Abstracts

Rationale: People with epilepsy have been shown to be less physically active and more sedentary than the general population. Physical activity promotion is difficult in all populations but is particularly challenging in people with epilepsy due to their unique barriers, which include an increased prevalence of depression. The aims of this study are to examine the 24-hour composition of physical activity behaviors in adults with refractory epilepsy and to explore the association of this 24-hour physical activity composition with depression using the novel compositional data analysis approach.


Methods: We collected cross-sectional physical activity (ActivPAL accelerometer) and depression (Neurological Disorder Depression Inventory in Epilepsy, NDDI-E) data in adults with refractory epilepsy during their enrollment visit for a randomized physical activity intervention trial. We used ANOVA to evaluate the association between the 24-hour physical activity composition and depression scores, controlling for seizure frequency as a covariate. We used compositional data analysis to explore how reallocation of 30 minutes per day among different physical activity behaviors (sedentary time, sleep, light physical activity, and moderate-to-vigorous physical activity) may affect depression scores in this population.


Results: 18 participants with adequate device wear time were included in the final analysis. The average 24-hour physical activity composition was 644.2 minutes in sleep, 731.4 minutes sedentary, 59.6 minutes in light activity, and 4.8 minutes in moderate-to-vigorous activity per day. The association between 24-hour physical activity behaviors and depression scores on the NDDI-E showed an effect size 𝜂2 = 0.37 (p = 0.08). Modeling reallocation of 30 minutes from any behavior to moderate-to-vigorous physical activity was associated lower scores on the NDDI-E (lower risk of depression). The largest improvement was seen when substituting light activity to moderate-to-vigorous activity (-2.06), such that for every 30-minute reallocation from light activity to moderate-to-vigorous activity, there was a ~2-unit decrease (improvement) in the NDDI-E depression score. Similar changes were projected for 30-minute reallocations from sleep and sedentary behavior to moderate-to-vigorous physical activity (-1.87 and -1.21, respectively). Mixed results were seen when reallocating 30 minutes to light physical activity.


Conclusions: Adults with refractory epilepsy in this sample, on average, spent a large amount

of time in sedentary behavior and very little time in moderate to vigorous physical activity. Compositional data analysis suggests that increasing moderate-to-vigorous physical activity in people with epilepsy may be reasonable target to help improve depression. Our future work will examine larger populations as well as longitudinal changes in depression scores with increases in light and moderate-to-vigorous physical activity.


Funding: This research was funded in part by National Center for Advancing Translational Sciences, National Institutes of Health, Grant #KL2TR001421, and the Wake Forest School of Medicine CTSA grant UL1TR00142.