Cardiovascular risk groups and mortality in an urban Swedish male population: The Malmo Preventive Project

Objectives. To describe the size, overlap and mortality of four cardiovascular risk groups, in order to give a scientific background for the prevention of cardiovascular disease in a representative urban population. Setting. Section of Preventive Medicine, Department of Medicine, Malmo University Hospital, Malmo, Sweden. Subjects. Between 1974 and 1984 22444 men born between 1949 and 1921, constituting 75% of the total male population in these age groups, took part in a comprehensive screening examination aimed at detecting risk factors for cardiovascular disease. Interventions. Those at high-risk of developing cardiovascular disease were referred to their general practitioner or to special clinics for hypertension, hyperlipidaemia and diabetes. The follow-up, which lasted until the end of 1991, averaged 12.2 years. Main outcome measures. Total death (n = 1450) and death from ischaemic heart disease (IHD) (n = 471). Results. Hypertension was found in 13%, hypercholesterolaemia in 19% and diabetes mellitus in 2.6% of the subjects; 49% of the subjects smoked. Multiple risk factors were found in over 17% of the total cohort. Despite the intervention, all-cause mortality during follow-up was increased three-fold in smokers and in men with hypercholesterolaemia, four-fold in hypertensive men and five-fold in men with diabetes, compared to men with no risk factors. The vast majority of deaths (81%) occurred in men who smoked, had hypertension or had high serum cholesterol. Ischaemic heart disease (IHD) was increased five-fold in smokers, seven-fold in men with hypercholesterolaemia, nine-fold in hypertensive men and 12-fold in men with diabetes. Again, the vast majority of IHD deaths (86%) occurred in the first three categories. Combinations of risk factors substantially increased total mortality as well as IHD mortality. Conclusions. The large proportion (64%) of the population with risk factors for cardiovascular disease and the substantially (5-12-fold) increased IHD mortality in those risk groups, calls for actions aimed at preventing premature IHD deaths. Such action should include measures directed towards the whole population and comprehensive treatment programmes for high-risk individuals, including intervention to stop smoking, The substantial overlap between risk factors calls for one high-risk clinic caring for all risk groups.