Associations among acute and chronic musculoskeletal pain, sleep duration, and C-reactive protein (CRP): A cross-sectional study of the UK biobank dataset

Both musculoskeletal pain and sleep disturbances are major health problems worldwide. Literature suggests that the two are reciprocally related and both may be associated with changes in C-reactive protein (CRP) levels. However, the relationships among musculoskeletal pain, sleep duration, and CRP remain unclear. In this cross-sectional study, we investigated the relationship between acute and chronic musculoskeletal pain, sleep, and inflammation using the data from the initial visit of the UK Biobank. 17,642 individuals with chronic musculoskeletal pain, 11,962 individuals with acute musculoskeletal pain, and 29,604 pain-free controls were included in the analysis. In addition, we validated the findings using data from the second visit assessment of the UK Biobank. We found that 1) chronic pain was associated with higher CRP levels compared to both acute pain and the pain-free controls; 2) chronic pain was associated with a lower sleep score (a measurement of sleep patterns), compared to acute pain and the pain-free controls; and acute pain was associated with lower sleep scores compared to the controls; 3) there was a significant negative association between the sleep score and CRP; 4) CRP may partially mediate the association between chronic pain and decreased sleep score. However, the effect size of the mediation was rather small, and the pathophysiological significance remains uncertain. Further validation is needed. These findings were partly replicated in the UK Biobank second visit assessment cohort with a smaller sample size. Our findings, which are based on the large UK Biobank dataset, support the interplay between musculoskeletal pain, sleep patterns, and the potential mediating role of CRP on this reciprocal relationship.

0228 Using Blue Light Therapy to Facilitate Recovery of Sleep and Psychological Functioning in PTSD

Introduction

Sleep problems are often described as the “hallmark symptoms” of post-traumatic stress disorder (PTSD). Patients with PTSD show numerous disruptions of emotional functioning. Experimental evidence has shown that the ability to retain extinction memories following fear conditioning is impaired in people with PTSD. Because of the key role of sleep in memory consolidation and emotional regulation, we hypothesized that regulating sleep and circadian rhythms with morning blue-wavelength light therapy would facilitate emotional recovery and the ability to retain extinction memories.

Methods

Eighty-four individuals with PTSD (56 female; Age=31.38, SD=8.9) underwent a well-validated fear conditioning and extinction protocol and were then randomly assigned to receive either 6-weeks of BLUE (469 nm; n=44) or placebo AMBER (578 nm; n=40) morning light therapy for 30-minutes daily. Participants returned to undergo post-treatment extinction recall when exposed to the same previously conditioned stimuli, and a functional magnetic resonance imaging (fMRI) while the same images were presented. Participants also completed a variety of emotional and mental health outcome measures and wore an actigraph to measure sleep over the 6-weeks.

Results

There was a significant interaction between light condition and time in bed and total sleep time (p<.05) indicating significant increases in sleep with blue versus amber light over treatment. Additionally, declines in symptoms of PTSD on the Clinician Administered PTSD Scale (CAPS-5) correlated with improvements in sleep for the blue, but not the amber light, group (all p-values <.05). During the fear conditioning and extinction paradigm, blue light was associated with significantly greater extinction recall compared to the amber light condition (p=.05). Finally, blue light resulted in decreased fMRI activation within the right amygdala and increased activation within the ventromedial prefrontal cortex to the previously feared and extinguished stimuli.

Conclusion

Blue light treatment was more effective than amber placebo at increasing sleep quantity, shifting circadian bedtime, reducing PTSD symptom severity, facilitating the retention of extinction memories, and reducing neural fear responses to previously feared stimuli. We suggest that improvements in sleep led to greater consolidation of extinction memories. These findings suggest that blue light treatment may facilitate treatment gains by improving sleep.

Support (If Any)

 

0675 Vagal Activity in REM Sleep Is Associated With Extinction Recall in Trauma Exposed Individuals but Not in Individuals With Post-Traumatic Stress Disorder

Introduction

Post-traumatic stress disorder (PTSD) is characterized by impaired fear extinction memory. Sleep, and especially REM sleep, facilitates consolidation of fear extinction. Therefore, it is postulated that abnormal sleep physiology in PTSD may contribute to its persistence. Recent studies suggest that vagal activity may support the memory benefit of sleep. In addition, a separate line of studies shows reduced vagal activity during sleep in PTSD. However, the link between extinction memory and vagal activity during sleep has not been investigated in PTSD. We examined the association of extinction recall with vagal activity, measured as heart rate variability (HRV), during REM sleep, in PTSD and matched controls.

Methods

Participants included individuals with PTSD (n=70) and trauma exposed controls (TEC; n=69). All participants completed 3 nights of ambulatory polysomnography that included ECG. After acclimation and baseline PSG nights, fear conditioning and extinction learning were carried out in the evening after which they completed a third ("consolidation") PSG night. Extinction recall was tested 24h later. During fear conditioning, partial reinforcement with a mild electric shock produced a conditioned skin conductance response (SCR) to the image of a colored lamp, which was immediately extinguished by un-reinforced presentations in a different room. Extinction recall was indexed by the degree to which SCR remained suppressed 24h later. HRV indices were calculated using Kubios software.

Results

Preliminary analyses included 20 individuals with PTSD and 37 TEC participants. In the TEC group, extinction recall was significantly correlated with REM sleep HRV measures that reflect vagal activity, including high frequency (HF) absolute power (Rs=0.51, p =0.009), HF normalized units (Rs=0.54, p =0.005) and RMSSD (Rs=0.40, p =0.046). In hierarchical regression models which included extinction recall as the dependent variable, HF absolute power accounted for a significant proportion of the variance, over and above a model that included %REM sleep, %N3 sleep, REM density and average duration of REM epochs (R2=0.50, F=5.06, p=0.04). These associations were not present in the PTSD group

Conclusion

Our preliminary results suggest that vagal activity during REM sleep is involved in the consolidation of extinction memory and that this mechanism may be impaired in PTSD.

Support (If Any)

R01MH109638 K23MH119322

0673 Script-Driven Imagery in PTSD: Comparing Reactivity to Imagery of Trauma Memories to Imagery of Trauma-Nightmare Memories

Introduction

Prolonged Exposure (PE) therapy produces therapeutic fear extinction via imaginal exposure to trauma memories. However, traumatic events that occurred in the distant past and the associated memories may become distorted or habituated. Posttraumatic nightmares are more recent, potentially salient, and may better support extinction learning. Physiological responses to imagery of a trauma and nightmare related to this trauma were compared to each other and to neutral imagery.

Methods

Twelve participants (mean age=26.16, 11 female) with PTSD (mean CAPS-5=27.83) and frequent trauma-related nightmares wrote accounts of their trauma. Participants then completed a 14-day sleep-monitoring period with diaries, actigraphy and two nights of ambulatory PSG. Participants narrated a nightmare report into an audio recorder when awoken by a nightmare or when recalled upon awakening. Two pairs of short narratives were created from the written account of the trauma and recording of a nightmare most similar to the trauma. These narratives (scripts) were audio-recorded by an investigator. Participants then underwent two script-driven imagery (SDI) sessions, one hour apart, during which they listened to either their two trauma-memory or their two nightmare-memory scripts (counterbalanced across participants) with 3 interspersed neutral scripts. Each script in an SDI session included baseline, listening, and imagery periods (approximately 30 sec apiece). Skin conductance (SC), heart rate (HR), and corrugator electromyography (EMG) biosignals were continuously recorded throughout each SDI session. For each script, HR, SC, and EMG means during the baseline period were subtracted from their respective imagery-period means. These difference scores were square-root transformed and analyzed by ANOVA with Type (trauma vs. nightmare) and Valence (trauma/nightmare vs. neutral) factors.

Results

Biosignals from scripts of both Types (trauma and nightmare) significantly exceeded those from their respective neutral scripts [HR:F(1,11)=23.42, p=0.0005; SC:F(1,11)=9.53, p=0.01; EMG:F(1,10)=8.0, p=0.018]. However, biosignals from trauma and nightmare scripts did not differ (p’s>0.39) nor did the Type x Valence interactions (p’s>0.10).

Conclusion

Physiological reactivity during imagery of a trauma memory and a trauma-related nightmare both significantly exceeded reactivity to neutral scenarios. Nightmare-memory and trauma-memory imagery produced similar reactivity. Thus, imagery of nightmares have potential utility as alternative PE stimuli.

Support (If Any)

This project was supported by NIMH grant 1R21MH121832-01A1 to E.P.S.

765 Anxiety and sleep in Generalized Anxiety Disorder with and without Insomnia Disorder

Introduction

Insomnia Disorder (ID) elevates risk of incident anxiety disorders and vice versa. We examined whether ID and poor sleep are associated with greater self-reported anxiety in persons with Generalized Anxiety Disorder (GAD).

Methods

Twenty-one participants with GAD and ID (GAD+/ID+) having Insomnia Severity Index (ISI) scores ≥ 13 (mean 17.8, SD 3.6) and 14 with GAD but not ID (GAD+/ID-) having ISI scores ≤ 12 (mean 6.4, SD 3.4) completed 14 days of actigraphy and sleep diaries as well as a night of ambulatory polysomnography (PSG) following an acclimation night. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA-T/C, -T/S), the Ford Insomnia Response to Stress Test (FIRST), the Penn State Worry Questionnaire (PSWQ), and the Anxiety Sensitivity Index (ASI). Differences in self-reported anxiety (STICSA, ASI, PSWQ) between GAD+/ID+ and GAD+/ID- were analyzed using t-tests. Relationships of anxiety with retrospective (PSQI, FIRST, ISI), longitudinal (actigraphy, diaries) and physiological (PSG) sleep variables were analyzed using simple regression.

Results

GAD+/ID+ versus GAD+/ID- participants showed trends toward higher anxiety on the PSWQ (p=0.075), ASI (p=0.072) and STICSA-T/S (p=0.078). PSQI scores were positively associated with STICSA-T/S, (R=0.417, p=0.018, N=32). Greater insomnia reactivity (FIRST) was associated with increased worry on the PSWQ (R=0.352, p=0.044, N=33). STICSA-T/C was negatively associated with mean diary (R= -0.440, p=0.015, N=30) and actigraph (R= -0.517, p=0.01, N=24) total sleep time (TST). Actigraph mean TST trended toward lower PSWQ (R= -0.376, p=0.058, N=26) while actigraph mean sleep efficiency (SE) trended toward lesser STICSA-T/C (R= -0.397, p=0.058). Greater REM% was associated with greater STICSA-T/C (R=0.613, p=0.0005, N=28) and STICSA-T/S (R=0.516, p=0.005), a relationship also seen in GAD+/ID+ alone (p=0.03 and 0.015 respectively, N=16). Slow Wave Sleep% (SWS%) was not associated with lesser STICSA-T/S across both groups (p=0.14) but was so in GAD+/ID+ (R= -0.539, p=0.031, N=16).

Conclusion

GAD+/ID+ versus GAD+/ID-, show greater worry, anxiety sensitivity and somatic anxiety. In GAD, shorter and poorer quality sleep measured retrospectively or averaged longitudinally, as well as greater REM%, are associated with greater somatic and cognitive anxiety. Among those with ID, greater SWS% is associated with less somatic anxiety.

Support (if any)

R21MH115279, R01MH109638

764 Neural activation accompanying fear conditioning and extinction in Generalized Anxiety Disorder with and without Insomnia Disorder

Introduction

We examined associations of sleep quality with neural responses to fear conditioning and extinction in individuals with Generalized Anxiety Disorder (GAD) with (INS) and without (NOI) Insomnia Disorder (ID). We hypothesized fear-related regions would show greater, and emotion-regulatory regions lesser activity in INS versus NOI and across both groups with decreasing sleep quality.

Methods

Participants were assigned to either an INS group with Insomnia Severity Index (ISI) ≥ 13 (N=21) or NOI with ISI ≤ 12 (N=14). Two weeks of actigraphy and sleep diaries were followed by a 2-session protocol with fMRI. During Session 1, mild electric shock produced conditioned fear to 2 different colors (CS+s) but not a third (CS-) (Fear Conditioning). Immediately afterward, one CS+ (CS+E) but not the other (CS+U) was extinguished (Extinction Learning). All 3 stimuli were presented 24h later (Extinction Recall). An acclimation/diagnostic ambulatory polysomnography (PSG) night was followed by PSGs before Session 1 and between Sessions 1 and 2. Using SPM8, t-tests compared groups, and multiple regressions predicted anterior cerebral activations (as a whole and as ROIs) using ISI, actigraph and diary sleep efficiency (SE) and latency (SOL), and sleep architecture.

Results

Beginning Fear Conditioning, differential activation to the reinforced stimulus (CS+>CS-) in the right insula was greater in INS than NOI, and greater actigraph SE predicted greater prefrontal activation. Change in activation to the CS+ across Extinction Learning (late CS+>early CS+) did not differentiate groups or correlate with sleep measures. During Extinction Recall, NOI versus INS showed less activation in bilateral amygdala ROIs (CS+E>CS-) but more activation in prefrontal regulatory regions (CS+U>CS-) and bilateral insula ROIs (both contrasts). Greater activation of prefrontal emotion-regulatory areas was associated with greater REM% (CS+E>CS+U and CS+E>CS-), lesser ISI (CS+E>CS- and CS+U>CS-), and greater actigraph SE (CS+U>CS). However for CS+E>CS+U, lesser diary SE and greater ISI were associated with greater prefrontal activity.

Conclusion

Results, on balance, suggest that persons with GAD and ID activated more fear-related and less prefrontal emotion-regulatory regions during fear conditioning and extinction recall than those with GAD alone. Across groups, greater REM% and sleep quality were associated with greater activity of emotion-regulatory areas.

Support (if any)

Funding: R21MH115279, R01MH109638

Go to Bed and You MIGHT Feel Better in the Morning—the Effect of Sleep on Affective Tone and Intrusiveness of Emotional Memories

Purpose of Review

It is important to examine what effect sleep has after an emotional experience. More knowledge about this topic could help inform us whether there are any potential sleep interventions that could help make sure that memories of negative emotional experiences are processed in the most adaptive manner possible.

Recent Findings

Findings on the role of sleep in altering reactivity to emotional stimuli have been highly varied, with significant findings in opposite directions. A new exciting development in the field is several studies finding that sleep seems to make memories of negative experiences less intrusive.

Summary

This review has mainly aimed to give an overview of the field, and of which issues need to be resolved. We argue for there being a strong need for standardization of how data are analyzed and presented, as well as for better methods for determining to what extent the effects of sleep are specific for a particular memory, or represent general changes in emotional reactivity.

Does Sleep Selectively Strengthen Certain Memories Over Others Based on Emotion and Perceived Future Relevance?

Sleep has been found to have a beneficial effect on memory consolidation. It has furthermore frequently been suggested that sleep does not strengthen all memories equally. The first aim of this review paper was to examine whether sleep selectively strengthens emotional declarative memories more than neutral ones. We examined this first by reviewing the literature focusing on sleep/wake contrasts, and then the literature on whether any specific factors during sleep preferentially benefit emotional memories, with a special focus on the often-suggested claim that rapid eye movement sleep primarily consolidates emotional memories. A second aim was to examine if sleep preferentially benefits memories based on other cues of future relevance such as reward, test-expectancy or different instructions during encoding. Once again, we first focused on studies comparing sleep and wake groups, and then on studies examining the contributions of specific factors during sleep (for each future relevance paradigm, respectively). The review revealed that although some support exists that sleep is more beneficial for certain kinds of memories based on emotion or other cues of future relevance, the majority of studies does not support such an effect. Regarding specific factors during sleep, our review revealed that no sleep variable has reliably been found to be specifically associated with the consolidation of certain kinds of memories over others based on emotion or other cues of future relevance.

The role of sleep in fear learning and memory

During the last 10 years, a large body of studies have used fear conditioning paradigms to study the role of sleep in the consolidation of fear and safety learning. This line of research could allow us to answer if it is adaptive or not to sleep in the aftermath of a negative experience, and if sleep has a role in consolidating extinction learning. This field has so far produced several contrasting findings. Thus, this review will not deliver many clear conclusions, but will instead be an attempt to summarize what we know at the moment, to describe the potential clinical applications of this research, and to discuss where to go from here.

Normalizing effects of modafinil on sleep in chronic cocaine users

OBJECTIVE

The purpose of the present study was to determine the effect of morning-dosed modafinil on sleep and daytime sleepiness in chronic cocaine users.

METHOD

Twenty cocaine-dependent participants were randomly assigned to receive modafinil, 400 mg (N=10), or placebo (N=10) every morning at 7:30 a.m. for 16 days in an inpatient, double-blind randomized trial. Participants underwent polysomnographic sleep recordings on days 1 to 3, 7 to 9, and 14 to 16 (first, second, and third weeks of abstinence). The Multiple Sleep Latency Test was performed at 11:30 a.m., 2:00 p.m., and 4:30 p.m. on days 2, 8, and 15. For comparison of sleep architecture variables, 12 healthy comparison participants underwent a single night of experimental polysomnography that followed 1 night of accommodation polysomnography.

RESULTS

Progressive abstinence from cocaine was associated with worsening of all measured polysomnographic sleep outcomes. Compared with placebo, modafinil decreased nighttime sleep latency and increased slow-wave sleep time in cocaine-dependent participants. The effect of modafinil interacted with the abstinence week and was associated with longer total sleep time and shorter REM sleep latency in the third week of abstinence. Comparison of slow-wave sleep time, total sleep time, and sleep latency in cocaine-dependent and healthy participants revealed a normalizing effect of modafinil in cocaine-dependent participants. Modafinil was associated with increased daytime sleep latency, as measured by the Multiple Sleep Latency Test, and a nearly significant decrease in subjective daytime sleepiness.

CONCLUSIONS

Morning-dosed modafinil promotes nocturnal sleep, normalizes sleep architecture, and decreases daytime sleepiness in abstinent cocaine users. These effects may be relevant in the treatment of cocaine dependence.

Emotion and cognition: feeling and character identification in dreaming

This study investigated the relationship between dream emotion and dream character identification. Thirty-five subjects provided 320 dream reports and answers to questions on characters that appeared in their dreams. We found that emotions are almost always evoked by our dream characters and that they are often used as a basis for identifying them. We found that affection and joy were commonly associated with known characters and were used to identify them even when these emotional attributes were inconsistent with those of the waking state. These findings are consistent with the finding that the dorsolateral prefrontal cortex, associated with short-term memory, is less active in the dreaming compared to the wake brain, while the paleocortical and subcortical limbic areas are more active. The findings are also consistent with the suggestion that these limbic areas have minimal input from the dorsolateral prefrontal cortex in the dreaming brain.