Circumpolar Populations Research Articles

Brown adipose tissue, energy expenditure, and biomarkers of cardio-metabolic health among the Yakut (Sakha) of northeastern Siberia.

This study provides the first investigation of non-shivering thermogenesis (NST) and brown adipose tissue (BAT) activity among an indigenous circumpolar population, the Yakut of northeastern Siberia. The study also examines the health significance of BAT activity in this population by testing the relationships between BAT thermogenesis and biomarkers of cardio-metabolic disease risk, such as percent body fat and blood glucose and cholesterol levels. Data were collected in the Sakha Republic (Yakutia) for 31 men and 43 women. Change in energy expenditure and BAT thermogenesis were quantified after a 30-minute mild cooling condition. Anthropometric dimensions, blood glucose, and lipid levels were also collected. On average, the skin temperature of the supraclavicular area was constant after cooling while the skin temperature of a point on the sternum dropped significantly (P < .001), thus suggesting the presence of active supraclavicular BAT among Yakut adults. Participants with evidence of greater BAT thermogenesis exhibited a larger percent change in energy expenditure (% ΔEE) and an increase in respiratory quotient (RQ) after cooling (P ≤ .05). While there was no relationship between BAT activity and blood lipid levels, BAT thermogenesis was positively associated with blood glucose levels (P < .01). Yakut adults exhibit evidence of active BAT deposits. Given that there is a significant relationship between BAT activity and % ΔEE, it is possible that BAT plays a role in NST among Yakut adults. While the relationship between BAT and body composition is inconclusive, participants with greater BAT seemed to preferentially utilize glucose during cold stress exposure.

Unusually high Deca-BDE concentrations and new flame retardants in a Canadian Arctic top predator, the glaucous gull

Despite a sustained effort in surveying flame retardants (FRs) in wildlife from industrialized regions, their occurrence in birds or any other wildlife species spanning the Arctic regions, particularly in North America, has received limited attention. This study investigated in the top predator glaucous gull (Larus hyperboreus) breeding in the Eastern Canadian Arctic (Cape Dorset, Nunavut) a comprehensive suite of FRs including unstudied halogenated and non-halogenated FRs of potential health concern, along with legacy organochlorines and mercury. The influence of diet acquired locally and in wintering areas on the tissue contaminant profiles was also investigated using δ15N and δ13C signatures in liver and feathers. The principal constituent in the Deca-brominated diphenyl ether (BDE) mixture, BDE-209, was remarkably the most concentrated PBDE congener determined in liver samples of Eastern Canadian Arctic glaucous gulls. This suggests dietary exposure from the local marine food web and perhaps also from nearby community landfills. Moreover, this study revealed for the first time the presence of 16 emerging halogenated and non-halogenated FRs in glaucous gulls from this Arctic region including HBB, DDC-CO (anti and syn isomers), PBEB, EHTBB, BEHTBP as well as a series of organophosphate esters (OPEs) (TCEP, TCIPP, TPP, TDCIPP, TDBPP, TBNP, TBOEP, TBEP, TCrP, EHDPP, and TEHP). With the exception of BDE-209, concentrations of other halogenated FRs and organochlorines were found to be in the lower range in liver of Eastern Canadian Arctic glaucous gulls compared to individuals from other circumpolar populations (Svalbard and Greenland). Mercury and methylmercury concentrations, however, were greater than reported elsewhere for glaucous gull populations.

Incorporating non-equilibrium dynamics into demographic history inferences of a migratory marine species.

Understanding how dispersal and gene flow link geographically separated the populations over evolutionary history is challenging, particularly in migratory marine species. In southern right whales (SRWs, Eubalaena australis), patterns of genetic diversity are likely influenced by the glacial climate cycle and recent history of whaling. Here we use a dataset of mitochondrial DNA (mtDNA) sequences (n = 1327) and nuclear markers (17 microsatellite loci, n = 222) from major wintering grounds to investigate circumpolar population structure, historical demography and effective population size. Analyses of nuclear genetic variation identify two population clusters that correspond to the South Atlantic and Indo-Pacific ocean basins that have similar effective breeder estimates. In contrast, all wintering grounds show significant differentiation for mtDNA, but no sex-biased dispersal was detected using the microsatellite genotypes. An approximate Bayesian computation (ABC) approach with microsatellite markers compared the scenarios with gene flow through time, or isolation and secondary contact between ocean basins, while modelling declines in abundance linked to whaling. Secondary-contact scenarios yield the highest posterior probabilities, implying that populations in different ocean basins were largely isolated and came into secondary contact within the last 25,000 years, but the role of whaling in changes in genetic diversity and gene flow over recent generations could not be resolved. We hypothesise that these findings are driven by factors that promote isolation, such as female philopatry, and factors that could promote dispersal, such as oceanographic changes. These findings highlight the application of ABC approaches to infer the connectivity in mobile species with complex population histories and, currently, low levels of differentiation.

Dietary and genetic influences on hemostasis in a Yup'ik Alaska Native population.

Fish and marine animals are important components of the subsistence diet of Alaska Native people, resulting in a high ω3 PUFA intake. The historical record for circumpolar populations highlights a tendency for facile bleeding, possibly related to ω3 PUFA effects on platelet activation and/or vitamin K-dependent clotting factors. To evaluate these two scenarios in Yup’ik people of southwestern Alaska, we examined the association between dietary ω3 PUFA intake and activities of clotting factor II, V, fibrinogen, PT, INR, PTT, and sP-selectin in 733 study participants, using the nitrogen isotope ratio of red blood cells as a biomarker of ω3 PUFA consumption. sP-selectin alone correlated strongly and inversely with ω3 PUFA consumption. Approximately 36% of study participants exhibited PIVKA-II values above the threshold of 2 ng/ml, indicative of low vitamin K status. To assess genetic influences on vitamin K status, study participants were genotyped for common vitamin K cycle polymorphisms in VKORC1, GGCX and CYP4F2. Only CYP4F2*3 associated significantly with vitamin K status, for both acute (plasma vitamin K) and long-term (PIVKA-II) measures. These findings suggest: (i) a primary association of ω3 PUFAs on platelet activation, as opposed to vitamin K-dependent clotting factor activity, (ii) that reduced CYP4F2 enzyme activity associates with vitamin K status. We conclude that high ω3 PUFA intake promotes an anti-platelet effect and speculate that the high frequency of the CYP4F2*3 allele in Yup’ik people (~45%) evolved in response to a need to conserve body stores of vitamin K due to environmental limitations on its availability.

Geographic structure in the Southern Ocean circumpolar brittle star Ophionotus victoriae (Ophiuridae) revealed from mtDNA and single-nucleotide polymorphism data.

Marine systems have traditionally been thought of as “open” with few barriers to gene flow. In particular, many marine organisms in the Southern Ocean purportedly possess circumpolar distributions that have rarely been well verified. Here, we use the highly abundant and endemic Southern Ocean brittle star Ophionotus victoriae to examine genetic structure and determine whether barriers to gene flow have existed around the Antarctic continent. Ophionotus victoriae possesses feeding planktotrophic larvae with presumed high dispersal capability, but a previous study revealed genetic structure along the Antarctic Peninsula. To test the extent of genetic differentiation within O. victoriae, we sampled from the Ross Sea through the eastern Weddell Sea. Whereas two mitochondrial DNA markers (16S rDNA and COI) were employed to allow comparison to earlier work, a 2b‐RAD single‐nucleotide polymorphism (SNP) approach allowed sampling of loci across the genome. Mitochondrial data from 414 individuals suggested three major lineages, but 2b‐RAD data generated 1,999 biallelic loci that identified four geographically distinct groups from 89 samples. Given the greater resolution by SNP data, O. victoriae can be divided into geographically distinct populations likely representing multiple species. Specific historical scenarios that explain current population structure were examined with approximate Bayesian computation (ABC) analyses. Although the Bransfield Strait region shows high diversity possibly due to mixing, our results suggest that within the recent past, dispersal processes due to strong currents such as the Antarctic Circumpolar Current have not overcome genetic subdivision presumably due to historical isolation, questioning the idea of large open circumpolar populations in the Southern Ocean.

Linkage and association analysis of circulating vitamin D and parathyroid hormone identifies novel loci in Alaska Native Yup'ik people.

BackgroundVitamin D deficiency is a well-documented public health issue with both genetic and environmental determinants. Populations living at far northern latitudes are vulnerable to vitamin D deficiency and its health sequelae, although consumption of traditional native dietary pattern rich in fish and marine mammals may buffer the effects of reduced sunlight exposure. To date, few studies have investigated the genetics of vitamin D metabolism in circumpolar populations or considered genediet interactions with fish and n-3 fatty acid intake.MethodsWe searched for genomic regions exhibiting linkage and association with circulating levels of vitamin D and parathyroid hormone (PTH) in 982 Yup’ik individuals from the Center for Alaska Native Health Research Study. We also investigated potential interactions between genetic variants and a biomarker of traditional dietary intake, the δ15N value.ResultsWe identified several novel regions linked with circulating vitamin D and PTH as well as replicated a previous linkage finding on 2p16.2 for vitamin D. Bioinformatic analysis revealed multiple candidate genes for both PTH and vitamin D, including CUBN, MGAT3, and NFKBIA. Targeted association analysis identified NEBL as a candidate gene for vitamin D and FNDC3B for PTH. We observed significant associations between a variant in MXD1 and vitamin D only when an interaction with the δ15N value was included. Finally, we integrated pathway level information to illustrate the biological validity of the proposed candidate genes.ConclusionWe provide evidence of linkage between several biologically plausible genomic regions and vitamin D metabolism in a circumpolar population. Additionally, these findings suggest that a traditional dietary pattern may modulate genetic effects on circulating vitamin D.Electronic supplementary materialThe online version of this article (doi:10.1186/s12263-016-0538-y) contains supplementary material, which is available to authorized users.

Lifestyle mediates seasonal changes in metabolic health among the yakut (sakha) of northeastern siberia.

Among indigenous circumpolar populations, extreme seasonality influences food availability and energy metabolism. Furthermore, subsistence patterns and wage labor opportunities shift with season. Thus, health measures among circumpolar populations likely exhibit seasonal changes that are influenced by lifestyle factors. This study examines how markers of cardio-metabolic health vary between summer and winter as a function of an individual's lifestyle and sex among the Yakut of northeastern Siberia. Anthropometric dimensions, serum lipids and glucose levels, blood pressure, and lifestyle data were collected for a sample of 115 Yakut participants (71 women, 44 men) in Berdygestiakh, Sakha Republic, Russia in the summer of 2009 and winter of 2011. Men and women experienced significant increases in total and HDL cholesterol and triglyceride levels from summer to winter. Women exhibited winter-time increases in adiposity and glucose levels. Men who reported greater market integration were more likely to have lower winter blood pressure levels. Additionally, time spent fishing was associated with lower winter-time LDL cholesterol, while foraging time was associated with higher HDL cholesterol. While seasonal changes in anthropometric dimensions were modest, Yakut men and women experienced significant increases in total cholesterol and HDL cholesterol from summer to winter. These results also suggest that while Yakut individuals with greater subsistence participation are more buffered from adverse seasonal changes in cholesterol levels, they may be at a greater risk for winter increases in blood pressure. Furthermore, the interactions between lifestyle and seasonal change in metabolic health appear to differ between Yakut women and men. Am. J. Hum. Biol. 28:868-878, 2016. © 2016Wiley Periodicals, Inc.

Assessing the health effects of climate change in Alaska with community-based surveillance

The environmental effects of climate change are greatest in the northern latitudes. There is a need for epidemiological investigations to assess the health impacts of climate change on the health of residents of the circumpolar north. This study employed a participatory, community-based surveillance system to collect repeated observations of environmental conditions and syndromic health outcomes in sentinel communities across three ecologically distinct regions of Alaska. The study revealed that unintentional injury was significantly more likely in months when respondents reported unseasonable environmental conditions, and particularly so when they changed travel plans as a consequence of those conditions. The study also found that incidence of respiratory syndromes, such as pollen allergies and asthma, were significantly higher during months when unseasonable environmental conditions were observed. We conclude that unseasonable environmental conditions likely associated with climate change are having adverse effects on the health of circumpolar northern populations.

On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management.

Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71% decline in the area of lichen-abundant forests over the last 60years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.

How ‘Circumpolar’ is Ainu Music? Musical and Genetic Perspectives on the History of the Japanese Archipelago

Understanding the cultural and genetic origins of the Ainu of northern Japan has important implications for understanding the history of the Japanese archipelago. Ethnomusicologists have tended to emphasise connections between Ainu music and a ‘circumpolar’ culture area. However, the ‘dual structure’ model from physical anthropology describes the Ainu as descendants of the first inhabitants of Japan with minimal circumpolar influence. To examine Ainu musical diversity empirically from a comparative perspective, we analysed 680 traditional songs from two Ainu and 33 surrounding East Asian and circumpolar populations. The Ainu repertoire contained a majority (∼50%) of unique stylistic song-types and lower frequencies of types shared with circumpolar (∼40%) and East Asian (∼10%) populations. These frequencies were similar to the corresponding frequencies of mitochondrial DNA types within the Ainu gene pool (∼50%, ∼30% and ∼20%, respectively), consistent with an emerging ‘triple structure’ model of Japanese archipelago history.

Observing the Changing Health of Circumpolar Peoples

This paper describes the elements involved in observing health in circumpolar regions, the status of current observation systems, and gaps within the monitoring networks. The aim is to provide a starting point for discussion of the role that health monitoring might play in developing Arctic observing networks and initiatives that aim to improve the health status of circumpolar populations. It is hoped that this background information will provide direction for further development of monitoring systems and networks through supporting data capture, analysis, and uptake.

A scoping review of Indigenous suicide prevention in circumpolar regions

BackgroundSuicide is a serious public health challenge in circumpolar regions, especially among Indigenous youth. Indigenous communities, government agencies and health care providers are making concerted efforts to reduce the burden of suicide and strengthen protective factors for individuals, families and communities. The persistence of suicide has made it clear that more needs to be done.ObjectiveOur aim was to undertake a scoping review of the peer-reviewed literature on suicide prevention and interventions in Indigenous communities across the circumpolar north. Our objective was to determine the extent and types of interventions that have been reported during past decade. We want to use this knowledge to support community initiative and inform intervention development and evaluation.DesignWe conducted a scoping review of online databases to identify studies published between 2004 and 2014. We included articles that described interventions in differentiated circumpolar Indigenous populations and provided evaluation data. We retained grey literature publications for comparative reference.ResultsOur search identified 95 articles that focused on suicide in distinct circumpolar Indigenous populations; 19 articles discussed specific suicide-related interventions and 7 of these described program evaluation methods and results in detail. The majority of publications on specific interventions were found in North American countries. The majority of prevention or intervention documentation was found in supporting grey literature sources.ConclusionDespite widespread concern about suicide in the circumpolar world and active community efforts to promote resilience and mental well-being, we found few recorded programs or initiatives documented in the peer-reviewed literature, and even fewer focusing specifically on youth intervention. The interventions described in the studies we found had diverse program designs and content, and used varied evaluation methods and outcomes. The studies we included consistently reported that it was important to use community-based and culturally guided interventions and evaluations. This article summarizes the current climate of Indigenous circumpolar suicide research in the context of intervention and highlights how intervention-based outcomes have largely remained outside of peer-reviewed sources in this region of the world.

Conservation genetics of high-arctic Gull species at risk: I. Diversity in the mtDNA control region of circumpolar populations of the Endangered Ivory Gull (Pagophila eburnea)

The high-arctic Ivory Gull (Pagophila eburnea) has recently undergone a sharp decline in numbers, and in Canada it is listed as “Endangered” under the Species-At-Risk Act. To test for circumpolar genetic distinctiveness, we examined 264 bp of the mtDNA Control Region Domain I from 127 museum specimens collected during the breeding season from northern Canada, Greenland, and Norway, and during the non-breeding season from adjacent overwintering grounds in Canada, Greenland, and a disjunct area in Alaska adjacent to the Bering Sea. Partition of genetic variance according to various phylogeographic and breeding ground models indicates no strong population structure, except that Alaska birds are consistently differentiated from other locations, and there are significant temporal shifts in haplotype frequencies. The evidence suggests that Ivory Gulls in Canada, Greenland, and Norway are a single genetic entity, in contrast to Alaska birds, which may represent a distinctive Siberian population.

Do physical activity and sedentary behavior relate to cardio-metabolic risk factor clustering in indigenous Siberian adults?

To investigate whether having multiple risk factors for cardio-metabolic disease is associated with objectively measured physical activity or sedentary behavior within a sample of Yakut (Sakha) of Siberia. This cross sectional study involved 63 Yakut adults (32 men) who were measured for cardio-metabolic risk factors. Free living physical activity and sedentary behavior were calculated from waist accelerometry. Correlations and t-tests were used to assess the relationship between moderate-vigorous physical activity (MVPA), sedentary behavior (SB), and individual risk factors and clustering of risk factors. These Yakut were physically active, with 54.4% spending at least 30 min in MVPA, with men being more active than women and women having less favorable cardio-metabolic profiles. These Yakut spent about 7.5 h in SB a day. SB was not related to cardio-metabolic risk factors. MVPA was significantly and negatively related to waist circumference and risk factor clustering in men and the total sample. MVPA was not related to women's risk factors. Objectively measured physical activity was related to lower risk of cardio-metabolic risk factor clustering within this sample of Yakut men, but not women. SB was not related to cardio-metabolic indicators. Physical activity may contribute to a reduction in clustering of metabolic risk factors within indigenous circumpolar populations.

Examining relationships between climate change and mental health in the Circumpolar North

Indigenous people living in the Circumpolar North rely, to varying degrees, on the natural environment and the resources it provides for their lifestyle and livelihoods. As a consequence, these Northern Indigenous peoples may be more sensitive to global climate change, which has implications for food security, cultural practices, and health and well-being. To date, most research on the human dimensions of climate change in the Circumpolar North has focused on biophysical issues and their consequences, such as changing sea ice regimes affecting travel to hunting grounds or the effects of melting permafrost on built infrastructure. Less is known about how these changes in the environment affect mental health and well-being. In this paper, we build upon existing research, combined with our community-based research and professional mental health practices, to outline some pathways and mechanisms through which climate change may adversely impact mental health and well-being in the Circumpolar North. Our analysis indicates that mental health may be affected by climate change due to changes to land, ice, snow, weather, and sense of place; impacts to physical health; damage to infrastructure; indirect impacts via media, research, and policy; and through the compounding of existing stress and distress. We argue that climate change is likely an emerging mental health challenge for Circumpolar Indigenous populations and efforts to respond through research, policy, and mental health programming should be a priority. We conclude by identifying next steps in research, outlining points for policy, and calling for additional mental health resources that are locally responsive and culturally relevant.

Seasonal variation in basal metabolic rates among the yakut (Sakha) of Northeastern Siberia

Previous research has shown that indigenous circumpolar populations have elevated basal metabolic rates (BMRs), yet few studies have explored whether metabolic rates increase during the winter. This study addresses this gap by examining seasonal variation in BMR and its associations with thyroid function and lifestyle factors among the Yakut (Sakha) of Siberia. Anthropometric dimensions, BMR, and thyroid hormone levels (free triiodothyronine [fT3], free thyroxine [fT4], thyroid-stimulating hormone [TSH]) were measured on two occasions (July/August, 2009 and January 2011) on a sample of 94 Yakut (Sakha) adults (35 men, 59 women) from the rural village of Berdygestiakh, Sakha Republic, Russia. Seasonal changes in BMR varied by age. Younger Yakut adults (19-49 years) showed significant elevations in winter-time BMR of 6% (P < 0.05), whereas older individuals (≥50 years) showed modest declines (2%; n.s.). Both younger and older Yakut men and women showed increased respiratory quotients during the winter. FT3 and fT4 levels significantly declined during the winter in both younger and older Yakut men and women (P < 0.05). Lifestyle factors were significant predictors of BMR variation, particularly among older men and women. Among the Yakut, increased wintertime BMR was observed among younger but not older adults, whereas all adults showed sharp reductions in free thyroid hormone levels during the winter. Among men, greater participation in subsistence activities was associated with increased BMRs and greater fat oxidation. Among women, variation in food use had the strongest impact on metabolic function.

Health of Indigenous Circumpolar Populations

Indigenous circumpolar populations have experienced profound transitions in lifeways over the past half-century as a result of economic development. Although there have been positive aspects of this social transformation, most circumpolar groups today have a triple burden of disease, with a modestly elevated infectious disease level, an elevated and increasing burden of chronic conditions such as obesity and cardiovascular disease, and high rates of mental health–related challenges. The health of contemporary circumpolar populations is not easily characterized because of dramatic regional differences that stem from socioeconomic disparities among nonindigenous groups, individual population histories, lifestyle factors, environmental pollution, and underlying biological variation. Overall health and well-being range from excellent among the Sami of Sweden and Norway to extremely poor among marginalized native populations in northern Russia. Circumpolar groups today are not only threatened by continued regional economic development and pollution, but also uniquely vulnerable to global climate change.

Assessing the social and physical determinants of circumpolar population health

IntroductionSystematic reviews of the social and physical determinants of health provide metrics for evaluation of programs to mitigate health disparities. Previous meta-analyses of the population health literature have identified several proximate social and physical determinants of population health in the circumpolar north including addiction, environmental exposures, diet/nutrition and global climate change. Proximate health determinants are most amenable to early detection and modification or mitigation through disease prevention or health promotion interventions.DesignThere is a need for research to replicate these findings based on the latest science. This presentation describes a study applying Dahlgren and Whitehead's (1991) socio-ecological model of health determinants to identify the proximate social and physical determinants of health in the circumpolar north.MethodsThe study consisted of a systematic review of recent studies that link determinants of health with the leading causes of mortality and morbidity in Alaska. Our search strategy employed a keyword search using the Circumpolar Health Bibliographic Database (CHBD) and 4 databases within the Web of Knowledge (WoK) data gateway. Keywords included various terms for the arctic, all relevant nations and territories within the region, as well as leading health outcomes.ResultsStudies meeting the following inclusion criteria were reviewed: original research within a circumpolar population, published in English during 2011, and involving a rigorous demonstration of a link between a social determinant and selected health outcomes.ConclusionsStudy conclusions includes a list of determinants identified, their associated outcomes and the study designs implemented to assess that association.

Is aging recorded in blood Cu and Zn isotope compositions?

Recent isotopic observations of animal samples indicate body accumulation of heavy zinc and light copper throughout life. This hypothesis has never been tested for humans, but the existence of a relationship between blood isotopic composition and age could be promising for age assessment methodologies. Dietary habits can also influence the blood zinc isotope composition, being an additional source of isotopic variation. In order to reduce this putative source of variation, we selected a population living in an isolated area (Sakha Republic, Russia) where diverse foods are of limited availability. We sampled blood from 8 male and 31 female Yakut volunteers between the ages of 18 and 74. Zinc, iron and copper were purified by liquid chromatography on ion exchange resin and their stable isotope ratios were measured using multiple-collector inductively coupled plasma mass spectrometry. According to observations of animal samples, the (66)Zn/(64)Zn ratio increases with age. We also observe that the (65)Cu/(63)Cu ratio decreases with age, whereas iron isotopic compositions are unrelated to age. The copper and zinc isotope compositions of the Yakut's blood are significantly lighter and heavier, respectively, than in samples of European and Japanese populations. The Yakut is a circumpolar population in which individuals have an elevated basal metabolic rate in response to cold stress. This elevated basal metabolic rate could enhance copper and zinc isotopic fractionation by accelerating the turnover of the copper and zinc stores.

Four Mutations in the SI Gene Are Responsible for the Majority of Clinical Symptoms of CSID

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