The Mediating Effect of Sleep Quality on the Relationship between PTSD and Physical Activity

Abstract

Study Objectives: Physical inactivity is linked to health outcomes such as obesity, diabetes, and psychiatric disorders. Sleep disturbance has been linked to the same adverse outcomes. We examine the infl uence of sleep on physical activity as a novel approach to understand these relationships. Specifi cally, our objective was to determine whether low sleep quality predicts low physical activity in posttraumatic stress disorder (PTSD), a disorder associated with sleep disturbance, physical inactivity, and poor health outcomes. Methods: We used data from the Mind Your Heart Study, a prospective cohort study of 736 outpatients recruited from two Department of Veterans Affairs (VA) medical centers. We assessed PTSD with the Clinician Administered PTSD Scale, sleep quality using an item from the Pittsburgh Sleep Quality Index, and physical activity by self-report at baseline and again one year later. Hierarchical multiple regression models and structural equation modeling were used to examine the relationships among PTSD, sleep, and physical activity. Results: Sleep quality but not PTSD status was prospectively associated with lower physical activity in a model adjusting for age, sex, apnea probability, depression, body mass index, and baseline physical activity (β = 0.129, SE = 0.072, p < 0.01). Structural equation modeling indicated that the results were consistent with sleep quality statistically mediating the relationship between PTSD status at baseline and physical activity one year later. Conclusions: Worse sleep quality predicts lower physical activity in PTSD, providing possible evidence for a behavioral pathway from disturbed sleep to poor physical health outcomes. Keywords: posttraumatic stress disorder, sleep quality, physical activity Citation: Talbot LS, Neylan TC, Metzler TJ, Cohen BE. The mediating effect of sleep quality on the relationship between PTSD and physical activity. J Clin Sleep Med 2014;10(7):795-801.

Replacing sedentary time with sleep, light, or moderate-to-vigorous physical activity: effects on self-regulation and executive functioning

“…It is also quite likely the type, quality, and quantity of these behaviors operate synergistically (Buman et al 2015). For instance, engaging in physical activity has demonstrable and positive effects on one’s sleep habits (Benloucif et al 2004; Dzierzewski et al 2014), while improved sleep has been shown to increase an individual’s ability to engage in physical activity the following day (Dzierzewski et al 2014; Lambiase et al 2013; Talbot et al 2014). Therefore, while reducing sedentary time is likely to have important implications for a number of psychosocial and health outcomes, it is certainly feasible that the activity with which sedentary behavior is substituted (i.e., sleep, light activity, MVPA) is likely to influence the type and magnitude of these effects.…”

Physical Activity, Mind Wandering, Affect, and Sleep: An Ecological Momentary Assessment

“…Indeed, poor sleep habits have been associated with a number of correlates of retrospective mind wandering, such as impaired working memory function [ 20 , 21 ] and negative affect [ 22 - 24 ]. Moreover, several studies have demonstrated that these habits contribute to lower levels of physical activity [ 25 - 27 ]. If one’s mind wandering is indeed associated with their participation in physical activity, sleep may be an important moderator of this relationship.…”

Predictors of multiple domains of functioning in Veterans with posttraumatic stress disorder: Results from the Mind Your Heart Study

“…Inflammation, in turn, is part of the pathogenesis of numerous chronic illnesses, such as cardiovascular disease, that could impair health and functioning in patients with PTSD (Brudey et al, ). Similarly, poor sleep quality has been linked to a number of psychological and physical health outcomes (Iliescu et al, ; Spira et al, ; Talbot et al, ; Vandrey, Babson, Herrmann, & Bonn‐Miller, ; Wong et al, ), including higher inflammation (for review, see Irwin, Olmstead, & Carroll, ). Taken together with the well‐established negative relationship between PTSD and sleep (Germain, ; Kobayashi, Boarts, & Delahanty, ; Maher, Rego, & Asnis, ), sleep quality likely represents an important target for both treatment and future research.…”

“…We assessed sleep quality using a single modified item derived from the Pittsburgh Sleep Quality Index (PSQI), which asks participants to rate their sleep quality during the last month from 0 ( very good ) to 4 ( very bad ; Buysse, Reynolds, Monk, Berman, & Kupfer, ). The PSQI has demonstrated excellent reliability (Buysse et al, ) and the current version of this question has been used in similar populations previously and predicted outcomes such as aggression (Caska et al, ) and physical activity (Talbot, Neylan, Metzler, & Cohen, ).…”