What else adds to hypertension in predicting stroke? An incident case-referent study

Objectives. To examine to what extent traditional biomedical risk factors a nd social factors can predict, separately or jointly, first-ever stroke eve nt, and to explore to what extent other risk factors might add to hypertens ion/elevated blood pressure as a stroke risk factor. Design. An incident case-referent study. Setting. The study was nested within the Vasterbotten Intervention Program (VIP) and the Northern Sweden MONICA cohorts. Subjects. The study involves 129 stroke cases with two randomly selected re ferents per case from the same study cohorts. Results. History of diabetes, dairy smoking, obesity (body mass index great er than or equal to 30 kg m(-2)), hypertension and living as an unmarried p erson were associated with an increased risk in univariate analysis. Howeve r, in the multivariate logistic regression analysis, only hypertension, dia betes and single marital status remained significant. There was a statistic ally significant interaction between hypertension and smoking and stroke. I nteraction of possible clinical relevance was also observed between hyperte nsion, history of diabetes and stroke. Conclusions. The study both emphasizes the multifactorial nature of stroke and illustrates that knowledge of interactions offers different strategic a pproaches when preventing stroke in clinical work. It is important, but not enough, to focus on blood pressure control. Diabetes prevention as well as prevention of smoking must also be considered as factors of major importan ce.