SEX DIFFERENCES IN THE EFFECTS OF EXERCISE ON COGNITION POST-STROKE: SECONDARY ANALYSIS OF A RANDOMIZED CONTROLLED TRIAL

Objective: To determine whether there are differences in exercise-associated changes in cognitive function between males and females living with stroke. Design: Secondary analysis of data from a prospective assessor-blinded randomized controlled trial. Participants: Fifty participants (50-80 years, >1 year post-stroke, able to walk >= 5 m). Methods: Participants were allocated into a 6-month aerobic exercise programme (14 males, 11 females) or balance and flexibility programme (15 males, 10 females). Working memory (Verbal Digit Span Backwards Test), selective attention and conflict resolution (Stroop Colour-Word Test), and set shifting/cognitive flexibility (Trail-Making Test B) were assessed before and after the programmes. Results: There was a group x time interaction in females (effect size 0.28, p= 0.03), which was not observed in males (effect size 0.01, p= 0.62). Females demonstrated a Stroop Colour-Word Interference test change of -2.3 s, whereas males demonstrated a change of +5.5 s following aerobic exercise. There were no differences between exercise groups in either sex for any of the other outcomes (working memory and set-shifting/cognitive flexibility). Conclusion: Females living with stroke may demonstrate a greater response to exercise on selective attention and conflict resolution compared with males with stroke. These findings suggest that there may be sex-specific effects of exercise on cognitive function in individuals with stroke.