The association of sleep and pain: an update and a path forward

The effect of rotator cuff repair on sleep quality: Influencing factors and the impact of narcotic medication on postoperative sleep patterns: A systematic review and meta-analysis

Background

Impaired sleep quality often drives patients with rotator cuff tears (RCT) to seek surgical intervention. This meta-analysis reviews the impact of arthroscopic rotator cuff repair (ARCR) on sleep quality beyond six months and identifies influencing factors, primarily narcotics, on sleep quality.

Methods

The search spanned PubMed, Google Scholar, Embase, and the Cochrane Central Register, targeting articles evaluating rotator cuff injury and sleep quality. Information gathered included study features, bias risk assessment, evaluation of sleep quality using sleep-specific patient-reported outcomes, and the effects of opiates on sleep outcomes.

Results

Ten studies, including 445 patients who underwent ARCR were included. The preoperative mean Pittsburgh Sleep Quality Index (PSQI) varied from 6.6 to 15. Eight studies presented a mean PSQI score of 3.6-7.1 at 6 months postoperatively; two studies reported mean score of 4.2 and 5.4 at 12 months. Both were found to be statistically significant by this meta-analysis compared to preoperative scores. Three studies found narcotic use, RCT size, alcohol consumption, diabetes, and hypertension to negatively affect PSQI scores.

Discussion

Arthroscopic rotator cuff repair significantly improves sleep quality at 6 and 12 months following surgery. Perioperative narcotic use, RCT size, alcohol consumption, diabetes, and hypertension may negatively impact sleep quality.

Bidirectional links between sleep and pain among heavy-drinking veterans with insomnia

Study Objectives

Military veterans often suffer from chronic pain and sleep issues at a greater frequency than the general population, leading some to self-medicate with alcohol. While research shows a connection between sleep and pain, few studies have examined bidirectional links between sleep and pain at the daily level-or the extent to which alcohol use may moderate these associations.

Methods

Heavy-drinking veterans seeking treatment for insomnia (N = 109, 82.5% male, mean age 38.9 years) completed 14 days of morning diaries documenting sleep patterns, pain intensity, and alcohol consumption. Multilevel modeling examined within- and between-person associations between sleep (quality, duration, and efficiency) and next-day pain as well as pain and same-night sleep.

Results

Individuals with longer sleep duration, better sleep quality, and higher sleep efficiency (SE) reported lower pain levels compared to those with shorter sleep, poorer sleep quality, and lower SE (p values <.001 to .01). In addition, on days when individuals experienced better sleep quality compared to their own average, they reported lower pain levels the following day (p = .01). In contrast to hypotheses, daily pain levels did not predict sleep outcomes at the daily within-person level, although significant between-person correlations were noted. Daily alcohol intake did not affect these relationships.

Conclusions

Sleep quality is associated with the daily experience of pain among heavy-drinking veterans with insomnia. Daily variations in sleep quality significantly impact pain, irrespective of alcohol consumption, highlighting a predominantly unidirectional influence from sleep to pain. These findings underscore the importance of optimizing sleep to mitigate pain in this population.

Intraoperative Sleep Spindle Activity and Postoperative Sleep Disturbance in Elderly Patients Undergoing Orthopedic Surgery: A Prospective Cohort Study

Purpose

This study aimed to investigate the relationship between intraoperative sleep spindle activity and postoperative sleep disturbance (PSD) in elderly orthopedic surgery patients.

Patients and Methods

In this prospective observational cohort study, we collected intraoperative electroencephalography (EEG) data from 212 elderly patients undergoing orthopedic surgery from May 2023 to December 2023. We used the Athens Insomnia Scale to assess sleep quality on postoperative day (POD) 1 and POD 3 and analyzed the correlation between intraoperative sleep spindle activity and PSD through logistic regression.

Results

The incidence of PSD was 65.6% on POD 1 and 41.9% on POD 3. On the first day, there were no significant differences in intraoperative sleep spindle characteristics between PSD and non-postoperative sleep disturbance (non-PSD) patients. However, by the third day, PSD patients showed lower sigma power compared to non-PSD patients, as well as lower spindle density in the bilateral frontopolar (Fp1/Fp2) and bilateral temporal (F7/F8) channels, with shorter average spindle duration (P < 0.05). Multivariate logistic regression analysis suggested that the average spindle density in F7/F8 channels (OR 0.543, 95% CI 0.375-0.786; P = 0.001) was an independent risk factor for PSD on POD 3. Furthermore, Mini-Mental State Examination (MMSE) could independently predict PSD on POD 1 (OR 0.806, 95% CI 0.656-0.991; P = 0.041) and POD 3 (OR 0.701, 95% CI 0.562-0.875; P = 0.002). Pain on movement and at rest were independently associated with PSD on POD 1 (OR 1.480, 95% CI 1.200-1.824; P < 0.001) and POD 3 (OR 1.848, 95% CI 1.166-2.927; P = 0.009), respectively.

Conclusion

Intraoperative mean spindle density in the F7/F8 channels was an independent risk factor for PSD on POD 3 in elderly patients undergoing orthopedic surgery. MMSE and postoperative pain also independently increased the risk of PSD.

Poor sleep quality among bedtime smartphone user medical students in Ethiopia, 2024

BACKGROUND

Smartphone use has become widespread and continues to grow rapidly. Medical students, already highly susceptible to sleep deprivation, may experience exacerbated issues due to smartphone usage, particularly at bedtime. Therefore, understanding the potential negative impacts of this behavior is crucial. This study aims to assess the prevalence and risk factors of sleep quality among medical students bed time smart phone users in Ethiopia.

SUBJECT AND METHODS

An institutional-based cross-sectional study design was employed, involving 354 undergraduate medical students selected through simple random sampling from Debre Marko's University, the University of Gondar, and Debre Berhan University. Data were collected using the Pittsburgh Sleep Quality Index and structured interviews. Variables with a p-value of ≤0.2 in bivariable regression were included in multivariable logistic regression. Crude odds ratios and adjusted odds ratios were calculated, while chi-square tests were used to assess assumptions. In multivariable regression, variables with a p-value of ≤0.05 were deemed significant predictors at the 95 % confidence interval.

RESULT

The results showed that among bedtime smartphone users, 67.52 % had a poor sleep quality index greater than 5. Poor sleep quality was significantly linked to factors such as sex, regular coffee consumption, the purpose of smartphone use, phone position during use, the duration of smartphone use, and a history of disease. Social media usage was the most common activity, accounting for 41.60 % of smartphone use, followed by watching videos (21.65 %).

CONCLUSION

This study highlights the detrimental effects of bedtime smartphone use on sleep quality, which subsequently impacts mental. Given these findings, it is strongly recommended that medical students reduce their smartphone use before bedtime to improve their sleep quality.

Comparative analysis of chronic neuropathic pain and pain assessment in companion animals and humans

Chronic neuropathic pain is underdiagnosed in companion animals. This paper will review the definition of pain and how classification and grading of neuropathic pain can be applied from human to veterinary medicine to increase the recognition of and the confidence in a neuropathic pain diagnosis. The mechanisms of nociception and the pathophysiology of the sensory systems that underlie the transition to chronic pain are described. Potential future methods for diagnosis and treatment of neuropathic pain in veterinary medicine are considered, utilizing the theoretical framework of pain behavior from humans and rodents. By discussing the current state of pain diagnosis in companion animals and increasing the recognition of chronic neuropathic pain, the goal is to increase understanding of chronic neuropathic pain in daily clinical practice and to aid the development of methods to diagnose and treat neuropathic pain.

Relationship Between Sleep Disturbances and Chronic Pain: A Narrative Review

Sleep disturbances and chronic pain are prevalent and interrelated conditions that have significant impact on individuals' quality of life. Understanding the intricate dynamics between sleep and pain is crucial for developing effective treatments that enhance the well-being of affected individuals and reduce the economic burden of these debilitating conditions. This narrative review examines the complex relationship between sleep disturbances and chronic pain. We describe the prevalence and types of sleep disturbances and sleep disorders in chronic pain patients. Posteriorly, we critically review the clinical and experimental evidence, investigating the relationship between sleep disturbances and chronic pain, aiming to clarify the impact of chronic pain on sleep and, conversely, the impact of sleep disturbances on pain perception. In conclusion, the literature largely agrees on the existence of a bidirectional relationship between chronic pain and sleep disturbances, though the strength of each direction in this association remains uncertain. Current evidence suggests that sleep impairment more strongly predicts pain than pain does sleep impairment. Additionally, addressing sleep disturbances in chronic pain patients is crucial, as poor sleep has been linked to higher levels of disability, depression, and pain-related catastrophizing.

Modulating the Pronociceptive Effect of Sleep Deprivation: A Possible Role for Cholinergic Neurons in the Medial Habenula

Sleep deprivation has been shown to exacerbate pain sensitivity and may contribute to the onset of chronic pain, yet the precise neural mechanisms underlying this association remain elusive. In our study, we explored the contribution of cholinergic neurons within the medial habenula (MHb) to hyperalgesia induced by sleep deprivation in rats. Our findings indicate that the activity of MHb cholinergic neurons diminishes during sleep deprivation and that chemogenetic stimulation of these neurons can mitigate the results. Interestingly, we did not find a direct response of MHb cholinergic neurons to pain stimulation. Further investigation identified the interpeduncular nucleus (IPN) and the paraventricular nucleus of the thalamus (PVT) as key players in the pro-nociceptive effect of sleep deprivation. Stimulating the pathways connecting the MHb to the IPN and PVT alleviated the hyperalgesia. These results underscore the important role of MHb cholinergic neurons in modulating pain sensitivity linked to sleep deprivation, highlighting potential neural targets for mitigating sleep deprivation-induced hyperalgesia.

Associations Among Sleep, Pain, and Medications for Opioid Use Disorder: a Scoping Review

Purpose of Review

We present current evidence on the associations among sleep, pain, and medications for opioid use disorder (MOUD) among individuals with opioid use disorder (OUD).

Recent Findings

We searched MEDLINE, Embase, PsycInfo, Web of Science, and Cochrane Library from inception until September 2023 for original research studies examining sleep, pain, and MOUD. We identified 19 manuscripts (14 were cross-sectional studies, four were prospective cohort studies, and one was a randomized controlled trial). Measures of sleep and pain varied. Sleep disturbance and pain were highly prevalent and associated. However, the associations between MOUD treatment characteristics (e.g., initiation, type, dose, and prior MOUD) and a) sleep and b) pain were mixed or unclear. Limited sample sizes and covariates such as opioid use disorder severity sometimes complicated the examination or interpretation of these associations. Few studies examined possible mediators underlying these associations.

Summary

While sleep and pain were consistently associated, it is unclear whether sleep and pain are associated with MOUD treatment characteristics or other covariates such as opioid use disorder severity. Future research on the associations among sleep, pain, and MOUD among individuals with OUD should consider a) comparing different MOUD treatments including formulations and dose schedules, b) qualitative and mixed methods studies to assess patient and provider preferences for the treatment of sleep and pain in OUD treatment settings, c) longitudinal studies that employ reliable and valid measures with sufficiently powered sample sizes to examine mediation and moderation, and d) testing whether interventions addressing pain or sleep among patients receiving MOUD improve pain, sleep, and MOUD outcomes.

Association of 24-h movement behaviors during Covid-19 pandemic with spinal musculoskeletal disorders in undergraduate students: a cross-sectional study

Background and Aims

Musculoskeletal disorders (MSD) are an important health problem, and the Covid-19 pandemic affected several lifestyle and health aspects worldwide, including moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB) and sleep time, which compose the 24-h movement guidelines (24-hMG). It is unclear whether meeting 24-hMG during pandemic have been associated with MSD in adult population and this study aimed to analyze the association of meeting 24-hMG with spinal MSD in undergraduate students during Covid-19 pandemic.

Methods

A sample of 71 undergraduate students were assessed (24.0 ± 6.6 years, 52% of women). MVPA was assessed by accelerometer, while daily time of SB and sleep were assessed by questionnaires. Spinal MSD was assessed by the Nordic questionnaire. Logistic regression models analyzed the association of meeting 24-hMG (individually and combined) with MSD, independently of age, sex, and body mass index.

Results

Spinal MSD affected 78.9% of sample. Only 11.3% of sample fully met the 24-hMG. Participants who did not meet both MVPA and SB guidelines were more likely to have MSD in low back (OR:3.45, p = 0.049) and spine (OR:3.78, p = 0.048) even after multiple adjustment. Otherwise, not meeting SB guideline was inversely associated with upper back MSD (OR:0.22, p = 0.012).

Conclusion

Meeting 24-hMG during Covid-19 pandemic were differently associated with spinal MSD, where combination of MVPA and SB shows to be protective against MSD in low back and in spine. However, the determinants of association between meeting SB guideline and higher upper back MSD still needs to be investigated.

Electroacupuncture alleviates paradoxical sleep deprivation-induced postoperative hyperalgesia via a7nAChR mediated BDNF/TrkB-KCC2 signaling pathway in the spinal cord

Perioperative Paradoxical sleep deprivation (PSD) is associated with postoperative hyperalgesia. However, the clinical therapeutic strategies for PSD-induced postoperative hyperalgesia are limited. Electroacupuncture (EA) has been used for attenuating many types of pain, including neuropathic pain and inflammatory pain, but its effect on PSD-induced postoperative hyperalgesia is still unclear, and its analgesia mechanism should be further explored. In this study, we designed to investigate the possible mechanism of PSD-induced postoperative hyperalgesia and the effect of EA on PSD-induced postoperative hyperalgesia, and whether the mechanism is related to the BDNF/TrkB signaling pathway mediated by α7nAChR in the spinal cord. The paw withdrawal thermal latency (PWTL) and paw withdrawal mechanical threshold (PWMT) of rats were used to detect PSD-induced hyperalgesia. The expression of α7nAChR, BDNF, TrkB and KCC2 in the spinal cord were evaluated by Western blot and immunofluorescence. The results showed that preoperative 24 h PSD significantly decreased the PWTL and PWMT. The expression of α7nAChR and KCC2 significantly downregulated in the spinal cord of PSD-induced postoperative hyperalgesia rats, the opposite was observed for BDNF and TrkB expression. Moreover, intrathecal injection of alpha-bungarotoxin (α-BGT), a selective antagonist for α7nAChR, not only aggravated the pain hypersensitivity, but also demonstrated a further decrease of α7nAChR and KCC2 expression and a further increase of BDNF and TrkB expression. EA stimulation increased the PWTL and PWMT values of PSD-induced postoperative hyperalgesia rats, significantly upregulated α7nAChR and KCC2 expression, and significantly downregulated BDNF and TrkB expression. Moreover, intrathecal injection of α-BGT suppressed the analgesic effect of EA, inhibited the enhancement of α7nAChR and KCC2 expression and the reduction of BDNF and TrkB expression induced by EA. In conclusion, our study indicated that 24 h PSD can cause postoperative hyperalgesia, and the mechanism may be related to the disorder of α7nAChR mediated BDNF/TrkB-KCC2 signaling pathway. EA can alleviate postoperative hyperalgesia induced by PSD, which may be related to its effect in activating α7nAChR, inhibiting the expression of BDNF/TrkB, and up-regulating the expression of KCC2 in the spinal cord.

Sleep and circadian rhythm disturbances as risk and progression factors for multiple chronic overlapping pain conditions: a protocol for a longitudinal study

Introduction

Chronic overlapping pain conditions (COPCs), such as chronic low back pain (cLBP) and fibromyalgia, frequently cooccur and incur substantial healthcare costs. However, to date, much focus has been placed on individual anatomically based chronic pain conditions, whereas little is known about the mechanisms underlying progression to multiple (more than 1) COPCs. This study aims to address the gap by investigating the role of common and modifiable risk factors, specifically sleep and circadian rhythm disturbances, in the development of multiple COPCs.

Methods

The study will enroll 300 participants with cLBP, including 200 with cLBP only and 100 with cLBP plus other COPCs (ie, fibromyalgia, temporomandibular disorders, irritable bowel syndrome, and chronic headaches) and follow them up for 12 months. Sleep and circadian rhythms will be assessed using wireless sleep electroencephalography, 24-hour evaluation of the rhythm of urinary 6-sulfatoxymelatonin, actigraphy, and sleep diaries. Pain amplification using quantitative sensory testing, psychological distress using validated self-report measures, and the number of pain sites using a pain body map will also be assessed.

Perspectives

This research aims to (1) comprehensively characterize sleep/circadian disturbances in individuals with single and multiple COPCs using multimodal in-home assessments; (2) examine the associations between sleep/circadian disturbances, changes in pain amplification, and psychological distress; and (3) investigate the relationship among these factors and the progression in the number of pain sites, a proxy for multiple COPCs. The findings will provide insights into the mechanisms leading to multiple COPCs, potentially informing treatment and prevention strategies for these complex conditions.

A study on the effect of fibromyalgia severity on sleep quality using inflammatory markers

Fibromyalgia syndrome (FMS) is a widespread musculoskeletal pain, often accompanied by fatigue and sleep disturbances. Poor sleep exacerbates inflammation and pain, potentially increasing levels of inflammatory markers. This study explored the effect of FMS severity on CRP levels, sleep quality and pain intensity. 89 FMS individuals were explored for FMS severity, pain and sleep quality. CRP levels in blood and erythrocyte sedimentation rate (ESR) were measured to assess inflammation. An increase in FMS severity was associated with an increase in CRP and ESR levels, pain intensity and sleep disturbances. However, a positive correlation between CRP levels and sleep quality indicates that Poor sleep quality in FMS may contribute to elevated CRP levels. Addressing sleep quality may mitigate the severity of FMS and its associated symptoms.

Does sleep quality mediate the association between post-traumatic stress disorder symptom severity and pain interference in trauma-affected refugees?

Poor sleep quality is well recognised in both post-traumatic stress disorder (PTSD) and pain conditions. Comorbid chronic pain is prevalent in populations with PTSD and is believed to maintain symptoms of PTSD and increase the complexity of the condition. Ongoing diminished sleep quality may serve to maintain pain and PTSD symptoms, and thus affect the efficacy of first-line PTSD treatment. This study examined the mechanisms underlying the PTSD-pain relationship over time by investigating if perceived sleep quality mediates the relationship between PTSD symptom severity and levels of pain interference. Furthermore, we considered whether the interrelation between these three variables could in fact be linked in an alternative model where the causality was reversed, with pain interference mediating the relation between PTSD severity and perceived sleep quality. Relationships among our variables were assessed within a path analysis framework, conducted and controlled for covariates using structural equation modelling and mediation analysis. The analysis of our hypothesised model revealed that improvement in perceived sleep quality was a significant partial mediator of the association between reduction in PTSD severity and pain interference. Approximately 28% of the effect of PTSD severity on pain interference was mediated by improvement in perceived sleep quality. Evaluation of our alternative model revealed a non-significant mediation effect. Sleep thus represents a modifiable mechanism that contributes to the mutual maintenance of PTSD and pain. The study is the first to investigate these relationships in trauma-affected refugees and thus contributes new knowledge and clinical implications for the treatment of poor sleep quality and pain symptomatology in trauma-affected refugees.

Bidirectional relationship between pain and sleep disturbance in middle-aged and older adults: evidence from the China health and retirement longitudinal study

Background

Pain is one of the most prevalent symptoms that disrupt daily functioning and has been increasing in prevalence. Sleep disturbances frequently occur in individuals with pain, making it difficult to initiate and maintain sleep. This study aims to examine the bidirectional correlation between pain and sleep quality/duration among middle-aged and older Chinese adults.

Participants and setting

This study analyzed data from individuals aged 45 years and above who participated in both the 2018 and 2020 baseline surveys of China Health and Retirement Longitudinal Study (CHARLS).

Methods

The bidirectional association between pain and sleep disturbance was assessed using multivariate logistic regression models, adjusting for various covariates.

Results

Among individuals without pain, those with unsatisfactory sleep quality were more likely to experience future pain, with an adjusted odds ratio (OR) of 1.74 (95% CI: 1.57 - 1.92). Conversely, among individuals with satisfactory sleep quality, those with pain were more likely to develop unsatisfactory sleep quality in the future, with an adjusted OR of 1.87 (95% CI: 1.69 - 2.07). Additionally, shorter sleep duration (<6 hours) was significantly associated with pain status (OR=1.39; 95% CI: 1.28 - 1.50). The incidence of developing short sleep duration in individuals with pain was also higher (OR=1.49; 95% CI: 1.38 - 1.61).

Conclusions

This research revealed a bidirectional relationship between pain and sleep disturbance in middle-aged and older Chinese adults, where each condition exacerbated the other. Recognizing and addressing this interconnected relationship was essential for effective management of both pain and sleep quality in this population.

Sleep Deprivation in Healthy Males Increases Muscle Afferents, Impairing Motor Preparation and Reducing Endurance

PURPOSE

Sleep deprivation (SD) reduces time to task failure during endurance exercises. The aim of our work was to study the effect of acute SD on the endurance of a skeletal hand muscle and to investigate cortical motor drive to muscle and perception of effort.

METHODS

Origin of the early exhaustion after SD might be insufficient cortical motor drive to muscle or motor inhibition because of excessive perception of effort. The supplementary motor area, the medial part of the premotor cortex, links the motor and sensory cortexes, prepares for voluntary movements, and may play a central role in the pathophysiology of impaired muscle endurance after SD. Supplementary motor area can be noninvasively assessed by electromyogram measuring amplitude of premotor potentials before hand movements. We investigated the effect of SD on muscle endurance in healthy volunteers performing moderate hand exercise by monitoring supplementary motor area activation and muscle afferents. Two sessions were performed, in random order, one after a normal sleep night and the other after a sleepless night.

RESULTS

Twenty healthy young men were included in this study. Sleep deprivation reduced time to task failure by 11%. Supplementary motor area activation was altered throughout the task and effort perception was increased.

CONCLUSIONS

Our results suggest that SD reduces skeletal muscle endurance by increasing the effects of muscle afferents on the supplementary motor area. Sleep alterations frequently reported in chronic diseases might reduce patients' capacity to achieve the low-intensity motor exercises required in everyday life. Our results should lead to the search for sleep disorders in patients with chronic pathology.

The relationship between sleep, pain,and musculoskeletal injuries in US Army Soldiers

INTRODUCTION

The purpose of this study was to investigate the relationship between sleep and pain in military personnel and to determine if metrics of sleep and pain intensity differ between the injured and uninjured in this population.

METHODS

Active-duty US Army Soldiers (n=308; 26.8±6.5 years, 82% male) from the 2nd Infantry Division, Joint Base Lewis-McChord, Washington, and 101st Airborne Division, Fort Campbell, Kentucky, completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and questionnaires about current musculoskeletal injuries and pain intensity (0=no pain to 10=worst imaginable pain). Pearson correlation coefficients were used to assess the association between pain and sleep. Differences in sleep and pain between injured and uninjured participants were determined using an analysis of covariance.

RESULTS

Pain intensity was positively correlated with sleep quality (global PSQI score, r=0.337, p<0.001) and daytime sleepiness (ESS score, r=0.163, p=0.005), and negatively associated with sleep duration (r=-0.118, p=0.039). Injured participants accounted for 37.7% (n=116) of the study population. Injured participants reported greater pain intensity (3.7±2.5 vs 1.3±1.9, p<0.001), were older (28.5±7.4 years vs 25.8±5.7 years, p=0.001) and in the service longer (6.3±6.3 years vs 4.6±4.7 years, p=0.013) than uninjured participants. Injured participants had higher global PSQI scores (9.0±4.1 vs 6.4±3.4, p<0.001), including each of the seven PSQI components (all p<0.050), and reported sleeping less per night than uninjured participants (5.7±1.3 hours vs 6.1±1.2 hours, p=0.026).

CONCLUSION

These data demonstrate that pain intensity is associated with sleep in active-duty US Army Soldiers and that those who report a musculoskeletal injury, regardless of age and time in service, report poorer sleep quality, shorter sleep durations, and greater levels of pain than uninjured Soldiers.

Association Between Objective Sleep and Clinical Outcomes in Older Adults With Low Back Pain Receiving Physical Therapy Care: A Secondary Analysis of a Responsiveness Study

BACKGROUND/OBJECTIVES

Sleep seems to be associated with worse low back pain (LBP) outcomes in older adults; however, studies investigating the association of objective sleep with future changes in LBP outcomes are lacking. The objectives of this study are as follows: (a) to investigate the association between objectively measured sleep with changes in clinical outcomes in older adults with LBP receiving physical therapy care and (b) to examine the cross-sectional association between sleep and pain catastrophizing.

METHODS

This was a prospective cohort study. We recruited older adults (≥60 years old) with chronic LBP undergoing physical therapy treatment. At baseline, we assessed participants' sleep (actigraphy for 10-14 days), pain intensity, disability, pain catastrophizing, and covariates. After 8 weeks, we reassessed pain intensity, disability, and self-perceived recovery. We ran linear regression models and Spearman coefficient tests.

RESULTS

Fifty-eight participants were included, and 51 completed follow-up assessments (60.8% women; mean age 70.1 ± 5.6 years). We found no associations between sleep quantity and efficiency with changes in pain intensity, disability, and self-perceived recovery after 8 weeks of physical therapy care. We found a correlation between sleep fragmentation and pain catastrophizing (r = .30; 95% confidence interval: [.03, .54]).

CONCLUSION

Objective sleep quantity and efficiency may not be associated with changes in LBP outcomes after physical therapy care in older adults. Among the sleep domains evaluated, sleep fragmentation may be the sleep domain with the strongest association with pain catastrophizing. Significance/Implications: Objectively measured sleep might not be a prognostic factor for LBP improvement in older adults. Future studies should explore the association between sleep fragmentation and pain catastrophizing.

Factors associated with pain-related functional interference in people with chronic low back pain enrolled in a physical exercise programme: the role of pain, sleep, and quality of life

OBJECTIVE

To identify the factors associated with the pain-related functional interference level in people with chronic low back pain.

DESIGN

Cross-sectional.

SUBJECTS/PATIENTS

Chronic low back pain patients.

METHODS

Sociodemographic data, pain intensity, pain-related functional interference, physical functioning and fitness, sleep quality, anxiety and depression, social support, and health-related quality of life were recorded. Descriptive and bivariate analyses were performed. A linear regression model was carried out to identify the factors associated with the pain-related functional interference level.

RESULTS

99 participants were involved (mean age: 54.37 SD: 12.44; women: 67.7%). 37.4%, 27.3%, and 35.4% were classified into low, moderate, and high pain-related functional interference level groups, respectively. Higher pain-related functional interference was associated with higher pain intensity (β: 0.724; p = 0.026), worse sleep quality (β: 0.077; p = 0.012), worse quality of life (physical (β: -0.539; p < 0.001) and mental (β: -0.289; p < 0.001), and lower consumption of weak opioids (β: -3.408; p = 0.037).

CONCLUSION

Beyond the pain experience and intensity among people with chronic low back pain, several biopsychosocial factors associated with this condition has been identified. Furthermore, higher pain intensity, worse sleep quality, worse quality of life, and weak opioids' consumption have been related to the pain-related functional interference of this population.

The Bidirectional Relationship Between Sleep and Pain in Crohn's Disease: A Daily Diary Study

BACKGROUND

Pain is common in Crohn's disease (CD) even after endoscopic healing is achieved. Depression, sleep disturbances, fatigue, and worry about pain impact the pain experience. There is a bidirectional relationship between sleep and pain, though it has received minimal attention in CD. Herein, we sought to comprehensively assess this relationship in CD using daily diaries.

METHOD

Patients with active symptoms of insomnia and CD were recruited as part of an ongoing clinical trial. Participants completed 14-day diaries on sleep patterns and CD symptoms. Temporal associations between sleep and pain were assessed using cross-lagged path analysis and controlled for age, sex, and menstrual cycle.

RESULTS

Overall, 26 participants completed 14-day diaries. All assessed aspects of sleep continuity disturbance were associated with worse next-day abdominal pain (Ps < 0.01). When assessed microlongitudinally, sleep onset latency predicted next-day pain (P = 0.07) and vice versa (P = 0.03). Similarly, nightly awakenings predicted next day pain (P = 0.02) and vice versa (P = 0.04). Sleep efficiency (P = 0.003), sleep quality (P < 0.001), and total sleep time (P = 0.04) predicted next-day pain whereas models with pain as the predictor were not significant.

CONCLUSIONS

Sleep continuity and abdominal pain are closely related, with sleep efficiency, total sleep time, and sleep quality potentially driving next-day abdominal pain. As interventions for pain in IBD are limited, it may be important to capitalize on the impact of sleep disturbances on pain to optimize overall wellbeing in people with CD.

Dopamine D2 receptors in the accumbal core region mediates the effects of fentanyl on sleep-wakefulness

Fentanyl, a potent analgesic and addictive substance, significantly impacts sleep-wakefulness (S-W). Acutely, it promotes wake, whereas chronic abuse leads to severe sleep disruptions, including insomnia, which contributes to opioid use disorders (OUD), a chronic brain disease characterized by compulsive opioid use and harmful consequences. Although the critical association between sleep disruptions and fentanyl addiction is acknowledged, the precise mechanisms through which fentanyl influences sleep remain elusive. Recent studies highlight the role of the dopaminergic system of the nucleus accumbens (NAc) in S-W regulation, but its specific involvement in mediating fentanyl's effects on S-W remains unexplored. We hypothesized that dopamine D2 receptors mediate fentanyl-induced effects on S-W. To test this hypothesis, male C57BL/6J mice, instrumented with sleep recording electrodes and bilateral guide cannulas above the accumbal core region (NAcC), were utilized in this study. At dark onset, animals were bilaterally administered sulpiride (D2 receptors antagonist; 250 ng/side) in the NAcC followed by an intraperitoneal injection of fentanyl (1.2 mg/Kg). S-W was examined for the next 12 h. We found that systemic administration of fentanyl significantly increased wakefulness during the first 6 h of the dark which was followed by a significant increase in NREM and REM sleep during the second 6 h of the dark period. D2-receptor blockade significantly reduced this effect as evidenced by a significant reduction in fentanyl-induced wakefulness during first 6 h of dark period and sleep rebound during the second 6 h. Our findings suggest that D2 receptors in the NAcC plays a vital role in mediating the fentanyl-induced changes in S-W.

Skeletal muscle relaxant for the treatment of fibromyalgia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND/IMPORTANCE

Fibromyalgia is a complex chronic pain disorder that significantly impairs patient well-being. Evaluating the efficacy of muscle relaxants for treating fibromyalgia is crucial for improving patient care.

OBJECTIVE

This study aimed to evaluate the analgesic efficacy of muscle relaxants in patients with fibromyalgia.

EVIDENCE REVIEW

A comprehensive literature search was conducted using PubMed, EMBASE, Web of Science, ClinicalTrials.gov, and the Cochrane Library. The search included randomized controlled trials (RCTs) comparing skeletal muscle relaxants with placebo/active analgesics for fibromyalgia. The primary outcome was pain intensity, measured by standardized mean difference (SMD) in pain scores. The risk of bias of included RCTs was assessed using the Cochrane Risk of Bias Assessment Instrument for Randomized Controlled Trials.

FINDINGS

14 RCTs (1851 participants) were included. Muscle relaxants were associated with a small but statistically significant reduction in pain scores compared with placebo or active treatment (SMD=-0.24, 95% CI=-0.32 to -0.15, p<0.001, 95% prediction interval=-0.40 to -0.08), with no significant inconsistency (I2=0, 95% CI=0% to 50.79%) and a moderate Grading of Recommendation, Assessment, Development and Evaluation rating. Secondary outcomes showed small, but statistically significant improvements in depression, fatigue and sleep quality. Muscle relaxants were associated with increased incidence of overall adverse effects, fatigue, abnormal taste, and drug withdrawal due to adverse effects.

CONCLUSIONS

Moderate quality evidence showed that muscle relaxants were associated with a small reduction in pain intensity for patients with fibromyalgia.

Fatigue and Sleep-related Impairment as Predictors of the Effect of Nonpharmacological Therapies for Active duty Service Members With Chronic Pain: A Secondary Analysis of a Pragmatic Randomized Clinical Trial

INTRODUCTION

First-line treatments for chronic pain include selected complementary and integrative health therapies, including spinal manipulation, acupuncture, yoga, and massage; and standard rehabilitative care, including physical and occupational therapies. This study aimed to uncover critical factors that contribute to pain impact and the effectiveness of complementary and integrative health therapies and standard rehabilitative care among people with chronic pain, with a focus on the role of sleep-related impairment.

MATERIALS AND METHODS

We conducted a secondary analysis of data from a pragmatic randomized clinical trial of 280 U.S. active duty service members with chronic pain.

RESULTS

Our study's multiple mediation analysis examined the indirect effect of complementary and integrative health therapies on pain impact through fatigue (β = - 0.43; 95% CI, -0.99 to -0.07). When stratified by sleep-related impairment, participants with T scores above the median of 62 demonstrated a significant negative indirect effect of complementary and integrative health therapies through fatigue (β = - 0.80; 95% CI, -2.31 to -0.14). This negative indirect effect was not significant for participants with sleep-related impairment T scores below the median (β = - 0.64; 95% CI, -1.48 to 0.07).

CONCLUSION

These findings suggest that complementary and integrative health therapies are particularly effective in reducing pain impact for individuals with higher levels of sleep-related impairment, and that the effect of complementary and integrative health therapies is supported primarily by reducing fatigue.

Who develops chronic pain after an acute lower limb injury? A longitudinal study of children and adolescents

ABSTRACT

Prevention of chronic pain is a major challenge in this area of clinical practice. To do this, we must be able to understand who is most at risk of developing chronic pain after an injury. In this study, we aimed to identify risk factors of chronic pain onset, disability, and pain interference after a lower limb musculoskeletal injury in children and adolescents between 8 to 16 years of age. We assessed biopsychosocial factors including age, sex, pubertal status, anxiety, depression, fear of pain, pain worry, adverse life events, and sleep in children. We also assessed risk factors in parents including parent anxiety, depression, parent pain catastrophising, and protective behaviours. Logistic and hierarchical linear regressions identified risk factors assessed immediately postinjury for outcomes assessed at 3 months postinjury. Fourteen percent (17/118 children) reported chronic pain 3 months after injury. There were significant between-group differences in children with and without chronic pain at baseline. Children with chronic pain reported higher pain intensity, disability, pain interference, child depression, fear of pain, and catastrophic thinking about their pain. Regressions showed child depression and fear of pain at baseline independently predicted chronic pain onset at 3 months, parent protectiveness predicted child pain interference at 3 months, and child depression, poor sleep, parent anxiety and pain catastrophising predicted disability. Most children recover after a lower limb injury, but a minority develop chronic pain predicted by important psychosocial risk factors, which could be addressed to prevent the onset of treatment-resistant chronic pain and disability.

Influence of chronotype on pain incidence during early adolescence

ABSTRACT

During adolescence major shifts in sleep and circadian systems occur with a notable circadian phase delay. Yet, the circadian influence on pain during early adolescence is largely unknown. Using 2 years of data from the Adolescent Brain Cognitive Development study, we investigated the impact of chronotype on pain incidence, moderate-to-severe pain, and multiregion pain 1 year later in U.S. adolescents. Based on the Munich ChronoType Questionnaire, chronotype was calculated as the midpoint between sleep onset and offset on free days, corrected for sleep debt over the week. Adolescents reported pain presence over the past month, and if present, rated pain intensity (0-10 numerical rating scale; ≥ 4 defined as moderate-to-severe pain) and body site locations (Collaborative Health Outcomes Information Registry Body Map; ≥2 regions defined as multiregion pain). Three-level random intercept logistic regression models were specified for each pain outcome, adjusting for baseline sociodemographic and developmental characteristics. Among 5991 initially pain-free adolescents (mean age 12.0 years, SD 0.7), the mean chronotype was 3:59 am (SD 97 minutes), and the 1-year incidence of pain, moderate-to-severe pain, and multiregion pain was 24.4%, 15.2%, and 13.5%, respectively. Each hour later chronotype at baseline was associated with higher odds of developing any pain (odds ratio [OR] = 1.06, 95% confidence interval [CI] = 1.01, 1.11), moderate-to-severe pain (OR = 1.10, 95% CI = 1.05-1.17), and multiregion pain (OR = 1.08, 95% CI = 1.02-1.14) during 1-year follow-up. In this diverse U.S. adolescent sample, later chronotype predicted higher incidence of new-onset pain.

Social determinants of health and youth chronic pain

OBJECTIVES

To identify the relationships between social determinants of health (SDOH) and chronic pain among U.S. youth (referring to children and adolescents).

METHODS

Data including a national sample of U.S. youth were retrieved from the 2022 National Survey of Children's Health. Twenty indicators within five SDOH-related domains (e.i., economic stability, social and community context, neighborhood and built environment, health care access and quality, and education access and quality) were included. The presence of chronic pain was assessed using a self-reported question, answered by the main caregiver. Associations of SDOH-related indicators and youth chronic pain were estimated using multi-variable logistic regression models, while adjusting for covariates (e.g., age, sex, ethnicity, weight status, and movement behaviors).

RESULTS

Data from 30,287 U S. youth aged 6-17 years (median [SD] age, 11.59 [3.30] years; 14,582 girls [48.97 %]) were collected. In 7.5 % of the final sample size, caregivers reported that they had chronic pain. Youth grow up in conditions with diverse SDOH profiles, including food insufficiency (OR = 1.46, 95 % CI: 1.01 to 2.10) and parental unemployment (OR = 1.56, 95 % CI: 1.15 to 2.12); low school engagement (OR = 1.48, 95 % CI: 1.14 to 1.92) and low school safety (OR = 1.65, 95 % CI: 1.14 to 2.39); limited access to quality health care (OR = 2.56, 95 % CI: 2.12 to 3.09), a high frequency of hospital visits (OR = 4.76, 95 % CI: 1.82 to 12.44), and alternative health care (OR = 2.57, 95 % CI: 2.07 to 3.20); bullying victimization (OR = 1.37, 95 % CI: 1.11 to 1.68) and community-based adverse childhood experiences (OR = 1.64, 95 % CI: 1.32 to 2.05); and disadvantageous amenity characteristics (OR = 1.38, 95 % CI: 1.05 to 1.79); resulted in higher odds of presenting chronic pain.

CONCLUSIONS

Different indicators included in the SDOH domains were associated with a higher probability of presenting chronic pain in U.S youth. These findings have implied relationships between the SDOH and chronic pain in youth, requiring a comprehensive approach to addressing health equity to prevent and reduce the presence of youth chronic pain.

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.

Degenerative temporomandibular joint diseases and their relation with sleep and emotional disturbance

OBJECTIVE

The relation of degenerative temporomandibular joint (TMJ) diseases (DJDs) with sleep and emotional disturbance were investigated.

METHODS

CBCT examination of patients (n = 358) with DC/TMD-defined intra-articular temporomandibular disorders was performed and stratified into NN: no DJD and no arthralgia; NA: no DJD with arthralgia; TO: osteoarthrosis; and TR: osteoarthritis. Sleep and emotional disturbance were assessed with the Pittsburgh Sleep Quality Index (PSQI) and Depression Anxiety Stress Scale-21 (DASS-21). Data were evaluated using non-parametric and multivariate logistic regression analyses (α = 0.05).

RESULTS

Distributions of NN, NA, TO, and TR groups were 23.2%, 27.1%,19.0%, and 30.7%, respectively. No significant differences in total-PSQI/DASS scores were detected among the four groups. The presence of pain and stress predicted poor quality sleep with odds ratios of 10.75 and 1.07, accordingly.

CONCLUSION

Sleep quality was affected more by arthralgia and stress than the presence of TMJ DJDs.

Improving Sleep in People with HIV and Chronic Pain: A Pilot Study of Brief Behavioral Treatment for Insomnia

OBJECTIVES

Insomnia and chronic pain are common symptoms in people with HIV. Poor sleep has been associated with chronic pain. While cognitive behavioral therapy for insomnia improves insomnia in clinical populations, there are barriers to people with HIV accessing treatment including the lack of trained providers and lengthy sessions. Only one study has examined the efficacy of brief behavioral treatment for insomnia (BBTI) in people with HIV. This study examined BBTI effects on sleep and pain in people with HIV.

METHODS

Ten adults with HIV and chronic pain completed a 4-week, telephone-delivered BBTI treatment. A control group (n = 10) completed a brief mindfulness training (BMT). The Insomnia Severity Index and Brief Pain Inventory were used to assess insomnia severity and pain outcomes, respectively.

RESULTS

There was a significant interaction between intervention and time on insomnia severity, F (2,14) = 5.7, p = .02, partial η2 = 0.45). The BBTI group demonstrated significant improvements in insomnia severity from pre- to post-intervention (p < .001) and from pre-intervention to one-month post-intervention (p = .001) compared to the BMT group. There was a significant interaction between intervention and time on pain interference, F (1,18) = 4.9, p = .02, partial η2 = 0.27). The BBTI group demonstrated a significant decrease in pain interference from pre- to post-intervention (p < .001) compared to the BMT group.

CONCLUSIONS

This pilot study demonstrated that BBTI improved insomnia in people with HIV for up to one-month post-treatment. Novel preliminary evidence suggests that BBTI may also improve pain outcomes in people with HIV.

Unique and cumulative effects of different subtypes of sleep problems on burnout among Chinese nurses

Objective

To investigate the unique and cumulative associations of different sleep problem subtypes with burnout among Chinese nurses.

Methods

A survey was conducted in Quanzhou, China, and a total of 744 nurses were included. Burnout was measured by Maslach Burnout Inventory-Human Services Survey across three dimensions: emotional exhaustion (EE), depersonalization (DP) and low personal accomplishment (PA). Pittsburgh Sleep Quality Index was used to measure 15 types of sleep problems. Binary logistic regression was employed to explore the association between sleep problems and burnout.

Results

Prevalence of sleep problems, high EE, high DP and low PA were 43.3, 6.9, 23.4, and 63.2%, respectively. Experience of sleep problems significantly increased risk for EE (OR = 1.31, 95%CI: 1.185-1.436), DP (OR = 1.08, 95%CI: 1.023-1.142) and PA (OR = 1.09, 95%CI: 1.036-1.146). Of the 15 sleep problem subtypes, "feel too cold" and "have pain" were significant predictors of high EE (OR = 3.89, 95%CI: 1.629-9.302; OR = 3.00, 95%CI: 1.314-6.827, respectively), and "daytime dysfunction" significantly predicted low PA (OR = 1.68, 95%CI: 1.135-2.491). Around 40.9% of nurses had reported more than three subtypes of sleep problems. Experiencing more than three subtypes of sleep problems were significantly associated with an increased risk of DP and PA (ORs range from 2.07 to 2.71).

Conclusion

These findings suggested that sleep problems was associated with an increased risk of burnout in nurses, with both unique and cumulative risks. Interventions should focus on the prevention and management of the effects of sleep problems among nurses.

Endogenous pain modulation after sleep restriction in migraine: a blinded crossover study

BACKGROUND

Patients with migraine are vulnerable to insufficient sleep, but the impact of sleep restriction is largely unknown. In addition, the importance of sleep may be different in patients with migraine who mostly have attack onsets during sleep, so called sleep-related migraine, compared to patients with non-sleep-related migraine. In this study we investigate the effect of sleep restriction on endogenous pain modulation in patients with migraine and healthy controls. We also compared the effect of sleep restriction in sleep-related and in non-sleep-related migraine.

METHODS

Measurements were conducted in 39 patients with migraine between attacks and 31 controls, once after habitual sleep and once after two consecutive nights of partial sleep restriction. There were 29 and 10 patients with non-sleep-related and sleep-related migraine respectively. Test stimulus was 2-min tonic noxious heat to the left volar forearm. Temporal summation was calculated as the regression coefficient for rated pain in the late part of this 2-min stimulation. Conditioning stimulus was right hand-immersion in 7 °C water. Conditioned pain modulation was defined as the difference in rated pain with and without the conditioning stimulus and was calculated for temporal summation and mean rated pain for the test stimulus. The effect of sleep restriction on temporal summation and conditioned pain modulation was compared in migraine subjects and controls using two-level models with recordings nested in subjects.

RESULTS

Conditioned pain modulation for temporal summation of heat pain tended to be reduced after sleep restriction in patients with migraine compared to controls (p = 0.060) and, in an exploratory analysis, was reduced more after sleep restriction in sleep-related than in non-sleep-related migraine (p = 0.017). No other differences between groups after sleep restriction were found for temporal summation or conditioned pain modulation.

CONCLUSION

Patients with migraine may have a subtly altered endogenous pain modulation system. Sleep restriction may have an increased pronociceptive effect on this system, suggesting a mechanism for vulnerability to insufficient sleep in migraine. This effect seems to be larger in sleep-related migraine than in non-sleep-related migraine.

Patterns of pain medication usage and self-reported pain in older Irish adults with osteoarthritis: A latent class analysis of data from the Irish Longitudinal Study on Ageing

BACKGROUND

This study aimed to identify and describe links between pain medication use and self-reported pain among people aged ≥ 50 years with osteoarthritis (OA) in an Irish population, and to examine the relationships between pain, medication usage and socioeconomic and clinical characteristics.

METHODS

Secondary data analysis of wave 1 cross-sectional data from The Irish Longitudinal Study on Ageing (TILDA) was undertaken of 1042 people with self-reported doctor-diagnosed OA. We examined use of medications typically included in OA clinical guidelines, including non-opioid analgesics (e.g. paracetamol), topical and oral non-steroidal anti-inflammatory drugs (NSAIDs), opioids and nutraceuticals. Latent Class Analysis (LCA) was used to identify underlying clinical subgroups based on medication usage patterns, and self-reported pain severity. Multinomial logistic regression was used to explore sociodemographic and clinical characteristic links to latent class membership.

RESULTS

A total of 358 (34.4%) of the 1042 people in this analysis were taking pain medications including oral NSAIDs (17.5%), analgesics (11.4%) and opioids (8.7%). Nutraceutical (glucosamine/chondroitin) use was reported by 8.6% and topical NSAID use reported by 1.4%. Three latent classes were identified: (1) Low medication use/no pain (n = 382, 37%), (2) low medication use/moderate pain (n = 523, 50%) and (3) moderate medication use/high pain (n = 137, 13%). Poorer self-rated health and greater sleep disturbance were associated with classes 2 and 3; depressive symptoms and female gender were associated with class 2, and retirement associated with class 3.

CONCLUSIONS

Whilst pain medication use varied with pain severity, different medication types reported broadly aligned with OA guidelines. The two subgroups exhibiting higher pain levels demonstrated poorer self-rated health and greater sleep disturbance.

Sleep and home parenteral nutrition in adults: A narrative review

Infusions of home parenteral nutrition (HPN) are often cycled at night coinciding with sleep episodes. Adult consumers of HPN are known to experience poor sleep attributed to frequent awakenings and long durations of wakefulness after falling asleep. Consequently, most consumers do not meet recommendations for sleep duration and quality or daytime napping. The primary underlying pathophysiology resulting in sleep problems is nocturia; however, other factors also exist, including disruptions caused by medical equipment (ie, pump alarms), comorbid conditions, dysglycemia, and medication use. Early guidance on sleep is imperative because of the central role of sleep in physical health and wellbeing, including mitigating complications, such as infection risk, gastrointestinal problems, pain sensitivity, and fatigue. Clinicians should routinely inquire about the sleep of their patients and address factors known to perturb sleep. Nonpharmacologic opportunities to mitigate sleep problems include education on healthy sleep practices (ie, sleep hygiene); changes in infusion schedules, volumes, rates, and equipment; and, possibly, behavioral interventions, which have yet to be examined in this population. Addressing comorbid conditions, such as mood disorders, and nutrition deficiencies may also help. Pharmacologic interventions and technological advancement in HPN delivery are also needed. Research on sleep in this population is considered a priority, yet it remains limited at this time.

Psychometric Properties of the Pictorial Pain Interference Questionnaire for Assessing Functional Interference in Chronic Low Back Pain

OBJECTIVE

To analyze the psychometric properties of the Pictorial Pain Interference Questionnaire (PPIQ) for evaluating functional interference in the population with chronic low back pain (CLBP).

DESIGN

Cross-sectional study.

SETTING

Rehabilitation Unit in a hospital.

PARTICIPANTS

Ninety-nine patients with CLBP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Functional interference was assessed using PPIQ. The following data were also collected: sociodemographic data; pain intensity (Numeric Pain Rating Scale [NPRS]); physical functioning (30-s arm curl, 30-s chair stand [30CST], and timed Up and Go [TUG] tests), fitness (International Physical Activity Questionnaire); quality of life (Short-Form 12 Health Survey version 1 [SF-12v1]); sleep quality (Spanish-validated 12-item Medical Outcomes Study Sleep scale [12-MOS Sleep]); anxiety and depression (Hospital Anxiety and Depression Scale [HADS]); and social support (Duke-UNK Functional Social Support Questionnaire). Internal consistency was analyzed using Cronbach's alpha, structural validity using exploratory factor analysis (EFA), and discriminant and convergent validity using bivariate analysis.

RESULTS

Ninety-nine patients with CLBP were included (age [mean ± SD]: 54.37±12.44 y); women, 67.7%). The EFA extracted 2 factors: "physical function and "social and sleep," which explained 57.75% of the variance. Excellent internal consistency was observed for the overall PPIQ score (Cronbach's α=0.866). Convergent validity was observed between the PPIQ and other functional measures (ρ: 0.52 and -0.47 for the TUG and 30CST, respectively; P<.001) and with the following variables: physical and mental component summaries of the SF-12v1 (ρ: -0. 55 and -0.52, respectively (P<.001); anxiety and depression of the HADS (ρ: 0.47 and 0.59, respectively (P<.001); NPRS (ρ: 0.45; P<.001); and index 9 of the 12-MOS Sleep scale (r: 0.49; P<.001).

CONCLUSIONS

The PPIQ is a valid instrument with good psychometric properties for measuring functional interference in people with CLBP. This questionnaire appears to be a feasible alternative when language or communication barriers exist in CLBP population.

Cognitive behavioral therapy for insomnia in people with chronic musculoskeletal pain. A systematic review and dose-response meta-analysis

The aims were (i) to determine the effects of Cognitive behavioral therapy for insomnia (CBT-I) on sleep disturbances, pain intensity and disability in patients with chronic musculoskeletal pain (CMP), and (ii) to determine the dose-response association between CBT-I dose (total minutes) and improvements in sleep disorders, pain intensity and disability in patients with CMP. A comprehensive search was conducted in PubMed/MEDLINE, Web of Science, CINAHL, and SCOPUS until December 17, 2023. Randomized clinical trials (RCTs) using CBT-I without co-interventions in people with CMP and sleep disorders were eligible. Two reviewers independently extracted data and assessed risk of bias and certainty of the evidence. A random effects meta-analysis was applied to determine the effects on the variables of interest. The dose-response association was assessed using a restricted cubic spline model. Eleven RCTs (n = 1801 participants) were included. We found a significant effect in favor of CBT-I for insomnia (SMD: -1.34; 95%CI: -2.12 to -0.56), with a peak effect size at 450 min of CBT-I (-1.65, 95%CI: -1.89 to -1.40). A non-significant effect was found for pain intensity. A meta-analysis of disability was not possible due to the lack of data. This review found benefits of CBT-I for insomnia compared to control interventions, with a large effect size. In addition, it was estimated that a 250-min dose of CBT-I had a large effect on reducing insomnia and that the peak effect was reached at 450 min. These novel findings may guide clinicians in optimizing the use of CBT-I in people with CMP and insomnia.

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.

Risk factors for temporomandibular disorders: a systematic review of cohort studies

OBJECTIVE

A systematic review was performed to synthesize and identify risk factors involved in TMD onset.

STUDY DESIGN

Electronic searches were conducted in PubMed, Web of Science, Scopus, Embase, PsyInfo and Lilacs databases, as well as in three gray literature databases (Google Scholar, ProQuest and Open grey). The studies were blindly assessed by two reviewers and selected by a pre-defined eligibility criterion. Risk of bias of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was evaluated for most related factors.

RESULTS

Twenty-one cohort studies were included. Significant factors were female gender, symptoms of depression and anxiety, perceived stress, sleep quality, symptoms of obstructive sleep apnea and presence of any comorbidity, such as Irritable Bowel Syndrome, lower back pain, headache frequency, tension-type headache, migraine and mixed headache. Moreover, high estrogen and low testosterone levels in utero, greater pain perception, jaw mobility pain, pain during palpation, orofacial anomalies, as well as extrinsic and intrinsic injuries were also significant.

CONCLUSIONS

Several factors seems to be involved in TMD onset, however, more studies with standardized methodology are necessary to confirm these findings.

Risk of Sleep Problems in Middle-Aged and Older Adults Experiencing Bodily Pains: Serial Multiple Mediation Estimates of Emotional Distress and Activity Limitations

OBJECTIVES

Pain is increasingly becoming common among middle-aged and older adults. While research on the association between pain characteristics and sleep problems (SP) is limited in low- and middle-income countries, the underlying mechanisms of the association are poorly understood. This study examines the association of bodily pain intensity and pain interference with SP and investigates the mediating role of activity limitation and emotional distress in this association.

METHODS

We analyzed population-based data, including 1,201 individuals aged ≥50 (mean [SD] age 66.14 [11.85] years) from the 2016-2018 AgeHeaPsyWel-HeaSeeB study in Ghana. Multiple OLS regressions and serial multiple mediation modeling using bootstrapping analyses examined direct and indirect effects from pain to SP through activity limitation and emotional distress.

RESULTS

Regressions demonstrated that pain intensity and interference were significantly associated with higher levels of activity limitation, emotional distress, and SP (range: β = 0.049-0.658). Bootstrapping analysis showed that activity limitation and emotional distress serially mediated the relationship between pain intensity and SP (total effect: β = 0.264, Bootstrap 95% confidence interval [CI] = 0.165-0.362; direct effect: (β = 0.107, Bootstrap 95% CI = 0.005-0.210; total indirect effect: β = 0.156, Bootstrap 95% CI = 0.005-0.210) accounting for ∼59%. Activity limitation and emotional distress mediated pain interference and SP association (total effect: β = 0.404, Bootstrap 95% CI = 0.318-0.490; direct effect: β = 0.292, Bootstrap 95% CI = 0.201-0.384; and total indirect effect: β = 0.112, Bootstrap 95% CI = 0.069-0.156) yielding ∼28%.

CONCLUSION

Our data suggest that activity limitation and emotional distress may convey stress-related risks of pain on SP. Future research should evaluate if activity limitation and emotional distress could be effective targets to reduce the effect of pain on sleep in later-life.

Prevalence of neck pain in higher secondary students (8th to 12th standard) due to e-learning during the COVID-19 pandemic period: An online survey

INTRODUCTION

Neck pain is a typical complaint among people who spend a lot of time on their devices. Due to the pandemic situation, students have recently shifted their studies from the classroom to e-learning, causing them to spend excessive hours on gadgets. Thus, it is of utmost importance to study the prevalence of neck pain in students using gadgets for e-learning. The purpose of this research was to study the prevalence of neck pain in higher secondary students using electronic gadgets for e-learning during the COVID-19 (coronavirus disease 2019) pandemic period.

METHOD

A survey-based study was carried out on 1007 students from 8th to 12th grade. Data was collected via Google Form and analyzed using SPSS software. Mann Whitney-U test and the Kruskal Wallis test were used for a comparative analysis.

RESULTS

In this study, a total of 1007 students participated, out of whom 615 reported experiencing neck pain. Of those experiencing neck pain, 268 were males and 347 were females, with mean pain intensities of 4.64 and 4.77 respectively.

CONCLUSION

The findings of the present study suggest that the prevalence of neck pain is higher in students using gadgets for e-learning.

Longitudinal examination of associations with the onset of pediatric chronic pain at different pain locations

ABSTRACT

Chronic pain is a frequent phenomenon in pediatrics. Little research explores whether there are factors that uniquely predict or accompany the onset of new chronic pain in different locations of the body. In this study, we report pediatric pain data for 3 location subsamples-headache, abdominal pain, and musculoskeletal pain-of a large secondary school sample (N = 2280). We distinguished between participants who experienced an onset of chronic pain and participants who had no chronic pain at the respective pain location within a 1-year period. We used regression and multilevel models to compare the 2 groups regarding factors previously associated with chronic pain. Our results indicate that irrespective of location, the onset of chronic pain is predicted by psychosocial factors, in particular, symptoms of depression (odds ratio [OR] = 1.13-1.17, P < 0.01) and anxiety (OR = 1.12-1.21, P < 0.05). Although the onset of headache is predicted by psychosocial factors only, the onsets of abdominal and musculoskeletal pain are additionally predicted by physiological factors such as level of physical activity. Many of the predictors were also accompanying factors. Regarding chronic abdominal pain, sleep deficiency did not predict pain onset but was a co-occurring phenomenon. Our findings underline the importance of mental health factors in the pain onset at all 3 body locations, whereas in chronic abdominal and musculoskeletal pain, physiological factors should also be considered. Measures of model fit, however, indicate that the occurrence of chronic pain is more complex and not well predicted by these factors alone.

Association between sleep duration and chronic musculoskeletal pain in US adults: a cross-sectional study

Background

This study aims to explore the association between sleep duration and the prevalence of chronic musculoskeletal pain (CMP).

Methods

A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2009-2010, which involved multiple centers across the United States. The study included 3,904 adults selected based on age and complete data availability. Demographic variables such as gender, age, race, and socioeconomic status (represented by the poverty-to-income ratio) were considered.

Results

Of the participants, 1,595 reported less than 7 h of sleep, 2,046 reported 7-8 h, and 263 reported more than 9 h of sleep. Short sleep duration was associated with higher odds of CMP (OR, 1.611, 95% CI: 1.224-2.120, p = 0.005). Long sleep duration also showed a higher prevalence (OR, 1.751; 95% CI, 0.923 to 3.321; p = 0.059), although this result was not statistically significant. A U-shaped relationship emerged (Effective degree of freedom (EDF) = 3.32, p < 0.001), indicating that 7 h of sleep was associated with the lowest odds of CMP. In individuals with sleep durations less than 7 h, each hour increment correlated with 22.8% reduced odds of CMP (OR, 0.772; 95% CI, 0.717-0.833; p = 0.002). Beyond 7 h, each hour increment was associated with 38.9% increased odds of CMP (OR, 1.389; 95% CI, 1.103-1.749; p = 0.049).

Conclusion

The findings suggest that both insufficient and excessive sleep durations are linked to a higher prevalence of CMP, highlighting the importance of optimal sleep duration for musculoskeletal health.

Sleeping <6.55 h per day was associated with a higher risk of low back pain in adults aged over 50 years: a Korean nationwide cross-sectional study

Background

Patients with low back pain (LBP) often suffer from sleep disorder, and insufficient sleep duration was recognized as a potential risk factor for LBP. Our aim was to explore the exact effect of sleep duration on LBP and the optimal sleep duration to reduce the risk of LBP.

Methods

Analyzing data from the Korean National Health and Nutrition Examination Survey (KNHANES), we investigated the association between sleep duration and LBP in individuals aged 50 years and older. We used logistic regression models, interaction stratification analysis, and threshold effect assessment to analyze the relationship between sleep duration and LBP.

Results

A total of 6,285 participants, comprising 3,056 males and 3,229 females with a median age of 63.1 years, were enrolled in the study. The association between sleep duration and LBP risk exhibited an L-shaped curve (p < 0.015) in RCS analysis. In the threshold analysis, the OR of developing risk of LBP was 0.864 (95% CI:0.78-0.957, p = 0.005) in participants with sleep duration <6.55 h. Each additional hour of sleep was associated with a 13.6% decrease in the risk of LBP. No significant association was observed between sleep duration ≥6.55 h and the risk of LBP. The risk of LBP did not decrease further with increasing sleep duration. Results remain robust across subgroups.

Conclusion

Our findings indicate that shorter sleep duration is a risk factor for LBP in adults aged over 50 years. We revealed an L-shaped association between sleep duration and LBP, with an inflection point at approximately 6.55 h per day. These results underscore the significance of sleep duration as a factor in the risk assessment for LBP.

Associations of Rest-Activity Rhythm Disturbances With Stroke Risk and Poststroke Adverse Outcomes

BACKGROUND

Many disease processes are influenced by circadian clocks and display ~24-hour rhythms. Whether disruptions to these rhythms increase stroke risk is unclear. We evaluated the association between 24-hour rest-activity rhythms, stroke risk, and major poststroke adverse outcomes.

METHODS AND RESULTS

We examined ~100 000 participants from the UK Biobank (aged 44-79 years; ~57% women) assessed with actigraphy (6-7 days) and 5-year median follow-up. We derived (1) most active 10-hour activity counts across the 24-hour cycle and the timing of its midpoint timing; (2) the least active 5-hour count and its midpoint; (3) relative amplitude; (4) interdaily stability; and (5) intradaily variability, for stability and fragmentation of the rhythm. Cox proportional hazard models were constructed for time to (1) incident stroke (n=1652) and (2) poststroke adverse outcomes (dementia, depression, disability, or death). Suppressed relative amplitude (lowest quartile [quartile 1] versus the top quartile [quartile 4]) was associated with stroke risk (hazard ratio [HR], 1.61 [95% CI, 1.35-1.92]; P<0.001) after adjusting for demographics. Later most active 10-hour activity count midpoint timing (14:00-15:26; HR, 1.26 [95% CI, 1.07-1.49]; P=0.007) also had higher stroke risk than earlier (12:17-13:10) participants. A fragmented rhythm (intradaily variability) was also associated with higher stroke risk (quartile 4 versus quartile 1; HR, 1.26 [95% CI, 1.06-1.49]; P=0.008). Suppressed relative amplitude was associated with risk for poststroke adverse outcomes (quartile 1 versus quartile 4; HR, 2.02 [95% CI, 1.46-2.48]; P<0.001). All associations were independent of age, sex, race, obesity, sleep disorders, cardiovascular diseases or risks, and other comorbidity burdens.

CONCLUSIONS

Suppressed 24-hour rest-activity rhythm may be a risk factor for stroke and an early indicator of major poststroke adverse outcomes.

Nonrestorative sleep and its associated factors in Chinese adolescents and the moderation effects of coffee or tea consumption

BACKGROUND

Nonrestorative sleep (NRS) is related to numerous adverse outcomes. There is rare evidence of its associated factors, especially in Chinese adolescents. This study aimed to explore the factors associated with NRS in Chinese adolescents and the potential moderation effects of coffee or tea consumption.

METHODS

This cross-sectional study invited adolescents attending Grades 7-11 in Nanjing, China, to complete a self-administered questionnaire, including their NRS, stress, anxiety, physical symptoms, depression, sociodemographics, and lifestyles. Linear regressions were applied to investigate the associated factors of their NRS, with the moderation effects of coffee or tea consumption and other characteristics being tested by additionally including their interactions.

RESULTS

Totally 481 adolescents (49% male, age 15.5 ± 1.5 years) were enrolled, with the average global NRS score of 42.16 ± 7.57. Higher family income (β = 2.01, P = 0.007), longer sleep duration (β = 2.33, P = 0.011), and moderate after-class activity (β = 1.50, P = 0.044) contributed less NRS, while higher educational level (β = -2.60, P = 0.033), more coffee or tea consumption (β = -1.68, P = 0.013), physical symptoms (β = -3.85, P < 0.001), stress (β = -0.23, P = 0.005), anxiety (β = -1.54, P = 0.045), and depression (β = -0.13, P = 0.014) contributed more NRS. Females (β = 0.82, P = 0.005), older age (β = -0.46, P = 0.029), and higher education level (β = -1.68, P < 0.001) contributed less refreshment from sleep, more physical/medical symptoms of NRS, and less daytime function, respectively. Coffee or tea consumption moderated the associations of somatic symptoms (β = 0.25, P = 0.021), stress (β = 0.29, P = 0.022), anxiety (β = 0.27, P = 0.005), and depression (β = 0.17, P = 0.021) with NRS.

CONCLUSIONS

Longer sleep duration, moderate after-class activity, reduced coffee or tea consumption, and promotion of physical and mental health may help reduce adolescents' NRS. Coffee or tea consumption may help buffer the negative associations of somatic symptoms, stress, anxiety, and depression with NRS.

The Contribution of Sleep Quality and Psychological Factors to the Experience of Within-Day Pain Fluctuations Among Individuals With Temporomandibular Disorders

We assessed the impact of day-to-day sleep quality and psychological variables (catastrophizing, negative affect, and positive affect) to within-day pain fluctuations in 42 females with painful temporomandibular disorders (TMD) using electronic diaries. More specifically, we examined the contribution of these variables to the likelihood of experiencing pain exacerbations defined as 1) an increase of 20 points (or more) in pain intensity on a 0 to 100 visual analog scale from morning to evening, and/or 2) a transition from mild-to-moderate pain over the course of the day; and pain decreases defined as 3) a decrease of 20 points (or more) in pain intensity (visual analog scale) from morning to evening, and/or 4) a reduction from moderate-to-mild pain over the day. The results indicated significantly main effects of sleep on both pain exacerbation outcomes (both P's < .05), indicating that nights with better sleep quality were less likely to be followed by clinically meaningful pain exacerbations on the next day. The results also indicated that days characterized by higher levels of catastrophizing were associated with a greater likelihood of pain exacerbations on the same day (both P's < .05). Daily catastrophizing was the only variable significantly associated with within-day pain decrease indices (both P's < .05). None of the other variables were associated with these outcomes (all P's > .05). These results underscore the importance of addressing patients' sleep quality and psychological states in the management of painful TMD. PERSPECTIVE: These findings highlight the significance of sleep quality and pain catastrophizing in the experience of within-day pain fluctuations among individuals with TMD. Addressing these components through tailored interventions may help to alleviate the impact of pain fluctuations and enhance the overall well-being of TMD patients.

Sleep disturbances in hospitalized children: a wake-up call

Although sleep is essential for (recovery of) health, it is adversely affected by hospitalization, due to disease discomfort, environmental noise, and care routines, causing reduced sleep and increased disturbances. This study evaluates factors affecting sleep quality and quantity in hospitalized children and compares inpatient sleep with sleep at home. Using an observational, prospective study design, we assessed sleep in hospitalized children aged 1-12 years, admitted to a tertiary center, and compared this with home 6-8 weeks after discharge. We measured total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), sleep efficiency, awakenings, and subjective sleep quality, using actigraphy, sleep diaries, and PROMIS questionnaires. We explored an array of sleep-disturbing factors. Regression analyses identified key determinants affecting sleep patterns, while mixed linear models compared sleep in hospital to sleep at home. Out of 621 eligible patients, 467 were invited, and 272 (58%) consented to participate. Key determinants of sleep included pain, number of previous admissions, (underlying) chronic illness, and environment-, staff-, and disease-related factors. Parents reported lower perceived sleep quality in the hospital compared to at home, 97-min (SE 9) lower TST, 100-min (5) longer WASO, more difficulties with falling asleep, lower sleep satisfaction, and more awakenings. Actigraphy outcomes revealed shorter TST (20 min (6)), but better sleep efficiency and fewer awakenings in the hospital. Conclusion: Sleep in hospital was compromised in comparison to sleep at home, primarily due to disturbances related to treatment, environment, and staff. These findings underscore the necessity and potential of relative simple interventions to improve sleep quality and minimize sleep disturbances in hospitalized children.

Adolescent Girls' Musculoskeletal Pain is More Affected by Insomnia Than Boys, and Through Different Psychological Pathways

Prior research has established that insomnia is predictive of pain in adolescents and that psychological mechanisms have a crucial role in this relationship. Adolescent girls report more insomnia and pain than boys, yet little is known of gender differences in how insomnia influences pain. This study assessed gender differences in levels and trajectories of insomnia and pain during adolescence, and whether rumination and negative mood mediated the effect of insomnia on pain. Longitudinal survey data measured on 5 annual occasions (Nbaseline = 2,767) were analyzed in a multigroup longitudinal serial mediation model. A final model was generated with insomnia as the predictor, rumination and depressed mood as mediators, pain as the outcome, and gender as the grouping variable. The results showed that insomnia predicted pain in adolescents, with an effect 3.5 times larger in girls than boys. Depressed mood was the main mediator in boys. In girls, rumination was the only significant mediator. There were significant gender differences in the effects of insomnia on rumination and pain, and in the effects of rumination on depressed mood and pain, with stronger effects in girls. These results highlight that girls and boys should be considered separately when studying the relationship between insomnia and pain. PERSPECTIVE: Levels of insomnia and pain are progressively higher in adolescent girls than boys, across adolescence. The predictive strength of insomnia symptoms for future pain is 3.5 times greater in girls, with distinct gender-specific underlying pathways: rumination partially mediates this effect in girls, while depressed mood does so in boys.

A Cross Sectional Survey of Factors Related to Cannabis Use as a Sleep Aid Among Canadian Cancer Survivors

OBJECTIVES

Poor sleep is a common side effect of cancer. Cannabis is increasingly used to manage cancer treatment-related symptoms, including sleep. This study investigated factors related to cannabis use for sleep among Canadian cancer survivors.

METHOD

Adult Canadian cancer survivors (N = 940) were recruited via the Angus Reid Institute and completed an online, cross-sectional survey. Univariate and multiple binomial logistic regression models identified factors associated with cannabis use for sleep.

RESULTS

Of the participants (Mage = 64.5 yrs; Women = 51.1%; White = 92.9%), 25.1% (n = 236) currently use cannabis for sleep. Participants were at greater odds of using cannabis for sleep if they identified as a gender other than man or woman (AOR = 11.132), were diagnosed with multiple medical conditions (2:AOR = 1.988; 3+:AOR = 1.902), two psychological conditions (AOR = 2.171), multiple sleep disorders (AOR = 2.338), insomnia (AOR = 1.942), bone (AOR = 6.535), gastrointestinal (AOR = 4.307), genitourinary (AOR = 2.586), hematological (AOR = 4.739), or an unlisted cancer (AOR = 3.470), received hormone therapy only (AOR = 3.054), drink heavily (AOR = 2.748), or had mild insomnia (AOR = 1.828). Older participants (AOR=.972) and those with sleep apnea were less likely to use cannabis for sleep (AOR=.560).

CONCLUSION

Given its prevalence, research is needed to understand how factors associated with cannabis use as a sleep aid among Canadian cancer survivors may influence its use and effectiveness and whether these factors are barriers to accessing evidence-based treatments.

Effects of Modifiable Activity-Related Health Behaviors on the Sleep-Pain Relationship in Adolescents

Poor sleep and chronic pain are commonly related in adolescents. Only 5% of adolescents meet recommendations for physical activity and screen time, both of which impact the experience of sleep and pain disturbances. Research is needed to better understand the sleep-pain relationship in adolescents and to identify potential protective factors, such as activity-related health behaviors. This study examined sleep, behaviors that influence activity (i.e., physical activity, screen time), and their interaction as predictors of pain in a sleep-disordered sample of 105 adolescents aged 12-18 presenting for polysomnography. A hierarchical multiple linear regression was conducted to examine these relationships. Consistent with hypotheses, worse insomnia predicted worse pain. However, other activity-related health behaviors did not influence this relationship, ps > .05. Findings suggest that sleep should be the focus of treatment for adolescents with primary sleep disorders to prevent the onset or exacerbation of pain.