Cardiovascular diseases in immigrants in Sweden

Aims: The general aim with this project was to elucidate coronary heart disease (CHD) morbidity and mortality among immigrants in Sweden, by investigating the morbidity from CHD, comparing all-cause and CHD mortality between immigrants in Sweden and natives in the country of birth, analyzing the trend of CHD, and estimating the prevalence of CHD risk factors.

Methods: The first study was designed as a follow-up study of the incidence of CHD among twelve immigrant groups. The second study was designed as a follow-up study on mortality from CHD among eight immigrant groups compared to their country of birth. The third study was designed as a follow-up study on the trend of CHD among eleven immigrant groups. In these three studies the material was based on the whole Swedish population. The fourth study was designed as a cross-sectional interview study of unhealthy behaviors and risk factors of CHD among eight immigrant groups in Sweden.

Results: In the first study, the age-adjusted risk of CHD was higher in most foreign-born groups than in Swedes, e.g. in nine out of twelve male groups, and in seven out of twelve female groups. After adjustment for level of education and employment status, the risks were still high, but on a lower level. In the second study, the all-cause mortality risk was lower among seven out of eight male immigrant groups and among six out of eight female immigrant groups than in their country of birth. The CHD mortality risk was lower in four out of eight male immigrant groups, and among two out of eight female immigrant groups, than in their country of birth. In the third study, the morbidity trend of CHD decreased slightly among men from Sweden, Finland, and the OECD during the 1990s. The contrary was observed in women from Southern Europe, Turkey, and Iran, in whom CHD morbidity increased. In the remaining immigrant groups the morbidity was unchanged. In the fourth study, the age-adjusted risk of smoking, physical inactivity, and obesity was higher among immigrants than Swedes. In all of the male immigrant groups, and in three of the female ones, the frequency of smoking behavior was increased. Further, there was an increased frequency of obesity in three female and two male groups and of physical inactivity in six male and female immigrant groups. In a second model, also adjusting for education, unemployment, and social network, the increased frequency of smoking, obesity, and physical inactivity remained in almost all groups.

Conclusions: Immigrants run an excess risk of CHD compared to Swedish-born persons. Despite this increased risk of CHD, the all-cause mortality risk was generally lower among immigrants than in their country of birth. The change of CHD mortality risk was more complex. It seemed as if low and high CHD risk countries could be defined, and that with migration, people tend to adopt the risk level of the new country. There was a declining trend of CHD only among a few male groups, while the decline ceased among the majority of groups, and the risk even increased in some of the female groups. This might be a sign of a breaking trend in these diseases. The increased risk of CHD among the majority of immigrant groups in Sweden might be explained by high prevalence of unhealthy behaviors and risk factors for CHD, such as smoking, obesity, and diabetes, which might be a lifestyle remnant from their country of birth or brought about by stressful migration and acculturation into a new social and cultural environment.

List of scientific papers

I. Gadd M, Johansson SE, Sundquist J, Wandell P (2003). Morbidity in cardiovascular diseases in immigrants in Sweden. J Intern Med. 254(3): 236-43.
https://pubmed.ncbi.nlm.nih.gov/12930232

II. Gadd M, Johansson SE, Sundquist J, Wandell P (2005). The trend of cardiovascular disease in immigrants in Sweden. Eur J Epidemiol. 20(9): 755-60.
https://pubmed.ncbi.nlm.nih.gov/16170658

III. Gadd M, Sundquist J, Johansson SE, Wandell P (2005). Do immigrants have an increased prevalence of unhealthy behaviours and risk factors for coronary heart disease? Eur J Cardiovasc Prev Rehabil. 12(6): 535-41.
https://pubmed.ncbi.nlm.nih.gov/16319542

IV. Gadd M, Johansson SE, Sundquist J, Wandell P (2006). Are there differences in all-cause and coronary heart disease mortality between immigrants in Sweden and in their country of birth?: A follow-up study of total populations. BMC Public Health. 6(1): 102. [Epub ahead of print]
https://pubmed.ncbi.nlm.nih.gov/16630338