Abstract 2977: Sex Differences and Hemoglobin Levels in Relation to Stroke Outcomes

Abstract

Background: Women have worse outcomes after ischemic stroke compared to men. Several mechanisms are postulated, including older age and a differential effect of sex hormones. We have previously shown that hemoglobin levels are associated with increased stroke volume and infarct expansion. Since women have lower hemoglobin values, we examined whether hemoglobin levels may be associated with poorer stroke outcomes in women. Methods: We retrospectively studied 274 patients (N = 121 women, N = 153 men) enrolled in a prospective study. We explored the relationship of hemoglobin with clinical outcome at 6 months, as measured by the modified Rankin Scale. We employed ordinal logistic regression to evaluate the effect of hemoglobin on clinical outcome and to explore the influence of sex on that association. Results: Women had a lower hemoglobin level (11.7 +/- 1.8 g/dL) compared to men (13.3 +/- 1.7 g/dL; P < 0.001). Low hemoglobin was correlated with worse 6-month mRS outcome in univariate analysis (P < 0.001). Lower hemoglobin remained independently associated with poorer outcome after adjustment for age, sex, blood glucose, NIH stroke scale score, hypertension, smoking and diabetes mellitus. The inclusion of hemoglobin in the model eliminated the independent effect of sex on outcome. Conclusions: Sex differences in stroke outcome may be mediated in part by lower hemoglobin levels, a potentially modifiable predictor. Further examination exploring whether hemoglobin has a causative role is warranted.