0874 Impact of Physical Activity on Subsequent Night's Sleep in Patients After Cardiac Surgery

Introduction After cardiac surgery, patients often experience sleep disturbances, including poor sleep quality and increased awakenings. Sleep benefits postoperative physical function and overall recovery and has been related to physical activity. Physical activity and sleep have daily variations, but no study has examined their relationships on a daily basis after cardiac surgery. To address this gap, we investigated the effects of daily physical activity on daily sleep in postsurgical cardiac patients. Methods Employing a longitudinal pilot study design, 33 adults aged 18 to 80 who had undergone cardiac surgery were recruited from one hospital in Chicago and using an online recruitment site. Daily physical activity and sleep were measured in participants’ homes using a wrist-worn ActiGraph over 7 days and nights. Sociodemographic and psychosocial factors were assessed through self-reported online questionnaires. Mixed-effects model analyses were applied to examine the effects of daily physical activity on five sleep variables; covariates were selected from bivariate correlational and regression analyses as well as previous research evidence. Results Participants were mostly male (57.6%), non-Hispanic whites (63.6%) and had a mean age of 60.8 ± 10.1 years. Their mean body mass index (BMI) indicated overweight (28.4 ± 5.2 kg/m2), and 54.6% had undergone coronary artery bypass graft surgery 85.7 ± 91.2 months earlier. In mixed-effects model analyses, higher moderate-to-vigorous physical activity was significantly associated with lower next-day sleep latency (b=-1.32, p<.05). Among covariates, lower depression (b=2.72, p<.05), higher companionship (b=0.37, p<.05), and higher instrumental support (b=2.40, p<.05) were associated with lower daily wake after sleep onset, increased daily sleep efficiency, and longer total sleep time, respectively. In addition, older age, higher BMI, and a higher comorbidity index predicted more daily sleep disturbances. Conclusion In postsurgical cardiac patients, daily physical activity should be assessed and managed as a means to enhance daily sleep. Tailoring sleep interventions to individuals based on their comorbidities and psychosocial factors is also important. Future research should explore interactions between daily physical activity and sleep in a larger sample of postsurgical cardiac patients during varying time periods after surgery and should comprehensively assess sleep status, including sleep disorders, daytime napping, and daytime sleepiness. Support (if any)