Risk factors for stroke in middle aged British men.

OBJECTIVE

To determine the risk factors for stroke in a cohort representative of middle aged British men.

DESIGN

Prospective study of a cohort of men followed up for eight years.

SETTING

General practices in 24 towns in England, Wales, and Scotland (the British regional heart study).

SUBJECTS

7735 men aged 40-59 at screening, selected at random from one general practice in each town.

MAIN OUTCOME MEASURE

Fatal and non-fatal strokes.

RESULTS

110 of the men had at least one stroke; there were four times as many non-fatal as fatal strokes. The relative risk of stroke was 12.1 in men who had high blood pressure (systolic blood pressure greater than or equal to 160 mm Hg) and were current smokers compared with normotensive, non-smoking men. Diastolic blood pressure yielded no additional information, and former cigarette smokers had the same risk as men who had never smoked. Heavy alcohol intake was associated with a relative risk of stroke of 3.8 in men without previously diagnosed cardiovascular disease. Men with pre-existing ischaemic heart disease had an increased risk of stroke, but only when left ventricular hypertrophy on electrocardiography was also present.

CONCLUSIONS

Systolic blood pressure, cigarette smoking, and left ventricular hypertrophy on electrocardiography in men with pre-existing ischaemic heart disease were found to be the major risk factors for stroke in middle aged British men. Heavy alcohol intake seemed to increase the risk of stroke in men without previously diagnosed cardiovascular disease. A large proportion of strokes should be preventable by controlling blood pressure and stopping smoking.