OBJECTIVE: To analyse the associations between the intake of fish and marine mammals and risk factors for cardiovascular disease, ie lipid profile, fasting blood glucose, blood pressure and obesity, in a population whose average consumption of n-3 fatty acids is high compared with Western countries. DESIGN: Information was obtained from a population survey in Greenland: interview data, clinical data and fasting blood samples were obtained from a random sample of Inuit from three towns and four villages. SUBJECTS: Two-hundred and fifty-nine adult Inuit (74% of the sample). RESULTS: Marine diet was positively associated with serum high-density lipoprotein (HDL) and blood glucose and inversely with very-low-density lipoprotein (VLDL) and triglyceride. Association with low-density lipoprotein (LDL), diastolic and systolic blood pressure, waist-hip ratio and body mass index were inconsistent and not statistically significant. The pattern was similar within groups with low, medium and high consumption of marine food. CONCLUSIONS: There are statistically significant associations between the consumption of marine food and certain lipid fractions in the blood also in this population with a very high average intake of marine food. The observation that blood glucose is positively associated with marine diet in a population survey is new and should be repeated. There was good agreement between the results for the reported consumption of seal and those for the biomarkers. SPONSORSHIP: The study was financially supported by the Greenland Home Rule, Directorate of Health and Research, the Commission for Scientific Research in Greenland, and the Danish Medical Research Council.
The concept of avoidable deaths suggests that certain deaths ought not occur in a given society because it is possible to prevent or treat the disease or condition. A list of avoidable deaths is time and community specific as it reflects the socioeconomic conditions, professional medical capacity and political will of the society. A list of avoidable deaths is proposed for Greenland which includes, inter alia, meningitis, lung cancer, acute respiratory infections, suicides, boat accidents and alcohol related diseases and accidents. All were considerably more common in Greenland than in Denmark and several showed an increasing time trend. The regional patterns were particularly clear for infectious diseases and accidents, which showed low mortality rates in the capital and other towns and high mortality rates in settlements and in the remote East Greenland, while mortality rates from suicides and alcohol related diseases were high in the capital and East Greenland and low in West Greenlandic settlements. It is concluded that further studies on preventable diseases and causes of death, in particular certain infectious diseases, accidents and suicides, are needed.
Surveys taken of blood pressure in Greenland indicated prevailing levels similar to those in the USA. Morphometrically measured renovasculopathies in 88 autopsies confirmed blood pressure levels comparable to the survey findings. At clinic visits, the recorded blood pressures in 48 of the autopsies verified the morphometric conclusions (r = 0.559). By all three approaches, similar levels of blood pressure were determined for the population of Greenland. The agreements in outcome from these approaches serve to substantiate the validity of all three methods. The overall outcome verifies a previous report placing Greenland among the nations which experience rapid rise of blood pressure with age and high prevalence rates for hypertension.
Juvenile amaurotic idiocy (JAI) is a rare disorder of autosomal recessive inheritance. It belongs to the so called ceroid lipofuscinoses and the central nervous system is the largest organ. Only very few reports refer to the accumulation of lipopigment in the heart of JAI patients. This study describes the morphology of the heart from all 13 patients with JAI in Denmark who died within a seven year period; electrocardiographic findings are related to structural changes. All compartments of the heart were involved, including the conduction system. Not only very substantial deposition of lipopigment was found in the myocytes, but we have also observed striking amounts of calcium and cholesterol compounds indicating a restrictive type of heart muscle disorder. These structural changes are uniform from case to case. Because of the nature of the disease only rather poor information of the cardiac state is available in JAI patients. 11 patients showed some cardiac enlargement. In 6 patients abnormal P-waves were recorded in the ECG suggesting increased atrial and ventricular diastolic pressure. 2 patients had bradycardia, probably due to sinus node involvement, and one patient developed complete right bundle branch block. However, in the 4 patients in whom the cardiac conduction system could be examined histologically no evidence of disturbance of cardiac impulse formation and conduction was seen in the few standard ECG strips available in spite of extensive deposition of abnormal material throughout the conduction system. There seems to be a discrepancy between the relatively minor functional disturbances observed and the heavy morphological changes of the entire heart. This aspect, however, may well be altered by an intensified clinical observation and examination of JAI patients.
Environmental pollution in the Arctic is due to long range transport from lower latitudes or to local industrial activities. Since the latter are not different from point source exposure in the rest of the world the paper focuses on the former aspect which is the main type of environmental pollution in the western Arctic. The environmental pollutants of major significance are heavy metals (mercury, cadmium, lead) and persistent organic pollutants (PCB's, pesticides) and the main exposure is through the traditional diet of sea mammals (mercury, cadmium, persistent organic pollutants) and through smoking (cadmium). There is rather strong evidence that lead is a (weak) risk factor for high blood pressure even at low levels of exposure. Apart from lead there is little evidence that the above mentioned pollutants are significantly related to cardiovascular diseases. Since the pollutants, however, are found in the traditional diet together with n-3 polyunsaturated fatty acids, monounsaturated fatty acids, and selenium which are believed to promote cardiovascular health there is an indirect link between the pollutants and cardiovascular disease. This becomes relevant when dietary guidelines are developed for arctic populations. Epidemiological evidence from Greenland relevant for this discussion is presented, i.e. i) findings from a countrywide interview survey on dietary habits which show that sea mammals are widely consumed and appreciated for health and other reasons and that there is virtually no fear of pollution, and ii) mortality results which do not support the hypothesis that the low rate of ischemic heart disease in Inuit is due to their traditional diet.
BACKGROUND: Mortality from ischaemic heart disease (IHD) and prevalence of coronary arteriosclerosis are low in Inuit of Greenland (Greenlanders). Aetiological considerations have so far focused mostly on diet and blood lipids. The present study is a comprehensive analysis of behavioural, clinical and serological cardiovascular risk factors for IHD in Greenlanders. METHODS: An interview survey from West Greenland (n = 1436) was supplemented with clinical measurements and blood sampling in selected towns and villages (n = 264). RESULTS: The average consumption of marine mammals and fish was 28 meals per month. In Greenland 14% of males and 30% of females were physically inactive compared with 14% and 17% in the general population of Denmark; 79% were current smokers and 22% smoked 15+ cigarettes per day compared with 42% and 21% in Denmark. High density lipoprotein (HDL) concentration was 1.6 mmol/l in Greenland (1.1 in Denmark) and triglyceride concentration 1.0 mmol/l (1.5). Obesity, blood pressure and total cholesterol were similar in Greenland and Denmark. There were significant differences between Greenlanders with a predominantly traditional childhood and those with a more westernized childhood with regard to diet, physical activity (in women) and blood lipids. CONCLUSIONS: In spite of an increased westernization of the Greenlanders' lifestyle and a high prevalence of several cardiovascular risk factors, mortality from IHD is still low. The change in risk factor patterns is, however, recent and an increased IHD mortality is still to be expected. Preventive measures should be initiated to reduce risk factors but they must take into consideration possible negative consequences of e.g. traditional outdoor activities and the consumption of marine mammals.
The high infant and child mortality in Greenland covers significant differences among geographic regions. In the capital, Nuuk, 14 of 1000 live born children die before their first birthday, in the remote communities of northern and eastern Greenland the figure is 45. An independently higher mortality risk has also been demonstrated in children of mothers with alcohol problems, frequent admissions to hospital, and various other characteristics. A substantial proportion of infant and child deaths are potentially avoidable, either through improved health services or through action at community level. Based on the results of a research project certain concrete actions have been proposed and adopted by the health authorities.
