Daily Sleep-Stress Reactivity and Functional Impairment in World Trade Center Responders.

BACKGROUND: How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that predict depression, anxiety, and insomnia. However, pathways between reactivity and functional impairment (e.g., impairment in social relationships and interpersonal functioning) have not been explored, which may be a critical pathway in understanding the link between reactivity and the development of psychological disorders. PURPOSE: We examined associations between reactivity and changes in functional impairment among a cohort of 9/11 World Trade Center responders. METHODS: Data from 452 responders (Mage = 55.22 years; 89.4% male) were collected between 2014 and 2016. Four baseline sleep and stress reactivity indices (i.e., sleep duration and efficiency reactivity to stress; stress reactivity to sleep duration and efficiency) were calculated from 14 days of sleep and stress data using random slopes from multilevel models. Functional impairment was assessed approximately 1 year and 2 years after baseline via semi-structured interviews. Latent change score analyses examined associations between baseline reactivity indices and changes in functional impairment. RESULTS: Greater baseline sleep efficiency reactivity to stress was associated with decreases in functioning (ß = -0.05, p = .039). In addition, greater stress reactivity to sleep duration (ß = -0.08, p = .017) and sleep efficiency (ß = -0.22, p < .001) was associated with lower functioning at timepoint one. CONCLUSION: People who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high reactivity who could benefit from preventative treatment may foster better social integration.

How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that may contribute to an individual's risk of developing of psychological disorders, such as depression, anxiety, and insomnia. It is possible that individuals with high sleep-stress reactivity are more likely to experience long-term functional impairment (e.g., impairment in social relationships and interpersonal functioning)­a predisposing factor for psychological disorders, yet this pathway has not been explored. Therefore, we examined associations between sleep-stress reactivity and changes in functional impairment across a 1-year period in a large sample of 9/11 World Trade Center responders. The study results suggest that 9/11 World Trade Center responders who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high sleep-stress reactivity who could benefit from preventative treatment may foster better social integration.

Longitudinal associations between PTSD and sleep disturbances among World Trade Center responders.

OBJECTIVE/BACKGROUND: Post-traumatic stress disorder (PTSD) is characterized by substantial disruptions in sleep quality, continuity, and depth. Sleep problems also may exacerbate PTSD symptom severity. Understanding how PTSD and sleep may reinforce one another is critical for informing effective treatments. PATIENTS/METHODS: In a sample of 452 World Trade Center 9/11 responders (mean age = 55.22, 89.4% male, 66.1% current or former police), we examined concurrent and cross-lagged associations between PTSD symptom severity, insomnia symptoms, nightmares, and sleep quality at 3 time points ∼1 year apart. Data were analyzed using random intercept cross-lagged panel models. RESULTS: PTSD symptom severity and sleep variables were relatively stable across time (intraclass correlation coefficients: 0.63 to 0.84). Individuals with more insomnia symptoms, more nightmares, and poorer sleep quality had greater PTSD symptom severity, on average. Within-person results revealed that greater insomnia symptoms and nightmares at Time 1 were concurrently associated with greater PTSD symptoms at Time 1. Insomnia symptoms were also concurrently associated with PTSD symptoms at Times 2 and 3, respectively. Cross-lagged and autoregressive results revealed that PTSD symptoms and nightmares predicted nightmares at the next timepoint. CONCLUSIONS: Overall, results suggest PTSD and sleep problems may be linked at the same point in time but may not always influence each other longitudinally. Further, individuals who experience more sleep disturbances on average may suffer from more debilitating PTSD. Evidence-based treatments for PTSD may consider incorporating treatment of underlying sleep disturbances and nightmares.

Bidirectional associations between daily PTSD symptoms and sleep disturbances: A systematic review.

Sleep disturbances are a core feature of posttraumatic stress disorder (PTSD) and can affect PTSD onset, maintenance, and recovery. However, there is conflicting evidence about the directionality of sleep and PTSD symptoms, particularly at the daily level. The current systematic review summarizes the literature on within-person associations between daily PTSD symptoms and sleep among trauma-exposed adults. We searched four databases using PRISMA 2020 guidelines. Of 2006 screened articles, six met inclusion criteria. Study sample sizes ranged from 30 to 202 participants, and studies assessed PTSD symptoms and sleep for 7-28 days. Two relatively consistent findings emerged: (1) shorter sleep and poorer quality sleep predicted greater next-day PTSD symptoms, and (2) greater PTSD symptoms predicted nightmares and poorer sleep quality that night. Individual study risk of bias was low to moderate. The current review provides initial support for a bidirectional association between daily self-reported sleep and PTSD symptoms. Potential clinical implications include targeting sleep via evidence-based PTSD interventions and using just-in-time adaptive interventions to disrupt the daily PTSD-sleep cycle. Findings also highlight areas for future research, such as the need to incorporate more objective sleep measures, examine PTSD symptom clusters, justify sample sizes and number of daily observations, and recruit more diverse samples.

Characterizing Patterns of Nurses' Daily Sleep Health: a Latent Profile Analysis.

BACKGROUND: Nursing is a demanding occupation characterized by dramatic sleep disruptions. Yet most studies on nurses' sleep treat sleep disturbances as a homogenous construct and do not use daily measures to address recall biases. Using person-centered analyses, we examined heterogeneity in nurses' daily sleep patterns in relation to psychological and physical health. METHODS: Nurses (N = 392; 92% female, mean age = 39.54 years) completed 14 daily sleep diaries to assess sleep duration, efficiency, quality, and nightmare severity, as well as measures of psychological functioning and a blood draw to assess inflammatory markers interleukin-6 (IL-6) and C-reactive protein (CRP). Using recommended fit indices and a 3-step approach, latent profile analysis was used to identify the best-fitting class solution. RESULTS: The best-fitting solution suggested three classes: (1) "Poor Overall Sleep" (11.2%), (2) "Nightmares Only" (8.4%), (3) "Good Overall Sleep" (80.4%). Compared to nurses in the Good Overall Sleep class, nurses in the Poor Overall Sleep or Nightmares Only classes were more likely to be shift workers and had greater stress, PTSD symptoms, depression, anxiety, and insomnia severity. In multivariate models, every one-unit increase in insomnia severity and IL-6 was associated with a 33% and a 21% increase in the odds of being in the Poor Overall Sleep compared to the Good Overall Sleep class, respectively. CONCLUSION: Nurses with more severe and diverse sleep disturbances experience worse health and may be in greatest need of sleep-related and other clinical interventions.