Smoking Raises the Risk of Total and Ischemic Strokes in Hypertensive Men

To examine the relation between cigarette smoking and risk of stroke and coronary heart disease among Japanese, we conducted a 14-year prospective study of 3,626 men aged 40-69, initially free from history of stroke and coronary heart disease. We identified 257 strokes (75 hemorrhagic and 173 ischemic strokes) and 100 coronary heart disease events. When we adjusted for age and other cardiovascular risk factors, a significant excess risk among current smokers of > 20 cigarettes/day vs. never-smokers was found for total stroke (relative risk (RR) = 1.6 (95% confidence interval (CI), 1.1-2.4)). The excess risk of total stroke was particularly evident among hypertensives (RR = 2.3 (1.2-4.4)). The multivariate RR of ischemic stroke was 1.6 (1.0-2.5) for total subjects, and 2.2 (1.0-5.0) among hypertensives. Significant excess risks among current smokers of > 20 cigarettes/day vs. never-smokers were also found for coronary heart disease (RR = 4.6 (1.6-12.9)) and total cardiovascular disease (1.9 (1.3-2.7)). The estimated proportion of the events attributable to current smoking was 30 (95% CI, 11-44)% for total stroke and 34 (5-54)% for coronary heart disease. In conclusion, current smoking of > 20 cigarettes per day increased the risk of both total stroke and ischemic stroke among Japanese middle-aged men, and particularly among middle-aged hypertensive men.