Sleep efficiency and physical performance differences between pain-free individuals and individuals with chronic lower back pain

Within the United States, chronic low back pain (cLBP) is a leading cause of pain and the second leading cause of disability. Individuals with cLBP frequently report sleep disturbances—most commonly, cLBP impacts sleep efficiency and quality. Additionally, cLBP most visibly impacts physical functioning with individuals with cLBP being not able to perform physical function tasks as effectively as pain-free individuals. Emerging evidence indicates that sleep has a significant relationship on physical functioning, however whether pain exacerbates sleep disturbances and physical functioning of people with cLBP, relative to pain-free individuals (PF) has not been previously examined. This study quantified differences by pain-status (cLBP and PF) for an individual's actigraphic sleep variables (e.g. sleep efficiency) and physical function, and examined the influence of pain on actigraphic variables and physical function in cLBP. Participants (cLBP = 102, PF = 45) completed the Short Physical Performance Battery (SPPB), daily pain ratings, and home sleep monitoring for 7-consecutive days/nights. Analyses revealed that cLBP individuals had reduced objective sleep quality (p = .003), and SPPB dynamic performance (p = .000), but not for static tasks (p >.05) compared to PF. Sleep quality prior to SPPB was associated with SPPB tasks for cLBP individuals (total battery r=.23) but not for PF (r=-.08). Additionally, daily pain ratings influenced sleep efficiency (p = .003), and pain from the night prior to SPPB was associated with worse outcomes for the dynamic SPPB tasks, but not the balance tasks for cLBP. Our findings suggest that sleep and pain may influence physical performance tasks for cLBP, but not PF– this further reinforces the importance of further examination of identifying whether pain or sleep are antecedents to reduced performance and outcomes in cLBP or if a bilateral relationship exists with pain severity and sleep quality. This work was supported by Examining Racial And SocioEconomic Disparities in cLBP; ERASED; R01MD010441.