Day-To-Day Relationships Between Physical Activity And Sleep Characteristics Among People With Heart Failure And Insomnia

Objective Examine the bidirectional relationships between within-person day-to-day fluctuations in physical activity (PA) and sleep characteristics among people with heart failure (HF) and insomnia. Participants Ninety-seven community-dwelling adults [median age 61.9 (interquartile range 55.3,70.9) years, female 41%] with stable HF and insomnia (insomnia severity index >7). Methods This sub-study longitudinally analyzed 15 consecutive days and nights of wrist actigraphy recordings, that were collected for baseline data prior to participation in a randomized controlled trial of cognitive behavioral therapy for insomnia. We used two-level mixed models of within- (daily) and between-participants variation to predict daytime PA counts/minutes from sleep variables (total sleep time, sleep efficiency) and predict sleep variables from PA. Results PA counts/minutes were low compared to prior cohorts that did not have HF (209 (166,259)) and negatively associated with NYHA class (standardized coefficient beta(s) = -0.14,p< .01), age (beta(s) = -0.13,p= .01), comorbidities (beta(s) = -0.19,p< .01), and body mass index (beta(s) = -0.12,p= .04). After adjustment for all significant covariates, the within-participant association of total sleep time with next-day PA was estimated to be positive among participants with NYHA class II-IV HF (beta(s) = 0.09,p= .01), while the within-participant association of PA with same-night total sleep time was estimated to be positive among participants aged >= 60 years (beta(s) = 0.10,p= .03). Conclusions Depending upon age and HF class, daytime PA was associated with longer same-night sleep and/or longer sleep was associated with greater next-day PA. Among those with more advanced HF, realistic sleep improvements were associated with clinically meaningful PA gains the next day.