Sex differences in outcomes after stroke in patients with diabetes in Ontario, Canada

Background — Outcomes after stroke in those with diabetes are not well characterized, especially by sex and age. We sought to calculate the sex- and age-specific risk of cardiovascular outcomes after ischemic stroke among those with diabetes.

Methods — Using population-based demographic and administrative health-care databases in Ontario, Canada, all patients with diabetes hospitalized with index ischemic stroke between April 1, 2002, and March 31, 2012, were followed for death, stroke, and myocardial infarction (MI). The Kaplan–Meier survival analysis and Fine–Gray competing risk models estimated hazards of outcomes by sex and age, unadjusted and adjusted for demographics and vascular risk factors.

Results — Among 25,495 diabetic patients with index ischemic stroke, the incidence of death was higher in women than in men (14.08 per 100 person-years [95% confidence interval [CI], 13.73-14.44] versus 11.89 [11.60-12.19]) but was lower after adjustment for age and other risk factors (adjusted hazard ratio [HR], .95 [.92-.99]). Recurrent stroke incidence was similar by sex, but men were more likely to be readmitted for MI (1.99 per 100 person-years [1.89-2.10] versus 1.58 [1.49-1.68] among females). In multivariable models, females had a lower risk of readmission for any event (HR, .96 [95% CI, .93-.99]).

Conclusions — In this large, population-based, retrospective study among diabetic patients with index stroke, women had a higher unadjusted death rate but lower unadjusted incidence of MI. In adjusted models, females had a lower death rate compared with males, although the increased risk of MI among males persisted. These findings confirm and quantify sex differences in outcomes after stroke in patients with diabetes.