Diabetes and impaired glucose tolerance among the inuit population of Greenland

The worldwide trend in diabetes awareness, treatment, and control from 1985 to 2022: a systematic review and meta-analysis of 233 population-representative studies

Background

With the rapid increase in the prevalence of DM, studies on the awareness, treatment, and control of this condition are essential. Therefore, this study aimed to review the literature and pool the awareness, treatment, and control of diabetes at the global, regional, and national levels.

Methods

In this systematic review and meta-analysis, several databases, including MEDLINE/PubMed, Institute of Scientific Information (ISI), Scopus, and Google Scholar, were searched using appropriate keywords up to June 2022. Observational studies investigating the awareness, treatment, and control of glucose levels among diabetic individuals were included. Awareness, treatment, and control were defined as the proportion of participants who were aware of their diabetes condition, treated pharmacologically, and achieved adequate glucose control, respectively. Two investigators independently conducted the study selection, data extraction, and quality assessment. Heterogeneity among studies was calculated using Chi-square, and a random-effect meta-analysis was used to pool the rates.

Results

A total of 233 studies published between 1985 and 2022 met the inclusion criteria. The included studies had a combined population of 12,537,968. The pooled awareness of DM was 60% (95%CI: 56-63) and ranged from 41% (25-57) in low-income countries to 68% (64-72) in high-income countries, with no significant trend observed over the assessed periods at the global level. The pooled treatment of DM globally was 45% (42-48) and varied from 37% (31-43) in lower-middle-income countries to 53% (47-59) in high-income countries, showing variation over the examined time period. Before 2000, the proportion of adequate DM control was 16% (12-20), which significantly improved and reached 22% (19-25) after 2010. The pooled awareness, treatment, and control of DM were higher in females, high-income countries, and urban areas compared to males, upper and lower-middle-income countries, and rural areas, respectively. The older adults population had higher awareness and treatment rates than the adult population, but their DM control did not differ significantly.

Conclusion

Despite the high level of awareness and treatment among the diabetic population, treatment success (control) is considerably low, particularly in low-income countries and rural areas. It is crucial to improve awareness, treatment, and control by strengthening the primary care system in all countries.

Inverted U-Shaped Association of Plasma Resolvin D2 With Atherosclerotic Cardiovascular Disease and the Mediation Effects of Serum Cholesterol: A Chinese Community-Based Study

BACKGROUND

Resolvin D2 (RvD2) has been reported to protect against the development of atherosclerosis in animal models. The objective of this study was to examine the prospective association between plasma RvD2 and the risk of atherosclerotic cardiovascular disease (ASCVD) at the population level.

METHODS AND RESULTS

A cohort of 2633 community-dwelling individuals aged 35-60 years was followed for 8 years in this study. Adjusted hazard ratios and 95% CIs for ASCVD outcomes according to baseline RvD2 levels were calculated using Cox proportional hazards models. Mediation analysis was used to test the indirect effect of serum cholesterol indicators on the association between RvD2 and ASCVD probability. In total, 284 new cases of ASCVD were identified during follow-up. An inverted U-shaped association between natural log (ln)-transformed RvD2 and incident ASCVD was determined, and the threshold value for lnRvD2 was 3.87. Below the threshold, each unit increase in lnRvD2 was associated with a 2.05-fold increased risk of ASCVD (95% CI, 1.13-3.74; P=0.019). Above the threshold, each unit increase in lnRvD2 was associated with a 36% reduced risk of ASCVD (95% CI, 0.51-0.80; P<0.001). In addition, the association between RvD2 and ASCVD probability was partially mediated by high-density lipoprotein cholesterol (15.81%) when lnRvD2 <3.87, but by total cholesterol (30.23%) and low-density lipoprotein cholesterol (30.13%) when lnRvD2 ≥3.87.

CONCLUSIONS

Both lower and higher RvD2 levels are associated with a reduced risk of ASCVD, forming an inverted U-shaped relationship. Furthermore, this association is partially mediated by total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol.

The effect of traditional diet on glucose homoeostasis in carriers and non-carriers of a common TBC1D4 variant in Greenlandic Inuit: a randomised crossover study

Consumption of traditional foods is decreasing amid a lifestyle transition in Greenland as incidence of type 2 diabetes (T2D) increases. In homozygous carriers of a TBC1D4 variant, conferring postprandial insulin resistance, the risk of T2D is markedly higher. We investigated the effects of traditional marine diets on glucose homoeostasis and cardio-metabolic health in Greenlandic Inuit carriers and non-carriers of the variant in a randomised crossover study consisting of two 4-week dietary interventions: Traditional (marine-based, low-carbohydrate) and Western (high in imported meats and carbohydrates). Oral glucose tolerance test (OGTT, 2-h), 14-d continuous glucose and cardio-metabolic markers were assessed to investigate the effect of diet and genotype. Compared with the Western diet, the Traditional diet reduced mean and maximum daily blood glucose by 0·17 mmol/l (95 % CI 0·05, 0·29; P = 0·006) and 0·26 mmol/l (95 % CI 0·06, 0·46; P = 0·010), respectively, with dose-dependency. Furthermore, it gave rise to a weight loss of 0·5 kg (95 % CI; 0·09, 0·90; P = 0·016) relative to the Western diet and 4 % (95 % CI 1, 9; P = 0·018) lower LDL:HDL-cholesterol, which after adjustment for weight loss appeared to be driven by HDL elevation (0·09 mmol/l (0·03, 0·15), P = 0·006). A diet-gene interaction was indicated on insulin sensitivity in the OGTT (p = 0·093), which reflected a non-significant increase of 1·4 (-0·6, 3·5) mmol/l in carrier 2-h glucose. A Traditional diet marginally improved daily glycaemic control and plasma lipid profile compared with a Westernised diet in Greenlandic Inuit. Possible adverse effects on glucose tolerance in carriers of the TBC1D4 variant warrant further studies.

The effect of diabetes and the diabetogenic TBC1D4 p.Arg684ter variant on kidney function in Inuit in Greenland

The aim of this study was to examine the effect of diabetes and the diabetogenic TBC1D4 variant on kidney function in Greenland in a population-based setting. Health survey data and TBC1D4 genotypes from 5,336 Greenlanders were used to estimate odds ratios (ORs) of albuminuria (>30 mg/g creatinine) and chronic kidney disease (CKD, eGFR <60 ml/min/1.73m²), comparing individuals with and without diabetes, including the effect of TBC1D4 variant. Of the 3,909 participants with complete data, 9.3% had diabetes. Albuminuria was found in 27.6% and 9.5% and CKD was found in 10.8% and 6.3% among those with and without diabetes, respectively. Diabetes was cross-sectionally associated with an increased risk of albuminuria (OR (95% CI) = 2.37 (1.69,3.33); p < 0.001) and the TBC1D4 variant protected against albuminuria (OR (95% CI) = 0.44 (0.22,0.90); p = 0.02) in a multivariable model. Neither diabetes nor the TBC1D4 variant significantly associated with CKD. The presence/absence of diabetes did not predict changes in eGFR and UACR in longitudinal analyses. Diabetes conferred an increased risk of albuminuria, and the TBC1D4 variant was associated with a decreased risk of albuminuria, but neither was associated with CKD. The potential renoprotective association of the TBC1D4 variant on albuminuria calls for further studies.

High quality of diabetes care in Greenland since the launch of Steno Diabetes Center Greenland 2020 - geographical disparities need attention

The aim of this study was to estimate the prevalence of diagnosed diabetes in Greenland and evaluate quality of care according to sex, region and healthcare unit within regions. Data on all inhabitants registered with diabetes were extracted from the electronic medical record. We found a crude prevalence of diagnosed diabetes in the population aged ≥ 20 years to be 4.7%, and the prevalence of diabetes standardised to the WHO world population was 4.0%. Compared to males, a significantly higher proportion of females had mean glycated haemoglobin (HbA1c) level below 7% (68.9% vs. 57.5%) and blood pressure below 140/90 mmHg (83.4% vs. 73.5%). Regarding healthcare unit within regions, quality of care was higher in regional cities compared to smaller cities, concerning proportion of persons having blood pressure measured regularly (86.0% vs. 71.7%), urine tested for albuminuria (70.6% vs. 51.2%), receiving eye examination (86.9% vs. 79.5%) and foot examination (87.9% vs. 79.4%). In conclusion, the prevalence of diagnosed diabetes in Greenland is the highest reported yet. The overall quality of diabetes care was high and significantly improved compared to 2018. We observed geographical inequality in diabetes care and improvements in the quality of care in specific remote locations are necessary to minimise health care disparities.

The Greenland population health survey 2018 - methods of a prospective study of risk factors for lifestyle related diseases and social determinants of health amongst Inuit

Since 1993, regular population health surveys in Greenland have supported and monitored the public health strategy of Greenland and have monitored cardiometabolic and lung diseases. The most recent of these surveys included 2539 persons aged 15+ from 20 communities spread over the whole country. The survey instruments included personal interviews, self-administered questionnaires, blood sampling, anthropometric measurements, blood pressure, ECG, oral glucose test, pulmonary function, hand grip strength and chair stand test. Blood samples were analysed for glucose, glycated haemoglobin (HbA1c), insulin, incretin hormones, cholesterol, kidney function, fatty acids in erythrocyte membranes and mercury, urine for albumin-creatinine ratio, and aliquots were stored at -80°C for future use. Data were furthermore collected for studies of the gut microbiome and diabetes complications. Survey participants were followed up with register data. The potential of the study is to contribute to the continued monitoring of risk factors and health conditions as part of Greenland's public health strategy and to study the epidemiology of cardiometabolic diseases and other chronic diseases and behavioural risk factors. The next population health survey is planned for 2024. The emphasis of the article is on the methods of the study and results will be presented in other publications.

Prevalence of patients using antihypertensive medication in Greenland, and an assessment of the importance of diagnosis for the associated quality of care - a cross-sectional study

This study aimed to estimate the age- and sex specific prevalence of patients using antihypertensive medication in Greenland, and compared the quality of care between patients with and without a diagnosis for hypertension. The study was a cross-sectional study comparing patients using antihypertensive medication in 2020 (6,629 patients) and 2021 (7,008 patients), respectively. For data from 2021, patients with a medical diagnosis code were identified. Data was obtained from the Greenlandic electronic medical record. The population of Greenland was used as background population. Quality of care was evaluated based on suggested indicators by international guidelines and goals from Steno Diabetes Centre Greenland. The prevalence of patients aged ≥20 years using antihypertensive medication had increased from 16.7% in 2020 to 17.5% in 2021. The prevalence increased by age and was higher among women compared to men. In 2021, the prevalence of patients aged ≥20 years with a medical diagnosis code for hypertension was 7.9%. The use of antihypertensive medication in Greenland is common. The associated quality of care was low. However, process indicators were significantly improved when patients had a medical diagnosis code. Future focus must be on initiating initiatives ensuring that more patients are registered with a medical diagnosis code.

Prevalence of Patients Receiving Urate-Lowering Medicine in Greenland and Denmark: A Cross-Sectional Case-Control Study

This study estimates the age- and sex-specific prevalence of patients receiving urate-lowering therapy (ULT) in Greenland and compares the results with estimates in Denmark. Characteristics of patients receiving ULT in Greenland were compared to age- and sex-matched controls. The study was designed as a cross-sectional case−control study based on nationwide data from medical and population registers in Greenland and Denmark. The prevalence of patients receiving ULT was significantly lower in Greenland (0.55%) compared to Denmark (1.40%) (p < 0.001). In both countries, the prevalence increased with age and was higher among men compared to women. In Greenland, patients receiving ULT were more often overweight, and more frequently received blood glucose-, lipid-, and blood pressure-lowering medicine including diuretics compared to age- and sex-matched controls. The prevalence of patients receiving ULT was significantly lower in Greenland compared to Denmark. Common life-style related risk factors for hyperuricemia and gout were observed frequently among ULT-treated patients compared to controls. Along with an increasing prevalence of lifestyle-related diseases in Greenland, the prevalence of patients receiving ULT may increase in the years to come. More focus on detection and management of hyperuricemia and gout in Greenland is warranted to improve quality of health care.

Non-alcoholic fatty liver disease in patients with type 2 diabetes in Greenland: a register-based cross-sectional study

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide due to its close association to the metabolic syndrome of type 2 diabetes mellitus (T2DM), obesity and insulin resistance. However, the prevalence and severity of NAFLD in Greenland remain unexplored. We aimed to estimate the prevalence of liver steatosis and fibrosis among Greenlanders and Danes with T2DM living in Greenland using biochemical surrogate markers. We included 1409 Greenlanders and 182 Danes with T2DM in this register-based cross-sectional study. Greenlanders had higher BMI and plasma lipid levels and lower HbA1c levels compared with Danes (p<0.05). Their median alanine aminotransferase (ALAT) levels were similar. However, more Greenlanders had elevated ALAT levels (20.5% vs. 11.5%, p<0.05). Greenlanders had lower FIB-4 scores than Danes, 0.91 (IQR: 0.66–1.27) vs. 0.97 (IQR: 0.78–1.34), without difference in FIB-4 score categories (p=0.27). The prevalence of advanced fibrosis was low in both populations (1.7–2.6%). In conclusion, Greenlanders with T2DM had better glycaemic control despite higher BMI and plasma lipids. A larger proportion of Greenlanders had elevated plasma ALAT levels, while FIB-4 scores were lower than Danes. These findings suggest that Greenlanders with T2DM may be less likely to develop liver complications than Danes with T2DM in Greenland.

The prevalence of diabetes among tuberculosis patients in Denmark

SETTING

It is estimated that 25% of the world's population are infected with Mycobacterium tuberculosis and that 463 million people are living with diabetes mellitus (DM), a number that is increasing. Patients with DM have three times the risk of developing tuberculosis (TB) and there is significant interaction between DM and TB, suggesting that DM affects not only risk of TB but also TB presentation, treatment response and outcome.

OBJECTIVE

The aim was determining the prevalence of DM among TB patients in Denmark and to assess risk factors.

DESIGN

Patient files from all notified TB cases in Denmark from 2009 to 2014 were retrospectively assessed.

RESULTS

In total, 1912 patients were included and 5.0% had DM. Patients with DM were older, had more comorbidities, came from outside Denmark, and had a higher mortality compared to non-DM-patients. None of the patients from Greenland had DM. Patients with low socio-economic status had a low prevalence of DM. We found a higher prevalence of DM among Danish-born < 54 year and migrant ≥ 75 year compared to a Danish background population.

CONCLUSION

We found a higher prevalence of DM among TB patients with known risk factors, and a surprisingly low prevalence among patients with low socioeconomic status and patients from Greenland.

The importance of increasing population diversity in genetic studies of type 2 diabetes and related glycaemic traits

Type 2 diabetes has a global prevalence, with epidemiological data suggesting that some populations have a higher risk of developing this disease. However, to date, most genetic studies of type 2 diabetes and related glycaemic traits have been performed in individuals of European ancestry. The same is true for most other complex diseases, largely due to use of 'convenience samples'. Rapid genotyping of large population cohorts and case-control studies from existing collections was performed when the genome-wide association study (GWAS) 'revolution' began, back in 2005. Although global representation has increased in the intervening 15 years, further expansion and inclusion of diverse populations in genetic and genomic studies is still needed. In this review, I discuss the progress made in incorporating multi-ancestry participants in genetic analyses of type 2 diabetes and related glycaemic traits, and associated opportunities and challenges. I also discuss how increased representation of global diversity in genetic and genomic studies is required to fulfil the promise of precision medicine for all.

Normative data on cardiovascular autonomic function in Greenlandic Inuit

INTRODUCTION

Diabetes is increasing among Greenlandic Inuit; however, the prevalence of cardiovascular autonomic neuropathy (CAN) is yet unknown. The assessment of CAN requires an ability to differentiate between normal and abnormal. The aim was to establish normative reference data of cardiovascular autonomic function in Greenlandic Inuit.

RESEARCH DESIGN AND METHODS

In this cross-sectional study, cardiovascular autonomic function was evaluated in participants without diabetes during the Greenlandic Population Study 2018 and in the town Qasigiannguit in 2020. Assessment included cardiovascular autonomic reflex tests (CARTs) and power spectral analysis of heart rate variability (HRV). Normative reference limits were estimated by applying piecewise linear quantile regression models at the fifth percentile. Models were adjusted for age and sex.

RESULTS

Based on examinations of 472 participants (61.7% females), normative reference data was established for all outcomes. Mean age was 54 years (SD 13.1). Higher age was inversely associated with all outcomes of CARTs and HRV. A linear fall in cardiovascular autonomic function tended to level off beyond age of 60 or 70 years for supine-to-upright position ratio and low frequency power. However, the number of observations in subjects older than 60 or 70 years was limited, which may have caused a flattening of the curve around that age. No other associations were found.

CONCLUSIONS

The general level of the CARTs and HRV for all age groups is notably lower than in previous studies from other nationalities. We speculate that sociodemographic and cultural aspects of the Greenlandic Inuit population including body mass index, smoking, physical activity and alcohol consumption may have affected the cardiovascular autonomic function.

Low prevalence of retinopathy among Greenland Inuit

To assess the prevalence of diabetic retinopathy (DR) among persons with diabetes and prediabetes participating in the 2018 Population Health Survey in Greenland (B2018), a follow-up survey of three previous health surveys. Participants were invited to a diabetes complication screening. We assessed the prevalence of DR using Optos Daytona Ultra-wide field fundus camera and assessed differences in prevalence according to demographic and clinical characteristics using chi square test and a t-test and assessed DR based on ethnicity. The overall prevalence of DR was 2% (10/483). Among participants with HbA₁c ≥48 mmol/mol (6.5%) DR prevalence was 9% (9/91), compared with <1% (1/382) among participants with HbA₁c <48 mmol/mol (6.5%). All participants with DR lived in towns. The mean Inuit genetic admixture was lower among participants with DR. The prevalence of DR is low in Greenland and almost non-existent among persons with HbA₁c below the diabetes threshold.

Diet and physical activity in Greenland: genetic interactions and associations with obesity and diabetes

The Inuit in Greenland have gone through dramatic lifestyle changes during the last half century. More time is spent being sedentary and imported foods replaces traditional foods like seal and whale. The population has also experienced a rapid growth in obesity and metabolic disturbances and diabetes is today common despite being almost unknown few decades ago. In this paper, we describe and discuss the role of lifestyle changes and genetics for Inuit metabolic health. Novelty: Cardiometabolic disease risk has increased in Greenland. Lifestyle changes and possibly gene-lifestyle interactions play a role.

The role of a traditional and western diet on glucose homeostasis in Greenlandic Inuit carriers and non-carriers of type 2 diabetes variant in the TBC1D4 gene: A protocol for a randomized clinical trial

INTRODUCTION

The lifestyle of Inuit in Greenland and worldwide is undergoing a transition from a fisher-hunter to a westernized society and meanwhile the prevalence of type-2 diabetes (T2D) has increased dramatically. Studies have shown that a common nonsense p.Arg684Ter variant in TBC1D4, which is frequent in Greenland, confers genetic susceptibility towards high risk of T2D. The aim of the study is to investigate whether a traditional marine diet, with high fat and low carbohydrate, will improve glycemic control in Greenland Inuit compared to a western diet. Moreover, we want to examine if the response is more pronounced in carriers of the p.Arg684Ter variant.

MATERIALS AND METHODS

We will conduct a randomized, clinical cross-over trial with two dietary intervention periods of four weeks duration. The diet intervention comprise provision of >20E% and instruction for the remaining part of the diet. We expect to include 30 homozygous carriers and 30 homozygous non-carriers of the p.Arg684Ter variant, aged 18-80 years, across three Greenlandic towns. The primary outcome is plasma (p)-glucose 2 h post an oral glucose tolerance test and we aim to have 80% power, at α = 0.05, to detect a difference of 1.1 mmol/L. We will also include supporting measures of glucose homeostasis, assess other markers of the metabolic syndrome and perform metabolome and microbiome profiling. The statistical analysis will be performed as complete case analyses using linear mixed models.

ETHICS AND DISSEMINATION

The study received approval by the Ethics Committee of Greenland (KVUG 2018-26) and will be disseminated via international peer-reviewed journal articles and conferences.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov identifier no. NCT04011904.

Evidence of dental agenesis in late pleistocene Homo

OBJECTIVE

Differential diagnosis and tabulation of cases of dental agenesis in Middle and Upper Paleolithic Western Eurasian humans to synthesize this data and to test previous hypotheses about when recent human patterns of third molar agenesis were established.

MATERIALS

139 Late Pleistocene human remains and 149 individuals from three Epi-Paleolithic/ Holocene non-agricultural comparative collections.

METHODS

All remains were visually and radiographically recorded by the author.

RESULTS

In addition to establishing that third molar agenesis was common during the Late Upper Paleolithic (22,500-10,000 years BP), this study suggests a pattern of increasing prevalence through time.

CONCLUSIONS

An increase in the prevalence of third molar agenesis in the Late Upper Paleolithic could indicate selection for dental size reduction and orthognathy, but also bio-cultural changes from more intensive food preparation techniques.

SIGNIFICANCE

Third molar agenesis, a well-known developmental defect, is often reported for recent human skeletal collections, but the prevalence of the condition for Pleistocene hominins had not been previously quantified in order to consider patterns through time. Hypotheses posited for the high prevalence of third molar agenesis, or hypodontia in general, in some recent human groups require an understanding of the prevalence of these traits in the past.

LIMITATIONS

Paleolithic skeletal remains are incomplete, so these values are under-estimations. Individuals are also separated diachronically and geographically and should not be assumed to represent a single population sample.

SUGGESTIONS FOR FURTHER RESEARCH

Hypotheses on some of the potential selective forces acting on dental size reduction and subsequent agenesis could be tested in recent humans.

Are marine n-3 fatty acids protective towards insulin resistance? From cell to human

Marine n-3 fatty acids improve most of the biochemical alterations associated with insulin resistance (IR). Experimental models of dietary-induced IR in rodents have shown their ability (often at a very high dose) to prevent IR, but with sometimes a tissue specific effect. However, in a high sucrose diet-induced IR rat model, they are unable to reverse IR once installed; in other rodent models (dexamethasone, Zucker rats), they are inefficacious perhaps because of the severity of IR. The very low incidence of type-2 diabetes (T2D) in Inuits in the 1960s, which largely increased over the following decades in parallel to the replacement of their traditional marine food for a western diet strongly suggests a protective effect of marine n-3 towards the risk of T2D; this was confirmed by reversal of its incidence in intervention studies reintroducing their traditional food. In healthy subjects and insulin-resistant non-diabetic patients, most trials and meta-analyses conclude to an insulin-sensitising effect and to a very probable preventive or alleviating effect towards IR. Concerning the risk of T2D, concordant data allow us to conclude the protective effect of marine n-3 in Asians while suspicion exists of an aggravation of risk in Westerners, but with the possibility that it could be explained by a high heterogeneity of studies performed in this population. Some longitudinal cohorts in US/European people showed no association or a decreased risk. Further studies using more homogeneous doses, sources of n-3 and assessment of insulin sensitivity methods are required to better delineate their effects in Westerners.

Prevalence, incidence, mortality, and quality of care of diagnosed diabetes in Greenland

AIMS

To estimate prevalence, incidence, and mortality of diagnosed diabetes in Greenland, and to evaluate quality of diabetes care among men and women, and patients living in towns and settlements.

METHODS

This study was designed as an observational cross-sectional study based on review of data obtained from the electronic medical record (EMR) in Greenland. All permanent residents of Greenland registered with a diabetes diagnosis in the EMR (N = 1498) were included.

RESULTS

The age-standardized prevalence of diabetes was 2.19% as of Nov 30, 2018. The age-standardized incidence was 147 per 100,000 per year and the age-standardized mortality was 62 per 10,000 person-year among people aged ≥0 years old (Dec 1, 2017 to Nov 30, 2018). Quality of diabetes care was slightly higher among women compared to men concerning proportion with annual measurement of glycated haemoglobin (HbA_1c) (89.9% vs. 85.8%; p < 0.015), blood pressure (83.7% vs. 76.7%; p < 0.001).The only difference observed in quality of care among settlements and towns was lower proportion tested for microalbuminuria within one year in settlements (50.3% vs. 40.1%; p < 0.001).

CONCLUSIONS

The age-standardized prevalence of diagnosed diabetes in Greenland was 2.19% and the prevalence of diagnosed diabetes among adults aged ≥20 years was 3.7%. Only minor differences in quality of care related to gender and place of residence were observed. Further improvements in quality of care are warranted.

Dietary habits, metabolic health and vitamin D status in Greenlandic children

OBJECTIVE

To compare the dietary habits of children living in northern villages and in the capital of Greenland, given the reported transition from traditional to westernised diet in adults over recent decades, and to explore the association between consumption of marine mammals and fish (MMF) and the children's metabolic profile and vitamin D status.

DESIGN

Children answered an FFQ encompassing sixty-four individual food types pooled into six food categories. Their pubertal stage, body fat, fitness level, metabolic profile (non-HDL-cholesterol, glycated Hb, insulin, glucose, high-sensitivity C-reactive protein) as well as serum 25-hydroxyvitamin D (25(OH)D) concentration were evaluated.

SETTING

Siorapaluk and Qaanaaq (north of Greenland) and Nuuk (west).

PARTICIPANTS

Children aged 6-18 years (n 177).

RESULTS

MMF were most frequently eaten by children from Siorapaluk (mean (sd): 73·4 (14·1) times/month), followed by children from Qaanaaq (37·0 (25·0) times/month), and least often eaten by children from Nuuk (23·7 (24·6) times/month; P < 0·001). Children from Qaanaaq consumed 'junk food' more frequently (P < 0·001) and fruits and vegetables less frequently (P < 0·01) than children from Nuuk. MMF consumption was positively associated with serum 25(OH)D concentration (P < 0·05), but the overall prevalence of vitamin D deficiency was high (18 %). No association was found between MMF consumption and metabolic parameters.

CONCLUSIONS

The dietary transition and influence of western diets have spread to the north of Greenland and only the most remote place consumed a traditional diet highly based on MMF. We found no strong associations of MMF consumption with metabolic health, but a positive association with vitamin D status.

Fish and marine fatty acids intakes, the FADS genotypes and long-term weight gain: a prospective cohort study

OBJECTIVE

We tested whether genetic variants near fatty acid desaturases gene (FADS) cluster, which were recently identified to be signatures of adaptation to fish-rich and n-3 polyunsaturated fatty acids (PUFAs)-rich diet, interacted with these dietary factors on change in body mass index (BMI).

DESIGN

Three FADS variants were examined for gene-diet interactions on long-term (~10 years) changes in BMI and body weight in four prospective cohort studies.

SETTING

Population based study.

PARTICIPANTS

11 323 women from the Nurses' Health Study (NHS), 6833 men from the Health Professionals Follow-up Study (HPFS) and replicated in 6254 women from the Women's Health Initiative (WHI) and 5 264 Chinese from the Singapore Chinese Health Study (SCHS).

MAIN OUTCOMES

Long-term (~10 years) changes in BMI and body weight.

RESULTS

In the NHS and HPFS cohorts, food-sourced n-3 PUFAs intake showed interactions with the FADS rs174570 on changes of BMI (P for interaction=0.02 in NHS, 0.05 in HPFS and 0.007 in combined). Such interactions were replicated in two independent cohorts WHI and SCHS (P for interaction=0.04 in WHI, 0.02 in SCHS and 0.001 in combined). The genetic associations of the FADS rs174570 with changes in BMI increased across the tertiles of n-3 PUFAs in all the cohorts. Fish intake also accentuated the genetic associations of the FADS rs174570 with long-term changes in BMI (pooled P for interaction=0.006). Viewed differently, long chain n-3 PUFAs intake showed stronger association with long-term changes in BMI among the rs174570 T carriers (beta=0.79 kg/m² per g, p=3×10^-5) than the rs174570 non-T carriers (beta=0.16 kg/m² per g, p=0.08). Similar results were observed for fish intake.

CONCLUSIONS

Our hypothesis-driven analyses provide replicable evidence that long chain n-3 PUFAs and fish intakes may interact with the FADS variant on long-term weight gain. Further investigation is needed to confirm our findings in other cohorts.

Prevalence of patients treated with anti-diabetic medicine in Greenland and Denmark. A cross-sectional register study

Diabetes mellitus is a large and growing worldwide health issue. Prior to this publication, a direct comparison of the prevalence of persons treated with anti-diabetic medicine in Greenland and Denmark has not been found. Therefore, the aim of this study is to estimate and compare the age- and gender-specific prevalence of patients treated with anti-diabetic medicine comparing Greenland and Denmark. The study was performed as a cross-sectional register study using data from population and medical registers in Greenland and Denmark. A total of 784 Greenlandic and 215,580 Danish patients treated with anti-diabetic medicine were included. The prevalence of patients aged 20-79 years treated with anti-diabetic medicine in Greenland was 2.6% (95% CI 2.4-2.8), much lower (p < 0.001) compared to Denmark with 5.2% (95% CI 5.2-5.2). The difference was less pronounced after excluding those treated with insulin and women below 45 years treated with metformin. In conclusion, this study showed a lower prevalence of patients treated with anti-diabetic medicine in Greenland than Denmark. The main reason may be a much higher prevalence of undiagnosed diabetes in Greenland, particularly among the middle-aged. Differences in awareness of diabetes and access to continued primary healthcare may be contributing factors.

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.

Seafood consumption patterns, their nutritional benefits and associated sociodemographic and lifestyle factors among First Nations in British Columbia, Canada

Objective

To describe seafood consumption patterns in First Nations (FN) in British Columbia (BC) and examine lifestyle characteristics associated with seafood consumption; to identify the top ten most consumed seafood species and their contributions to EPA and DHA intake; and to estimate dietary exposure to methylmercury, polychlorinated biphenyls and dichlorodiphenyldichloroethylene.

Design

Dietary and lifestyle data from the First Nations Food Nutrition and Environment Study, a cross-sectional study of 1103 FN living in twenty-one communities across eight ecozones in BC, Canada, were analysed. Seafood consumption was estimated using a traditional FFQ. Seafood samples were analysed for contaminant contents.

Results

Seafood consumption patterns varied significantly across BC ecozones reflecting geographical diversity of seafood species. The top ten most consumed species represented 64 % of total seafood consumption by weight and contributed 69 % to the total EPA+DHA intake. Mean EPA+DHA intake was 660·5 mg/d in males, 404·3 mg/d in females; and 28 % of FN met the Recommended Intake (RI) of 500 mg/d. Salmon was the most preferred species. Seafood consumption was associated with higher fruit and vegetable consumption, lower smoking rate and increased physical activity. Dietary exposure to selected contaminants from seafood was negligible.

Conclusions

In FN in BC, seafood continues to be an essential part of the contemporary diet. Seafood contributed significantly to reaching the RI for EPA+DHA and was associated with a healthier lifestyle. Given numerous health benefits, seafood should be promoted in FN. Efforts towards sustainability of fishing should be directed to maintain and improve access to fisheries for FN.

Cancer Incidence and Mortality in Greenland 1983-2014 - Including Comparison With the Other Nordic Countries

BACKGROUND

During the last decades, social and life-style changes in Greenland have led to an increase in the incidence of several non-communicable diseases. Our aim is to present the cancer incidence and mortality in Greenland and compare the results with the other Nordic countries.

METHODS

The data stems from The Danish Cancer Registry and The Danish Register of Causes of Death. Comparable data on cancer incidence and mortality in Denmark, Finland, Iceland, Norway, Sweden, and Greenland are available through collaboration between Nordic Cancer Registries (NORDCAN). We included all individuals residing in Greenland and diagnosed with or died of a cancer from 1983 to 2014.

FINDINGS

The total number of cancer cases in Greenland for the study period was 4716 and there were 3231 cancer deaths. Respiratory and gastrointestinal cancers had the highest incidence as well as mortality in Greenland for the entire time period and for both sexes. Compared to the other Nordic countries, Greenland had significantly higher incidence and mortality rates for several cancers. Cancer of the lip, oral cavity, and pharynx, respiratory cancer, and cancer of unknown sites had the highest incidence rate ratios (2.3-3.9) and mortality rate ratios (2.7-9.9) for both sexes. The time trend from 1983 to 2014 showed a significant increase in cancer incidence in Greenland with nearly the same incidence level as the other Nordic countries. While the cancer mortality decreased in the other Nordic countries during the time period studied, there was no change in the cancer-specific mortality in Greenland.

INTERPRETATIONS

The trends in cancer incidence and mortality in Greenland compared to the other Nordic countries have not been reported earlier. These data underline a need to focus on cancer-specific mortality in Greenland and prevention of high-incidence cancers related to well-established risk factors.

Genetic determinants of glycated hemoglobin levels in the Greenlandic Inuit population

We previously showed that a common genetic variant leads to a remarkably increased risk of type 2 diabetes (T2D) in the small and historically isolated Greenlandic population. Motivated by this, we aimed at discovering novel genetic determinants for glycated hemoglobin (HbA1C) and at estimating the effect of known HbA1C-associated loci in the Greenlandic population. We analyzed genotype data from 4049 Greenlanders generated using the Illumina Cardio-Metabochip. We performed the discovery association analysis by an additive linear mixed model. To estimate the effect of known HbA1C-associated loci, we modeled the effect in the European and Inuit ancestry proportions of the Greenlandic genome (EAPGG and IAPGG, respectively). After correcting for multiple testing, we found no novel significant associations. When we investigated loci known to associate with HbA1C levels, we found that the lead variant in the GCK locus associated significantly with HbA1C levels in the IAPGG ([Formula: see text]). Furthermore, for 10 of 15 known HbA1C loci, the effects in IAPGG were similar to the previously reported effects. Interestingly, the ANK1 locus showed a statistically significant ancestral population differential effect, with opposing directions of effect in the two ancestral populations. In conclusion, we found only 1 of the 15 known HbA1C loci to be significantly associated with HbA1C levels in the IAPGG and that two-thirds of the loci showed similar effects in Inuit as previously found in European and East Asian populations. Our results shed light on the genetic effects across ethnicities.

Genetic architecture: the shape of the genetic contribution to human traits and disease

Genetic architecture describes the characteristics of genetic variation that are responsible for heritable phenotypic variability. It depends on the number of genetic variants affecting a trait, their frequencies in the population, the magnitude of their effects and their interactions with each other and the environment. Defining the genetic architecture of a complex trait or disease is central to the scientific and clinical goals of human genetics, which are to understand disease aetiology and aid in disease screening, diagnosis, prognosis and therapy. Recent technological advances have enabled genome-wide association studies and emerging next-generation sequencing studies to begin to decipher the nature of the heritable contribution to traits and disease. Here, we describe the types of genetic architecture that have been observed, how architecture can be measured and why an improved understanding of genetic architecture is central to future advances in the field.

Microvascular complications in Nuuk, Greenland, among Greenlanders and non-Greenlanders diagnosed with type 2 diabetes

AIM

The objective of this study was to estimate and compare between Greenlanders and non-Greenlanders living in Nuuk the proportion of patients with type 2 diabetes with microvascular complications.

METHODS

This study was performed as a cross-sectional register study based on information in the Electronic Medical Record (EMR). All patients diagnosed with type 2 diabetes and with permanent addresses in Nuuk were included. Patients born in Greenland were considered to be Greenlanders, while patients born outside Greenland were considered as non-Greenlanders. Proportions of patients with retinopathy, microalbuminuria, nephropathy and neuropathy were estimated based on information from the EMR.

RESULTS

A total of 393 patients (295 Greenlanders and 98 non-Greenlanders) were included. In total 83.0% of all patients have been screened for retinopathy, while 66.4% were screened for microalbuminuria and 64.6% for neuropathy within a two year period. The most frequent microvascular complication was neuropathy, which was observed among half (49.6%) of all patients followed by microalbuminuria (28.4%), retinopathy (10.7%) and nephropathy (7.3%). Retinopathy was observed among 21.4% of the non-Greenlanders compared to only 7.0% of the Greenlanders (p = .001). Microalbuminuria was also observed more frequently (p = .047) among non-Greenlanders (37.5%) than among Greenlanders (24.9%).

CONCLUSION

Greenlanders seem to be less prone to especially retinopathy than are non-Greenlanders.

High awareness of diabetes in the health care system in Greenland measured as a proportion of population tested with glycated haemoglobin within 2 years

BACKGROUND

Sixty years ago diabetes was almost non-existent in Greenland and until the beginning of this century awareness of diabetes was quite minimal. A high prevalence of undiagnosed diabetes has been reported in repeated population surveys. Increased focus on diabetes has been made a priority within the health care system since 2008, and in 2010 glycated haemoglobin was introduced as a diagnostic tool to further facilitate the diagnosis of diabetes.

OBJECTIVE

The aim of this study was to estimate the age and gender specific use of glycated haemoglobin in 2014 and 2015, as an indicator of diagnostic activity and awareness of diabetes, and to estimate the prevalence of diagnosed pre-diabetes and diabetes among adults in Greenland aged 20-79 years of age.

METHODS

The study was performed as an observational, cross sectional register study based on information gleaned from the electronically laboratory system used in Greenland including all patients tested with glycated haemoglobin at least once in 2014 or 2015.

RESULTS

A total of 10,127 patients were tested with glycated haemoglobin in 2014 or 2015 corresponding to 18.1% of the whole population. Among adults aged 20-79 years 9506 patients were tested corresponding to 24.0% of the total adult population. More females (32.5%) than males (16.5%) aged 20-79 years old were tested (p < 0.001). The prevalence of diagnosed diabetes and high risk pre-diabetes among adults aged 20-79 years was 4.3 and 6.8% respectively.

CONCLUSION

In conclusion use of glycated haemoglobin is widely used in the health care system in Greenland indicating a high awareness of diabetes in the population and by the health care system. Still, awareness of undiagnosed diabetes remains an important issue and additional strategies targeting males under 70 years old must be considered.

Changing living conditions, life style and health

Human health is the result of the interaction of genetic, nutritional, socio-cultural, economic, physical infrastructure and ecosystem factors. All of the individual, social, cultural and socioeconomic factors are influenced by the environment they are embedded in and by changes in this environment. The aim of the paper is to illustrate the influence of environmental change on living conditions and life style and some of the mechanisms through which such changes affect physical and mental health. The interrelationship between environmental and societal change is illustrated by an example from a small community in Greenland, where changing environmental conditions have influenced fishing and employment opportunities to the extent that the size of the population has changed dramatically. The link between social change and health is shown with reference to studies on education, housing and occupation as well as life style changes. The paper further illustrates the relationship between the rapid socio-cultural and economic change and the health of the population. Psychosocial stress is reflected in problems such as alcohol abuse, violence and suicide, and these factors have been shown in studies on migration and transitions in health to be connected to changes in lifestyle and living conditions.

Changes since 1980 in body mass index and the prevalence of overweight among inschooling children in Nuuk, Greenland

OBJECTIVE

The aim of the study was to examine the trends which have occurred during the past generation in body mass index (BMI) and in the prevalence of overweight and obesity among children in public schools in Nuuk, Greenland.

STUDY DESIGN

The study is a retrospective cohort study of BMI among inschooling children (age 6 or 7 years old). A database was created on the basis of files from school-nurses containing information on height and weight among children having attended school in Nuuk since 1970. The database contained 10,121 measurements in total, whereas 2,801 were on inschooling children. Measurements from these children form the basis of this study. Mean and quartiles of BMI among the inschooling children in 5-year intervals were used to determine the development in BMI since 1980. On the basis of international cut-points for use among children and adolescents, the proportion of overweight and obese children and the trends since 1980 were determined.

RESULTS

The mean BMI has risen by a total of a bit more than 6% since 1980, corresponding to a rise of 1.2-3.8% for every 5-year period. Increases are also observed when assessing the proportion of overweight and obese, which were 6.6% and 0.9%, respectively, among the inschooling children during the period 1980-1984. These proportions increased to 16.5% and 5.2%, respectively, in 2000-2004.

CONCLUSION

This study has provided evidence that during the past two decades, children in Nuuk have undergone a development towards a higher prevalence of overweight and obesity.

Research with Arctic peoples: Unique research opportunities in heart, lung, blood and sleep disorders

Arctic peoples are spread over eight countries and comprise 3.74 million residents, of whom 9% are indigenous. The Arctic countries include Canada, Finland, Greenland (Denmark), Iceland, Norway, Russia, Sweden and the United States. Although Arctic peoples are very diverse, there are a variety of environmental and health issues that are unique to the Arctic regions, and research exploring these issues offers significant opportunities, as well as challenges. On July 28-29, 2004, the National Heart, Lung, and Blood Institute and the Canadian Institutes of Health Research co-sponsored a working group entitled "Research with Arctic Peoples: Unique Research Opportunities in Heart, Lung, Blood and Sleep Disorders". The meeting was international in scope with investigators from Greenland, Iceland and Russia, as well as Canada and the United States. Multiple health agencies from Canada and the United States sent representatives. Also attending were representatives from the International Union for Circumpolar Health (IUCH) and the National Indian Health Board. The working group developed a set of ten recommendations related to research opportunities in heart, lung, blood and sleep disorders; obstacles and solutions to research implementation; and ways to facilitate international comparisons. These recommendations are expected to serve as an agenda for future research.

Body proportions in healthy adult Inuit in East Greenland in 1963

OBJECTIVES

It is important to know the starting point when describing changes in Inuit in transition.

STUDY DESIGN

The original charts of 1,852 individuals from the epidemiological investigation in East Greenland around 1963 performed by Littauer and colleagues were recovered recently. They included height, weight and a physical investigation.

METHODS AND RESULTS

The focus of this paper was adult Inuit body proportions in 1963 by ten-year age groups excluding participants with disabilities affecting body build. Relatively stable values were seen in both genders with age. Median values in men/women aged 20 years and above were: height 164/153.5 cm, weight 64/54 kg and BMI 23.7/23.1. Men aged 50 years and above had a little lower height and weight than young men. Women aged 40-49 years had a higher weight and BMI, but this evened out in the older age groups. Median BMI was relatively high compared to WHO definition.

CONCLUSIONS

The data from 1963 gives a starting point for evaluating changes in Inuit body build and the prevalence of overweight. Furthermore, they indicate a need for Inuit-specific normal BMI delineation.

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.

The Effect of an Extreme and Prolonged Population Bottleneck on Patterns of Deleterious Variation: Insights from the Greenlandic Inuit

The genetic consequences of population bottlenecks on patterns of deleterious genetic variation in human populations are of tremendous interest. Based on exome sequencing of 18 Greenlandic Inuit we show that the Inuit have undergone a severe ∼20,000-year-long bottleneck. This has led to a markedly more extreme distribution of allele frequencies than seen for any other human population tested to date, making the Inuit the perfect population for investigating the effect of a bottleneck on patterns of deleterious variation. When comparing proxies for genetic load that assume an additive effect of deleterious alleles, the Inuit show, at most, a slight increase in load compared to European, East Asian, and African populations. Specifically, we observe <4% increase in the number of derived deleterious alleles in the Inuit. In contrast, proxies for genetic load under a recessive model suggest that the Inuit have a significantly higher load (20% increase or more) compared to other less bottlenecked human populations. Forward simulations under realistic models of demography support our empirical findings, showing up to a 6% increase in the genetic load for the Inuit population across all models of dominance. Further, the Inuit population carries fewer deleterious variants than other human populations, but those that are present tend to be at higher frequency than in other populations. Overall, our results show how recent demographic history has affected patterns of deleterious variants in human populations.

Toward Precision Medicine: TBC1D4 Disruption Is Common Among the Inuit and Leads to Underdiagnosis of Type 2 Diabetes

OBJECTIVE

A common nonsense mutation in TBC1D4 was recently found to substantially increase the odds of type 2 diabetes in Greenlandic Inuit, leading to exclusively increased postprandial glucose. We investigated the frequency and effect of the TBC1D4 mutation on glucose metabolism and type 2 diabetes diagnosis among Canadian and Alaskan Inuit.

RESEARCH DESIGN AND METHODS

Exome sequencing of the TBC1D4 variant was performed in 114 Inuit from Nunavik, Canada, and Sanger sequencing was undertaken in 1,027 Alaskan Inuit from the Genetics of Coronary Artery Disease in Alaskan Natives (GOCADAN) Study. Association testing evaluated the effect of the TBC1D4 variant on diabetes-related metabolic traits and diagnosis.

RESULTS

The TBC1D4 mutation was present in 27% of Canadian and Alaskan Inuit. It was strongly associated with higher glucose (effect size +3.3 mmol/L; P = 2.5 x 10^-6) and insulin (effect size +175 pmol/L; P = 0.04) 2 h after an oral glucose load in homozygote carriers. TBC1D4 carriers with prediabetes and type 2 diabetes had an increased risk of remaining undiagnosed unless postprandial glucose values were tested (odds ratio 5.4 [95% CI 2.5-12]) compared with noncarriers. Of carriers with prediabetes or type 2 diabetes, 32% would remain undiagnosed without an oral glucose tolerance test (OGTT).

CONCLUSIONS

Disruption of TBC1D4 is common among North American Inuit, resulting in exclusively elevated postprandial glucose. This leads to underdiagnosis of type 2 diabetes, unless an OGTT is performed. Accounting for genetic factors in the care of Inuit with diabetes provides an opportunity to implement precision medicine in this population.

Prevalence of diagnosed diabetes and quality of care among Greenlanders and non-Greenlanders in Greenland

AIMS

To estimate the actual prevalence of diagnosed diabetes in Greenland as at 2014, and to evaluate the quality of diabetes care among Greenlanders and non-Greenlanders in Greenland, six years after a national diabetes program was initiated.

METHODS

The study was designed as an observational cross-sectional study based on review of data obtained from the electronic medical record (EMR) in Greenland. All permanent residents of Greenland who as at October 2014 were registered with the diagnosis diabetes in the EMR (n=1071) were included in the study. The prevalence was calculated using the population in Greenland as at first of June 2014 as background population. Quality of diabetes care was determined using indicators proposed by the Organization for Economic Cooperation and Development.

RESULTS

The prevalence among Greenlanders aged 20-79years was 2.36% (95% CI 2.19-2.52) and significantly lower than the prevalence among non-Greenlanders in the same age group, which was 3.69% (95% CI 2.18-4.20). More Greenlanders than non-Greenlanders had glycosylated haemoglobin below 7.0% (53mmol/mol), blood pressure below 140/90mmHg and their blood pressure measured within the last year. No other differences in quality of diabetes care were observed between the groups.

CONCLUSIONS

A higher prevalence of diagnosed diabetes was observed among non-Greenlanders compared to Greenlanders, while no major differences were observed in quality of care between the two groups. The overall prevalence of diagnosed diabetes has increased compared to earlier studies. Continued monitoring of prevalence and quality of care is recommended.

Ethnic difference in the prevalence of pre-diabetes and diabetes mellitus in regions with Sami and non-Sami populations in Norway - the SAMINOR1 study

Objective

The aim of this study was to measure the prevalence of pre-diabetes and diabetes mellitus in rural populations of Norway, as well as to explore potential ethnic disparities with respect to dysglycaemia in Sami and non-Sami populations.

Design

Cross-sectional population-based study.

Methods

The SAMINOR1 study was performed in 2003–2004. The study took place in regions with both Sami and non-Sami populations and had a response rate of 60.9%. Information in the SAMINOR1 study was collected using two self-administered questionnaires, clinical examination and laboratory tests. The present analysis included 15,208 men and women aged 36–79 years from the SAMINOR1 study.

Results

Age-standardised prevalence of pre-diabetes and diabetes mellitus among Sami men was 3.4 and 5.5%, respectively. Corresponding values for non-Sami men were 3.3 and 4.6%. Age-standardised prevalence of pre-diabetes and diabetes mellitus for Sami women was 2.7 and 4.8%, respectively, while corresponding values for non-Sami women were 2.3 and 4.5%. Relative risk ratios for dysglycaemia among Sami participants compared with non-Sami participants were significantly different in different geographical regions, with the southern region having the highest prevalence of pre-diabetes and diabetes mellitus among Sami participants.

Conclusion

We observed a heterogeneity in the prevalence of pre-diabetes and diabetes mellitus in different geographical regions both within and between different ethnic groups.

Associations between Vitamin D Status and Type 2 Diabetes Measures among Inuit in Greenland May Be Affected by Other Factors

OBJECTIVE

Epidemiological studies have provided evidence of an association between vitamin D insufficiency and type 2 diabetes. Vitamin D levels have decreased among Inuit in Greenland, and type 2 diabetes is increasing. We hypothesized that the decline in vitamin D could have contributed to the increase in type 2 diabetes, and therefore investigated associations between serum 25(OH)D3 as a measure of vitamin D status and glucose homeostasis and glucose intolerance in an adult Inuit population.

METHODS

2877 Inuit (≥18 years) randomly selected for participation in the Inuit Health in Transition study were included. Fasting- and 2hour plasma glucose and insulin, C-peptide and HbA1c were measured, and associations with serum 25(OH)D3 were analysed using linear and logistic regression. A subsample of 330 individuals who also donated a blood sample in 1987, were furthermore included.

RESULTS

After adjustment, increasing serum 25(OH)D3 (per 10 nmol/L) was associated with higher fasting plasma glucose (0.02 mmol/L, p = 0.004), 2hour plasma glucose (0.05 nmol/L, p = 0.002) and HbA1c (0.39%, p<0.001), and with lower beta-cell function (-1.00 mmol/L, p<0.001). Serum 25(OH)D3 was positively associated with impaired fasting glycaemia (OR: 1.08, p = 0.001), but not with IGT or type 2 diabetes.

CONCLUSIONS

Our results did not support an association between low vitamin D levels and risk of type 2 diabetes. Instead, we found weak positive associations between vitamin D levels and fasting- and 2hour plasma glucose levels, HbA1c and impaired fasting glycaemia, and a negative association with beta-cell function, underlining the need for determination of the causal relationship.

Complex Genetics of Type 2 Diabetes and Effect Size: What have We Learned from Isolated Populations?

Genetic studies in large outbred populations have documented a complex, highly polygenic basis for type 2 diabetes (T2D). Most of the variants currently known to be associated with T2D risk have been identified in large studies that included tens of thousands of individuals who are representative of a single major ethnic group such as European, Asian, or African. However, most of these variants have only modest effects on the risk for T2D; identification of definitive 'causal variant' or 'causative loci' is typically lacking. Studies in isolated populations offer several advantages over outbred populations despite being, on average, much smaller in sample size. For example, reduced genetic variability, enrichment of rare variants, and a more uniform environment and lifestyle, which are hallmarks of isolated populations, can reduce the complexity of identifying disease-associated genes. To date, studies in isolated populations have provided valuable insight into the genetic basis of T2D by providing both a deeper understanding of previously identified T2D-associated variants (e.g. demonstrating that variants in KCNQ1 have a strong parent-of-origin effect) or providing novel variants (e.g. ABCC8 in Pima Indians, TBC1D4 in the Greenlandic population, HNF1A in Canadian Oji-Cree). This review summarizes advancements in genetic studies of T2D in outbred and isolated populations, and provides information on whether the difference in the prevalence of T2D in different populations (Pima Indians vs. non-Hispanic Whites and non-Hispanic Whites vs. non-Hispanic Blacks) can be explained by the difference in risk allele frequencies of established T2D variants.

Association between whole blood mercury and glucose intolerance among adult Inuit in Greenland

OBJECTIVES

The Arctic diet is partly constituted by traditional food characterized by top predator animals such as whales, walrus, and seals with high mercury content. Mercury exposure has been associated with glucose intolerance in Western populations. We studied the association between whole blood mercury and glucose intolerance in a highly exposed non-Western population

METHODS

Cross-sectional study of 2640 Inuit (18+ years) with information on ancestry, smoking, waist circumference, total energy intake, and physical activity. Mercury, fasting- and 2-h plasma glucose, insulin, and c-peptide were measured in blood. Fasting participants without diabetes were classified into normal glucose tolerance, impaired glucose tolerance, impaired fasting glycemia, or type 2 diabetes. We calculated hepatic insulin resistance with homoeostatic model assessment - insulin resistance index, peripheral insulin sensitivity by ISI0,120., and relative beta cell function by c-peptide/insulin ratio. We conducted adjusted linear- and logistic regression analyses.

RESULTS

For an increase in whole blood mercury of 5 µg/L we found a positive association with fasting glucose [% change=0.25 (95% CI: 0.20; 0.30); p<0.001], and 2-h glucose [% change=0.23 (95% CI: 0.05; 0.40); p=0.01]. Mercury was weakly associated with impaired fasting glycemia [OR=1.03 (95% CI: 1.02; 1.05)], and type 2 diabetes [OR=1.02 (95% CI: 1.01; 1.04)].

CONCLUSION

While the study found a weak but statistically significant association between whole blood mercury and both impaired fasting glycemia and type 2 diabetes, no associations were found with measures of underlying disturbances in glucose homoeostasis.

High protein and cholesterol intakes associated with emergence of glucose intolerance in a low-risk Canadian Inuit population

Objective

The rate of type 2 diabetes mellitus among Inuit is 12·2 % in individuals over 50 years of age, similar to the Canadian prevalence. Given marked dietary transitions in the Arctic, we evaluated the dietary and other correlates of not previously diagnosed glucose intolerance, defined as type 2 diabetes mellitus, impaired fasting glucose or impaired glucose tolerance.

Design

Cross-sectional analyses were limited to adults with a completed 2 h oral glucose tolerance test and without pre-existing diabetes. Anthropometric assessments, health and medication usage questionnaires and a 24 h dietary recall were administered.

Setting

Canadian International Polar Year Inuit Health Survey (2007–2008).

Subjects

Inuit adults (n 777).

Results

Glucose intolerance was associated with older age and adiposity. Percentage of energy from protein above the Acceptable Macronutrient Distribution Range of 35 %, compared with intake within the range, was associated with increased odds of glucose intolerance (OR=1·98; 95 % CI 1·09, 3·61) in multivariable analyses. Further, cholesterol intake in the highest three quartiles combined (median exposures of 207, 416 and 778 mg/d, respectively) compared with the lowest quartile (median intake of 81 mg/d) was associated with glucose intolerance (OR=2·15; 95 % CI 1·23, 3·78) in multivariable analyses. Past-day traditional food consumption was borderline protective of glucose intolerance (P=0·054) and high fibre intake was not significantly protective (P=0·08).

Conclusions

The results contribute to the existing literature on high protein and cholesterol intakes as they may relate to diabetes risk.