Risk-factor profile for the incidence of subarachnoid and intracerebral haemorrhage, cerebral infarction, and unspecified stroke during 21 years' follow-up in men

Abstract

Aims: To study the risk-factor profile for the incidence of non-fatal and fatal stroke among middle-aged men according to the stroke subtypes subarachnoid or intracerebral haemorrhage, cerebral infarction, and unspecified stroke. Methods: The study design is a prospective cohort study. A total of 16,209 men aged 40—49 years resident in Oslo were screened for cardiovascular disease risk factors in 1972—73. Of these, 14,403 men had no cardiovascular symptoms or diseases or diabetes. The incidence of stroke after 21 years of follow-up of all men was extracted from hospital records and linkage to Statistics Norway. Results: A total of 429 non-fatal and 107 fatal stroke events were registered. Case fatality within 28 days (number and percentage of cases) was 51% (41, 7.7%) for subarachnoid haemorrhage, 39% (67, 12.6%) for cerebral haemorrhage, 10% (246, 46.3%) for cerebral infarct, and 19% (177, 33.4%) for unspecified stroke. Risk of stroke (not subarachnoid haemorrhage) increased with the presence of symptoms or a history of cardiovascular disease or diabetes. In multivariate analysis of men without CVD or diabetes, high blood pressure was a risk factor for all subtypes of stroke; furthermore, daily smoking was a risk factor for all subtypes except subarachnoid haemorrhage. Serum cholesterol and glucose concentrations and height (inverse association) were independently associated with cerebral infarction. Smoking was a significantly stronger predictor of fatal than non-fatal events. Conclusions: The risk-factor profile differed according to the underlying subtype of stroke. Cerebral infarction clearly shared with myocardial infarction the classical risk factors, including non-fasting glucose concentration.