Effect of blood pressure and diabetes on stroke in progression.

Progression of acute stroke after arrival at hospital is frequent and the prognosis severe. However, risk factors and mechanisms behind progression are largely unknown. A prospective, community-based study of 868 patients with acute stroke was undertaken to discover factors of importance in the development of stroke in progression. Diagnosis of progression was based on the Scandinavian Neurological Stroke Scale. Patients were divided according to whether progression occurred early (within 36 hours from stroke onset) or late (within the first week from onset). Results were analysed by comparing patients with and without progression. Marked progression developed in 32%. Risk factors for early progression were identified as systolic blood pressure on admission (decreased the relative risk by 0.66 per 20 mm Hg increase, 95% CI 0.55-0.83) and diabetes (increased the relative risk by 1.9, 95% CI 1.1-3.3). Stroke severity was the only risk factor found in late progression (OR 1.4 per 20-point increase in stroke severity, 95% CI 1.1-1.7). These relations were independent of age, sex, blood glucose, heart disease, and other stroke risk factors. Early progression is related to systolic blood pressure and diabetes. Late progression is related to initial stroke severity. Although this study does not prove that a causal relationship exists between systolic blood pressure and the development of early progression, such a relationship would, however, explain our findings.