Sven Hassler

The burden of stomach cancer in indigenous populations: a systematic review and global assessment

Objective Stomach cancer is a leading cause of cancer death, especially in developing countries. Incidence has been associated with poverty and is also reported to disproportionately affect indigenous peoples, many of whom live in poor socioeconomic circumstances and experience lower standards of health. In this comprehensive assessment, we explore the burden of stomach cancer among indigenous peoples globally. Design The literature was searched systematically for studies on stomach cancer incidence, mortality and survival in indigenous populations, including Indigenous Australians, Maori in New Zealand, indigenous peoples from the circumpolar region, native Americans and Alaska natives in the USA, and the Mapuche peoples in Chile. Data from the New Zealand Health Information Service and the Surveillance Epidemiology and End Results (SEER) Program were used to estimate trends in incidence. Results Elevated rates of stomach cancer incidence and mortality were found in almost all indigenous peoples relative to corresponding non-indigenous populations in the same regions or countries. This was particularly evident among Inuit residing in the circumpolar region (standardised incidence ratios (SIR) males: 3.9, females: 3.6) and in Maori (SIR males: 2.2, females: 3.2). Increasing trends in incidence were found for some groups. Conclusions We found a higher burden of stomach cancer in indigenous populations globally, and rising incidence in some indigenous groups, in stark contrast to the decreasing global trends. This is of major public health concern requiring close surveillance and further research of potential risk factors. Given evidence that improving nutrition and housing sanitation, and Helicobacter pylori eradication programmes could reduce stomach cancer rates, policies which address these initiatives could reduce inequalities in stomach cancer burden for indigenous peoples.

Risk factors for cardiovascular diseases among Swedish Sami – a controlled cohort study

Objective. To investigate the occurrence of clinical, psychosocial and behavioural risk factors for cardiovascular diseases (CVD) among reindeer herding (RS) and non-reindeer herding Sami (NRS). Study Design. A retrospective cohort study, comparing risk factors behind CVD between Sami and non-Sami, RS and NRS, and Sami men and women. Methods. A cohort of 611 Swedish Sami (276 men and 335 women) was constructed from national population registers. A twice as large control cohort of non-Sami was created, matched by age, gender and area of residence. Information on risk factors was obtained from a database containing clinical and psychosocial-behavioural data from a regional CVD preventive programme for the period 1990–2001. Results. The Sami and the non-Sami showed similar risk factor patterns. The main differences were related to working conditions and lifestyle factors of the RS. The RS men had lower blood pressure, were more physically active and had higher job demand and decision latitude. The RS women showed more negative scores on the indices of the job strain model. Conclusions. Previously reported differences in CVD mortality between Sami and non-Sami, and Sami men and women, can only partly be explained by different exposure to the psychosocial and behaviour risk factors investigated in this study.

Stroke and acute myocardial infarction in the Swedish Sami population : Incidence and mortality in relation to income and level of education

Background: Gender differences in cardiovascular diseases (CVD) among the Sami have been reported previously. The aim of the present study was to investigate the incidence of and mortality from stroke, subarachnoid haemorrhage (SAH), and acute myocardial infarction (AMI) in the Swedish Sami population between 1985 and 2002, and to analyse the potential impact of income and level of education on cardiovascular morbidity and mortality. Methods: A Sami cohort of 15,914 persons (4,465 reindeer herding and 11,449 non-herding Sami) were followed up from 1985 to 2002 with regard to incidence and mortality rates of AMI, stroke, and SAH. Incidence and mortality ratios were calculated using a demographically matched non-Sami control population (DMC) as the standard (71,550 persons). Results: There was no elevated risk of developing AMI among the Sami compared with the DMC. However, the mortality ratio of AMI was significantly higher for Sami women. Higher incidence rates of stroke and SAH for both Sami men and women was observed, but no differences in mortality rates. Apart from the reindeer-herding men who demonstrated lower levels of income and education, the income and education levels among Sami were similar to the DMC. Conclusions: High mortality rates from AMI rather than stroke explain the excess mortality for CVD previously shown among Sami women. The results suggest that the differences in incidence of stroke between herding and non-herding Sami men, and between Sami women and non-Sami women, are caused by behavioural and psychosocial risk factors rather than by traditional socioeconomic ones.

Fatal accidents and suicide among reindeer herding Sami in Sweden

Objective. Over the last decades, reindeer-herding management has experienced dramatic changes, e.g. increased motorization and socio-economic pressure. The aim of the present study was to investigate whether these changes have increased the risk of fatal, work-related accidents and suicide between 1961 and 2000. Study design and methods. A cohort containing 7,482 members of reindeer-herding Sami families was extracted from national population registers. Information on fatal accidents and suicide was obtained from the Swedish Causes of Death Register, and compared to the expected number of deaths in a demographically matched control population of non-Sami. Results. The male reindeer herding Sami showed a significantly increased risk of dying from accidents such as vehicle accidents and poisoning. No significant 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 was observed for most types of external causes of death except suicide. Conclusions. 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, and that commercial reindeer management is one of the most dangerous occupations in Sweden.

Cancer risk in the reindeer breeding Saami population of Sweden, 1961-1997

The Saami people are the natives of northern Scandinavia and the Kola Peninsula. In a cohort of 2033 Swedish reindeer breeding Saamis, the cancer risks between 1961 and 1997 were studied. In total, 193 cases of cancer were observed versus 322 expected in the general Swedish population and 249 in a geographically matched reference population of non-Saamis. In comparison to non-Saamis living in the same area, the reindeer breeding Saamis showed a statistically significant lower risk of developing cancer of the prostate and of malignant lymphoma, whereas the risk of stomach cancer was significantly higher. Although there were no statistically significant changes of cancer risks over time, temporal trends were indicated towards a decreased risk of cancer in the stomach and the prostate. The results suggest that the explanations of the low cancer risk of the reindeer breeding Saamis, in relation to the non-Saamis in the same environment, are to be found among lifestyle and/or genetic factors.

Cancer in the Sami population of Sweden in relation to lifestyle and genetic factors

The reindeer herding Sami of Sweden have low incidences of cancer. The aim of the present study was to investigate the cancer risk in a large cohort of Swedish Sami, containing Sami with different lifestyle and genetic Sami heritage. A cohort of 41,721 Sami identified in official national registers between 1960 and 1997, was divided into two sub-populations - reindeer herding Sami (RS) and non-reindeer herding Sami (NRS). A demographically matched non-Sami reference population (NS) was used as standard when incidence and mortality ratios were calculated. Incidence and mortality data were obtained from the Swedish Cancer and Cause of Death Registers for the period 1961–2003. For Sami men, lower risks were found for cancers of the colon and prostate, and for malignant melanoma and non-Hodkins lymphoma, but higher for stomach cancer. The Sami women showed higher risks for cancers of the stomach and the ovaries, but lower risk for cancer of the bladder. The RS demonstrated lower relative cancer risks compared with the NRS. The lowest relative risk was found among the RS men, while the highest were observed among the NRS women. The RS men who had adopted a more westernized lifestyle showed a similar relative risk for prostate cancer as that of the NS living in the same region. Most of these differences in cancer risks could probably be ascribed to differences in lifestyle. It is concluded that the traditional Sami lifestyle contains elements, e.g. dietary contents and physical activity that may protect them from developing cancer.

Cancer among the Sami : a review on the Norwegian, Swedish and Finnish Sami populations

Objectives. The Sami are the Indigenous people of the northernmost parts of Sweden, Finland and Norway, and of the Kola Peninsula of Russia. The present review summarizes the main results from studies on cancer morbidity and mortality among the Sami and discusses these results in relation to exposure of known risk factors. Study Design. Literature review. Methods. A systematic search over the time period 1966–2008 for relevant articles was conducted on MEDLINE. Updates and recalculations of some of the results from the original data were also done. Results. Nine articles whose main focus is on cancer incidence or mortality among the Sami were identified. In all studies, the overall incidence of cancer or cancer mortality was lower among the Sami in comparison with the national populations. The differences were less striking in relation to regional reference populations, but the rates were still significantly lower for all populations of Sami, except for Swedish Sami women. Beyond the general trend of a lower cancer incidence among the Sami, there were some notable differences between the various Sami subpopulations. Conclusions. The risk of developing and dying from cancer is low among the Sami. A life-style that includes cancer-protective factors, such as certain dietary components and physical activity, is the most likely explanation for the lower incidence of cancer among the Sami.

Adherence to a traditional lifestyle affects food and nutrient intake among modern Swedish Sami

Abstract Objectives. To compare the nutrient and food intake of Sami still engaged in reindeer herding (traditionallifestyle or reindeer-herding Sami [RS]) and Sami not involved in reindeer herding (industrializedlifestyle or non-reindeer-herding Sami [NRS]) with other northern Swedish populations. Study design. Cross-sectional analysis of data from a prospective cardiovascular interventionprogram in northern Sweden. Methods. Data were used from a prospective cardiovascular intervention program in northernSweden. Sami recruited into this study were divided according to whether they were involved inreindeer herding (traditional lifestyle, RS) (66 females, 79 males) or not (NRS) (255 females, 195males), and compared to non-Sami from the same area taking part in the same study (controls)(499 females, 501 males). Subjects completed a Food Frequency Questionnaire (FFQ) and clinicalparameters were analysed. Results. RS had a higher overall intake of energy for both females (P<0.01) and males (P<0.05), but not total food intake compared to controls and NRS. The overall Sami diet was characterizedby a higher proportion of energy from protein and fat. RS had a lower energy adjusted intake ofvitamins A and E, and fibre, and a higher intake of sodium. RS and NRS both had a lower intakeof vegetables and a higher intake of meat, and for RS, fish. Nutrient and food-intake patterns weresimilar for males and females. Conclusions. Classification of Sami into RS and NRS indicates that a traditional lifestyle defined byoccupation is reflected in differences in food and nutrient intake.

Sense of coherence and self-reported health among Roma people in Sweden - a pilot study

Objectives. The Roma people have been known in Europe for a 1000 years, during which they have usually been the subject of discrimination and oppression leading to isolation, powerlessness and poor health. The objective of this study is to investigate the sense of coherence (SOC) in relation to self-reported health among a group of Roma people in southwest Sweden. Study design. A cross-sectional, quantitative pilot study. Methods. A questionnaire was constructed based on the Short-Form Health Survey (SF-12) and Antonovskys Sense of Coherence Scale (SOC-13) and was distributed among Roma people in southwest Sweden (n = 102). Self-reported health was summarised in a physical score (PCS) and a mental score (MCS). Comparisons were made with a general Swedish majority population and a Sami population. Results. The health scores were significantly lower among the Roma people compared to Swedes – PCS: Roma 46.0 (Swedes 52.0) and MCS: Roma 47.5 (Swedes 52.6). The SOC score for the Roma people (54.4) was significantly lower than that of the Swedes (65.2) and Sami (65.0). Conclusions. The low SOC with the Swedish majority society is a strong indication of the marginalisation and exclusion of the Roma people from mainstream society. Low scores in self-reported health among the Roma people also establishes the serious health risks the Roma people are experiencing through their present life situation.

Unnatural deaths in reindeer-herding Sami families in Sweden, 1961-2001

Objectives. Unnatural deaths among Indigenous populations, including the Swedish Sami, occur more often than among the general population. To find prevention strategies, we explored the circumstances of the unnatural deaths of members of reindeer-herding Sami families. Study design. The number of deaths from among a cohort of 7,482 members of reindeer-herding Sami families were retrieved from the National Board of Health and Welfare for the years 1961– 2001. Methods. An evaluation of the information from autopsy records at the National Board of Forensic Medicine, police reports, and available medical records identified 158 unnatural deaths. These were then analysed in detail. Results. Transport-related deaths and suicides were the most common unnatural deaths among Swedish reindeer-herding Sami family members. Suicides contributed to 23% of all deaths, road traffic accidents to 16%, and snowmobile fatalities to 11%. The accidents generally reflected an “outdoor lifestyle” and the working conditions were characterized by the use of off-road vehicles such as snowmobiles. Half of the number of victims tested positive for alcohol and alcohol abuse was documented in 15% of all victims. Conclusions. The results indicate that alcohol is an important factor in preventing unnatural deaths among reindeer-herding Sami, together with increased safety of both on-road and off-road transportation.