Causes of death and incidences of cancer and cardiovascular diseases

The Sami people are the natives of northern Scandinavia and the Kola Peninsula. The knowledge of the demography, health and living conditions of the Swedish Sami is extremely limited. Over the last decades, only a few studies have been published addressing health and disease in this population. The overall shortage of knowledge on the health situation of the Sami population, not only in Sweden but also in Norway, Finland and Russia, is in contrast to the large amount of detailed information on health, demographic and socio-economic issues that is available for indigenous people in e.g. North America, Greenland and Australia. The encounter with the western society has for many native populations had dramatic health consequences. Early contacts brought infectious diseases such as smallpox and tuberculosis, while western influence during the last five decades have had more profound effects on the lifestyle causing a dramatic increase of lifestyle related western diseases such as cancer, diabetes, stroke, obesity and hypertension. The mental health has also been negatively affected in many native populations due to the western influence with dramatic increase of suicide rates and drug abuse. The relationship between acculturation and health has been of longstanding interest when studying the health situation among indigenous peoples. In circumpolar peoples the processes of acculturation and adaptation has often been manifested as dramatic, unfavourable changes in health. Although the role and status of the Sami population in Sweden has been described in a historical context, these aspects have not been thoroughly evaluated in relation to health. The overall objective of this thesis was to investigate the health conditions of the Sami population of Sweden using causes of death and incidences of cancer and cardiovascular diseases as health indicators, and to evaluate their possible association with demographical and acculturative factors such as assimilation, integration, separation and marginalization. In order to establish a large database for epidemiological studies of the Swedish Sami population, an attempt was made to reconstruct the Sami population by using the available national population registers where the Sami population can be extracted in one way or another. A Sami cohort was constructed departing from a group of index-Sami identified as either reindeer herding Sami or Sami eligible to vote for the Sami parliament. Relatives to index-Sami were identified in the National Kinship Register and added to the cohort. The cohort contained a total of 41 721 persons (7 482 reindeer herding Sami and 34 239 non-herding Sami) and selections from this population were used for the different studies. A four times as large demographically matched non-Sami control population was compiled the same way. A study of causes of death in the Sami population of Sweden 1961-2000 showed that the differences in overall mortality and life expectancy of the Sami, both reindeer herding Sami and non-herding Sami, compared to the control population were relatively small. However, Sami men showed significantly lower SMR for cancers but higher for external cause of injury. For Sami women, significantly higher SMR was found for diseases of the circulatory system and diseases of the respiratory system. An increased risk of dying from subarachnoid haemorrhage was observed among both Sami men and women. The observed differences might be due to lifestyle, psychosocial and/or genetic factors. Male reindeer herding Sami showed a significantly increased risk of dying from accidents such as vehicle accidents and poisoning. No increased risk of suicide was observed. A comparison between the periods of 1961-1980 and 1981-2000 showed non-significant differences in risk although a trend towards increased risks were observed for most types of external causes of death, except suicide. It is suggested that the increased socio-economic pressure and the extensive use of terrain vehicles have increased the risk for fatal accidents among Swedish reindeer herders. It is concluded that commercial reindeer management is one of the most dangerous occupations in Sweden. The cancer risk in the reindeer herding Sami population of Sweden was studied between 1961 and 1997. In comparison to non-Sami living in the same area, the reindeer herding Sami showed a statistically significant lower risk of contracting cancer of the prostate and of malignant