Sex differences and hemoglobin levels in relation to stroke outcomes

Abstract

Objective: Women have worse outcomes after stroke compared to men. Since women have lower hemoglobin values, we examined whether hemoglobin levels may associate with worse stroke outcomes in women.

Methods: We retrospectively studied 274 patients enrolled in a prospective multicenter study. We explored the relationship of hemoglobin with clinical outcome at 6 months, as measured by the modified Rankin Scale (mRS). Ordinal logistic regression was used to evaluate the independent effect of hemoglobin on clinical outcome, and to explore the influence of sex on that association.

Results: Women had a lower mean hemoglobin level (11.7 ± 1.8 g/dL) compared to men (13.3 ± 1.7 g/dL). Low hemoglobin was associated with worse 6-month mRS outcomes in univariate analysis (p < 0.001). Lower hemoglobin remained independently associated with poor outcome after adjustment for comorbid disease, stroke severity, age, and sex. The inclusion of hemoglobin in the model attenuated the independent effect of sex on outcome.

Conclusions: Sex differences in stroke outcome are linked to lower hemoglobin level, which is more prevalent in women. Further examination of this potentially modifiable predictor is warranted.

Figure. Ranges of modified Rankin Scale are shown for each hemoglobin quintile (n = 55)