Diabetes in Greenland and its relationship with urbanization.

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 [OR(diabetes) = 1.5 (1.0-2.3), OR(IFG) = 1.9 (1.2-2.3)] and villages [OR(diabetes) = 1.2 (0.8-1.9), OR(IFG) = 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.

Childhood conditions and education as determinants of adult height and obesity among Greenland Inuit.

Height and obesity are risk factors for cardiovascular disease and other physical and mental health conditions. Their association with childhood socioeconomic position has been demonstrated in studies among European and a few third world populations. In a random sample of adult Greenland Inuit (N = 2302) we studied the association between childhood socioeconomic conditions and height as well as prevalence of obesity (BMI > or = 30) in a cross sectional design. In block recursive graphical independence models, height was associated with mother's place of birth, birth cohort, childhood residence, alcohol problems in childhood home, and education among both men and women. Obesity was associated with mother's place of birth (for men) and with alcohol problems (for women). In General Linear Models, men with an all rural background and no education beyond primary school measured on average 165.1 cm compared with 172.1 cm for men with an all urban background (P < 0.001); women measured 153.9 and 161.1 cm (P < 0.001). Rural-urban differences in prevalence of obesity were not statistically significant. The height differences were considerably larger than between educational groups in European countries and of the same order of magnitude as those reported between men from the 17th century and men from 400 BC in the European and Mediterranean region. The rural-urban gradient in height follows the socioeconomic gradient and may negatively affect cardiovascular risk among the rural Greenlanders, while their physically active lifestyle and high consumption of n-3 fatty acids may counteract this.

A cross-sectional study of the association between persistent organic pollutants and glucose intolerance among Greenland Inuit.

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.

Prevalence of the metabolic syndrome among the Inuit in Greenland. A comparison between two proposed definitions.

AIMS: To estimate the prevalence of the metabolic syndrome among Greenland Inuit according to the World Health Organization (WHO) definition and the definition suggested by the National Cholesterol Education Program (NCEP). METHODS: From 1999 to 2001, 917 adult Inuit participated in a health survey in Greenland. The examination included a 75-g oral glucose tolerance test (OGTT). Body mass index (BMI), waist circumference, waist-to-hip ratio and blood pressure were measured. Plasma glucose, serum insulin, lipids and urine albumin/creatinine ratio were measured. The metabolic syndrome was diagnosed according to the WHO criteria 1999 and to the working definition suggested by the NCEP 2001. RESULTS: Using the WHO and the NCEP criteria, 20.7% and 17.9% of the participants had the metabolic syndrome, respectively. There was a moderate agreement between the two definitions, kappa = 0.56 (95% CI 0.51-0.61). Of those with the WHO metabolic syndrome, 37.9% did not have the NCEP syndrome, and 28.5% of those with the NCEP syndrome were not classified with the metabolic syndrome under the WHO criteria. Compared with the WHO syndrome, men with the NCEP syndrome had higher mean values of waist circumference, BMI and triglycerides, and lower mean values of high-density lipoprotein (HDL) cholesterol; among women, triglycerides were higher with the NCEP syndrome. CONCLUSION: The metabolic syndrome is common among Inuit using either the WHO definition or the proposed NCEP definition. The classification disagreement is considerable and a universally accepted definition is needed.

Serum lipids of Greenland Inuit in relation to Inuit genetic heritage, westernisation and migration.

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.

Physical violence, self rated health, and morbidity: is gender significant for victimisation?

STUDY OBJECTIVE: To analyse gender differences in associations between physical violence and self rated health and self reported morbidity among a random sample of adults in Denmark. DESIGN AND SETTING: Two questions on self rated health and self reported morbidity respectively, were obtained from a cross sectional national health interview survey conducted among 12 028 adults (16 years +) in Denmark in 2000. A question on six different forms of physical violence was obtained from a supplementary self administered questionnaire given to the same sample. The reporting period for experienced physical violence was the past 12 months and for morbidity symptoms, the past 14 days. MAIN RESULTS: Men aged 16-24 years were significantly more likely to have experienced violence than women (OR = 3.2, 95% CI = 2.3 to 4.2). Female victims of physical violence were significantly more likely to rate their health as poor (OR = 2.02, 95% CI = 1.41 to 2.89) and to report anxiety (OR = 2.14, 95% CI = 1.35 to 3.37), depression (OR = 2.36, 95% CI = 1.55 to 3.60), and stomach ache (OR = 1.58, 95% CI = 1.01 to 2.47) than female non-victims. Male victims of physical violence were only significantly more likely to report stomach ache (OR = 1.73, 95% CI = 1.03 to 2.89) than male non-victims. CONCLUSIONS: Associations between physical violence and poor self rated health and self reported morbidity were found to be significant for women, but not for men. It is probable that gender differences in experiences of violence, as well as gender differences in health related self perception, contribute to a gender specific process of victimisation. Improved knowledge about the relation between gender specific violence and victimisation as a gender specific consequence is essential for targeting violence prevention.

35 years of ICCH: evolution or stagnation of circumpolar health research?

The first Circumpolar Health symposium took place in Fairbanks in 1967. Approximately every three years since, an increasing number of researchers have met to present and discuss the health conditions of the North. We analysed the proceedings from the 11 congresses and the abstracts from the 12th congress in 2003 and found a shift of focus from biology to sociology of health. Today, circumpolar health research is primarily focused on three major topics: 1. epidemiology of indigenous peoples of the North; 2. health care delivery in the North; and 3. the effect of physical factors on human physiology and health. Despite the diverse research interests, it is remarkable how a community of circumpolar scientists and practitioners has emerged over the past 35 years.

Trends in the dietary patterns and prevalence of obesity among Greenlandic school children.

OBJECTIVE: The aim of the study was to examine the trends in the dietary patterns of selected food items and in the prevalence of self-perceived obesity in a population of Greenlandic schoolchildren. STUDY DESIGN: The study is based on three school surveys among Greenlandic schoolchildren, class 6 to 11 in public schools, and contributing to the Health Behaviour in School-aged Children (HBSC) Study. Data are collected through self-completed questionnaires administered in the classroom. Three surveys have been carried out in Greenland in 1994, 1998 and 2002 with the participation of 2,999, 3,057 and 2,010 pupils, respectively. RESULTS: The intake of vegetables has increased significantly since 1994, and the intake of fruits, sweets and soft drink has decreased significantly at a 5% level. An unchanged high proportion of schoolchildren report to be on a diet or consider themselves obese. CONCLUSION: Most of the observed trends are positive, with regard to intake of vegetables and sweets and consumption of soft drinks. The fact that a high proportion of schoolchildren consider themselves to be obese must be assumed to have a negative impact on the psychological well-being of this population. The results of the survey can reveal changes which have occurred over time for the specified population. This knowledge can be used in public health work and planning.

Incidence of myocardial and cerebral infarction in Nuuk, Greenland.

INTRODUCTION: Myocardial and cerebral infarction are held to be rare among the Inuit, whereas cerebral haemorrhage is thought to be frequent. Recent studies have questioned these beliefs. We report data form our institution. METHOD: Retrospective data collection and review of all charts from Greenlandic patients from the Nuuk area admitted to the city hospital, Dronning Ingrids Hospital, from 1999 to 2002. RESULTS: A total of 8 patients with myocardial infarction were found, median age 70 years, 4 with ST elevation MI and 4 with non-ST elevation MI. Two of the former had thrombolysis. Thirty-five patients were admitted with stroke, excluding subarachnoid haemorrhage, median age 65 years. Of these, twenty-nine had a CT. Five scans were reported as being normal, one patient had an intracerebral haemorrhage and twenty-three had cerebral infarctions. Six had no CT. One of these was admitted comatose and died without regaining consciousness, the rest were minor strokes in patients over 70. CONCLUSION: Myocardial infarction is a rare disease in Greenlanders, whereas stroke is four times as frequent. The overwhelming majority of strokes are infarctions, whereas intracerebral haemorrhage seems to account only for a small minority.

Parkinson's disease among Inuit in Greenland: organochlorines as risk factors.

OBJECTIVES: In the present study we investigate organochlorines as possible risk factors for Parkinson's disease (PD) in an arctic population. This has never been done before. STUDY DESIGN: Case-control study of Inuit in Greenland. MATERIALS AND METHODS: Plasma from 31 PD (20 males and 11 females) (mean age 69 yr) and 122 controls (57 males and 65 females) (mean age 61 yr) was analysed for 31 PCBs and pesticides by dual-column GC-ECD and GC-NCI/MS. RESULTS: Plasma concentrations of PCBs and pesticides were markedly increased in both PD and controls. The concentrations did not differ between the PD cases and controls. However, the mean DDE concentration was higher in PD than in controls (42.1 and 15.0 microg/l, respectively, and with a wide range among the PD cases). The difference was significant for log transformed DDE values after control for age and sex (p=0.005). CONCLUSION: A few epidemiological studies indicate a possible connection between exposure to pesticides and PD. The idea that exposure to organochlorines may be an important risk factor for PD among the Inuit in Greenland requires more investigations.

Acculturation and mental health--empirical verification of J.W. Berry's model of acculturative stress.

OBJECTIVES: Many studies concerning mental health among ethnic minorities have used the concept of acculturation as a model of explanation, in particular J.W. Berry's model of acculturative stress. But Berry's theory has only been empirically verified few times. The aims of the study were to examine whether Berry's hypothesis about the connection between acculturation and mental health can be empirically verified for Greenlanders living in Denmark and to analyse whether acculturation plays a significant role for mental health among Greenlanders living in Denmark. STUDY DESIGN AND METHODS: The study used data from the 1999 Health Profile for Greenlanders in Denmark. As measure of mental health we applied the General Health Questionnaire (GHQ-12). Acculturation was assessed from answers to questions about how the respondents value the fact that children maintain their traditional cultural identity as Greenlander and how well the respondents speak Greenlandic and Danish. The statistical methods included binary logistic regression. RESULTS: We found no connection between Berry's definition of acculturation and mental health among Greenlanders in Denmark. On the other hand, our findings showed a significant relation between mental health and gender, age, marital position, occupation and long-term illness. CONCLUSION: The findings indicate that acculturation in the way Berry defines it plays a lesser role for mental health among Greenlanders in Denmark than socio-demographic and socio-economic factors. Therefore we cannot empirically verify Berry's hypothesis.

Obesity and central fat pattern among Greenland Inuit and a general population of Denmark (Inter99): relationship to metabolic risk factors.

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.

Inuit health in Greenland: a population survey of life style and disease in Greenland and among Inuit living in Denmark.

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.

Metabolism of bisphenol A in zebrafish (Danio rerio) and rainbow trout (Oncorhynchus mykiss) in relation to estrogenic response.

The kinetics of bisphenol A (BPA) were investigated in zebrafish (Danio rerio) exposed to 100 microg BPA/l. BPA uptake was measured during a 7-day period followed by an elimination phase of similar duration. After 2, 6, 12, 24, 48, 72, 120 and 168 h of uptake/elimination, fish were analysed for their content of BPA, bisphenol A glucuronic acid (BPAGA) and bisphenol A sulfate (BPAS). Within the first 24 h steady state levels of BPA, BPAGA and BPAS were reached and the total body concentrations were calculated to be 569, 12,600 and 39.9 ng/g fish, respectively. Elimination rates of the three compounds in zebrafish were estimated by fitting the data to a compartment model. An initial rapid elimination phase was observed for BPA and BPAS with total body half lives (T(1/2)) of <1.1 h and 30 min, followed by a slower second elimination phase with T(1/2) values of 139 and 71 h, respectively. Excretion of BPAGA occurred from a single compartment with a T(1/2) of 35 h. The steady state concentration of BPA and its metabolites were investigated in rainbow trout (Oncorhynchus mykiss) exposed to 100 microg BPA/l. The toxicokinetic parameters from zebrafish and rainbow trout were compared; including previously published data on the rainbow trout. The data indicate that the smaller estrogenic sensitivity observed for the zebrafish may be caused by a more rapid metabolism of BPA in the zebrafish liver.

Contribution of population surveys to the study of cardiovascular disease and diabetes in Greenland.

Two population surveys with focus on cardiovascular disease and diabetes were carried out among the Greenland Inuit in 1993-94 and 1999-2001. The number of participants was 264 (1993-94 study) and 2056 (1999-2001 survey) Inuit living in Denmark, towns in Greenland, and villages. Compared with the general population of Denmark, the Inuit had a high consumption of marine food, but regional and demographic variation was marked. Smoking prevalence was high, being approximately 70% among adults in 1999-2001. Blood pressure was lower than in Denmark and the serum lipid profile was healthier (high HDL cholesterol and low triglyceride). The risk factor pattern is consistent with neither an increased, nor a decreased cardiovascular risk profile. Longitudinal studies are needed to determine the incidence of cardiovascular diseases and diabetes, and to establish causal links between traditional risk factors and disease in this non-European population.

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

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

Higher blood pressure among Inuit migrants in Denmark than among the Inuit in Greenland.

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 >/or =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.

Uptake, metabolism and excretion of bisphenol A in the rainbow trout (Oncorhynchus mykiss).

The uptake, metabolism and excretion of the oestrogenic chemical bisphenol A (BPA) were studied in juvenile rainbow trout (Oncorhynchus mykiss). BPA was detectable in plasma, liver and muscle after 2 h of water exposure at 0.44 microM (100 microg BPA/l), and a steady state was reached within 12-24 h. The concentration of the glucuronidated degradation product in the plasma was about twice that of the parent compound. A plasma half life of BPA was calculated as 3.75 h following injection of the compound. The vitellogenin synthesis was measured in response to the BPA treatment, and a lag period of 5 and 7 days between injection of the compound and a significant vitellogenin response was observed for females and males, respectively. At the time of the vitellogenin response no BPA could be detected in the liver tissue from either male or female fish. These results indicate that fish briefly exposed to elevated levels of oestrogenic chemicals might develop a response several days later.