Sleep disturbances and sleep disorders in adults living with chronic pain: a meta-analysis

Sleep duration and pain during the COVID-19 pandemic with depression and chronic diseases as mediators

The bidirectional relationship between sleep duration and pain during the COVID-19 pandemic remains poorly understood. This study explores these interactions and the mediating roles of depression and chronic diseases using data from the China Health and Retirement Longitudinal Study (CHARLS) cohort. A cross-sectional analysis was conducted on 15,979 participants aged 45 and older. Sleep duration was self-reported, and pain was assessed using validated anatomical charts. Depression symptoms were measured using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10), and chronic diseases were self-reported. Personal activity during the pandemic was measured using the Personal Activity Score during COVID-19 (PAS-COVID-19). The results showed a significant association between deviations from optimal sleep duration and increased pain frequency. Participants with both shorter and longer sleep durations reported higher pain levels, with depression and chronic diseases acting as significant mediators. However, personal activity did not significantly mediate the association between sleep duration and pain. These findings underscore the complex interplay among sleep duration, pain, depression, and chronic diseases during the COVID-19 pandemic, emphasizing the importance of integrated interventions to manage these interconnected health issues.

Mechanisms of the Native American pain inequity: predicting chronic pain onset prospectively at 5 years in the Oklahoma Study of Native American Pain Risk

ABSTRACT

A pain inequity exists for Native Americans (NAs), but the mechanisms are poorly understood. The Oklahoma Study of Native American Pain Risk (OK-SNAP) addressed this issue and recruited healthy, pain-free NAs and non-Hispanic Whites (NHWs) to attend 2 laboratory visits and assessed mechanisms consistent with the biopsychosocial model of pain: demographics, physical variables, psychosocial factors, and nociceptive/pain phenotypes. Then participants were surveyed every 6 months to assess for chronic pain onset. Results at the 2-year follow-up found that NAs were ∼3x more likely than NHWs to develop chronic pain. Moreover, psychosocial factors (discrimination, stress, pain-related anxiety), cardiometabolic load (higher body mass index and blood pressure, lower heart rate variability), and impaired inhibition of spinal nociception partly mediated the pain inequity. The present study examined mechanisms of chronic pain at the 5-year follow-up for OK-SNAP. Results found that the NA pain inequity worsened-NAs were 4x more likely to develop chronic pain (OR = 4.025; CI = 1.966, 8.239), even after controlling for baseline age, sex assigned at birth, income, and education. Moreover, serial mediation models replicated paths from the 2-year follow-up that linked psychosocial variables, cardiometabolic load, and impaired inhibition of spinal nociception to chronic pain onset. Further, 2 new significant paths were observed. One linked discrimination, stress, sleep problems, and facilitated pain perception to increased pain risk. The other linked discrimination with higher spinal nociceptive threshold and pain risk. These results provide further evidence for a NA pain inequity and identify multiple psychosocial, cardiometabolic, and pronociceptive targets for primary interventions.

The bidirectional relationship between sleep problems and chronic musculoskeletal pain: a systematic review with meta-analysis

ABSTRACT

Chronic musculoskeletal pain and sleep problems/disorders exhibit a recognized bidirectional relationship; yet, systematic investigations of this claim, particularly in a prospective context, are lacking. This systematic review with meta-analysis aimed to synthesize the literature on the prospective associations between sleep problems/disorders and chronic musculoskeletal pain. A comprehensive search across 6 databases identified prospective longitudinal cohort studies in adults examining the relationship between sleep problems/disorders and chronic musculoskeletal pain. Random-effects meta-analyses, using the Hartung-Knapp adjustment for 95% confidence intervals (CIs), were conducted, and all results were presented as odds ratios (ORs). Certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach. Including 16 articles from 11 study populations (116,746 participants), meta-analyses indicated that sleep problems at baseline may heighten the risk of chronic musculoskeletal pain in both short term (OR 1.64, 95% CI 1.01-2.65) and long term (OR 1.39, 95% CI 1.21-1.59). The evidence for different sleep problem categories was very uncertain. Chronic musculoskeletal pain at baseline may increase the risk of short-term sleep problems (OR 1.56, 95% CI 1.02-2.38), but long-term evidence was very uncertain. The impact of only local or only widespread pain on short-term sleep problems was very uncertain, whereas widespread pain may elevate the risk of long-term sleep problems (OR 2.0, 95% CI 1.81-2.21). In conclusion, this systematic review with meta-analysis suggests that sleep problems are associated with an increased risk of chronic musculoskeletal pain, but the bidirectional nature of this relationship requires further investigation.

Chronic pain management and sleep disorders

Chronic pain affects the quality of life for millions of people worldwide. There is a bidirectional link between pain and sleep: poor sleep quality exacerbates pain, and pain disrupts sleep. Addressing this cycle is crucial for effective pain management and improving patients' overall health outcomes.

Pain in your day? Get sleep treatment anyway! The role of pain in insomnia treatment efficacy in women veterans

Insomnia and pain disorders are among the most common conditions affecting United States adults and veterans, and their comorbidity can cause detrimental effects to quality of life among other factors. Cognitive behavioural therapy for insomnia and related behavioural therapies are recommended treatments for insomnia, but chronic pain may hinder treatment benefit. Prior research has not addressed how pain impacts the effects of behavioural insomnia treatment in United States women veterans. Using data from a comparative effectiveness clinical trial of two insomnia behavioural treatments (both including sleep restriction, stimulus control, and sleep hygiene education), we examined the impact of pain severity and pain interference on sleep improvements from baseline to post-treatment and 3-month follow-up. We found no significant moderation effects of pain severity or interference in the relationship between treatment phase and sleep outcomes. Findings highlight opportunities for using behavioural sleep interventions in patients, particularly women veterans, with comorbid pain and insomnia, and highlight areas for future research.

Association between obstructive sleep apnea and temporomandibular disorders: A meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a very common condition in patients with temporomandibular disorders (TMD). However, there is little evidence of a connection between them.

OBJECTIVE

The aim of this systematic review and meta-analysis is to assess the association between OSA and TMD in adult population.

METHODS

Case-control, cross-sectional and cohort studies on the association between TMD and OSA were searched in the EMBASE, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, Web of Science, Google Scholar, Open Grey and Pro Quest databases. TMD should be assessed using Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD) and OSA using polysomnography (PSG) and/or a validated questionnaire. The risk of bias was evaluated using the Joanna Briggs Institute Critical Assessment Checklists; and an association meta-analysis was performed. The effect measure included the odds ratio (OR) in dichotomous variables and a 95% confidence interval (CI). Certainty of evidence was determined by analysing groups using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Out of the 1024 articles screened, 7 met the inclusion criteria for the qualitative synthesis, and 6 for quantitative analysis. All articles were classified at low risk of bias. A positive association with OSA was found in patients with TMD (OR = 2.61; 95% CI = 2.31, 2.95). A significant association was also found irrespective to the OSA diagnostic methods applied (for studies using PSG + validated questionnaires: OR = 2.74; 95% CI = 2.11, 3.57; for studies using validated questionnaires only: OR = 2.55; 95% CI = 2.22, 2.92). GRADE was moderate.

CONCLUSION

Patients with TMD presented a significant association with OSA regardless of the OSA diagnostic method (PSG and/or validated questionnaires). OSA screening should be part of the TMD examination routine. Furthermore, due to the different OSA assessment methods used and the small number of studies included, there is a need to include a larger number of studies using PSG to better elucidate this association.

Do Maladaptive Imaging Beliefs Predict Self-Reported Pain Interference and Physical Function in Patients With Musculoskeletal Disorders?

OBJECTIVE: To determine if maladaptive imaging beliefs correlated with, and predicted pain interference and physical function outcomes in people with musculoskeletal pain disorders. DESIGN: A prospective cohort study of patients with musculoskeletal disorders receiving outpatient physical therapy from April 2022 to August 2023. METHODS: Four questions about imaging were asked to assess maladaptive beliefs, the need to rule out serious conditions, guide treatment, determine diagnosis, and validate symptoms. Correlations with beliefs and outcomes were assessed using Kendall's tau rank and Spearman's rho correlation coefficients. Generalized linear models determined if these beliefs predicted outcomes at baseline and 6 weeks. RESULTS: The cohort included 152 participants (mean [standard deviation] age: 56.13 [15.13]; 32.2% male). Maladaptive imaging beliefs correlated positively with pain interference and negatively with physical function. The need to rule out serious conditions and validate symptoms correlated with pain interference (range: τb = 0.17, 0.20; P = .003, .0121) and physical function (range: ρ = -0.22, -0.22; P = .006, .008). All but 1 belief correlated with pain interference (range: τb = 0.19, 0.24; P<.001, .004) and physical function (range: ρ = -0.26, -0.21; P = .001, .009) at 6 weeks. Each additional belief slightly increased pain interference at 6 weeks (β = 0.01; 95% CI: 0.001, 0.03; P = .04) and lowered physical function at both baseline (β = -0.97; 95% CI: -1.66, -0.28; P = .01) and 6 weeks (β = -0.76; 95% CI: -1.37, -0.15; P = .02). CONCLUSION: Maladaptive imaging beliefs were significantly (albeit weakly) correlated with pain and physical function. Each additional maladaptive imaging belief increased pain interference at 6 weeks and lowered physical function at baseline and 6 weeks. Beliefs about the necessity of imaging to properly manage musculoskeletal disorders may influence outcomes. J Orthop Sports Phys Ther 2024;54(9):1-10. Epub 5 July 2024. doi:10.2519/jospt.2024.12625.

Bibliometric analysis of functional magnetic resonance imaging studies on chronic pain over the past 20 years

PURPOSE

The utilization of functional magnetic resonance imaging (fMRI) in studying the mechanisms and treatment of chronic pain has gained significant popularity. However, there is currently a dearth of literature conducting bibliometric analysis on fMRI studies focused on chronic pain.

METHODS

All the literature included in this study was obtained from the Science Citation Index Expanded of Web of Science Core Collection. We used CiteSpace and VOSviewer to analyze publications, authors, countries or regions, institutions, journals, references and keywords. Additionally, we evaluated the timeline and burst analysis of keywords, as well as the timeline and burst analysis of references. The search was conducted from 2004 to 2023 and completed within a single day on October 4th, 2023.

RESULTS

A total of 1,327 articles were retrieved. The annual publication shows an overall increasing trend. The United States has the highest number of publications and the main contributing institution is Harvard University. The journal PAIN produces the most articles. In recent years, resting-state fMRI, the prefrontal cortex, nucleus accumbens, thalamus, and migraines have been researched hotspots of fMRI studies on chronic pain.

CONCLUSIONS

This study provides an in-depth perspective on fMRI for chronic pain research, revealing key points, research hotspots and research trends, which offers valuable ideas for future research activities. It concludes with a summary of advances in clinical practice in this area, pointing out the need for critical evaluation of these findings in the light of guidelines and expert recommendations. It is anticipated that further high-quality research outputs will be generated in the future, which will facilitate the utilization of fMRI in clinical decision-making for chronic pain.

A Narrative Review of the Reciprocal Relationship Between Sleep Deprivation and Chronic Pain: The Role of Oxidative Stress

Sleep is crucial for human health, insufficient sleep or poor sleep quality may negatively affect sleep function and lead to a state of sleep deprivation. Sleep deprivation can result in various health problems, including chronic pain. The intricate relationship between sleep and pain is complex and intertwined, with daytime pain affecting sleep quality and poor sleep increasing pain intensity. The article first describes the influence of sleep on the onset and development of pain, and then explores the impact of daytime pain intensity on nighttime sleep quality and subsequent pain thresholds. However, the primary emphasis is placed on the pivotal role of oxidative stress in this bidirectional relationship. Although the exact mechanisms underlying sleep and chronic pain are unclear, this review focuses on the role of oxidative stress. Numerous studies on sleep deprivation have demonstrated that it can lead to varying degrees of increased pain sensitivity, while chronic pain leads to sleep deprivation and further exacerbates pain. Further research on the role of oxidative stress in the mechanism of sleep deprivation-induced pain sensitization seems reasonable. This article comprehensively reviews the current research on the interrelationship between sleep deprivation, pain and the crucial role of oxidative stress.

Most dynorphin neurons in the zona incerta-perifornical area are active in waking relative to non-rapid-eye movement and rapid-eye movement sleep

Dynorphin is an endogenous opiate localized in many brain regions and spinal cord, but the activity of dynorphin neurons during sleep is unknown. Dynorphin is an inhibitory neuropeptide that is coreleased with orexin, an excitatory neuropeptide. We used microendoscopy to test the hypothesis that, like orexin, the dynorphin neurons are wake-active. Dynorphin-cre mice (n = 3) were administered rAAV8-Ef1a-Con/Foff 2.0-GCaMP6M into the zona incerta-perifornical area, implanted with a GRIN lens (gradient reflective index), and electrodes to the skull that recorded sleep. One month later, a miniscope imaged calcium fluorescence in dynorphin neurons during multiple bouts of wake, non-rapid-eye movement (NREM), and rapid-eye movement (REM) sleep. Unbiased data analysis identified changes in calcium fluorescence in 64 dynorphin neurons. Most of the dynorphin neurons (72%) had the highest fluorescence during bouts of active and quiet waking compared to NREM or REM sleep; a subset (20%) were REM-max. Our results are consistent with the emerging evidence that the activity of orexin neurons can be classified as wake-max or REM-max. Since the two neuropeptides are coexpressed and coreleased, we suggest that dynorphin-cre-driven calcium sensors could increase understanding of the role of this endogenous opiate in pain and sleep.

The mediating roles of depressive symptoms and social participation in the relationship between the effects of pain and cognitive function among Chinese older adults: A longitudinal study

Decline in cognitive function poses a substantial burden on individuals, families, and society. However, the longitudinal potential mechanism underlying the link of pain and cognitive function remains unclear. Using data of 4247 participants aged 60 years and over from the China Health and Retirement Longitudinal Study in 2011, 2013, 2018, and 2020, we discussed the longitudinal predictive effect of pain on cognitive function and the mediating effects of depressive symptoms and social participation. The longitudinal mediation model analysis revealed that pain could not directly influence cognitive function, but it could indirectly predict cognitive function through the independent mediation effects of depressive symptoms and social participation. Moreover, the association between pain and cognitive function was serially mediated by depressive symptoms and social participation. Diversified interventions aimed at relieving pain and depressive symptoms, and increasing social participation in older adults would be beneficial for their cognitive function.

To what degree patient-reported symptoms of central sensitization, kinesiophobia, disability, sleep, and life quality associated with 24-h heart rate variability and actigraphy measurements?

OBJECTIVES

Chronic musculoskeletal pain is associated with decreased parasympathetic and increased sympathetic activity in the autonomic nervous system. The objective of this study was to determine the associations between objective measures of heart rate variability (a measure of autonomic nervous system function), actigraphy (a measure of activity and sleep quality), respiration rates, and subjective patient-reported outcome measures (PROMs) of central sensitization, kinesiophobia, disability, the effect of pain on sleep, and life quality.

METHODS

Thirty-eight study subjects were divided into two subgroups, including low symptoms of central sensitization (n = 18) and high symptoms of central sensitization (n = 20), based on patient-reported scores on the Central Sensitization Inventory (CSI). Heart rate variability (HRV) and actigraphy measurements were carried out simultaneously in 24 h measurement during wakefulness and sleep.

RESULTS

A decrease in HRV during the first 2 h of sleep was stronger in the low CSI subgroup compared to the high CSI subgroup. Otherwise, all other HRV and actigraphy parameters and subjective measures of central sensitization, disability, kinesiophobia, the effect of pain on sleep, and quality of life showed only little associations.

DISCUSSION

The high CSI subgroup reported significantly more severe symptoms of disability, kinesiophobia, sleep, and quality of life compared to the low CSI subgroup. However, there were only small and nonsignificant trend in increased sympathetic nervous system activity and poorer sleep quality on the high central sensitization subgroup. Moreover, very little differences in respiratory rates were found between the groups.

The Impact of Sleep Disturbances on Endogenous Pain Modulation: A Systematic Review and Meta-Analysis

The bidirectional relationship between sleep and pain problems has been extensively demonstrated but despite all the accumulating evidence, their shared mechanisms are currently not fully understood. This review examined the association between sleep disturbances, defined as a broad array of sleep-related outcomes (eg, poor quality, short duration, insomnia), and endogenous pain modulation (EPM) in healthy and clinical populations. Our search yielded 6,151 references, and 37 studies met the eligibility criteria. Qualitative results showed mixed findings regarding the association between sleep disturbances and temporal summation of pain (TSP) and conditioned pain modulation (CPM), with poor sleep more commonly associated with decreased pain inhibition in both populations. Quantitative results indicated that such associations were not statistically significant, neither in healthy populations when EPM outcomes were assessed for changes pre-/post-sleep intervention (TSP: .31 [95%CI: -.30 to .92]; P = .321; CPM: .40 [95%CI: -.06 to .85] P = .088) nor in clinical populations when such association was assessed via correlation (TSP: -.00 [95%CI: -.22 to .21] P = .970; CPM: .12 [95%CI: -.05 to .29]; P = .181). For studies that reported results by sex, meta-analysis showed that experimental sleep disturbances impaired pain inhibition in females (1.43 [95%CI: .98-1.88]; P < .001) but not in males (-.30 [95%CI: -2.69 to 1.60]; P = .760). Only one study investigating the association between sleep disturbances and offset analgesia was identified, while no studies assessing spatial summation of pain were found. Overall, this review provides a comprehensive overview of the association between sleep disturbances and EPM function, emphasizing the need for further investigation to clarify specific mechanisms and phenotypic subtypes. PERSPECTIVE: This review shines a light on the association between sleep disturbances and endogenous pain modulation function. Qualitatively, we found a frequent association between reduced sleep quality and impaired pain inhibition. However, quantitatively such an association was not corroborated. Sex-specific effects were observed, with females presenting sleep-related impaired pain inhibition but not males.

Effect of chronic intermittent hypoxia on ocular and intraoral mechanical allodynia mediated via the calcitonin gene-related peptide in a rat

STUDY OBJECTIVES

Obstructive sleep apnea, a significant hypoxic condition, may exacerbate several orofacial pain conditions. The study aims to define the involvement of calcitonin gene-related peptide (CGRP) in peripheral and central sensitization and in evoking orofacial mechanical allodynia under chronic intermittent hypoxia (CIH).

METHODS

Male rats were exposed to CIH. Orofacial mechanical allodynia was assessed using the eyeblink test and the two-bottle preference drinking test. The CGRP-immunoreactive neurons in the trigeminal ganglion (TG), CGRP-positive primary afferents projecting to laminae I-II of the trigeminal spinal subnucleus caudalis (Vc), and neural responses in the second-order neurons of the Vc were determined by immunohistochemistry. CGRP receptor antagonist was administrated in the TG.

RESULTS

CIH-induced ocular and intraoral mechanical allodynia. CGRP-immunoreactive neurons and activated satellite glial cells (SGCs) were significantly increased in the TG and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly higher in CIH rats compared to normoxic rats. Local administration of the CGRP receptor antagonist in the TG of CIH rats attenuated orofacial mechanical allodynia; the number of CGRP-immunoreactive neurons and activated SGCs in the TG, and the density of CGRP-positive primary afferent terminals and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly lower compared to vehicle-administrated CIH rats.

CONCLUSIONS

An increase in CGRP in the TG induced by CIH, as well as orofacial mechanical allodynia and central sensitization of second-order neurons in the Vc, supported the notion that CGRP plays a critical role in CIH-induced orofacial mechanical allodynia.

Clinical Phenotypes Supporting the Relationship Between Sleep Disturbance and Impairment of Placebo Effects

Lack of good sleep or insomnia can lead to many health issues, including an elevated risk of cardiovascular disease, obesity, fatigue, low mood, and pain. While chronic pain negatively impacts sleep quality, the relationship between descending pain modulatory systems like placebo effects and sleep quality is not thoroughly known. We addressed this aspect in a cross-sectional study in participants with chronic pain. Placebo effects were elicited in a laboratory setting using thermal heat stimulations delivered with visual cues using classical conditioning and verbal suggestions. We estimated the levels of insomnia severity with the Insomnia Severity Index and the sleep quality with the Pittsburg Sleep Quality Index. The previous night's sleep continuity was assessed as total sleep time, sleep efficiency, and sleep midpoint the night before the experiment. 277 people with chronic pain and 189 pain-free control individuals participated. Participants with chronic pain and insomnia showed smaller placebo effects than those with chronic pain without insomnia. Similarly, poor sleep quality was associated with reduced placebo effects among participants with chronic pain. Clinical anxiety measured by Depression Anxiety Stress Scales partially mediated these effects. In contrast, placebo effects were not influenced by the presence of insomnia or poor sleep quality in pain-free participants. Sleep continuity the night before the experiment did not influence the placebo effects. Our results indicate that participants who experience insomnia and/or poor sleep quality and chronic pain have smaller placebo effects, and that the previous night sleep continuity does not influence the magnitude of placebo effects. PERSPECTIVE: This study examined the relationship between sleep disturbances and experimentally induced placebo effects. We found that individuals with chronic pain who experience insomnia and poor sleep quality demonstrated reduced placebo effects compared to their counterparts with good sleep quality and no insomnia.

Validity and Reliability of the Greek Version of Pittsburgh Sleep Quality Index in Chronic Non-Specific Low Back Pain Patients

The purpose of this study was to investigate psychometric properties of the Greek translation of Pittsburgh Sleep Quality Index (GR-PSQI) in a Greek chronic non-specific low back pain (CNSLBP) sample, thus, providing insight on its clarity and acceptability as a widely used sleep assessment tool in clinical practice. Asymptomatic volunteers (n = 73) and CNSLBP volunteers (n = 47), participated in the study. For the assessment of construct validity, the known-groups method was used. Thus, all the participants (asymptomatic and CNSLBP) completed the GR-PSQI. For the assessment of concurrent validity, the CNSLBP participants additionally completed the following validated questionnaires for depression, insomnia and sleep quality: Beck Depression Inventory Questionnaire (BDI), Insomnia Severity Index (ISI), and Sleep Quality Numeric Rating Scale (SQNRS). For the assessment of test-retest reliability, the CNSLBP participants completed the GR-PSQI a second time, one week after the first time. The results showed excellent test-retest reliability (ICC = 0.969, SEM = 0.90, SDD = 2.49%) and internal consistency (Cronbach α = 0.985), moderate to good concurrent validity (from r = 0.556 to r = 0.860) among PSQI, BDI, SQNRS, and ISI, as well as excellent construct validity (p = 0.000) between the two groups. The Greek translation of PSQI could be a valuable tool for Greek healthcare professionals in both clinical and research environments.

Associations of multimorbidity with body pain, sleep duration, and depression among middle-aged and older adults in China

BACKGROUND

Multimorbidity, body pain, sleep disturbance, and depression are major clinical and public health challenges. This paper aimed to examine the associations of multimorbidity with body pain, sleep duration, and depression; and whether the associations varied by socioeconomic status.

METHODS

Data was derived from four waves of the nationally representative China Health and Retirement Longitudinal Study (CHARLS), including participants aged 45 years and older in 2011. 12 physical non-communicable diseases and 1 mental chronic disease were used to measure multimorbidity. Educational attainment and annual per-capita household consumption expenditure were employed as proxies for socioeconomic status.

RESULTS

Of the 16,931 participants aged 45 + years old, the proportion of people with multimorbidity was 37.87% at baseline. The number of multimorbidity increased with older age and higher socioeconomic status. Multimorbidity was associated with more body pain (incidence rate ratio (IRR) = 1.53, 95% CI = 1.45-1.61), and decreased sleep duration (β = -0.26, 95% CI = -0.36--0.15). Furthermore, multimorbidity was associated with increased depression risks (odds ratio (OR) = 1.54, 95% CI = 1.44-1.64, adjusted for sociodemographic variables), with the mediating effects of the number of body pain and sleep duration. The associations between multimorbidity and depression persisted among different socioeconomic groups.

CONCLUSIONS

Multimorbidity was associated with increased body pain, decreased sleep duration, and further led to increased depression risks. It is necessary to pay attention to the multimorbidity of middle-aged and older adults, relieve their body pain, guarantee sufficient sleep, so as to reduce depression risks.

Elevated prevalence and treatment of sleep disorders from 2011 to 2020: a nationwide population-based retrospective cohort study in Korea

OBJECTIVES

This study used National Health Insurance claims data from Korea to report the prevalence of sleep disorders and treatment status, including traditional Korean medicine, in the last 10 years.

METHODS

This is a retrospective cohort study in Korea. All diagnosis and prescription data, including herbal medicine claims, from the Health Insurance Review and Assessment Service from 2011 to 2020 were reviewed. Prevalence estimation, direct medical expenses and prescribed amounts for sleep disorders were recorded.

RESULTS

The prevalence of sleep disorders increased from 3 867 975 (7.62%) in 2011 to 7 446 846 (14.41%) in 2020, nearly doubling over 10 years. Insomnia was observed in 91.44% (n=9 011 692) of the patients. The mean number of hospital visits per patient for sleep disorders was 11.5 (±26.62). Benzodiazepines are the most commonly prescribed medications for sleep disorders, and gamma-isoyosan is the most frequently prescribed herbal medicine.

CONCLUSIONS

Sleep disorders are continuously increasing, as is the use of medical services-personal and social medical expenses are also increasing accordingly. Sleep disorders should be recognised as a significant health problem that needs to be actively addressed to improve quality of life.

Sleep and Pain: A Role for the Anterior Cingulate Cortex, Nucleus Accumbens, and Dopamine in the Increased Pain Sensitivity Following Sleep Restriction

Persistent pain conditions and sleep disorders are public health problems worldwide. It is widely accepted that sleep disruption increases pain sensitivity; however, the underlying mechanisms are poorly understood. In this study, we used a protocol of 6 hours a day of total sleep deprivation for 3 days in rats to advance the understanding of these mechanisms. We focused on gender differences and the dopaminergic mesocorticolimbic system. The findings demonstrated that sleep restriction (SR) increased pain sensitivity in a similar way in males and females, without inducing a significant stress response. This pronociceptive effect depends on a nucleus accumbens (NAc) neuronal ensemble recruited during SR and on the integrity of the anterior cingulate cortex (ACC). Data on indirect dopaminergic parameters, dopamine transporter glycosylation, and dopamine and cyclic adenosine monophosphate (AMP)-regulated phosphoprotein-32 phosphorylation, as well as dopamine, serotonin, and norepinephrine levels, suggest that dopaminergic function decreases in the NAc and ACC after SR. Complementarily, pharmacological activation of dopamine D2, but not D1 receptors either in the ACC or in the NAc prevents SR from increasing pain sensitivity. The ACC and NAc are the main targets of dopaminergic mesocorticolimbic projections with a key role in pain modulation. This study showed their integrative role in the pronociceptive effect of SR, pointing to dopamine D2 receptors as a potential target for pain management in patients with sleep disorders. These findings narrow the focus of future studies on the mechanisms by which sleep impairment increases pain sensitivity. PERSPECTIVE: This study demonstrates that the pronociceptive effect of SR affects similarly males and females and depends on a NAc neuronal ensemble recruited during SR and on the integrity of the ACC. Findings on dopaminergic function support dopamine D2 receptors as targets for pain management in sleep disorders patients.

Comparative effectiveness of non-pharmacological interventions on sleep in individuals with chronic musculoskeletal pain: A systematic review with network meta-analysis

This network meta-analysis aimed to estimate the comparative effectiveness of non-pharmacological interventions on sleep in individuals with chronic musculoskeletal pain. Seven databases were systematically searched up to February 2023. A random-effects network meta-analysis in a frequentist framework was performed to synthesize continuous data as standardized mean differences (SMD) along with a 95% confidence interval (95% CI). A total of 15,641 records were identified, and 107 randomized controlled trials involving 8,121 participants were included. Of 14 identified interventions, eight were significantly more effective than passive control in improving sleep quality at immediate post-intervention (SMDs = 0.67-0.74), with cognitive behavioral therapy (CBT) being the most effective treatment (SMD = 0.74, 95% CI: 0.45-1.03). Only CBT demonstrated sustained effects at short-term (SMD = 1.56; 95% CI: 0.62-2.49) and mid-term (SMD = 1.23; 95% CI: 0.44-2.03) follow-ups. Furthermore, CBT significantly improved subjective (SMD = 0.64; 95% CI: 0.25-1.03) and objective (SMD = 0.30; 95% CI: 0.01-0.59) sleep efficiency compared with passive control at immediate post-intervention. Our findings support CBT as the first-line treatment for improving sleep in individuals with chronic musculoskeletal pain, given its superior effectiveness across multiple sleep outcomes and its sustainable effects until mid-term follow-up. However, the certainty of evidence for these interventions in improving sleep quality was very low to low.

Global trends and development of acupuncture for stroke: A review and bibliometric analysis

The objective of this review is to elaborate on the status, hotspots, and trends of researches on acupuncture for stroke over the past 26 years. Publications about acupuncture for stroke were downloaded from the Web of Science Core Collection, and these papers were published up to December 31, 2022. A bibliometric analysis of acupuncture for stroke was conducted by CiteSpace (6.2.R4) and VOSviewer (1.6.17). In this study, VOSviewer was used for visual analysis of countries, institutions, authors, journals, keywords, and co-cited references. CiteSpace was used to draw a keyword burst map and a co-cited reference burst map. A total of 534 papers were obtained from the Web of Science Core Collection. The number of papers per year showed a rapid upward trend. The most productive country and institution in this field were China (452) and the Fujian University of Traditional Chinese Medicine (43), respectively. Tao Jing had the highest number of articles (34), and EZ Longa was the most popular author (129 co-citations). Neural Regeneration Research (51) was the most productive journal, and Stroke (1346) was the most co-cited journal. An paper written by EZ Longa was the most influential reference, with the highest citation count. The hotspots and frontiers of this area of research were focused on the mechanisms of acupuncture, especially its neural regenerative or neuroprotective effects. This study used CiteSpace and VOSviewer for bibliometric analysis to provide researchers with information on the research status, hotspots, and trends in acupuncture for stroke research over the past 26 years.

Development, Insults and Predisposing Factors of the Brain's Predictive Coding System to Chronic Perceptual Disorders-A Life-Course Examination

The predictive coding theory is currently widely accepted as the theoretical basis of perception and chronic perceptual disorders are explained as the maladaptive compensation of the brain to a prediction error. Although this gives us a general framework to work with, it is still not clear who may be more susceptible and/or vulnerable to aberrations in this system. In this paper, we study changes in predictive coding through the lens of tinnitus and pain. We take a step back to understand how the predictive coding system develops from infancy, what are the different neural and bio markers that characterise this system in the acute, transition and chronic phases and what may be the factors that pose a risk to the aberration of this system. Through this paper, we aim to identify people who may be at a higher risk of developing chronic perceptual disorders as a reflection of aberrant predictive coding, thereby giving future studies more facets to incorporate in their investigation of early markers of tinnitus, pain and other disorders of predictive coding. We therefore view this paper to encourage the thinking behind the development of preclinical biomarkers to maladaptive predictive coding.

Association of Risk Factors and Comorbidities With Chronic Pain in the Elderly Population

INTRODUCTION/OBJECTIVE

Chronic pain disorders affect about 20% of adults in the United States, and it disproportionately affects individuals living in the neighborhoods of extreme socioeconomic disadvantage. In many instances, chronic pain has been noted to arise from an aggregation of multiple risk factors and events. Therefore, it is of importance to recognize the modifiable risk factors. The aim of this study was to investigate the comorbid medical conditions and risk factors associated with chronic pain disorders in patients aged 65 years and older.

METHODS

Our team retrospectively reviewed medical records of elderly patients (65 years and older) who were evaluated in our outpatient medicine office between July 1, 2020 and June 30, 2021 for acute problems, management of chronic medical problems, or well visits. We divided our patients into a group who suffered from chronic pain disorder, and another group who did not have chronic pain disorder. The association of variables were compared between those groups.

RESULTS

Of the 2431 patients, 493 (20.3%) had a chronic pain disorder. A higher frequency of females in the group with chronic pain disorder was found compared to the group without a chronic pain disorder (60.6% vs 55.2%; P = .033). The mean ages between the two groups were similar in the group with a chronic pain disorder compared to the group without (76.35 ± 7.5 year vs 76.81 ± 7.59 year; P = .228). There were significant associations of certain comorbidities in the group with a chronic pain disorder compared to the group without a chronic pain disorder, such as depression (21.9% vs 15.2%; P < .001), anxiety (27.0% vs 17.1%; P < .001), chronic obstructive pulmonary disease (8.7% vs 6.1%; P = .036), obstructive sleep apnea (16.8% vs 11.6%; P = .002), gastroesophageal reflux disease (40.8% vs 29.0%; P < .001), osteoarthritis (49.3% vs 26.1%; P < .001), other rheumatologic diseases (24.9% vs 19.4%; P = .006), and peripheral neuropathy (14.4% vs 5.3%; P < .001).

CONCLUSION

Female sex, depression, anxiety, chronic obstructive pulmonary disease, obstructive sleep apnea, gastroesophageal reflux disease, osteoarthritis, other rheumatologic diseases, and peripheral neuropathy were significantly associated with chronic pain disorder in elderly patients, while BMI was not associated with chronic pain disorder.

Bruxism and oro-facial pain not related to temporomandibular disorder conditions: Comorbidities or risk factors?

INTRODUCTION

Bruxism has historically been of particular interest to the field of dentistry, primarily due to the inferred damage it may cause to the dentition and supporting periodontal structures. The definition of bruxism itself has undergone multiple changes over time. In addition, the effects of bruxism as it relates to oro-facial pain conditions has remained a debatable topic.

PURPOSE

To review the available literature relating to bruxism and non-temporomandibular disorder (TMD) pain conditions.

METHODS

A literature search was conducted with the assistance of an expert librarian. The following databases were reviewed: PubMed, MEDLINE, EMBASE and Google Scholar. For additional references, articles were also retrieved by hand search from the selected papers. Any articles that were not published in English, or the focus were related to temporomandibular disorders were excluded.

CONCLUSIONS

While bruxism and certain headache conditions do tend to occur together frequently, evidence relating to any clear common pathophysiological mechanism has yet to be fully elucidated. Robust evidence as it relates to the relationship between bruxism and other non-TMD oro-facial pains is also lacking.

Do Patients with Chronic Spinal Pain and Comorbid Insomnia Have More Features of Central Sensitization? A Case-Control Study

BACKGROUND

Chronic spinal pain (CSP) is a major public health problem worldwide, frequently related to sleep problems. Central sensitization (CS) may worsen the clinical picture of CSP patients with insomnia. The aim of this study was to compare self-reported and objectively measured clinical outcomes between insomniac CSP patients with comorbid insomnia with and without symptoms of CS.

METHODS

A case-control study on baseline self-reported sleep, functioning, and psychological distress through online questionnaires. Objective sleep and physical activity parameters and pressure pain thresholds (PPTs) were assessed through polysomnography, actigraphy, and digital algometry, respectively. Independent sample t-test and Mann-Whitney U tests were used to examine possible differences in the outcome measures between the groups.

RESULTS

Data from 123 participants were included and revealed no statistically significant group for objective sleep and physical activity parameters. The CS group, however, presented with worse self-reported sleep (quality sleep, insomnia severity, and dysfunctional beliefs about sleep), increased mental and physical fatigue, and higher psychological distress (anxiety and depressive symptoms), and reported lower PPTs.

CONCLUSIONS

symptoms of CS may influence perceived sleep and affect functional health and well-being perception but do not seem to affect objective sleep and physical activity.

Sleep-EEG in comorbid pain and insomnia: implications for the treatment of pain disorders

Introduction

Patients with chronic pain experience a high prevalence of comorbid insomnia, which is associated with functional impairment. Recent advances in sleep electroencephalography (sleep-EEG) may clarify the mechanisms that link sleep and chronic pain. In this clinical update, we outline current advancements in sleep-EEG assessments for pain and provide research recommendations.

Results

Promising preliminary work suggests that sleep-EEG spectral bands, particularly beta, gamma, alpha, and delta power, may create candidate neurophysiological signatures of pain, and macro-architectural parameters (e.g., total sleep time, arousals, and sleep continuity) may facilitate EEG-derived sleep phenotyping and may enable future stratification in the treatment of pain.

Conclusion

Integration of measures obtained through sleep-EEG represent feasible and scalable approaches that could be adopted in the future. We provide research recommendations to progress the field towards a deeper understanding of their utility and potential future applications in clinical practice.

Mapping the associations of daily pain, sleep, and psychological distress in a U.S. sample

Chronic pain, sleep problems, and psychological distress (PD) can be disabling conditions and previous research has shown that they are associated. The nuances of the comorbid nature of these conditions may be important to understand for those who treat these conditions. This study examined the bidirectional associations of these health factors concurrently and over time in a sample of U.S. adults (N = 1,008, Mage = 57.68) from the Midlife in the United States (MIDUS) study. Participants reported on their daily pain, sleep quantity, and psychological distress over eight days. A modified Random Intercept Cross-lagged Panel Model was used to analyze the relations, starting with the whole sample and then a comparison of those with and without chronic pain. Results indicated that nightly variation in sleep quantity predicted next day psychological distress for both groups. Sleep quantity also predicted next-day pain, but only for individuals with chronic pain. Associations between pain and psychological distress were found both at the daily level and individual (between-person) level. This between-person association was stronger for those with chronic pain. The lagged associations between sleep, and both pain and psychological distress for the chronic pain group indicate that, increased quantity of sleep predicts decreased next-day pain and psychological distress. Providers could consider this unidirectional lagged relationship when prioritizing treatment for patients with these comorbid conditions. Future research may examine whether responsive, just-in-time treatments might intervene after participants wake from a poor night's sleep to counteract the negative effects of reduced sleep on PD and pain.

Sleep During Menopause

Postmenopause is defined retrospectively after 12 consecutive months of amenorrhea. It represents the end of the reproductive period and ovarian failure. A decrease in estrogen leads to several changes in the short and long term. Among the early changes, vasomotor symptoms (hot flashes) are particularly common, occurring in about 70% of women. In addition, there are changes in mood, anxiety, depression, and insomnia. Insomnia occurs in almost 60% of postmenopausal women. Psychosocial aspects may also affect sleep. Proper diagnosis may lead to adequate treatment of sleep disturbances during menopause. Hormonal or other complementary therapies can improve sleep quality.

Sleep characteristics and pain in middle-aged and older adults: Sex-specific impact of physical and sitting activity

OBJECTIVES

The relationship between poor sleep health and worse pain is established. Physical activity has been successful in reducing chronic pain and improving sleep in aging adults. Despite known sex differences (more women than men experiencing chronic pain and insomnia), sex-specific patterns of interactive associations between physical activity, sleep, and pain remain unexplored. This study tested whether physical and sitting activity moderated associations between sleep characteristics and pain intensity, and whether sex further moderated these relationships.

METHODS

Participants aged 50+ (N = 170, Mage = 64.34, 72 women) completed an online survey measuring pre-sleep arousal (Pre-sleep Arousal Scale), sleep (Pittsburgh Sleep Quality Index), past month average pain intensity, and physical activity (International Physical Activity Questionnaire). Multiple regressions evaluated whether minutes of physical activity (total, vigorous, moderate, walking) or sitting activity, pre-sleep arousal, sleep, sex, or their interaction was associated with pain. Analyses controlled for education, difficulty walking, body mass index, total medical conditions, pain medication, and depressive/anxiety symptoms.

RESULTS

In women, vigorous activity interacted with total pre-sleep arousal and somatic pre-sleep arousal in its association with pain. Higher total arousal and somatic arousal were associated with worse pain intensity only for women who reported highest levels of vigorous activity. No such associations were observed for men or for other physical or sitting activity levels.

CONCLUSIONS

Vigorous physical activity may exacerbate the association between more pre-sleep arousal and worse pain in middle-aged and older women. Research should explore potential sex-specific mechanisms (e.g., inflammatory cytokines, arousal neural networks) underlying these results.

The endocannabinoid N-arachidonoyl dopamine is critical for hyperalgesia induced by chronic sleep disruption

Chronic pain is highly prevalent and is linked to a broad range of comorbidities, including sleep disorders. Epidemiological and clinical evidence suggests that chronic sleep disruption (CSD) leads to heightened pain sensitivity, referred to as CSD-induced hyperalgesia. However, the underlying mechanisms are unclear. The thalamic reticular nucleus (TRN) has unique integrative functions in sensory processing, attention/arousal and sleep spindle generation. We report that the TRN played an important role in CSD-induced hyperalgesia in mice, through its projections to the ventroposterior region of the thalamus. Metabolomics revealed that the level of N-arachidonoyl dopamine (NADA), an endocannabinoid, was decreased in the TRN after CSD. Using a recently developed CB1 receptor (cannabinoid receptor 1) activity sensor with spatiotemporal resolution, CB1 receptor activity in the TRN was found to be decreased after CSD. Moreover, CSD-induced hyperalgesia was attenuated by local NADA administration to the TRN. Taken together, these results suggest that TRN NADA signaling is critical for CSD-induced hyperalgesia.

The effectiveness of exercise and physical activity programs on fatigue and sleep in people with arthritis - A systematic review with meta-analysis

This systematic review aimed to systematically investigate the literature on the effectiveness of exercise and physical activity programs on fatigue and sleep in people with arthritis. For that, seven databases were searched for relevant randomized controlled trials. After the searches, 36 studies investigating 2281 participants were included. Risk of bias assessments were done by two independent reviewers using the Cochrane Risk of Bias tool 2. Random-effects meta-analyses were performed, and the Grading of Recommendations Assessment, Development and Evaluation framework was used to judge the certainty of evidence. The evidence on benefits of exercise and physical activity programs on fatigue and sleep parameters in people with osteoarthritis and psoriatic arthritis was either lacking or inconclusive. There was very low to low certainty evidence for a slight benefit of exercise and physical activity programs on fatigue at short-term in people with ankylosing spondylitis and rheumatoid arthritis. However, the evidence was very uncertain for the medium- and long-term as well as for any sleep parameters. The results indicate that exercise and physical activity programs may offer some benefits on fatigue for people with arthritis in the short-term, although the best type of exercise remains uncertain. The available evidence on improvements in sleep was insufficient to draw strong conclusions.

Catastrophizing and acceptance are mediators between insomnia and pain intensity-an SQRP study of more than 6,400 patients with non-malignant chronic pain conditions

Background

Sleep problems (insomnia) and chronic pain are associated. Chronic pain and insomnia/insufficient sleep quality share similar symptoms and features. Although they have a bidirectional relationship, more research is needed to understand how they interact via mediators and how moderators influence this relationship.

Aims

In this large clinical registry-based cohort study (N = 6,497), we investigate important mediators between insomnia and pain intensity in a cross-sectional sample of chronic pain patients using advanced path analysis. In addition, we investigate whether some background variables were moderators of the identified important paths or not and the correlation patterns between insomnia and pain intensity in relation to the mediators.

Methods

This study includes a cohort of adult patients with chronic non-cancer pain from the Swedish Quality Registry for Pain Rehabilitation (SQRP) with data on patient-reported outcome measures (PROMs) (2008-2016). The PROMs cover the background, pain aspects, psychological distress, pain-related cognitions, activity/participation, and health-related quality of life variables of the patients. Partial least squares structural equation modeling was used to explore the direct and indirect (via mediators) relationships between insomnia and pain intensity at baseline.

Results

In this cohort study, insomnia was prevalent at 62.3%, and both direct and indirect mediating paths were present for the insomnia-pain intensity relationship. All of the mediating effects combined were weaker than the direct effect between insomnia and pain intensity. The mediating effects via catastrophizing and acceptance showed the strongest and equal mediating paths, and mediating effects via fear avoidance were the second strongest. Insomnia showed stronger direct significant correlations with psychological distress, catastrophizing, and acceptance compared with those of pain intensity. Sex, age, education level, spatial extent of pain, or body mass index did not moderate the mediating paths.

Discussion and conclusion

This study confirms the existence of significant direct and mediating paths between reported insomnia and pain intensity. Future studies should focus on illuminating how sleep interventions influence pain intensity and other important key factors that contribute to the distress of chronic pain patients.

Emotional Dynamics in Fibromyalgia: Pain, Fatigue, and Stress Moderate Momentary Associations Between Positive and Negative Emotions

Affective disruptions, particularly deficits in positive affect, are characteristic of fibromyalgia (FM). The Dynamic Model of Affect provides some explanations of affective disruptions in FM, suggesting that the inverse association between positive and negative emotions is stronger when individuals with FM are under greater stress than usual. However, our understanding of the types of stressors and negative emotions that contribute to these affective dynamics is limited. Using ecological momentary assessment (EMA) methods, 50 adults who met the FM survey diagnostic criteria rated their momentary pain, stress, fatigue, negative emotions (depression, anger, and anxiety), and positive emotions 5X/day for eight days using a smartphone application. Results of multilevel modeling indicate that, consistent with the Dynamic Model of Affect, there was a stronger inverse association between positive emotion and negative emotions during times of greater pain, stress, and fatigue. Importantly, this pattern was specific to depression and anger, and was not present for anxiety. These findings suggest that fluctuations in fatigue and stress may be just as important or more important than fluctuations in pain when understanding the emotional dynamics in FM. In addition, having a more nuanced understanding of the role that different negative emotions play may be similarly important to understanding emotional dynamics in FM. PERSPECTIVE: This article presents new findings on the emotional dynamics in FM during times of increased pain, fatigue, and stress. Findings highlight the need for clinicians to conduct a comprehensive evaluation of fatigue, stress, and anger in addition to more routinely assessed depression and pain when working with individuals with FM.

Effects of different transcranial magnetic stimulations on neuropathic pain after spinal cord injury

Introduction

Repetitive transcranial magnetic stimulation (rTMS) is an effective non-invasive cortical stimulation technique in the treatment of neuropathic pain. As a new rTMS technique, intermittent theta burst stimulation (iTBS) is also effective at relieving pain. We aimed to establish the pain-relieving effectiveness of different modalities on neuropathic pain. The study was conducted in individuals with spinal cord injury (SCI) and different modalities of rTMS.

Methods

Thirty-seven individuals with SCI were randomly allocated to three groups, in which the "iTBS" group received iTBS, the "rTMS" group received 10 Hz rTMS, and the "iTBS + rTMS" group received iTBS and 10 Hz rTMS successively of the primary motor cortex 5 days a week for 4 weeks, and they all underwent the full procedures. The primary outcome measure was change in the visual analog scale (VAS), and the secondary outcomes were measured using the Hamilton Rating Scale for Depression (HAM-D) and the Pittsburgh Sleep Quality Index (PSQI). All the outcomes were evaluated at 1 day before stimulation (baseline), 1 day after the first week of stimulation (S1), and 1 day after the last stimulation (S2).

Results

The VAS scores showed significant pain improvement after 4 weeks of stimulation (p = 0.0396, p = 0.0396, and p = 0.0309, respectively) but not after 1 week of stimulation. HAM-D scores declined, but the decreases were not significant until 4 weeks later (p = 0.0444, p = 0.0315, and p = 0.0447, respectively). PSQI scores were also significantly decreased after 4 weeks of stimulation (p = 0.0446, p = 0.0244, and p = 0.0088, respectively). Comparing the three modalities, VAS, HAM-D, and PSQI scores at S1 showed no differences, and, at S2, VAS scores showed significant differences (p = 0.0120; multiple comparisons showed significant differences between iTBS and iTBS + rTMS, p = 0.0091), while the HAM-D and PSQI scores showed no differences.

Discussion

The primary and secondary outcomes all showed significant improvement, indicating that the three different modalities were all effective at relieving the pain. However, not all the three stimulations were of same effectiveness after treatment; there were statistical differences in the treatment of neuropathic pain between iTBS as a priming stimulus and as a single procedure.

A two-branch trade-off neural network for balanced scoring sleep stages on multiple cohorts

Introduction

Automatic sleep staging is a classification process with severe class imbalance and suffers from instability of scoring stage N1. Decreased accuracy in classifying stage N1 significantly impacts the staging of individuals with sleep disorders. We aim to achieve automatic sleep staging with expert-level performance in both N1 stage and overall scoring.

Methods

A neural network model combines an attention-based convolutional neural network and a classifier with two branches is developed. A transitive training strategy is employed to balance universal feature learning and contextual referencing. Parameter optimization and benchmark comparisons are conducted using a large-scale dataset, followed by evaluation on seven datasets in five cohorts.

Results

The proposed model achieves an accuracy of 88.16%, Cohen's kappa of 0.836, and MF1 score of 0.818 on the SHHS1 test set, also with comparable performance to human scorers in scoring stage N1. Incorporating multiple cohort data improves its performance. Notably, the model maintains high performance when applied to unseen datasets and patients with neurological or psychiatric disorders.

Discussion

The proposed algorithm demonstrates strong performance and generalizablility, and its direct transferability is noteworthy among similar studies on automated sleep staging. It is publicly available, which is conducive to expanding access to sleep-related analysis, especially those associated with neurological or psychiatric disorders.

Supporting Machine Learning Model in the Treatment of Chronic Pain

Conventional therapy options for chronic pain are still insufficient and patients most frequently request alternative medical treatments, such as medical cannabis. Although clinical evidence supports the use of cannabis for pain, very little is known about the efficacy, dosage, administration methods, or side effects of widely used and accessible cannabis products. A possible solution could be given by pharmacogenetics, with the identification of several polymorphic genes that may play a role in the pharmacodynamics and pharmacokinetics of cannabis. Based on these findings, data from patients treated with cannabis and genotyped for several candidate polymorphic genes (single-nucleotide polymorphism: SNP) were collected, integrated, and analyzed through a machine learning (ML) model to demonstrate that the reduction in pain intensity is closely related to gene polymorphisms. Starting from the patient's data collected, the method supports the therapeutic process, avoiding ineffective results or the occurrence of side effects. Our findings suggest that ML prediction has the potential to positively influence clinical pharmacogenomics and facilitate the translation of a patient's genomic profile into useful therapeutic knowledge.

Alterations of pain pathways by experimental sleep disturbances in humans: central pain-inhibitory, cyclooxygenase, and endocannabinoid pathways

STUDY OBJECTIVES

There is strong evidence that sleep disturbances are an independent risk factor for the development of chronic pain conditions. The mechanisms underlying this association, however, are still not well understood. We examined the effect of experimental sleep disturbances (ESDs) on three pathways involved in pain initiation/resolution: (1) the central pain-inhibitory pathway, (2) the cyclooxygenase (COX) pathway, and (3) the endocannabinoid (eCB) pathway.

METHODS

Twenty-four healthy participants (50% females) underwent two 19-day long in-laboratory protocols in randomized order: (1) an ESD protocol consisting of repeated nights of short and disrupted sleep with intermittent recovery sleep; and (2) a sleep control protocol consisting of nights with an 8-hour sleep opportunity. Pain inhibition (conditioned pain modulation, habituation to repeated pain), COX-2 expression at monocyte level (lipopolysaccharide [LPS]-stimulated and spontaneous), and eCBs (arachidonoylethanolamine, 2-arachidonoylglycerol, docosahexaenoylethanolamide [DHEA], eicosapentaenoylethanolamide, docosatetraenoylethanolamide) were measured every other day throughout the protocol.

RESULTS

The central pain-inhibitory pathway was compromised by sleep disturbances in females, but not in males (p < 0.05 condition × sex effect). The COX-2 pathway (LPS-stimulated) was activated by sleep disturbances (p < 0.05 condition effect), and this effect was exclusively driven by males (p < 0.05 condition × sex effect). With respect to the eCB pathway, DHEA was higher (p < 0.05 condition effect) in the sleep disturbance compared to the control condition, without sex-differential effects on any eCBs.

CONCLUSIONS

These findings suggest that central pain-inhibitory and COX mechanisms through which sleep disturbances may contribute to chronic pain risk are sex specific, implicating the need for sex-differential therapeutic targets to effectively reduce chronic pain associated with sleep disturbances in both sexes.

CLINICAL TRIALS REGISTRATION

NCT02484742: Pain Sensitization and Habituation in a Model of Experimentally-induced Insomnia Symptoms. https://clinicaltrials.gov/ct2/show/NCT02484742.

Sleep disorders in chronic pain and its neurochemical mechanisms: a narrative review

Chronic pain (CP) is a prevalent problem, and more than half of patients with CP have sleep disorders. CP comorbidity with sleep disorders imposes immense suffering and seriously affects the patient's quality of life, which is a challenging issue encountered by clinicians. Although the reciprocal interactions between pain and sleep have been studied to some degree, there is still a lack of awareness and comprehensive description of CP comorbidity with sleep disorders. In this narrative review article, we summarize the current knowledge about the present estimates of the prevalence of comorbid sleep disorders in CP patients, sleep detection methods, sleep characterization in CP, and the effect of sleep disorders on CP and current therapies. We also summarize current knowledge of the neurochemical mechanisms of CP comorbidity with sleep disorders. In conclusion, insufficient attention has been paid to the role of sleep disorders in CP patients, and CP patients should be screened for sleep disorders in the clinic. Special attention should be given to a possible risk of drug-drug interaction when using two types of drugs targeting pain and sleep simultaneously. The current insight into the neurobiological mechanisms underlying CP comorbidity with sleep disorders is still rather limited.

Chronic pain is common and worsens daytime sleepiness, insomnia, and quality of life in veterans with obstructive sleep apnea

STUDY OBJECTIVES

Chronic noncancer pain (CP) commonly co-occurs with obstructive sleep apnea (OSA) and may contribute to greater symptom burden. The study aims were to (1) characterize CP among veterans with OSA and (2) examine differences in sleepiness (Epworth Sleepiness Scale), insomnia symptoms (Insomnia Severity Index), and quality of life (Short Form Health Survey-20) in veterans with OSA with or without pre-existing CP.

METHODS

An observational, cross-sectional, study of 111 veterans with newly diagnosed, untreated OSA was conducted. Descriptive statistics characterized the sample and comorbid CP outcomes. Regression analyses were performed to investigate associations between self-reported CP and sleep-related symptoms or quality of life while controlling for potential confounders.

RESULTS

CP was reported by 69.5% (95% confidence interval: 61.8%, 76.2%) of participants. Having CP was associated with increased Epworth Sleepiness Scale (12.7 ± 5.5 vs 10.2 ± 5.2; P = .021) and Insomnia Severity Index scores (18.1 ± 6.2 vs 13.7 ± 7.4; P = .002), and worse quality of life across all Short Form Health Survey-20 domains.

CONCLUSIONS

There is a high prevalence of CP among veterans with OSA and symptom burden is higher in patients with OSA and CP. Future investigations should address symptom response and burden to OSA treatment in comorbid OSA and CP to guide outcome expectancies and residual OSA symptom treatment plans.

CITATION

Saconi B, Kuna ST, Polomano RC, Compton PA, Keenan BT, Sawyer AM. Chronic pain is common and worsens daytime sleepiness, insomnia, and quality of life in veterans with obstructive sleep apnea. J Clin Sleep Med. 2023;19(6):1121-1132.

Time Management Behavior Structural Equation Model Predicts Global Sleep Quality in Traditional Entry University Students

Background

Poor sleep is commonplace among traditional entry university students. Lifestyle modifications, such as time management behaviors, may improve sleep quality by allocating sufficient time for sleep and mitigating stress-associated sleep latency inefficiencies.

Purpose

The purpose of our study was to evaluate time management behaviors as predictors of sleep quality in traditional entry university students. We hypothesized time management behaviors would predict perceived control of time, which in turn, would predict global sleep quality.

Methods

A cross-sectional convenience sample of university students (n=302) completed a 73-item instrument comprised of the Pittsburgh Sleep Quality Index and the Time Management Behavior scale. Model building procedures included exploratory factor analysis, confirmatory factor analysis, and structural equation modeling.

Results

Our specified model identified significant paths between setting goals and priorities (β= .261; p=.012), mechanics of time management (β=.210; p=.043) and preference for organization (β=.532; p<.001) for perceived control of time (R2=.300 p<.001). We further identified a significant path between perceived control of time and global sleep quality (R2=.196, p=.022).

Discussion

Our study suggests time management behaviors are associated with global sleep quality.

Translation to Health Education Practice

Health education interventions addressing sleep quality of traditional entry university students should consider incorporating time management behaviors.

The interplay between symptoms of insomnia and pain in people with osteoarthritis: A narrative review of the current evidence

Osteoarthritis (OA) is a leading cause of disability worldwide and clinical pain is the major symptom of OA. This clinical OA-related pain is firmly associated with symptoms of insomnia, which are reported in up to 81% of people with OA. Since understanding the association between both symptoms is critical for their appropriate management, this narrative review synthesizes the existing evidence in people with OA on i) the mechanisms underlying the association between insomnia symptoms and clinical OA-related pain, and ii) the effectiveness of conservative non-pharmacological treatments on insomnia symptoms and clinical OA-related pain. The evidence available identifies depressive symptoms, pain catastrophizing and pain self-efficacy as mechanisms partially explaining the cross-sectional association between insomnia symptoms and pain in people with OA. Furthermore, in comparison to treatments without a specific insomnia intervention, the ones including an insomnia intervention appear more effective for improving insomnia symptoms, but not for reducing clinical OA-related pain. However, at a within-person level, treatment-related positive effects on insomnia symptoms are associated with a long-term pain reduction. Future longitudinal prospective studies offering fundamental insights into neurobiological and psychosocial mechanisms explaining the association between insomnia symptoms and clinical OA-related pain will enable the development of effective treatments targeting both symptoms.

The relationship between pain intensity and insomnia in women with deep endometriosis, a cross-sectional study

PURPOSE

To investigate the relationship between pain intensity and insomnia frequency in women with a diagnosis of deep endometriosis. The hypothesis is that these patients with moderate or severe pain have a higher frequency of insomnia than those with mild or no pain.

METHODS

We conducted a cross-sectional study of women with deep endometriosis categorized by pelvic pain intensity based on a numerical scale. Insomnia was assessed through a self-reported questionnaire, and multiple logistic regression was used to control for confounders between pain and insomnia.

RESULTS

We included 234 women in the study, 39 (17%) without pelvic pain; 66 (29%) with mild pain; 53 (23%) moderate pain; and 76 (32%) severe pain. Twenty-nine (74%) pain-free women and 50 (75%) with mild pain had no insomnia; only 3 (8%) of the former and 3 (4%) of the latter group had severe insomnia. However, twenty-nine (55%) women with moderate pain and 37 (48%) with severe pain had insomnia. The logistic regression model showed that moderate to severe pain increased insomnia 2.8 times, twice for every 10 years of pain duration, and twice in women with low education levels.

CONCLUSIONS

Women with moderate or severe pain had a high frequency of insomnia, increasing management complexity in patients with deep endometriosis. Pain intensity, pain duration, and low education level increased the chance of insomnia in those patients.

Sleep quality and polysomnographic changes in patients with chronic pain with and without central sensitization signs

BACKGROUND

Insufficient sleep is common nowadays and it can be associated with chronic pain.

OBJECTIVE

To describe the main polysomnographic findings in patients with chronic musculoskeletal pain and to estimate the association between sleep quality, polysomnography variables and chronic musculoskeletal pain.

METHODS

This cross-sectional research analyzed a database from polysomnography type 1 exams results and then collected data via an electronic form from these patients. The form collected sociodemographic data and presented clinical questionnaires for measuring sleep quality, sleepiness, pain intensity and central sensitization signs. Pearson's correlation coefficient and odds ratio were used to estimate the associations.

RESULTS

The mean age of the respondents was 55.1 (SD 13.4) years. The mean score of the Central Sensitization Inventory showed signs of central sensitization (50.1; SD 13.4) in the participants. Most patients (86%) had 1 or more nocturnal awakenings, 90% had one or more episodes of sleep apnea, 47% had Rapid Eye Movement sleep phase latency greater than 70-120 min and the mean sleep efficiency among all participants was 81.6%. The Pittsburgh Sleep Quality Index score was correlated with the CSI score (r = 0.55; 95% CI: 0.45, 0.61). People with central sensitization signs have 2.6 times more chance to present sleep episodes of blood oxygen saturation below 90% (OR = 2.62; 95% CI:1.23, 6.47).

CONCLUSION

Most people with central sensitization signs had poor sleep quality, night waking episodes and specific disturbances in sleep phases. The findings showed association between central sensitization, sleep quality, nocturnal awakening, and changes in blood oxygen saturation during sleep.

Does poor sleep quality lead to increased low back pain the following day?

OBJECTIVES

This study explored the relationship between sleep quality and next-day pain intensity for people with low back pain and investigated whether there was any evidence that this relationship was causal.

METHODS

We conducted a secondary analysis of an observational study that investigated sleep quality in people with low back pain. People with low back pain were recruited from primary care and the community. Sleep quality was measured with subjective (self-report) and objective (polysomnography (PSG)) measures. PSG analysis classifies sleep into stages, of which slow-wave sleep (SWS) is thought to have a key role in maintaining or increasing pain intensity. We drew directed acyclic graphs to identify possible confounders of the relationship between both measures of sleep quality, and pain intensity. We constructed two linear regression models to explore the effect of subjective and objective sleep quality on next-day pain intensity before and after confounder adjustment.

RESULTS

Thirty-nine participants were included in the study. For participants with low back pain, self-reported better quality sleep β=-0.38 (95% CI -0.63 to -0.13), or spending a greater proportion of time in SWS β=-0.12 (95% CI -0.22 to -0.02) was associated with lower next day pain intensity. After confounder adjustment, the effect reduced and was no longer significant for either self-reported β=-0.18 (95% CI -0.46 to 0.10), or SWS β=-0.08 (95% CI -0.18 to 0.03).

CONCLUSIONS

Sleep quality, whether measured by self-report or proportion of time in SWS, was associated with next day pain intensity for people with low back pain. However, this relationship is likely to be confounded and therefore not likely to be causal.

The impact of the COVID-19 pandemic on orofacial pain practice: Perceptions from a convenience sample of orofacial pain practitioners

BACKGROUND

COVID-19 has had a substantial impact on people's lives. Increasing evidence indicates that patients with chronic pain particularly are being affected; however, few articles have examined how the pandemic has affected the care or clinical presentation of patients with orofacial pain. The aim of this study was to describe COVID-19-related changes in referral patterns and numbers, in patient demographics, in patients' seeking treatment for problems, and in administrative procedures in 3 orofacial pain clinical settings.

METHODS

Practitioners participating in the American Academy of Orofacial Pain webinar titled "Practicing Orofacial Pain, Headache, and Sleep Care During the COVID-19 Pandemic" completed a voluntary anonymous online survey. Survey respondents completed general questions related to their orofacial pain practices and about perceptions of their patients' symptoms. For statistical analysis, the authors calculated frequencies and used analysis of variance for continuous variables or Likert scale variables and the χ² test for dichotomous or categorical variables. Statistical significance was set at P value of .05 or below.

RESULTS

Practitioners noted an increase in new patients with orofacial pain. Of the participants, 33% indicated the onset of their patients' pain was often or extremely often related to COVID-19. The 5 most common symptoms that providers felt were aggravated in their patients were masticatory muscle myalgia, anxiety, tension-type headache, bruxism, and insomnia or fragmented sleep.

CONCLUSION

The COVID-19 pandemic has resulted in a marked increase in the number of patients seeking consultation for orofacial pain and associated symptoms.

PRACTICAL IMPLICATIONS

Because of the COVID-19 pandemic, orofacial pain practitioners have noticed an increase in orofacial pain symptoms across practice settings.

Pain interferes with daily activities, emotions and sleep in adults with severe, moderate and mild haemophilia: A national cross-sectional survey

INTRODUCTION

Pain is a major issue in people with haemophilia (PwH). Few studies comprehensively assessed pain in PwH using a biopsychosocial framework and studies in mild PwH are lacking.

AIM

To assess pain prevalence, pain interference and their relationship with health-related quality of life (HR-QoL) in male adults with haemophilia.

METHODS

A survey was initiated by the Belgian national member organisation. Pain in the last 24 h, pain severity (BPI-PS) and pain interference (BPI-PI) scores were obtained with the Brief Pain Inventory short-form (BPI). HR-QoL was evaluated with the EQ-5D-3L, giving the health utility index (EQ-HUI). Associations between EQ-HUI, BPI-PS and BPI-PI were analysed using Pearson's correlation test. A multiple regression analysed the relationship between HR-QoL and BPI-PS, with age and haemophilia severity as confounding factors.

RESULTS

Within 185 respondents (97, 31 and 57 respectively severe, moderate and mild PwH), 67% (118/177) reported pain. In severe, moderate and mild PwH, respectively 86% (79/92), 71% (22/31) and 32% (17/54) reported pain. Median [IQR] BPI-PS, BPI-PI and EQ-HUI scores were respectively 1.5 [.0; 4.0], 1.6 [.0; 3.6] and .81 [.69; 1.00]. PwH reported pain interference with general activity (56% (99/176)), psychosocial factors such as mood (53% (93/175)), and sleep (51% (90/177)). Moderate correlations were found between EQ-HUI, BPI-PS and BPI-PI. After adjusting for age and haemophilia severity, BPI-PS explained 14% of HR-QoL variance.

CONCLUSIONS

Pain is a major issue amongst PwH, including people with mild haemophilia. Pain interferes with activities, emotions, sleep and HR-QoL, arguing for a comprehensive biopsychosocial approach of pain.

Association between night pain and quality of life in women: A general population sleep study

BACKGROUND

Women with pain present decreased sleep duration and quality of life, but little is known about the consequences of nighttime pain on overall health. Our goal was to compare levels of anxiety, depression and fatigue in women with pain during the night with those without pain. We hypothesized that pain perception is associated with the worsening of fatigue and mood.

METHODS

In total, 244 women aged 20-80 years who took part in the Epidemiologic Sleep Study (EPISONO) met the inclusion criteria, 85 in the self-reported pain group and 171 in the control group. Participants were assigned to the pain group if they both responded (i) they generally had pain, according to Pre-Sleep Questionnaire (PSQ) and (ii) their pain generally interfered with their sleep 3 or more times a week, according to Pittsburg Sleep Quality Index (PSQI). Those who answered negatively to both questions were allocated to the control group. All participants underwent a full night laboratory polysomnography, and completed questionnaires related to fatigue, depression, anxiety and quality of life.

RESULTS

Pain group participants had a significantly lower perception of quality of life, and significantly higher levels of fatigue (5.4 times), anxiety and depression. Pain perception was also correlated to levels of anxiety and depression in the psychological (r_s  = -0.463, -0.607, respectively) and social (r_s  = -0.423, -0.438, respectively) quality of life domains.

CONCLUSIONS

Nighttime pain in women was associated with decreased quality of life, worsening mood and fatigue. Our data shows the importance of investigating pain and its deleterious effects on women's health.

SIGNIFICANCE

Our study highlights that women experiencing nighttime pain also reported worse mood outcomes and decreased quality of life, regardless of the level and type of pain. Our data, based on association analysis and not investigating causality, suggest it is important to consider nighttime pain in clinical care to improve quality of life and general health.