Search

Diabet. Med. 29, 755-760 (2012) Abstract Background and aim Most studies show that diabetes increases with migration and urbanization. Previous studies from Greenland have shown inconsistent associations between cardiovascular risk and urbanization. Thus, the aim was to study the association between diabetes and urbanization among Greenland Inuit. Methods A total of 3089 adult Inuit aged 18 years and older participated in a geographically representative, population-based study 'Inuit Health in Transition Study'. The examination included a 75 g oral glucose tolerance test and anthropometric measurements. Information on socio-demographic characteristic and health behaviour was obtained by interview or questionnaire. The participants were categorized according to degree of urbanization into three groups based on current place of residence: (1) participants living in towns (> 2000 inhabitants), (2) participants living in small towns (< 2000 inhabitants) and (3) participants living in villages (< 500 inhabitants). Results The total prevalence of diabetes was 9% of which 79% were previously unknown. Nine per cent had impaired glucose tolerance and 19% had impaired fasting glycaemia (IFG). Compared with towns, odds rations (ORs) for diabetes and impaired fasting glycaemia were higher in small towns [ORdiabetes = 1.5 (1.0-2.3), ORIFG = 1.9 (1.2-2.3)] and villages [ORdiabetes = 1.2 (0.8-1.9), ORIFG = 1.3 (0.9-2.0)], whereas no association was seen for impaired glucose tolerance. The inverse association between urbanization and diabetes and impaired fasting glycaemia persisted after adjustment for relevant confounders. Conclusion Diabetes and impaired fasting glycaemia decreased with urbanization contrary to the results of most studies. It appears that Greenland Inuit follow the pattern usually observed in industrialized countries with the highest risk of diabetes in the lower socio-economic groups. [ABSTRACT FROM AUTHOR]

BACKGROUND: The association between obesity and cardiovascular disease risk differs across populations. Whether such differences in obesity-related risk factors exist within population groups of the same genetic origin but with differences in lifestyle remains to be determined. OBJECTIVE: The aim was to analyze whether obesity was associated with the same degree of metabolic disturbances in 2 groups of genetically homogeneous Inuit who were exposed to considerable differences in lifestyle. DESIGN: We studied obesity and cardiovascular disease risk factors in a cross-sectional population survey of 2311 Inuit living in Denmark (n = 995) or Greenland (n = 1316). The participants received an oral-glucose-tolerance test. Blood tests were supplemented by structured interviews and anthropometric and blood pressure measurements. RESULTS: The trend in the association between obesity and metabolic effects was not significantly different in the Inuit populations, but the values of several risk factors were significantly different. At any given level of obesity, Inuit residents in Greenland had lower blood pressure and lower concentrations of triacylglycerol and postchallenge plasma glucose and insulin than did the Inuit migrants in Denmark. The trend in the association with obesity categories was different only for HDL cholesterol, with higher concentrations observed in women Inuit migrants in Denmark than in women Inuit residents in Greenland. CONCLUSIONS: The health risk associated with obesity clearly varies within groups of Inuit living in Greenland and Inuit migrants living in Denmark. The findings indicate that lifestyle factors modify the cardiovascular disease risk associated with obesity. Copyright © 2006 American Society for Nutrition [ABSTRACT FROM AUTHOR]

Study objective: Previous studies of blood pressure among the Inuit have given inconsistent results and studies comparing Inuit migrants with those living in traditional Inuit areas are absent. The purpose of the study was to compare the blood pressure of the Inuit in Greenland with that of Inuit migrants in Denmark.Design: Questionnaire, interview, and clinical examination in a cross sectional random population sample.Setting: A population based survey among Inuit in Greenland and Inuit migrants in Denmark.Participants: 2046 Inuit aged >/= 18, 61% of the sample.Main results: Age and gender adjusted blood pressures were 117/72 mm Hg in Greenland and 127/81 mm Hg among the migrants (p<0.001). In both populations, blood pressure increased with age and body mass index, and was higher among men and non-smokers. In Greenland, blood pressure increased with the level of school education. The associations with Inuit heritage, alcohol, diet, and physical activity were not significant. The difference between the two populations persisted after adjusting for age, gender, body mass index, education, and smoking. Among those who had completed high school, there was no difference between the systolic blood pressure of the two populations while the difference for diastolic blood pressure was much less than for those with less education.Conclusions: Blood pressure was lower among the Inuit in Greenland than among the Inuit migrants in Denmark but the difference was absent (systolic pressure) or reduced (diastolic pressure) among the better educated. The results suggest that the blood pressure of the Inuit, especially Inuit men, may be responsive to factors related to the modern Western way of life. [ABSTRACT FROM AUTHOR]

The Greenlandic population, a small and historically isolated founder population comprising about 57,000 inhabitants, has experienced a dramatic increase in type 2 diabetes (T2D) prevalence during the past 25 years. Motivated by this, we performed association mapping of T2D-related quantitative traits in up to 2,575 Greenlandic individuals without known diabetes. Using array-based genotyping and exome sequencing, we discovered a nonsense p.Arg684Ter variant (in which arginine is replaced by a termination codon) in the gene TBC1D4 with an allele frequency of 17%. Here we show that homozygous carriers of this variant have markedly higher concentrations of plasma glucose (β = 3.8 mmol l(-1), P = 2.5 × 10(-35)) and serum insulin (β = 165 pmol l(-1), P = 1.5 × 10(-20)) 2 hours after an oral glucose load compared with individuals with other genotypes (both non-carriers and heterozygous carriers). Furthermore, homozygous carriers have marginally lower concentrations of fasting plasma glucose (β = -0.18 mmol l(-1), P = 1.1 × 10(-6)) and fasting serum insulin (β = -8.3 pmol l(-1), P = 0.0014), and their T2D risk is markedly increased (odds ratio (OR) = 10.3, P = 1.6 × 10(-24)). Heterozygous carriers have a moderately higher plasma glucose concentration 2 hours after an oral glucose load than non-carriers (β = 0.43 mmol l(-1), P = 5.3 × 10(-5)). Analyses of skeletal muscle biopsies showed lower messenger RNA and protein levels of the long isoform of TBC1D4, and lower muscle protein levels of the glucose transporter GLUT4, with increasing number of p.Arg684Ter alleles. These findings are concomitant with a severely decreased insulin-stimulated glucose uptake in muscle, leading to postprandial hyperglycaemia, impaired glucose tolerance and T2D. The observed effect sizes are several times larger than any previous findings in large-scale genome-wide association studies of these traits and constitute further proof of the value of conducting genetic association studies outside the traditional setting of large homogeneous populations.

Objective: A high amount of subcutaneous fat is suggested to explain the observation of lower obesity-associated metabolic risk among Inuit than among Europeans. We examined the association between measures of obesity (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT], BMI, waist circumference [WC], and percentage of body fat) and the indices of glucose metabolism (fasting and 2-h glucose levels, insulin resistance per homeostasis model assessment [HOMA-IR], and the insulin sensitivity index [ISI0,120]) among Greenland Inuit., Research Design and Methods: A total of 3,108 adult Inuit participated in a population-based study. The examination included a 75-g oral glucose tolerance test and anthropometric measurements. VAT and SAT were measured by ultrasound according to a validated protocol. Information on sociodemographic characteristics and health behaviors was obtained by interview., Results: Mean SATs were 1.8 and 3.5 cm in men and women, respectively. Mean VATs were 7.0 and 6.3 cm in men and women, respectively. The total prevalence of type 2 diabetes was 9%. Percentage of body fat generally was most strongly associated with all outcomes. Both SAT and VAT were significantly associated with glucose intolerance, fasting and 2-h plasma glucose levels, HOMA-IR, and ISI0,120. VAT was more strongly associated with all outcomes than was SAT. After further adjustment for BMI or WC, VAT was associated with glucose intolerance and insulin resistance, whereas there was a trend toward a negative or no association with SAT., Conclusions: High mean values of SAT may to a large extent explain the high WC in Inuit populations, and this is suggested to contribute to the lower observed metabolic risk for a given level of obesity.

OBJECTIVE To compare screen-detected diabetes prevalence and the degree of diagnostic agreement by ethnicity with the current oral glucose tolerance test (OGTT)-based and newly proposed A1C-based diagnostic criteria. RESEARCH DESIGN AND METHODS Six studies (1999-2009) from Denmark, the U.K., Australia, Greenland, Kenya, and India were tested for the probability of an A1C > or =6.5% among diabetic case subjects based on an OGTT. The difference in probability between centers was analyzed by logistic regression adjusting for relevant confounders. RESULTS Diabetes prevalence was lower with the A1C-based diagnostic criteria in four of six studies. The probability of an A1C > or =6.5% among OGTT-diagnosed case subjects ranged widely (17.0-78.0%) by study center. Differences in diagnostic agreement between ethnic subgroups in the U.K. study were of the same magnitude as between-country comparisons. CONCLUSIONS A shift to an A1C-based diagnosis for diabetes will have substantially different consequences for diabetes prevalence across ethnic groups and populations.

Objectives: To examine the association between the content of n-3 fatty acids and insulin resistance in an Inuit population., Study Design: The Inuit Health in Transition Study was carried out between 2003 and 2007 in Greenland as a cross-sectional study. Our preliminary results are based on the first 452 participants aged 18 and above. Only participants with at least 1 Inuit grandparent and without diabetes were included., Methods: The contents of n-3 fatty acids and the n-3/n-6 ratio were measured in the erythrocyte membrane phospholipids. BMI was calculated and questions concerning diabetes and ethnicity were answered. Insulin resistance was estimated using the HOMA-IR index based on fasting-glucose and fasting-insulin., Results: We found an inverse association between C20:5 n-3 (EPA), C22:3 n-3, the n-3/n-6 ratio and HOMA-IR and a positive association between C18:3 n-3 cis and HOMA-IR. When adjusted for age, gender, BMI and ethnicity, the association remained statistically significant for C20:5 n-3 (EPA), C22:3 n-3 and C18:3 n-3 cis., Conclusions: Our findings suggest that some types of n-3 fatty acids may have a protective effect against insulin resistance. The role of potential confounders such as physical activity, diet, energy intake, socio-economic status and contaminants deserves further exploration.

Aims/hypothesis: Some evidence supports the hypothesis that persistent organic pollutants (POPs) may increase the risk of type 2 diabetes. The Inuit population in Greenland, which is highly exposed to POPs due to a high intake of marine mammals, has experienced a rapid increase in diabetes prevalence over the last 30 years. Thus the aim was to study the association between POPs and glucose intolerance and markers of insulin resistance and insulin secretion using a population-based design., Methods: From 1999 to 2002 the Greenland population study was carried out among adult Inuit living in Greenland. The examination included a 75 g OGTT, anthropometric measurements, a structured interview, and blood tests. Plasma glucose and serum insulin were analysed, and three defined subclasses of POPs were analysed in a subgroup. Associations were adjusted for age, sex, waist circumference, Inuit heritage, cigarette smoking, alcohol consumption and educational level., Results: Data on POPs were available on 692 individuals, 305 men (mean age 50 years) and 387 women (mean age 49 years). The prevalence of diabetes was 10.3%, and 10.5% had impaired glucose tolerance. The concentrations of several POPs were exceptionally high. While no associations were found between POPs and stages of glucose intolerance or markers of insulin resistance, POPs were significantly inversely associated with stimulated insulin concentrations and homeostasis model assessment of beta cell function., Conclusions/interpretation: The study indicates that POPs may affect insulin secretion rather than being involved in the pathogenesis of insulin resistance. No association was seen between POPs and glucose intolerance or markers of insulin resistance.

Purpose: To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland., Design: Population-based cross-sectional study., Participants: All > or =60-year-olds born in Greenland and living in the communities of Nuuk and Sisimiut, Greenland., Methods: The presence and form of early (ARM) and late age-related macular disease (AMD) were determined by grading color fundus photographs using the international classification and grading system for ARM and AMD., Main Outcome Measures: Prevalences of ARM and AMD were assessed by masked grading of fundus photographs., Results: Overall, 695 persons were included in the study (response rate, 74.8%). Prevalence of any ARM was 52.3%. Age-related maculopathy was present in the worse eye in 50.0%, 58.8%, and 44.7% of age groups 60 to 69, 70 to 79, and > or =80, respectively. Prevalence of any AMD was 9.5%. Any AMD was present in the worse eye in 3.9%, 14.6%, and 43.2% of age groups 60 to 69, 70 to 79, and > or =80. Prevalences of pure geographic atrophy (GA) in one or both eyes, exudative degeneration in one or both eyes, and GA in one eye and exudative degeneration in the other eye were 2.3%, 6.1%, and 1.1%, respectively., Conclusions: The prevalence of ARM is higher than in most other populations studied, and the prevalence of AMD in the oldest age group is higher than in most other populations studied. The prevalence of exudative degeneration is higher than the prevalence of GA, in contrast to findings in some of the Nordic countries-particularly Iceland-and earlier observations in Greenland.

Objective: It is a common notion that coronary heart disease (CHD) is rare among the Inuit, possibly due to a high intake of omega-3-fatty acids. The scientific evidence for this is weak and to some extent based on uncertain mortality statistic. The aim of this study was to assess the prevalence of markers of CHD among Greenland Inuit, and to study associations between markers of CHD and behavioral and biological variables., Design: We studied prevalence of angina pectoris (AP), self-reported myocardial infarction (MI), and ECG defined MI and ischaemia in a population survey among 1316 Inuit living in Greenland. Blood tests were supplemented by structured interviews, anthropometry, and measurements of blood pressure, and the participants received an oral glucose tolerance test., Results: The prevalence of symptomatic CHD (AP, self-reported MI) was 7.3% among men and 6.9% among women, and 12.2% and 13.4% of men and women had ischaemic ECG changes. The overall prevalence of CHD (AP+self-reported MI+ECG defined MI) was 10.8% in men and 10.2% in women. The highest prevalence was observed in the least westernized areas in Greenland. Physical inactivity, low education, dyslipidemia, hypertension and diabetes were associated with CHD., Conclusion: The prevalence of markers of CHD was not different from that in Western populations. The Inuit is a population undergoing rapid social and health transitions, with the emergence of cardiovascular risk factors, and there is a need for critical rethinking of cardiovascular epidemiology in this population.

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.

Objectives: The study aimed to estimate the prevalence of diabetes and impaired glucose intolerance (IGT) among Inuit migrants living in Denmark, and to compare with findings from Greenland. Further, we analyzed determinants for diabetes and impaired glucose metabolism., Study Design: Cross-sectional, population-based epidemiological study., Methods: This cross-sectional study included randomly selected Inuit migrants in Denmark aged 34 years and above. Diabetes and IGT were diagnosed using the oral glucose tolerance test. Body mass index (BMI) and waist circumference were measured, and blood samples were taken from each subject. Socio-demographic characteristics were investigated using a questionnaire. For comparison, data from the Greenland Population Study were used (n = 917)., Results: Of 506 eligible subjects, 256 (51%) participated. Twenty-six subjects had diabetes (10.2%) and twenty-eight had IGT (10.9%). Of those with diabetes, 64% had not been previously diagnosed. The prevalences of diabetes and IGT were not significantly different from those among Inuit in Greenland. Significant predictors of diabetes and impaired glucose metabolism (IGM) were found to be age, waist circumference and physical inactivity. The association between waist circumference and diabetes was significantly stronger among Inuit migrants in Denmark than among Inuit in Greenland., Conclusions: The prevalence of diabetes is high among the Inuit migrants in Denmark. However, unlike that reported in most studies, the prevalence was not significantly higher in the migrant population compared with the population of origin.

Background: The reputed low prevalence of cardiovascular disease among the Inuit has recently been challenged. Studies have shown total cholesterol among the Inuit to differ little from that of western populations and the association between cholesterol and atherosclerosis to be inconsistent., Methods: We studied serum lipids in a population survey among 2114 Inuit living in Denmark or in West Greenland. Blood tests were supplemented by structured interviews, anthropometry and measurements of blood pressure., Findings: Compared with the general population of Denmark, total cholesterol was higher among Inuit women, while HDL-cholesterol was higher among Inuit men. Triglyceride was lower among Inuit of both sexes. Cholesterol and triglyceride varied according to westernisation, diet, alcohol consumption and smoking. In a multivariate analysis, serum lipids also differed significantly between pure and genetically mixed Inuit: HDL-cholesterol was higher among the genetically pure Inuit, while among men triglyceride was lower and among women total and LDL-cholesterol were higher., Interpretation: Among the Inuit, serum lipids are significantly associated with westernisation and genetic heritage. The effect of westernisation is to some extent due to dietary changes. From a cardiovascular health point of view, westernisation within Greenland is associated with unfavourable lipid changes while migration to Denmark is associated with favourable lipid changes.

Objective: To investigate whether the obesity observed among the Inuit of Greenland and in a general Danish population was associated with the same degree of metabolic disturbances., Design: Comparison of data from two population-based cross-sectional surveys conducted in 1999-2001., Subjects: A total of 7892 individuals aged 30-60 y, 1108 Inuit participants from the Greenland Population study, and 6784 Danish participants in the Danish Inter99 study., Measurements: Height, weight, waist and hip circumference were measured, and BMI and waist-to-hip ratio were calculated. The participants received a standard 75 g OGTT. s-Triglyceride, s-HDL cholesterol, fasting and 2 h p-glucose and s-insulin were analysed. Blood pressure was measured. Information on lifestyle factors was obtained by a questionnaire and interview., Results: The Inuit had lower levels of 2-h glucose and insulin, blood pressure, triglyceride, and higher levels of HDL cholesterol than the Danish participants at any given level of obesity. Fasting glucose and fasting insulin levels within obesity categories were not different in the two populations. Adjustment for physical activity, smoking, school education, and alcohol consumption did not change these findings., Conclusion: The trends in the association between obesity and metabolic effects among the Inuit and a Northern European population were the same, but the levels of the risk factors were significantly different. This may be due to genetic factors and differences in body composition.

During 1997-2001 a population survey was carried out amongst Greenland Inuit living in Denmark and West Greenland (Nuuk, Sisimiut, Qasigiannguit and four villages in Uummannaq municipality). Data collection comprised an interview, a questionnaire, clinical examinations and sampling of biological specimens (blood, urine, subcutaneous fat tissue). The clinical examinations included anthropometric measurements, an oral glucose tolerance test, ECG, ultrasound of thyroid gland and carotid arteries, a skin prick test, and lung function. The data collection areas in Greenland ranged from the westernized capital of Nuuk (pop. app. 13,000) to small fishing and hunting villages (pop. app. 250). A total of 4,162 persons aged 18+ participated in the study; clinical examinations were performed on 2,056 of these, 739 from Denmark and 1317 from Greenland. Some of the above mentioned procedures were performed on a subset of the participants. The participation rate was 62%. We provide an overview of the background of the study and a detailed description of the methods employed for the data collection. A set of standard tables are provided for the indigenous population of Greenland. These cover statistics for selected variables by gender and ten-year age groups.

Objective: To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization., Design: Cross-sectional, population-based epidemiological study., Subjects: A total of 2046 adult Greenlanders (Inuit), 61% of those invited to participate, living in three areas of Greenland and in Denmark., Measurements: Height, weight, waist and hip circumferences were measured and body mass index (BMI in kg/m(2)) and waist-hip ratio calculated. Sociocultural information was obtained by questionnaire and interview. Westernization was estimated by language and place of residence., Results: The prevalence of obesity (>or=30 kg/m(2)) was 16 and 22% among men and women in Greenland (P=0.004), and 12 and 11%, respectively, in Denmark (NS). Westernization was accompanied by a decrease in the proportion of obese people, in particular among women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland., Conclusion: BMI and central fat patterning decrease with Westernization among Greenland Inuit women contrary to most studies of migrants. The changes were less prominent among men. This suggests a reduced cardiovascular risk profile with Westernization among Greenland Inuit.

Objective: To assess the prevalence of diabetes and impaired glucose tolerance (IGT) among the Inuit population of Greenland and to determine risk factors for developing glucose intolerance., Research Design and Methods: This cross-sectional study included 917 randomly selected adult Inuit subjects living in three areas of Greenland. Diabetes and IGT were diagnosed using the oral glucose tolerance test. BMI and waist-to-hip ratio were measured and blood samples were taken from each subject. Sociodemographic characteristics were investigated using a questionnaire., Results: The age-standardized prevalences of diabetes and IGT were 10.8 and 9.4% among men and 8.8 and 14.1% among women, respectively. Of those with diabetes, 70% had not been previously diagnosed. Significant risk factors for diabetes were family history of diabetes, age, BMI, and high alcohol consumption, whereas frequent intake of fresh fruit and seal meat were inversely associated with diabetic status. Age, BMI, family history of diabetes, sedentary lifestyle, and place of residence were significant predictors of IGT., Conclusions: The prevalence of diabetes is high among the Inuit of Greenland. Heredity was a major factor, while obesity and diet were important environmental factors. The high proportion of unknown cases suggests a need for increased diabetes awareness in Greenland.