Sleep quality is associated with walking under dual-task, but not single-task performance

Objectives: The objective of this study was to assess the relationship between sleep behavior and gait performance under single-task (ST) and dual-task (DT) walking conditions in community-dwelling older adults. Methods: Walking under ST and DT conditions was evaluated in 34 community-dwelling older adults, 64.7% women, mean age 71.5 (SD +/- 5.8). Gait-speed and gait-variability data were collected using the OPAL wearable sensors of the Mobility Lab. Sleep behavior (sleep efficiency [SE] and sleep latency [SL]) was assessed using actigraphy, over 5 consecutive nights. Results: Lower SE was associated with decreased gait speed and increased stride-length variability during DT (rs = 0.35; p = 0.04; rs = -0.36; p = 0.03, respectively), whereas longer SL was associated with increased stride-length variability during DT (rs = 0.38; p = .03). After controlling for age and cognition, SE accounted for 24% and 33% of the variability in stride length and stride time. No associations were found between sleep and gait measures under ST walking. Conclusions: Lower SE is associated with decreased gait speed and increased gait variability under DT conditions that are indicative of an increased risk for falls in older adults. Our findings support clinical recommendations to incorporate the evaluation of sleep quality in the context of risk assessment for falls. (C) 2016 Elsevier B.V. All rights reserved.