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

Changes in weight status among "Ju/'hoansi" San hunter-gatherers between 1968/69 and 1987-The effects of nutritional transition, sex and age

BACKGROUND

Changes in lifestyle and dietary habits that hunter-gatherer populations have undergone in recent decades have often led to rising obesity rates with disastrous consequences for their health.

OBJECTIVES

The associations between dietary habits and weight status were studied in 238 "Ju/'hoansi" San (93 women and 145 men) aged between 18 and 65 years in northern Namibia in 1987. Weight status was estimated based on the World Health Organization body mass index (BMI) categories, and dietary habits were recorded using food recall methods. Anthropometrics and weight status were compared with those of a sex- and age-matched sample of "Ju/'hoansi" San people collected by Nancy Howell in 1968/69.

RESULTS

Body weight had increased significantly among "Ju/'hoansi" San people from 1968/69 to 1987. The number of underweight people decreased from 1968/69 to 1987. In 1987, most participants (60.9%) were of normal weight. Overweight was found in 1.3% of the women, but not among men. No participants were obese. Less than 4% of the women and less than 2% of the men consumed exclusively traditional hunter-gatherer food. Westernized food products were significantly (p < 0.001) more common among men and younger people. Dietary patterns were significantly associated with weight status. The less traditional the diet, the higher the BMI (p < 0.001).

CONCLUSION

The transition to domestic agricultural and westernized foods was positively associated with increasing BMI. Overweight, however, was still an extremely rare condition in this population in 1987.

Cardiovascular Disease Risk Factors in Women: The Impact of Race and Ethnicity: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of death in women, yet differences exist among certain racial and ethnic groups. Aside from traditional risk factors, behavioral and environmental factors and social determinants of health affect cardiovascular health and risk in women. Language barriers, discrimination, acculturation, and health care access disproportionately affect women of underrepresented races and ethnicities. These factors result in a higher prevalence of cardiovascular disease and significant challenges in the diagnosis and treatment of cardiovascular conditions. Culturally sensitive, peer-led community and health care professional education is a necessary step in the prevention of cardiovascular disease. Equitable access to evidence-based cardiovascular preventive health care should be available for all women regardless of race and ethnicity; however, these guidelines are not equally incorporated into clinical practice. This scientific statement reviews the current evidence on racial and ethnic differences in cardiovascular risk factors and current cardiovascular preventive therapies for women in the United States.

Sex differences in obesity prevalence and cardiometabolic factors among Western Alaska Native people

BACKGROUND AND AIMS

Obesity is associated with increased risks of cardiovascular disease, type 2 diabetes, and other chronic diseases. Prevalence estimates for metabolic disorders are well documented in many populations, but Alaska Native groups are understudied. The Western Alaska Tribal Collaborative for Health Study combines data from three Alaska Native study cohorts to assess differences in obesity prevalence and associations with cardiometabolic risk factors by sex.

METHODS AND RESULTS

Analyses were based upon a sample of 3985 adult Yup'ik and Inupiat participants with a mean age of 40 years. Prevalence of obesity and metabolic risk factors was assessed according to nationally recognized guidelines. Regression analysis was used to evaluate the association between obesity and cardiometabolic risk factors, including lipids, blood pressure and glucose. The prevalence of obesity (BMI ≥ 30) was significantly higher in women (40%) than men (20%). Only 18.6% of men had a waist circumference (WC) > 102 cm, while 58% of women had a WC > 88 cm (p < 0.001). Women had higher mean HDL-C and triglyceride levels compared to men, while systolic and diastolic blood pressure, LDL-C, and glucose means were higher in men than in women. In multivariate analyses, BMI and WC were significantly associated with all of the cardiometabolic risk factors, although these associations were more pronounced in men than women.

CONCLUSION

The high prevalence of obesity and central adiposity among AN women is an important public health concern. Differences in associations between obesity and cardiometabolic risk factors by sex warrants further investigation to develop effective intervention programs.

A national study on weight classes among children in Greenland at school entry

OBJECTIVES

To estimate the proportion of gender-specific thinness, overweight and obesity among children born in 2005 at school entry in Greenland and to compare figures between the capital, Nuuk, with the rest of Greenland.

STUDY DESIGN

A cross-sectional study based on data from Electronic Medical Records (EMR).

METHODS

All children born in 2005 with permanent address in Greenland at the time of data extraction with a registered weight and height in EMR from January 1st 2011 to January 31st 2013 were included in the study. Information about height without shoes and weight in light indoor clothing was obtained. Body Mass Index (BMI) was calculated. Participants were categorized into age and gender-specific weight classes based on the International Obesity Task Force (IOTF) cut-offs for child overweight, obesity and thinness.

RESULTS

A total of 842 children born in 2005 were identified. Of those, 72% (N=607, 308 boys and 299 girls) had a recorded weight and height in the study period. In total, 74.6% (71.2-78.1) were categorized as of normal weight. The proportion of children with overweight was 15.8% (12.9-18.7) while 6.8% (4.8-8.8) were obese. In all, 2.9% were categorized as thin. The proportion of overweight among boys (12.7%) was lower (p=0.031) than among girls (19.1%), and boys in Nuuk had a lower median BMI compared to the rest of Greenland. No differences in distribution of age and gender-specific overweight and obesity were observed between the capital and the rest of Greenland.

CONCLUSION

Nearly 1 quarter of Greenlandic children are overweight or obese at school entry. No differences were observed between Nuuk and the rest of Greenland. Information about weight and height is available in the EMR for the majority of all children at school entry in Greenland. Continuous monitoring of the proportion of overweight and obesity among children using data from the EMR in Greenland is recommended.

Development of a quantitative food frequency questionnaire for use among the Yup'ik people of Western Alaska

Alaska Native populations are experiencing a nutrition transition and a resulting decrease in diet quality. The present study aimed to develop a quantitative food frequency questionnaire to assess the diet of the Yup'ik people of Western Alaska. A cross-sectional survey was conducted using 24-hour recalls and the information collected served as a basis for developing a quantitative food frequency questionnaire. A total of 177 males and females, aged 13-88, in six western Alaska communities, completed up to three 24-hour recalls as part of the Alaska Native Dietary and Subsistence Food Assessment Project. The frequency of the foods reported in the 24-hour recalls was tabulated and used to create a draft quantitative food frequency questionnaire, which was pilot tested and finalized with input from community members. Store-bought foods high in fat and sugar were reported more frequently than traditional foods. Seven of the top 26 foods most frequently reported were traditional foods. A 150-item quantitative food frequency questionnaire was developed that included 14 breads and crackers; 3 cereals; 11 dairy products; 69 meats, poultry and fish; 13 fruit; 22 vegetables; 9 desserts and snacks; and 9 beverages. The quantitative food frequency questionnaire contains 39 traditional food items. This quantitative food frequency questionnaire can be used to assess the unique diet of the Alaska Native people of Western Alaska. This tool will allow for monitoring of dietary changes over time as well as the identification of foods and nutrients that could be promoted in a nutrition intervention program intended to reduce chronic disease.

Forty-five year trends in overweight and obesity in an indigenous arctic Inuit Society in transition and spatiotemporal trends

OBJECTIVES

Overweight and obesity associate with increased morbidity and premature death. Westernization of societies heralds rising obesity rates. A steep increase in body mass index (BMI) and overweight in Greenland from 1963 to 1998 led us to follow-up on height, weight, BMI, and rates of overweight among populations in Greenland and assess time trends between different stages of transition.

METHODS

BMI was calculated from height and weight measured on Inuit and non-Inuit aged 50 through 69 years surveyed in 1963, 1998, and 2008 in Ammassalik district in East Greenland and in 1998 and 2008 in the capital Nuuk in West Greenland.

RESULTS

A total of 1,186 were surveyed in 1963 (52 men/63 women), 1998 (309/226), and 2008 (297/239). BMI increased with time (P < 0.001; 1963/1998/2008 23.3/24.3/26.2 kg/m(2) ). In addition, BMI increased with urbanization in Inuit men (P = 0.001; settlements/town/city, in 1998, 23.9/24.9/25.5 kg/m(2) ; in 2008, 25.0/26.0/27.0 kg/m(2) ) while not in Inuit women (P = 0.18). The number of overweight Inuit (BMI >27 kg/m(2) ) increased with time in men (4.0/25.6/33.2% in 1963/1998/2008, P = 0.001) and in women (13.6/30.7/37.3%, P = 0.001). BMI was above 30 kg/m(2) in 2.0/10.8/17.5% of all Inuit men in 1963/1998/2008 (P = 0.003) and in 8.3%/23.0/24.5% of all Inuit women (P = 0.02) respectively.

CONCLUSIONS

Overweight and obesity rates rise with time and with societal transition in Greenland. Settlements and town are catching up with the city where the rate of increase is diminishing, although there were gender differences.

Cardiovascular Disease Among Alaska Native Peoples

Although Alaska Native peoples were thought to be protected from cardiovascular disease (CVD), data now show that this is not the case, despite traditional lifestyles and high omega-3 fatty acid intake. In this article, the current understanding of CVD and its risk factors among Alaska Native peoples, particularly among the Yupik and Inupiat populations, will be discussed, using data from three major studies funded by the National Institutes of Health: Genetics of Coronary Artery Disease among Alaska Natives (GOCADAN), Center for Native Health Research (CANHR), and Education and Research Towards Health (EARTH). Data from these epidemiologic studies have focused concern on CVD and its risk factors among Alaska Native peoples. This review will summarize the findings of these three principal studies and will suggest future directions for research and clinical practice.

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.

The legacy of the Alaska Siberia Medical Research Program: a historical perspective

BACKGROUND

The Alaska Siberia Medical Research Program was established at the University of Alaska (UA) at a time when there was no research funded by the National Institutes of Health (NIH) that was concerned with Alaska Native health issues. The program grew out of a dire need for an understanding of the apparently rapidly growing health problems in the Native community. The initial plan included the following objectives.

OBJECTIVES

The objectives are to develop a self-sustaining infrastructure for biomedical research by gaining support from Alaska Natives, UA, national political leaders, NIH and the Russian Academy of Medical Science (RAMS); to identify researchers committed to helping Alaska Natives; to develop meaningful, Native-driven participatory research; to carry out necessary research to form the foundation for future research; and to develop circumpolar collaborations.

RESULTS

The objectives were achieved because of the extraordinary and cheerful contributions by all participants in the program. The collaborative research resulted in some 70 published manuscripts identifying and characterizing research-neglected health problems. Unique risk factors for diabetes, cardiovascular disease, alcoholism and seasonal affective disorders were characterized and institutionalized prevention programs were established. The effort of the program led to U.S. Congressional action establishing the University of Alaska as a minority institution, leading to the funding of a variety of successful NIH-funded research centres and programs at the university that are concerned with Native health problems.

CONCLUSION

A small, visionary investment by the University of Alaska for establishing the program led to a co-operative effort by the UA, RAMS, Alaska Native Health communities and the NIH that resulted in the development of self-sustaining medical research efforts in Alaska and Siberia. The program spawned pilot studies, leading to NIH-funded research that has provided fundamental insights into the etiology of health problems and their reduction by research-based intervention and prevention programs.

Does sitting height ratio affect estimates of obesity prevalence among Canadian Inuit? Results from the 2007-2008 Inuit Health Survey

OBJECTIVES

High sitting height ratio (SHR) is a characteristic commonly associated with Inuit morphology. Inuit are described as having short leg lengths and high trunk-to-stature proportions such that cutoffs for obesity derived from European populations may not adequately describe thresholds of disease risk. Further, high SHR may help explain the reduced impact of BMI on metabolic risk factors among Inuit relative to comparison populations. This study investigates the relationship between SHR and body mass index (BMI) in Inuit.

METHODS

Subjects are 2,168 individuals (837 males and 1,331 females) from 36 Inuit communities in the Canadian Arctic. Mean age is 42.63 ± 14.86 years in males and 41.71 ± 14.83 years in females. We use linear regression to examine the association between age, sex, height, sitting height, SHR, waist circumference (WC), and BMI. We then evaluate the efficacy of the relative sitting height adjustment as a method of correcting observed BMI to a population-standardized SHR.

RESULTS

Mean BMI is significantly higher than among non-Inuit Canadians. Obesity prevalence is high, particularly among Inuit women. In the regression, only age and WC are significant predictors of BMI. While SHR is significantly greater than that of the US population, there is substantial agreement between overweight and obesity prevalence using observed and corrected BMI.

CONCLUSIONS

We find no consistent relationship between SHR and BMI and suggest the unique anthropometric and metabolic profile observed in Inuit arise from factors not yet delineated. More complex anthropometric and imaging studies in Inuit are needed.

Assessing diet and lifestyle in the Canadian Arctic Inuit and Inuvialuit to inform a nutrition and physical activity intervention programme

Inuit in Nunavut (NU) and Inuvialuit in the Northwest Territories (NWT), Canada, were traditionally nomadic peoples whose culture and lifestyle were founded on hunting and gathering foods from the local environment, primarily land and marine mammals. Lifestyle changes within the last century have brought about a rapid nutrition transition, characterised by decreasing consumption of traditional foods and an associated increase in the consumption of processed, shop-bought foods. This transition may be attributed to a multitude of factors, such as acculturation, overall food access and availability, food insecurity and climate change. Obesity and risk for chronic disease are higher in the Canadian Arctic population compared with the Canadian national average. This present review describes the study population and methodologies used to collect data in order to study the nutrition transition amongst Aboriginal Arctic populations and develop Healthy Foods North (HFN), a novel, multi-institutional and culturally appropriate programme that aims to improve dietary adequacy and reduce risk of chronic disease. Included in this special issue of the Journal of Human Nutrition and Dietetics are papers describing dietary intake patterns, physical activity levels, dietary behaviours, chronic disease prevalence and psychosocial factors that potentially mediate behaviour. A further paper describes how these data were utilised to inform and develop Healthy Foods North.

Development and use of FFQ among adults in diverse settings across the globe

In nutritional epidemiology, development of valid dietary assessment instruments specific to populations in diverse settings is of paramount importance. Such instruments are essential when trying to characterise dietary patterns and intake, investigate diet-disease associations, inform and evaluate nutrition interventions, assess nutrient-gene interactions, conduct cross-country comparison studies and monitor nutrition transitions. The FFQ is a relatively inexpensive tool for measuring long-term dietary intake for large populations and for allowing researchers to track dietary changes over time. However, FFQ must be population specific to capture the local diet and available foods. Collecting 24-h dietary recalls and utilising community feedback to build the FFQ ensures that a culturally appropriate instrument is developed. This article presents several examples describing FFQ development and utilisation in different settings globally. In the Canadian Arctic, FFQ were developed and utilised to inform and evaluate a community-based intervention programme, characterise the diet and track dietary changes occurring among Inuit and Inuvialuit, populations experiencing rising rates of chronic disease and likely to be extremely vulnerable to the potential effects of climate change. Another example is an FFQ developed to assess sodium intake and evaluate a sodium reduction trial in a high-risk population in Barbados. An example is provided from Brazil, where an FFQ was developed to assess associations between diet, heterocyclic aromatic amines and colorectal adenoma among Japanese Brazilians and to conduct cross-country comparisons. These and other case studies highlight the diversity in dietary intake between populations and the need for FFQ to be developed to capture this diversity.

Prevalence and distribution of the c.1436C→T sequence variant of carnitine palmitoyltransferase 1A among Alaska Native infants

OBJECTIVES

To use genotype analysis to determine the prevalence of the c.1436C→T sequence variant in carnitine palmitoyltransferase 1A (CPT1A) among Alaskan infants, and evaluate the sensitivity of newborn screening by tandem mass spectrometry (MS/MS) to identify homozygous infants.

STUDY DESIGN

We compared MS/MS and DNA analyses of 2409 newborn blood spots collected over 3 consecutive months.

RESULTS

Of 2409 infants, 166 (6.9%) were homozygous for the variant, all but one of whom were of Alaska Native race. None of the homozygous infants was identified by MS/MS on the first newborn screen using a C0/C16 + C18 cutoff of 130. Among 633 Alaska Native infants, 165 (26.1%) were homozygous and 218 (34.4%) were heterozygous for the variant. The prevalence was highest in Alaska's northern/western regions (51.2% of 255 infants homozygous; allele frequency, 0.7).

CONCLUSIONS

The CPT1A c.1436C→T variant is prevalent among some Alaska Native peoples, but newborn screening using current MS/MS cutoffs is not an effective means to identify homozygous infants. The clinical consequences of the partial CPT1A deficiency associated with this variant are unknown. If effects are substantial, revision of newborn screening, including Alaska-specific MS/MS cutoffs and confirmatory genotyping, may be needed.

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.

Polyunsaturated fatty acids effect on serum triglycerides concentration in the presence of metabolic syndrome components. The Alaska-Siberia Project

Serum fatty acids (FAs) have wide effects on metabolism: Serum saturated fatty acids (SFAs) increase triglyceride (TG) levels in plasma, whereas polyunsaturated fatty acids (PUFAs) reduce them. Traditionally, Eskimos have a high consumption of omega-3 fatty acids (omega3 FAs); but the Westernization of their food habits has increased their dietary SFAs, partly reflected in their serum concentrations. We studied the joint effect of serum SFAs and PUFAs on circulating levels of TGs in the presence of metabolic syndrome components. We included 212 men and 240 women (age, 47.9 +/- 15.7 years; body mass index [BMI], 26.9 +/- 5.3) from 4 villages located in Alaska for a cross-sectional study. Generalized linear models were used to build surface responses of TG as functions of SFAs and PUFAs measured in blood samples adjusting by sex, BMI, and village. The effects of individual FAs were assessed by multiple linear regression analysis, and partial correlations (r) were calculated. The most important predictors for TG levels were glucose tolerance (r = 0.116, P = .018) and BMI (r = 0.42, P < .001). Triglyceride concentration showed negative associations with 20:3omega6 (r = -0.16, P = .001), 20:4omega6 (r = -0.14, P = .005), 20:5omega3 (r = -0.17, P < .001), and 22:5omega3 (r = -0.26, P < .001), and positive associations with palmitic acid (r = 0.16, P < .001) and 18:3omega3 (r = 0.15, P < .001). The surface response analysis suggested that the effect of palmitic acid on TG is blunted in different degrees according to the PUFA chemical structure. The long-chain omega3, even in the presence of high levels of saturated fat, was associated with lower TG levels. Eicosapentaenoic acid (20:5omega3) had the strongest effect against palmitic acid on TG. The total FA showed moderate association with levels of TG, whereas SFA was positively associated and large-chain PUFA was negatively associated. The Westernized dietary habits among Eskimos are likely to change their metabolic profile and increase comorbidities related to metabolic disease.

Assessing dietary intake in a population undergoing a rapid transition in diet and lifestyle: the Arctic Inuit in Nunavut, Canada

The aims of the present study were to (1) characterise the diets of adult Inuit; (2) highlight foods for a nutritional and lifestyle intervention programme; (3) develop a quantitative FFQ (QFFQ) to evaluate the programme and monitor changes in dietary intake in this population over time. A dietary survey using single 24-h dietary recalls was conducted among Inuit aged between 19 and 87 years in two communities in Nunavut, Canada. Eighty-seven subjects completed the recalls (response rate was approximately 73 %). The mean energy intake for men and women was 9530 and 6939 kJ, respectively. The intakes of dietary fibre and the majority of vitamins and minerals (especially vitamins A, D, and E, total folate and Ca) were far below the recommendations. Traditional foods contributed 40 and 42 %, respectively, to protein and Fe intakes. Non-nutrient-dense store-bought foods were consumed much more frequently than the nutrient-dense traditional foods. Foods high in fat and sugar were highlighted, and will be replaced by healthier, more nutrient-dense alternatives to address the dietary inadequacies for the nutritional intervention programme. A 154-item QFFQ was developed and pilot tested in the Arctic Inuit. The present study highlighted foods to be targeted for a nutritional and lifestyle intervention programme not previously undertaken in this population. This QFFQ is culturally appropriate and specific for evaluating the effectiveness of the programme, as well as monitoring nutritional transition in this population.

Estimated dietary exposure to fluorinated compounds from traditional foods among Inuit in Nunavut, Canada

Increasing evidence shows that persistent organic pollutants such as perfluorinated compounds (PFCs) are found in the Arctic ecosystem and their prevalence is causing human health concerns. The objective of this study was to estimate dietary exposure to PFCs among Inuit in northern Canada. Perfluorooctane sulfonate (PFOS), perfluorinated carboxylates (PFCA C(7)-C(11)) and fluorotelomer unsaturated carboxylic acids (6:2, 8:2 and 10:2 FTUCA) were measured in 68 traditional foods collected in Nunavut between 1997 and 1999. Total PFC concentrations were highest in caribou liver (mean+/-standard deviation; 6.2+/-5.5 ng g(-1)), ringed seal liver (minimum, maximum; 7.7, 10.2 ng g(-1)), polar bear meat (7.0 ng g(-1)), and beluga meat (minimum, maximum; 7.0, 5.8 ng g(-1)). Inuit food intake data from 24-h recalls conducted in Nunavut between 1997 and 1999 were used for the calculation of PFC exposure. Mean daily dietary exposure was calculated to range from 210 to 610 ng person(-1) (0.6-8.5 ng kg body weight(-1)) for 754 individuals. Dietary exposure to PFCs was statistically significantly higher in men in the 41-60 year age group (p<0.05) than younger men (<40 years old) and women from the same age group. Traditional foods contributed a higher percentage to PFC exposure than market foods in all age and gender groups. Caribou meat contributed 43-75% of daily PFC dietary exposure. Health risks associated with these estimated exposure levels are minimal based on current toxicological information available from animal feeding studies. However, it is important to monitor the concentrations of PFCs in key food items given that PFCA levels have been found to be increasing in the Canadian Arctic.

Prevalence of smoking and its relationship with carotid atherosclerosis in Alaskan Eskimos of the Norton Sound region: the GOCADAN study

Since 2000, the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study has been collecting information on cardiovascular disease (CVD) and its risk factors from 1,214 Alaska Natives of the Norton Sound region, a population with increasing rates of heart disease and stroke. Because smoking was reported in a large proportion of the participants, this analysis was undertaken to evaluate smoking patterns and their relation to other risk factors and to CVD. The relationships among smoking habits and demographic factors, body mass index, plasma fibrinogen, prevalent hypertension, and carotid plaque were evaluated. Eighty percent of participants had smoked 100+ cigarettes in their lifetime. Fifty-seven percent of women and 63% of men (p = .12) were current smokers: one in four smokers had quit. Current smokers (OR = 2.1; 95% CI = 1.1-3.8) and those who had quit <5 years ago (OR = 1.6; 95% CI = 1.1-2.2) were more likely than non-smokers to have carotid plaque. Pack-years smoked also were correlated with carotid plaque. The high prevalence of smoking and low rates of cessation in this population demonstrate an urgent need for smoking prevention and cessation programs among Alaskan Eskimos of the Norton Sound region and other Alaska Native groups.

Common set of genes regulates low-density lipoprotein size and obesity-related factors in Alaskan Eskimos: Results from the GOCADAN Study

Increasing incidence of cardiovascular disease in traditionally low-risk Alaskan Eskimos is a cause for concern. The purpose of this study was to examine the genetic and environmental correlations of low-density lipoprotein (LDL) subfractions with obesity-related factors in Alaskan Eskimos, using data from the first 954 participants of the Genetics of Coronary Artery Disease in Alaska Natives Study. Estimates of genetic and environmental influence were calculated using a maximum likelihood variance component method implemented in SOLAR. Mean values of weight, body mass index (BMI), and waist were 73.4 +/- 0.5 kg, 27.6 +/- 0.2 kg/m2, and 88.0 +/- 0.4 cm, respectively. LDL, and its small (LDL1), medium (LDL2), and large (LDL3) subfractions, had mean values of 115.8 +/- 1.2 mg/dl, 8.3 +/- 0.4 mg/dl, 19.6 +/- 0.8 mg/dl, and 71.5 +/- 1.5 mg/dl, respectively. Bivariate analysis displayed significant genetic correlations between LDL subfractions and obesity-related factors: LDL1 with BMI (rhoG = 0.67, P < 0.05), waist (rhoG = 0.80, P < 0.001), and subscapular and tricep skinfolds (rhoG = 0.93, P < 0.005, and rhoG = 0.78, P < 0.05, respectively); LDL2 with BMI (rhoG = 0.52, P < 0.05), waist (rhoG = 0.46, P < 0.05), and tricep skinfold (rhoG = 0.60, P < 0.05); and mean LDL size with BMI (rhoG = -0.36), waist (rhoG = -0.42,), and subscapular and tricep skinfolds (rhoG = -0.44 and -0.43, respectively) (P < 0.005). These results show that a common set of genes is influencing LDL size and obesity-related factors in Alaskan Eskimos.

A successful diabetes prevention study in Eskimos: the Alaska Siberia project

OBJECTIVES

To test the efficacy of a simple intervention method to reduce risk factors for type 2 diabetes (DM) and cardiovascular disease (CVD) in Alaskan Eskimos.

STUDY DESIGN

The study consisted of 1) a comprehensive screening for risk factors of 454 individuals in 4 villages, 2) a 4-year intervention and 3) a repetition of the screening in year 5 to test the efficacy of the intervention.

METHODS

Personal counseling (1hr/year) stressed the consumption of more traditional foods high in omega-3 fatty acids and less of certain specific store-bought foods high in palmitic acid, which was identified as being associated with glucose intolerance.

RESULTS

The intervention resulted in significant reductions in plasma concentrations of total cholesterol (p = 0.0001), LDL cholesterol (p = 0.0001), fasting glucose (p = 0.0001), diastolic blood pressure (p = 0.0007) and improved glucose tolerance (p = 0.0006). This occurred without loss of body weight. Sixty percent of the participants had improved glucose tolerance; only one of the 44 originally identified with impaired glucose tolerance (IGT) developed DM during the study.

CONCLUSIONS

Dramatic improvements of risk factors for DM and CVD were achieved in the intervention by primarily stressing the need for changes in the consumption of specific fats. The results suggest that fat consumption is an important risk factor for DM.

Eskimos have CHD despite high consumption of omega-3 fatty acids: the Alaska Siberia project

OBJECTIVES

The thirty-year-old hypothesis that omega-3 fatty acid (FA) may "reduce the development of thrombosis and atherosclerosis in the Western World" still needs to be tested. Dyerberg-Bang based their supposition on casual observations that coronary atherosclerosis in Greenlandic Inuit was 'almost unknown' and that they consumed large amounts of omega-3 FAs. However, no association was demonstrated with data.

STUDY DESIGN

Cross-sectional study.

METHODS

454 Alaskan Eskimos were screened for coronary heart disease (CHD), using a protocol that included ECG, medical history, Rose questionnaire, blood chemistries, including plasma FA concentrations, and a 24-hour recall and a food frequency questionnaire assessment of omega-3 FA consumption.

RESULTS

CHD was found in 6% of the cohort under 55 years of age and in 26% of those > or = 55 years of age. Eskimos with CHD consume as much omega-3 FAs as those without CHD, and the plasma concentrations confirm that dietary assessment.

CONCLUSIONS

Average daily consumption of omega-3 FAs among Eskimos was high, with about 3-4 g/d reported, compared with 1-2 g/d used in intervention studies and the average consumption of 0.2 g/d by the American population. There was no association between current omega-3 FA consumption/blood concentrations and the presence of CHD.

A genetic and epidemiologic study of cardiovascular disease in Alaska natives (GOCADAN): design and methods

This article is a report of the design and methods of the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) Study. This longitudinal, population-based study was initiated to investigate the genetic determinants of cardiovascular disease and its risk factors. Between October 2000 and April 2004, this family study enrolled 1,214 Eskimos from several coastal villages in the Norton Sound region of Western Alaska. Examinations included a physical, laboratory determinations, and measures of subclinical disease. This study will generate a genome-wide scan for loci influencing cardiovascular disease-related traits. Relations between subclinical atherosclerosis and markers of inflammation will be examined using historic and newly drawn samples. The study will provide data on CVD prevalence, risk factors and the relative contribution of genetic and environmental determinants in Alaska Native peoples. Data from this study will contribute to the delivery of health-care and prevention of CVD in Alaska Eskimos and other populations.

Springtime macronutrient intake of Alaska natives of the Bering Straits Region: the Alaska Siberia Project

OBJECTIVES

The diet of Alaska Natives is a complicated mix of native and imported foods. Dietary intake, which may have changed considerably in the past several decades, has important implications for risk of chronic disease. The objective of this study was to add to the knowledge of dietary intake of Alaska Natives of the Bering Straits Region by describing the macronutrient intake of adults.

STUDY DESIGN

Observational study of dietary intake.

METHODS

A 24-hour dietary recall was administered among all consenting, non-pregnant residents of four villages, aged 25 years, or more.

RESULTS

Data are presented for 209 men and 225 women, who represent 48% of eligible participants. Dietary intake was higher in proportion of energy from protein and lower in proportion of carbohydrate than non-Hispanic white Americans overall. Higher energy and protein intakes were reported for men. Comparisons were also made among Alaskan ethnic groups and previous Alaskan surveys.

CONCLUSION

This study of diet among Alaska Natives demonstrates consistency with other recent work. Differences in diet from earlier 20th century observations, such as higher carbohydrate and lower protein intake, are consistent with documented acculturation in Alaska and other circumpolar regions.

Molecular mechanisms associated with leptin resistance: n-3 polyunsaturated fatty acids induce alterations in the tight junction of the brain

High-fat diets cause peripheral leptin resistance, and dietary lipid composition affects sensitivity to leptin. We examined the role of n-3 polyunsaturated fatty acid (PUFA) in peripheral leptin resistance. Dietary PUFAs (0.4% wt/wt) caused insensitivity to peripherally but not intracerebroventricularly administered leptin. n-3 PUFA increased body weight, associated with a significant reduction of leptin concentration in the cerebrospinal fluid. Dietary n-3 PUFA reduced transport of endogenous or exogenously administered leptin into the brain, associated with increased expression of hypothalamic occludin, but caused no change in expression of leptin receptors, proteins associated with leptin signaling or other tight junction proteins. Continuous intracerebroventricular infusion of an antisense morpholino oligonucleotide targeted to occludin mRNA reversed n-3 PUFA-induced insensitivity to peripherally administered leptin. We conclude that n-3 PUFA induces peripheral leptin resistance via an increase in the expression of hypothalamic occludin, reducing paracellular transport of leptin into the brain.

Dietary intakes vary with age among Eskimo adults of Northwest Alaska in the GOCADAN study, 2000-2003

Dietary factors influence the development of cardiovascular disease (CVD). The diet of Alaskan Eskimos differs from that of other populations. We surveyed Eskimo adults in Northwest Alaska to document their usual dietary intakes, differences based on gender and age, and sources of selected nutrients, and to generate appropriate dietary advice to reduce CVD. Interviewers surveyed 850 men and women 17-92 y old, using a quantitative food-frequency instrument. We observed many significant (chi(2) analysis P < 0.05) differences in nutrient intakes among 3 age-groups. Energy intake from carbohydrate was negatively related to participant age-group (P < or = 0.01). Energy intake from all fats (P < 0.001) and polyunsaturated fat (P < or = 0.01) was positively related to age-group among both men and women in contrast to other studies in which age differences were either not observed or decreased with age. Native foods were major sources of monounsaturated and polyunsaturated fats, including 56% of (n-3) fatty acids primarily from seal oil and salmon. However, Native foods contributed significantly less to the diets of young adults than to those of elders, especially among women. Store-bought foods were the main sources of energy, carbohydrate, fat, saturated fat, and fiber for all adults. Based on their nutrient density and potential to inhibit CVD, continued consumption of traditional foods is recommended. Variations in intake by age may portend changing eating patterns that will influence CVD as participants age. These data will contribute to understanding dietary risk factors for cardiovascular disease in this population.

Heart Disease Prevention for Alaska Native Women: A Review of Pilot Study Findings

BACKGROUND

Although historically Alaska Native women have had a relatively low incidence of cardiovascular disease (CVD), this pattern has changed dramatically in recent years. Alaska Native leaders have identified decreasing cardiovascular risk as an intervention priority.

METHODS

From October 2000 to April 2001, Southcentral Foundation, an Alaska Native-owned and managed health corporation in Anchorage, conducted a pilot randomized controlled trial of a heart disease prevention program tailored for Alaska Native women. The aim was to assess feasibility and cultural acceptability and to develop enrollment procedures. Of 76 women who enrolled, 44 were randomized to the intervention group. Thirty-seven of 44 attended at least two intervention sessions, 23 completed prequestionnaires and postquestionnaires, and 27 returned for 12-month follow-up screening. Thirty of 32 control group participants returned for 12-month follow-up screening. The intervention included 12 weekly sessions on lifestyle change and goal setting. At baseline and 12 months, participants' height, weight, resting blood pressure, fasting lipid levels, and blood glucose were measured. At sessions 1 and 12, participants completed assessments regarding diet, physical activity, tobacco use, and psychosocial status.

RESULTS

At 12 weeks, significant improvements were noted in moderate walking and physical activity self-efficacy. Also observed was substantial movement from the contemplation and preparation stages to the action stage regarding physical activity and heart-healthy eating.

CONCLUSIONS

Although the small sample size precludes drawing conclusions about the intervention's effect, participants reported lifestyle and psychosocial changes. The pilot study resulted in protocol changes that improved the design and implementation of a subsequent large-scale study.

Diabetes among Alaska Natives: a review

This review summarizes the published information on diabetes mellitus and gestational diabetes among Alaska Natives. The most recently published age-adjusted prevalence was 28.3/1000 in 1998. There is evidence of a steadily increasing prevalence, documented both by cross sectional screening studies and patient registry methods. The overall incidence rates in 1986-1998 of lower extremity amputation (6.1/1000) and renal replacement therapy (2.1/1000) appear to be lower than those in other Native American populations in the United States. Incidence of stroke and MI in 1986-1998 varied widely by ethnic group and gender with Eskimo women having the highest rate of stroke (19.6/1000), and Aleut men the highest rate of MI (14/1000). The overall mortality among diabetic Alaska Native people in 1986-1993 (43.2/1000) was somewhat lower than that in other US diabetic populations, with heart disease being the most common cause of death. A high rate of gestational diabetes (6.7%) was reported in one region in 1987-88, but this appeared to decline following nutritional education intervention. In screening studies, the prevalence of abnormal glucose tolerance has been found to be positively associated with body mass index and negatively associated with daily seal oil or salmon consumption and higher levels of physical activity. Observations on the prevalence and relationships among other factors in the insulin resistance syndrome are summarized. Suggestions for prevention of diabetes and further studies are presented.

Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants

OBJECTIVE

To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization.

DESIGN

Cross-sectional, population-based epidemiological study.

SUBJECTS

A total of 2046 adult Greenlanders (Inuit), 61% of those invited to participate, living in three areas of Greenland and in Denmark.

MEASUREMENTS

Height, weight, waist and hip circumferences were measured and body mass index (BMI in kg/m(2)) and waist-hip ratio calculated. Sociocultural information was obtained by questionnaire and interview. Westernization was estimated by language and place of residence.

RESULTS

The prevalence of obesity (>or=30 kg/m(2)) was 16 and 22% among men and women in Greenland (P=0.004), and 12 and 11%, respectively, in Denmark (NS). Westernization was accompanied by a decrease in the proportion of obese people, in particular among women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland.

CONCLUSION

BMI and central fat patterning decrease with Westernization among Greenland Inuit women contrary to most studies of migrants. The changes were less prominent among men. This suggests a reduced cardiovascular risk profile with Westernization among Greenland Inuit.