Effects of sex difference on clinical features of acute ischemic stroke in Japan

Background: Sex differences in stroke characteristics and outcomes have been inconsistent. The goal of this study was to determine the influence of sex on underlying patient characteristics, stroke subtypes and conditions, and outcomes after ischemic stroke from a nationwide registration study.

Methods: A total of 33,953 patients with acute ischemic stroke, including 13,323 women, were registered in a multicenter, hospital-based registration study based on a computerized database from 162 Japanese institutes (the Japan Standard Stroke Registry Study) between January 2000 and November 2007.

Results: Women were significantly older than men at stroke onset (75.0 ± 11.7 v 69.3 ± 11.4 years; P < .0001). After age adjustment, women more frequently had cardioembolic events (odds ratio [OR] 1.090; 95% confidence interval [95% CI] 1.036-1.146; P = .0009) and other strokes (OR 1.177; 95% CI 1.079-1.284; P = .0003) and were more hypertensive (OR 1.056; 95% CI 1.006-1.108; P = .0267) and more dyslipidemic (OR 1.301; 95% CI 1.234-1.373; P < .0001) than men. After multivariate adjustment, onset-to-arrival time was longer (β = 0.0554; P = .026), the initial National Institutes of Health Stroke Scale score was higher (β = 0.1565; P < .001), and the duration of hospitalization was longer (β = 0.035; P = .010) in women than in men. At hospital discharge, women less commonly had a modified Rankin Scale (mRS) score of 0 to 1 (OR 0.802; 95% CI 0.741-0.868; P < .0001) and more commonly had a mRS score of 4 to 6 (OR 1.410; 95% CI 1.293-1.537; P < .0001) than men.

Conclusions: Women developed more severe strokes than men in Japan. After multivariate adjustment for initial severity and other characteristics, acute care hospital stays were longer and stroke outcomes at discharge were worse in women than in men.