language articles published from Jan 1, 1980, to Dec 20, 2017, reporting the prevalence of proximate determinants of tuberculosis and preventive programmes targeting these determinants in Indigenous communities worldwide. We included any randomised controlled trials, controlled studies, cohort studies, cross-sectional studies, case reports, and qualitative research. Exclusion criteria were articles in languages other than English, full text not available, population was not Indigenous, focused exclusively on children or older people, and studies that focused on pharmacological interventions.

FINDINGS

Of 34 255 articles identified, 475 were eligible for inclusion. Most studies confirmed a higher prevalence of proximate determinants in Indigenous communities than in the general population. Diabetes was more frequent in Indigenous communities within high-income countries versus in low-income countries. The prevalence of alcohol use was generally similar to that among non-Indigenous groups, although patterns of drinking often differed. Smoking prevalence and smokeless tobacco consumption were commonly higher in Indigenous groups than in non-Indigenous groups. Food insecurity was highly prevalent in most Indigenous communities evaluated. Substance use was more frequent in Indigenous inhabitants of high-income countries than of low-income countries, with wide variation across Indigenous communities. The literature pertaining to HIV, crowding, and housing conditions among Indigenous peoples was too scant to draw firm conclusions. Preventive programmes that are culturally appropriate targeting these determinants appear feasible, although their effectiveness is largely unproven.

INTERPRETATION

Indigenous peoples were generally reported to have a higher prevalence of several proximate determinants of tuberculosis than non-Indigenous peoples, with wide variation across Indigenous communities. These findings emphasise the need for community-led, culturally appropriate strategies to address smoking, food insecurity, and diabetes in Indigenous populations as important public health goals in their own right, and also to reduce the burden of tuberculosis.

FUNDING

Canadian Institutes of Health Research.

Diabetes care in the dispersed population of Greenland. A new model based on continued monitoring, analysis and adjustment of initiatives taken

Diabetes used to be a rare condition among Inuit in Greenland. However, research in recent decades has shown a high prevalence of undiagnosed diabetes. Addressing diabetes in the geographically dispersed population of Greenland presents a challenge to the health care system. In 2008, a new model of diabetes care was introduced in Greenland that included continual monitoring, analysis, and adjustment of initiatives taken. The overall aim of this review was to review the feasibility of the monitoring of an ongoing national diabetes care programme. After ten years of observation it was clear that monitoring of such a programme based on information in electronic medical records in Greenland was feasible. It was found that the majority of the population in Greenland was in contact with the health care system. Increased diagnostic activity resulted in an increased prevalence of diagnosed diabetes. The quality of diabetes care in Greenland and the testing effectiveness of gestational diabetes were improved. Microvascular complications were frequently observed among Greenlandic diabetic patients, except for retinopathy that was as an exception. In summary, this model may improve diabetes care and potentially care for other chronic conditions in Greenland, and may also be helpful in other remote settings where chronic disease care is difficult.Abbreviations: AD: Anno Domini; ADA: American Diabetes Association; BC: Before Christ; BMI: Body Mass Index; BP: Blood Pressure; CWB: Capillary Whole Blood; EMR: Electronic Medical Record; EASD: European Association for Study of Diabetes; GA: Gestational Age; GDM: Gestational Diabetes Mellitus; FIGO: The International Federation of Gynaecology and Obstetrics; HbA1c: Glycosylated haemoglobin; IDF: International Diabetes Federation; LDL: Low density lipoprotein; NDQIA: National Diabetes Quality Improvement Alliancel; NICE: National Institute for Health and Care Excellence; OECD: Organisation for Economic Co-operation and Development; OGTT: Oral Glucose Tolerance Test; QIH: Queen Ingrid Hospital; RCT: Randomised Controlled Tria;l T1D: Type 1 Diabetes; T2D: Type 2 Diabetes; UACR: Urine Albumin Creatinine Ratio; WHO: World Health Organisation.

FFA4 (GPR120) as a fatty acid sensor involved in appetite control, insulin sensitivity and inflammation regulation

Unsaturated long-chain fatty acids have been suggested to be beneficial in the context of cardiovascular disorders based in epidemiologic studies conducted in Greenland and Mediterranean. DHA and EPA are omega-3 polyunsaturated fatty acids that are plentiful in fish oil, and oleic acid is an omega-9 monounsaturated fatty acid, rich in olive oil. Dietary intake of these unsaturated long-chain fatty acids have been associated with insulin sensitivity and weight loss, which contrasts with the impairment of insulin sensitivity and weight gain associated with high intakes of saturated long-chain fatty acids. The recent discovery that free fatty acid receptor 4 (FFA4, also known as GPR120) acts as a sensor for unsaturated long-chain fatty acids started to unveil the molecular mechanisms underlying the beneficial functions played by these unsaturated long-chain fatty acids in various physiological processes, which include the secretions of gastrointestinal peptide hormones and glucose homeostasis. In this review, the physiological roles and therapeutic significance of FFA4 in appetite control, insulin sensitization, and inflammation reduction are discussed in relation to obesity and type 2 diabetes from pharmacological viewpoints.

Predictions of type 2 diabetes and complocations in Greenland in 2014

OBJECTIVES

The objective of this study was to predict the prevalence of type 2 diabetes and the associated burden to the health care system in Greenland posed by diabetic complications by 2014. The predictions were based on changes in demographic variables and obesity.

STUDY DESIGN

Projection model based on two cross-sectional population surveys from 1993 and 1999.

METHODS

The development in BMI was described and projected to 2014 under two assumptions: 1) distribution of BMI is constant from 1999, and 2) the trend in BMI found in the surveys will continue until 2014. The prevalence of type 2 diabetes was predicted under these assumptions and based on the observed association between BMI and type 2 diabetes. The prevalence of complications was estimated using the 2nd assumption, as was the prevalence of hypertension, dyslipidemia, Ischemic Heart Disease (IHD) and stroke in the non-diabetic population in 2014.

RESULTS

The prevalence of type 2 diabetes was not predicted to increase by 2014 under the 1st assumption. It was predicted to increase from 11% to 23% for women, but not for men under the 2nd assumption. Approximately half of the cases of cardiovascular disease and cardiovascular risk factors predicted by 2014 were attributable to diabetes.

CONCLUSIONS

The prevalence of type 2 diabetes was predicted to increase in Greenland, and the number of complications was predicted to double from 1999 to 2014. Both prophylactic and treatment initiatives are needed to deal with the extra burden posed by type 2 diabetes to the Greenlandic health care system in 2014.

Inuit anthropometry and insulin resistance

OBJECTIVES

Due to the increasing prevalence of obesity among Inuit, a study was conducted in an Inuit community to evaluate the anthropometric correlates of indices of insulin resistance using the homeostasis model assessment index (IR(HOMA)) and the insulin sensitivity index (ISI(0,120)).

STUDY DESIGN

Data were collected as part of a health screening in a Baffin community in Nunavut, Canada, among adults 18 years of age and above.

METHODS

A total of 52 Inuit participated in the health screening of which 46 completed both the fasting and the 2-hour blood tests. Insulin sensitivity indices could be calculated on 45 participants.

RESULTS

Results for women indicated that in age-adjusted linear regression analyses, body mass index, waist circumference (WC) and percent body fat (%BF) predicted IR(HOMA), and ISI(0,120) (p < 0.05). For men, %BF predicted IR(HOMA), and WC and %BF predicted ISI0,120 (p < or = 0.05).

CONCLUSIONS

The present study suggests that increasing rates of obesity among Inuit will have health consequences and that anthropometry is a useful tool to indirectly assess insulin resistance/sensitivity.

Review Article: 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.

The Alaska Education and Research Towards Health (EARTH) Study: cancer risk factors

The Alaska Education and Research Towards Health (EARTH) Study assessed cancer risk among 3,821 Alaska Native people (AN). We present the prevalence of selected cancer risk factors and comparison with Healthy People 2010 goals. Participants completed extensive computer-assisted self-administered questionnaires on diet, physical activity, tobacco and alcohol use, cancer screening, family history of cancer, and environmental exposures. Measurement data were collected on blood pressure, height, weight, waist/hip circumference, fasting serum lipids, and glucose. Cancer risk factors are high for the Alaska EARTH study population. For all risk factors studied except for vegetable consumption, Alaska EARTH Study participants did not meet Healthy People 2010 goals. This study is unique in providing questionnaire and measurement data of cancer risk factors on a larger study sample than any previous study among AN living in Alaska. Data show that the prevalence of most cancer risk factors exceeded national recommendations. Given the disease disparities that exist for the AN population, these data provide important baseline data that can be used to target health interventions and reduce health disparities.

Factors related to fruit, vegetable and traditional food consumption which may affect health among Alaska Native People in Western Alaska

Objectives

Determine intake of fruits, vegetables and traditional foods (TF), availability of foods, and attitudes towards increasing their consumption.

Study design

Establish community baseline through a cross-sectional sample of residents who were weighed, measured and interviewed. Village stores were surveyed for food availability, price and quality.

Methods

Eighty-eight respondents self-identified as the household member primarily responsible for food shopping and cooking were surveyed in 3 Western Alaska Native villages using a food frequency questionnaire, and village stores were evaluated using food environment surveys.

Results

Overweight (BMI[kg/m²] >25) was present in 68% of participants. Fruit and vegetable intake (3.3 median servings/day) was low in comparison to recommended intakes of 5–9 servings/d. Seventy-two per cent were eating less than 5 servings/d of fruits and vegetables combined. Thirty-four per cent of respondents were trying to eat more vegetables; 41% were trying to eat more fruits. The median number of servings of TF was 3.2/d (mean 4.3/d). Seventy-seven per cent of respondents reported that they ate enough TF.

Conclusion

Recommendations to continue use of TF and increase intake of fruits and vegetables are consistent with local attitudes. Our findings indicate that increasing the availability of fruits and vegetables would be well received. Information from this study provides a basis for nutrition education and food supplement programs that is responsive to the needs and perceptions of the residents. Continued TF intake and increased fruit and vegetable intake have the potential to benefit the health of rural residents.

Genetic polymorphisms in carnitine palmitoyltransferase 1A gene are associated with variation in body composition and fasting lipid traits in Yup'ik Eskimos

Variants of carnitine palmitoyltransferase 1A (CPT1A), a key hepatic lipid oxidation enzyme, may influence how fatty acid oxidation contributes to obesity and metabolic outcomes. CPT1A is regulated by diet, suggesting interactions between gene variants and diet may influence outcomes. The objective of this study was to test the association of CPT1A variants with body composition and lipids, mediated by consumption of polyunsaturated fatty acids (PUFA). Obesity phenotypes and fasting lipids were measured in a cross-sectional sample of Yup'ik Eskimo individuals (n = 1141) from the Center of Alaska Native Health Research (CANHR) study. Twenty-eight tagging CPT1A SNPs were evaluated with outcomes of interest in regression models accounting for family structure. Several CPT1A polymorphisms were associated with HDL-cholesterol and obesity phenotypes. The P479L (rs80356779) variant was associated with all obesity-related traits and fasting HDL-cholesterol. Interestingly, the association of P479L with HDL-cholesterol was still significant after correcting for body mass index (BMI), percentage body fat (PBF), or waist circumference (WC). Our findings are consistent with the hypothesis that the L479 allele of the CPT1A P479L variant confers a selective advantage that is both cardioprotective (through increased HDL-cholesterol) and associated with reduced adiposity.

Hypertriglyceridemic-waist phenotype and glucose intolerance among Canadian Inuit: the International Polar Year Inuit Health Survey for Adults 2007-2008

BACKGROUND

Inuit have not experienced an epidemic in type 2 diabetes mellitus, and it has been speculated that they may be protected from obesity's metabolic consequences. We conducted a population-based screening for diabetes among Inuit in the Canadian Arctic and evaluated the association of visceral adiposity with diabetes.

METHODS

A total of 36 communities participated in the International Polar Year Inuit Health Survey. Of the 2796 Inuit households approached, 1901 (68%) participated, with 2595 participants. Households were randomly selected, and adult residents were invited to participate. Assessments included anthropometry and fasting plasma lipids and glucose, and, because of survey logistics, only 32% of participants underwent a 75 g oral glucose tolerance test. We calculated weighted prevalence estimates of metabolic risk factors for all participants.

RESULTS

Participants' mean age was 43.3 years; 35% were obese, 43.8% had an at-risk waist, and 25% had an elevated triglyceride level. Diabetes was identified in 12.2% of participants aged 50 years and older and in 1.9% of those younger than 50 years. A hypertriglyceridemic-waist phenotype was a strong predictor of diabetes (odds ratio [OR] 8.6, 95% confidence interval [CI] 2.1-34.6) in analyses adjusted for age, sex, region, family history of diabetes, education and use of lipid-lowering medications.

INTERPRETATION

Metabolic risk factors were prevalent among Inuit. Our results suggest that Inuit are not protected from the metabolic consequences of obesity, and that their rate of diabetes prevalence is now comparable to that observed in the general Canadian population. Assessment of waist circumference and fasting triglyceride levels could represent an efficient means for identifying Inuit at high risk for diabetes.

Diabetes prevalence, incidence, complications and mortality among Alaska Native people 1985-2006

OBJECTIVES

To examine trends in diabetes prevalence, incidence, complications and mortality between 1985 and 2006 among Alaska Native people.

STUDY DESIGN

We used data from the population-based Alaska Native Diabetes Registry, which includes all people who receive care in the Alaska Tribal Health System.

METHODS

We compared the periods of 1986-1990 and 2002-2006 for diabetes-related amputations, renal replacement and mortality using Poisson regression. Complications and mortality data were examined for trends using Poisson regression. Survival analyses for those diagnosed since 31 December 1985 were performed using the Cox proportional hazard model.

RESULTS

Age-adjusted diabetes prevalence increased from 17.3 in 1985 to 47.6/1,000 in 2006. The number of Alaska Native people living in Alaska with diabetes increased from 610 in 1985 to 3,386 in 2006. Diabetes incidence rates have also increased. Comparing age-adjusted rates for the 5-year periods 1986-1990 and 2002-2006, amputations decreased from 5.3 to 2.6/1,000, renal replacement decreased from 3.3 to 1.2/1,000 and mortality decreased from 41.7 to 33.2/1,000. Yearly analyses showed a downward trend for amputations, renal replacement and mortality rates. Survival analyses showed a significantly higher hazard ratio for any amputations, major amputations and renal replacement for the earlier time period compared to the most recent time period.

CONCLUSIONS

An increase in risk factors, awareness, funding and case-finding may be contributing to the increase in prevalence and incidence of diagnosed diabetes. While diabetes prevalence and incidence are increasing among Alaska Native people, our results suggest that even in remote, rural areas, complications and mortality can be reduced.

Red blood cell delta15N: a novel biomarker of dietary eicosapentaenoic acid and docosahexaenoic acid intake

BACKGROUND

The long-chain omega-3 (n-3) fatty acids derived from fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a reduced risk of cardiovascular disease and other chronic diseases. Study of the associations between EPA and DHA intake and disease requires a valid biomarker of dietary intake; however, the direct measurement of tissue fatty acid concentrations is expensive and time consuming.

OBJECTIVE

Because the nitrogen stable isotope ratio ((15)N/(14)N, expressed as delta(15)N) is elevated in fish, we investigated whether delta(15)N is a valid alternative biomarker of EPA and DHA intake.

DESIGN

We examined the relation between red blood cell (RBC) delta(15)N and RBC EPA and DHA in a community-based sample of 496 Yup'ik Eskimos with widely varying intake of n-3 fatty acids. We also assessed the correlation between delta(15)N and dietary EPA and DHA intake based on 24-h dietary recalls and 3-d food records completed by a subset of 221 participants.

RESULTS

RBC delta(15)N was strongly correlated with RBC EPA and DHA (r = 0.83 and 0.75, respectively). These correlations differed only modestly by sex and age class. RBC delta(15)N also correlated with dietary EPA and DHA intake (r = 0.47 and 0.46, respectively) and did not differ by sex and age.

CONCLUSIONS

The results strongly support the validity of RBC delta(15)N as a biomarker of EPA and DHA intake. Because the analysis of RBC delta(15)N is rapid and inexpensive, this method could facilitate wide-scale assessment of EPA and DHA intake in clinical and epidemiologic studies.

Metabolic syndrome: prevalence among American Indian and Alaska native people living in the southwestern United States and in Alaska

BACKGROUND

Metabolic syndrome occurs commonly in the United States. The purpose of this study was to measure the prevalence of metabolic syndrome among American Indian and Alaska Native people.

METHODS

We measured the prevalence rates of metabolic syndrome, as defined by the National Cholesterol Education Program, among four groups of American Indian and Alaska Native people aged 20 years and older. One group was from the southwestern United States (Navajo Nation), and three groups resided within Alaska. Prevalence rates were age-adjusted to the U.S. adult 2000 population and compared to rates for U.S. whites (National Health and Nutrition Examination Survey [NHANES] 1988-1994).

RESULTS

Among participants from the southwestern United States, metabolic syndrome was found among 43.2% of men and 47.3% of women. Among Alaska Native people, metabolic syndrome was found among 26.5% of men and 31.2% of women. In Alaska, the prevalence rate varied by region, ranging among men from 18.9% (western Alaska) to 35.1% (southeast), and among women from 22.0% (western Alaska) to 38.4 % (southeast). Compared to U.S. whites, American Indian/Alaska Native men and women from all regions except western Alaska were more likely to have metabolic syndrome; men in western Alaska were less likely to have metabolic syndrome than U.S. whites, and the prevalence among women in western Alaska was similar to that of U.S. whites.

CONCLUSION

The prevalence rate of metabolic syndrome varies widely among different American Indian and Alaska Native populations. Differences paralleled differences in the prevalence rates of diabetes.

Traditional foods and physical activity patterns and associations with cultural factors in a diverse Alaska Native population

OBJECTIVES

To determine the prevalence of traditional food and physical activity use and associations with cultural factors among 3,830 Alaska Native and American Indian (AN/AI) people enrolled in the Education and Research Towards Health (EARTH) Study in 3 regions of Alaska.

STUDY DESIGN

Cross-sectional analysis of baseline data from a cohort study.

METHODS

Participants (2,323 women and 1,507 men) completed a computer-assisted self-administered questionnaire that included information on diet, physical activity, life-style and cultural factors.

RESULTS

Over 92% of participants reported eating at least 1 traditional food in the past year. The top 3 traditional foods reported were fish, moose and agutaq (a mixture of berries and fat). The percentage of people who consumed traditional foods varied by region and age but not by sex (p < 0.01). Almost 70% of participants engaged in at least one traditional harvesting physical activity. Picking berries or greens, cutting/smoking fish or meat and fishing were the most common activities. Participation in traditional physical activity was highest in south-west Alaska and was higher among men than women, but did not differ by age (p < 0.01). Both traditional food and physical activity were associated with greater tribal self-identification, speaking a Native language at home, using traditional remedies and participating in or attending traditional events (p < 0.05).

CONCLUSIONS

The EARTH Study found relationships between traditional food use, physical activities, cultural activities and behaviours. Consumption of a variety of traditional foods and participation in traditional physical activities remain an important part of the contemporary Alaska Native life-style. Efforts to promote and sustain these foods and activities in AN/AI populations may lead to improved health outcomes.

Cancer patterns in Inuit populations

Inuit people inhabit the circumpolar region, with most living in Alaska, northwest Canada, and Greenland. Although malignant diseases were believed to be almost non-existent in Inuit populations during the beginning of the 20th century, the increasing life expectancy within these populations showed a distinct pattern, characterised by a high risk of Epstein-Barr virus-associated carcinomas of the nasopharynx and salivary glands, and a low risk of tumours common in white populations, including cancer of the prostate, testis, and haemopoietic system. Both genetic and environmental factors seem to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet, and reproductive factors. This Review will briefly summarise the current knowledge on cancer epidemiology in Inuit populations, with emphasis on the characteristic Inuit types of cancer.

Fatty acid consumption and metabolic syndrome components: the GOCADAN study

Fatty acids (FAs) have been related to changes in glucose and lipid metabolism. In this article, the authors assess the association between intake of specific FAs and components of the metabolic syndrome (MS) in adult Eskimos. A total of 691 Inupiat Eskimos (325 men and 366 women), aged 34 to 75 years, were examined as part of the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. The investigation included a physical examination, blood pressure measurements, blood sampling under fasting conditions, 2-hour oral glucose tolerance test, and a personal interview including a validated food frequency questionnaire. Components of MS were defined according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel criteria. Consumption of individual FAs showed associations with MS components. Long-chain omega-3 FAs, from fish and sea mammals, were associated with lower blood pressure, serum triglycerides, and 2-hour glucose and higher high-density lipoprotein cholesterol, fasting insulin, and homeostasis model assessment. Saturated fat consumption was associated with higher triglyceride levels and blood pressure. Trans-FA consumption was associated with higher blood pressure. Consumption of long-chain omega-3 FAs from marine sources may improve certain MS components, and thus may reduce risk for cardiovascular disease. High consumption of saturated FAs and trans-FAs may have an adverse effect on MS.

Are the circumpolar Inuit becoming obese?

This paper reviews the ethnographic, historical, and recent epidemiological evidence of obesity among the Inuit/Eskimo in the circumpolar region. The Inuit are clearly at higher risk for obesity than other populations globally, if "universal" measures based on body mass index (BMI) and waist circumference and criteria such as those of WHO are used. Inuit women in particular have very high mean waist circumference levels in international comparisons. Given the limited trend data, BMI-defined obesity is more common today than even as recently as three decades ago. Inuit are not immune from the health hazards associated with obesity. However, the "dose-response" curves for the impact of obesity on metabolic indicators such as plasma lipids and blood pressure are lower than in other populations. Long-term, follow-up studies are needed to determine the metabolic consequences and disease risks of different categories of obesity. At least in one respect, the higher relative sitting height among Inuit, obesity measures based on BMI may not be appropriate for the Inuit. Ultimately, it is important to go beyond simple anthropometry to more accurate determination of body composition studies, and also localization of body fat using imaging techniques such as ultrasound and computed tomography. Internationally, there is increasing recognition of the need for ethnospecific obesity criteria. Notwithstanding the need for better quality epidemiological data, there is already an urgent need for action in the design and evaluation of community-based health interventions, if the emerging epidemic of obesity and other chronic diseases are to be averted.

Fish-seafood consumption, obesity, and risk of type 2 diabetes: an ecological study

OBJECTIVES

There is substantial evidence that type 2 diabetes increases with the degree and duration of obesity. This study was conducted to examine the association, at the international level, between fish and seafood consumption and the prevalence of type 2 diabetes, taking into account the prevalence of obesity.

METHODS

An ecological study of 41 countries in five continents with different socio-demographic characteristics and sanitary conditions was carried out. Data on the prevalence of diabetes and obesity as well as food balance sheets were collected from websites. Correlations between the variables studied were followed by an exploration of their interaction.

RESULTS

After adjustment for total energy intake, there was a significant correlation (rho=0.81, P<0.0001) between the prevalence of type 2 diabetes in the 20- to 44- and 45- to 64-year age groups. Type 2 diabetes in the 45- to 64-year age group was about 5 times higher than in the 20- to 44-year age group. Obesity was positively associated with type 2 diabetes in both age groups (rho=0.39; P=0.012 and rho=0.48; P=0.002 in the 20- to 44- and 45- to 64-year age groups, respectively). An interaction effect was found between diabetes, obesity and total fish and seafood consumption. In countries with low fish and seafood consumption, the prevalence of type 2 diabetes increased significantly with obesity (0.8 +/- 0.3% vs. 2.5 +/- 1.8%; P=0.002 and 3.3 +/- 2.6% vs. 11.0 +/- 3.9%; P<0.0001 for the 20- to 44- and 45- to 64-year age groups, respectively). In countries with a greater prevalence of obesity, there was evidence of significantly reduced type 2 diabetes with high fish and seafood consumption (2.5 +/- 1.8% vs. 0.9 +/- 0.7%; P=0.007 and 11.0 +/- 3.9% vs. 6.2 +/- 4.1%; P=0.041 for the 20- to 44- and 45- to 64-year age groups, respectively).

CONCLUSION

The results of this study suggest that high fish and seafood intake may reduce the risk of type 2 diabetes in populations with a high prevalence of obesity.

Cancer in Greenlandic Inuit 1973-1997: a cohort study

The increasing westernization of the Arctic countries may influence the very particular cancer profile of these populations. Our objective was to investigate the development in cancer incidence from 1973 to 1997 in a large and well-defined Inuit population in Greenland. Greenland is part of the Danish Kingdom, and population statistics covering both countries are available from the same registry resource. Data from the Danish Civil Registration System and from the Danish Cancer Registry were used to calculate age-standardized cancer incidence rates for the periods 1973-1987 and 1988-1997 for persons born in Greenland. Using rates for Denmark, sex-specific standardized incidence ratios (SIRs) for 1988-1997 were calculated. Furthermore, age- and sex-specific incidence rates in the 2 periods were calculated for selected cancers. Total cancer incidence increased from 248.5 to 277.9 per 100,000 person-years in men and from 269.4 to 302.2 per 100,000 person-years in women. The incidence of lung, stomach, breast and colon cancer increased, whereas the incidence of cervical cancer decreased. Compared to the Caucasian population in Denmark, high SIRs were found for cancers of the nasopharynx, salivary gland, esophagus, stomach and cervix and low SIRs for testis, bladder, prostate, breast and hematologic cancers. Overall cancer incidence among Greenlandic Inuit is increasing as a result of increases in several cancers that are common in Western populations. A significant increase in the incidence of stomach cancer in both sexes, which contrasts global trends for this cancer, warrants further investigation.

Diabetes and impaired glucose tolerance among the inuit population of Greenland

OBJECTIVE

To assess the prevalence of diabetes and impaired glucose tolerance (IGT) among the Inuit population of Greenland and to determine risk factors for developing glucose intolerance.

RESEARCH DESIGN AND METHODS

This cross-sectional study included 917 randomly selected adult Inuit subjects living in three areas of Greenland. Diabetes and IGT were diagnosed using the oral glucose tolerance test. BMI and waist-to-hip ratio were measured and blood samples were taken from each subject. Sociodemographic characteristics were investigated using a questionnaire.

RESULTS

The age-standardized prevalences of diabetes and IGT were 10.8 and 9.4% among men and 8.8 and 14.1% among women, respectively. Of those with diabetes, 70% had not been previously diagnosed. Significant risk factors for diabetes were family history of diabetes, age, BMI, and high alcohol consumption, whereas frequent intake of fresh fruit and seal meat were inversely associated with diabetic status. Age, BMI, family history of diabetes, sedentary lifestyle, and place of residence were significant predictors of IGT.

CONCLUSIONS

The prevalence of diabetes is high among the Inuit of Greenland. Heredity was a major factor, while obesity and diet were important environmental factors. The high proportion of unknown cases suggests a need for increased diabetes awareness in Greenland.

Atopic sensitization among children in an arctic environment

BACKGROUND

Asthma has been reported to be rare among Inuits, but so far total and specific IgE levels have never been determined in arctic populations.

OBJECTIVE

To determine the prevalence of atopy in children living in an arctic environment, and to examine whether atopy and total IgE levels were associated with parental place of birth, as a measure of ethnicity, and travel history.

MATERIAL AND METHODS

All schoolchildren in Sisimiut, a community on the West coast of Greenland, were screened for atopy. Blood samples were analysed for total IgE and for specific IgE against inhalant and food allergens. Information on place of birth of children and their parents was obtained from national registries. Information on travel history was obtained from self-administered questionnaires.

RESULTS

A total of 1031 schoolchildren aged 5 to 18 years had a blood sample drawn (85% of available children for the study). Of these, 151 (14.6%) children were sensitized to at least one inhalant allergen and 42 (4.1%) to at least one food allergen. Sensitization to grass was most common, whereas sensitization to mugwort, birch, animal-dander and house-dust mite was infrequent. Children whose parents were both born abroad had a higher risk of sensitization to inhalant allergens compared with children born of Greenlandic parents (OR = 8.6, 95% CI 2.8-27.1). Furthermore, children who had been abroad had a higher risk of sensitization towards pollen (OR = 1.6, 95% CI 1.0-2.5) and animal-dander (OR = 2.1, 95% CI 1.0-4.6) after adjustment for confounders. Both atopic and non-atopic children demonstrated high levels of total IgE (medians of 251 and 58 kU/L).

CONCLUSIONS

Compared with European findings Greenlandic children have high levels of total IgE but a low prevalence of allergic sensitization towards inhalant allergens. This may be due to a low genetic susceptibility to atopy and less allergen exposure, as well as to living conditions in an arctic environment.

Overweight and obesity among Alaskan Eskimos of the Bering Straits Region: the Alaska Siberia project

OBJECTIVE

To document the height, weight, BMI and prevalence of obesity for Eskimo residents of four villages of the Bering Straits Region of Alaska.

DESIGN AND SUBJECTS

454 Non-pregnant residents over 24 y of age, with at least one Eskimo grandparent participated in one cross sectional survey within each village.

MEASUREMENTS

Height, weight, calculation of BMI (kg/m2), proportion of 'overweight' (BMI 25-29.9), and proportion of 'obese' (BMI>/=30).

RESULTS

For women and men, respectively, mean heights were 153.4 and 165.2 cm; weights were 64.2 and 71.6 kg; and BMI were 27.2 and 26.2 kg/m2 after age standardization. For women, 27.9% were overweight, and 32.8% were obese compared with 36.2% and 15.6%, respectively, for men. Alaskan Eskimo participants of the Alaska Siberia Project had a significantly lower proportion of total overweight (BMI>/=25, 54.9% for women, and 32.0% for men) compared with the three sites of the Strong Heart Study, which ranged from 65.9 to 80.2% for women and 53.6 to 66.7% for men. Compared with American men of all races, the proportion of overweight and obese participants was similar for Eskimo men. The proportion of obese was significantly higher for Eskimo women compared with American women of all races, but the proportion of overweight was similar.

CONCLUSION

Although the prevalence of obesity among the Alaskan Eskimos is lower than for American Indians, the high proportion of overweight observed in this study is of concern for Alaskan Eskimo adults, especially for women.

The epidemic of obesity in American Indian communities and the need for childhood obesity-prevention programs

American Indians of all ages and both sexes have a high prevalence of obesity. The high prevalence of diabetes mellitus in American Indians shows the adverse effects that obesity has in these communities. Obesity has become a major health problem in American Indians only in the past 1-2 generations and is believed to be associated with the relative abundance of high-fat foods and the rapid change from active to sedentary lifestyles. Intervention studies are urgently needed in American Indian communities to develop and test effective strategies for weight reduction. The poor success rate of adult obesity treatment programs in the general population points to the need to develop prevention approaches aimed toward children. Because eating and physical activity practices are formed early in life and may be carried into adulthood, prevention programs that encourage increased physical activity and healthful eating habits targeted toward young people need to be developed and tested. To be most effective, interventions must be developed with full participation of the American Indian communities.

Hypertension in Alaska Natives: association with overweight, glucose intolerance, diet and mechanized activity

OBJECTIVE

Determine the prevalence of hypertension in Alaska Natives and evaluate risk factors.

DESIGN

Population-based univariate and multivariate analysis of blood pressure in 1124 Alaska Natives over 20 years of age.

RESULTS

The sample had mean: age 45 years, body mass index 27, systolic pressure 123 mmHg and diastolic pressure 73 mmHg. The age-adjusted rate of hypertension > or = 160/95 mmHg was 9.1% and 6.8% among Athabascan Indians and Yup'ik Eskimos, respectively. After controlling for age and sex there was significantly more hypertension among Athabascan Indians (OR = 1.53, CI = 1.07-2.2, p = 0.019) compared to Yup'ik Eskimos. Race was significantly associated with blood pressure > or = 140/90 when controlled for age and overweight (p = 0.01, OR = 0.78, CI = 0.69-0.95). The presence of hypertension was significantly associated with the following: intake of non-indigenous food (p = 0.01); mechanized activities (p = 0.01); and glucose intolerance in both women (p = 0.043) and men (p = 0.001). Multiple regression analysis revealed age (OR = 1.06, CI = 1.05-1.08) and overweight in both men (OR = 3.02, CI = 1.85-4.93) and women (OR = 2.76, CI = 1.81-4.19) to be significantly associated with BP > or = 140/90.

CONCLUSION

Hypertension is no longer rare in Alaska Natives and is associated with overweight, non-indigenous diet, mechanized activities, and glucose intolerance.

Toward comprehensive obesity prevention programs in Native American communities

Obesity is a particularly important challenge to the health status of Native Americans. This challenge is manifest in the increasing rates of non-insulin-dependent diabetes mellitus among Native Americans. Most studies of Native American infants, preschool children, schoolchildren, and adults have confirmed a high prevalence of overweight. Historical studies suggest that for many Native American communities the high rates of obesity are a relatively recent phenomenon. The specific reasons for the increase in obesity among Native Americans have not been determined, although it has been hypothesized that Native Americans have a genetic predisposition to overweight in a "westernized" environment of abundant food and decreased energy expenditure. Few detailed studies of diet or of physical activity levels of contemporary Native Americans have been published. Community-based interventions to modify diet and activity levels to prevent obesity in Native American communities are needed. Preliminary evidence from two formative school-based programs in the Southwest suggest that Native American communities are receptive to school-based interventions, and that such programs may be able to slow the rate of excess weight gain and to improve fitness in school children. Because of the cultural diversity among Native Americans, future studies should focus on collecting community- and region-specific data, and should emphasize the need for obesity prevention through culturally appropriate community- and school-based behavioral interventions.

Dietary change and obesity associated with glucose intolerance in Alaska Natives

OBJECTIVE

To investigate frequency of food intake, body weight, and glucose intolerance in Alaska Natives.

DESIGN

Height, weight, and random blood glucose levels were measured and a frequency-of-food-intake questionnaire was obtained. This questionnaire classified persons as consumers of indigenous foods or nonindigenous foods within three food groups. Those with a random blood glucose measurement > or = 6.72 mmol/L received an oral glucose tolerance test.

SETTING

Community screening in 15 villages in Alaska.

SUBJECTS

Nutrition screenings were done for 1,124 Alaska Native residents aged 20 years or older. An oral glucose tolerance test was done for 202 subjects.

OUTCOMES MEASURED

Subjects were classified as consumers of indigenous or nonindigenous foods within three food groups. A diagnosis of non-insulin-dependent diabetes mellitus (NIDDM) was made on the basis of World Health Organization criteria. A determination of overweight was made on the basis of National Center for Health Statistics criteria.

STATISTICAL ANALYSIS

A chi 2 test with Yates correction, t test, and linear regression, with two-sided P values.

RESULTS

Athabascan Indians had twice the rate of NIDDM as Yup'ik Eskimos with significantly higher frequency of nonindigenous food intake, plus lower frequency of indigenous carbohydrate and fat intake. Subjects < or = 30 years old consumed significantly more nonindigenous protein and fat and low-nutrient-density carbohydrates than those > or = 60 years old. Persons who had glucose intolerance reported significantly greater consumption of nonindigenous protein and less seal oil. Incidence of overweight was significantly higher than was found 25 years ago. Participants with glucose intolerance were significantly more overweight than others.

CONCLUSION

A pattern of increased frequency of nonindigenous protein, low-nutrient-density carbohydrate, and fat intake with less indigenous carbohydrate and fat consumption was found in subjects < or = 30 years old and in association with the higher rate of NIDDM found in the Athabascan Indians. Persons with glucose intolerance were significantly more overweight than others.

APPLICATIONS

Although the nutritional value of indigenous foods for reducing disease risk should be promoted, nutrition education, especially among young adults, should also include building skills to select and prepare nonindigenous foods to attain a healthful diet. Although snacking is a concern, dietary fat was the most significant factor in obesity and NIDDM.