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

Abstract

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.