Sleep as a predictive factor for the onset and resolution of multi-site pain: a 5-year prospective study

Psychophysical changes after total sleep deprivation and experimental muscle pain

Sleep disturbances exacerbate chronic pain, increase psychological load, and increase inflammation. Delayed onset muscle soreness (DOMS) mimics aspects of chronic pain, predominantly affecting peripheral pain mechanisms, while experimental sleep provocations have been shown to impact central pain mechanisms. This study aimed to combine a DOMS model with total sleep deprivation (TSD) to create a novel model affecting both peripheral and central pain mechanisms. A total of 30 healthy participants attended two sessions (baseline and follow-up) separated by 24 h of TSD and a home rating after 48 h. Assessments of interleukin 6 (IL-6) levels, sleep quality, pain catastrophising, affect, and symptoms of depression and anxiety were included in the baseline and follow-up sessions. Additionally, pressure pain and tolerance thresholds, temporal summation, and conditioned pain modulation (CPM) were assessed using cuff-pressure algometry in the baseline and follow-up sessions. DOMS was induced with eccentric calf raises during the baseline session followed by 24 h of TSD. At follow-up pain tolerance (p = 0.012) was significantly reduced, and CPM (p = 0.036) was significantly impaired compared to baseline. Psychological changes included decreases in pain catastrophising (p = 0.027), positive affect (p < 0.001), negative affect (p = 0.003), and anxiety (p = 0.012). Explorative regression models predicted 58% and 68% of DOMS pain intensity after 24 and 48 h, respectively, based on baseline body mass index, pain thresholds, psychological measures, and IL-6 (p < 0.01). Combining DOMS with 1 night of TSD induced pain hypersensitivity, impaired CPM, and altered psychological states. A combination of baseline inflammation, psychological measures, and pain sensitivity significantly predicted DOMS pain intensity after 24 and 48 h.

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.

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.

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.

Associations between pain, health, and lifestyle factors in 10-year-old boys and girls from a Swedish birth cohort

BACKGROUND

Pain is common in children and its associations with various biopsychosocial factors is complex. Comprehensive pain assessments could contribute to a better understanding of pediatric pain, but these assessments are scarce in literature. The aim of this study was to examine differences in pain prevalence and pain patterns in 10-year-old boys and girls from a Swedish birth cohort and to study associations between pain, health-related quality of life and various lifestyle factors stratified by sex.

METHODS

866 children (426 boys and 440 girls) and their parents from the "Halland Health and Growth Study" participated in this cross-sectional study. Children were categorized into two pain groups, "infrequent pain" (never-monthly pain) or "frequent pain" (weekly-almost daily pain), based on a pain mannequin. Univariate logistic regression analyses, stratified by sex, were performed to study associations between frequent pain and children's self-reports of disease and disability and health-related quality of life (Kidscreen-27, five domains), and parents' reports of their child's sleep (quality and duration), physical activity time, sedentary time, and participation in organized physical activities.

RESULTS

The prevalence of frequent pain was 36.5% with no difference between boys and girls (p = 0.442). Boys with a longstanding disease or disability had higher odds of being in the frequent pain group (OR 2.167, 95% CI 1.168-4.020). Higher scores on health-related quality of life in all five domains for girls, and in two domains for boys, was associated with lower odds of being categorized into the frequent pain group. Frequent pain was associated with poor sleep quality (boys OR 2.533, 95% CI 1.243-5.162; girls OR 2.803, 95% CI 1.276-6.158) and more sedentary time (boys weekends OR 1.131, 95% CI 1.022-1.253; girls weekdays OR 1.137, 95% CI 1.032-1.253), but not with physical activity.

CONCLUSIONS

The high prevalence of frequent pain needs to be acknowledged and treated by school health-care services and the healthcare sector in order to prevent pain from influencing health and lifestyle factors negatively in children.

An Exploration of the Influence of Non-Biomechanical Factors on Lifting-Related LBP

Objective: The primary objective was to compare non-biomechanical factors between manual workers with and without a history of LBP related to lifting. A secondary objective was to investigate associations between the change in pain intensity during repeated lifting (termed pain ramp) and non-biomechanical factors tested in the LBP group. Methods: Manual workers currently in lifting occupations with and without a history of lifting-related LBP were recruited (21 LBP and 20 noLBP) and took part in a repeated (100) lift task. A series of non-biomechanical factors, including psychological, work-related, lifestyle, whole health and psychophysical factors, were collected. Psychophysical factors (pressure pain thresholds (PPTs) and fatigue) were also measured at different time points. Associations between pain ramp during lifting and non-biomechanical factors were investigated with linear regression. Results: The LBP group reported worse perceived sleep quality, more musculoskeletal pain sites other than LBP and greater symptoms related to gastrointestinal complaints and pseudo-neurology compared to the group with no history of LBP. The group with LBP were also slightly more worried about the lifting task and felt more fatigued at the end of the lifting task. The feeling of fatigue during lifting was positively associated with pain ramp in the LBP group. Anxiety and gastrointestinal complaints were weakly negatively associated with pain ramp during lifting. Conclusions: The group differences of poorer perceived sleep, greater non-specific health complaints, slightly more worry about the lifting task and more perceived fatigue in the LBP group highlight the complex and multi-factorial nature of LBP related to lifting. The feeling of fatigue was positively associated with pain ramp in the LBP group, suggesting a close relationship with pain and fatigue during lifting that requires further exploration.

Including a Three-Party Meeting Using the Demand and Ability Protocol in an Interdisciplinary Pain Rehabilitation Programme for a Successful Return to Work Process

The Demand and Ability Protocol (DAP) is used in three-party meetings involving an employee, an employer, and a representative from the rehabilitation team. The aim of this study is to investigate the inclusion of an intervention using the DAP in an interdisciplinary pain rehabilitation programme (IPRP) compared to usual care. This non-randomised controlled trial included patients assigned to an IPRP in Sweden. The intervention group received a DAP intervention targeting their work situation in addition to the usual care provided by the IPRP. The control group received IPRP only. Outcome measures were collected from the Swedish Quality Registry for Pain Rehabilitation. Results demonstrated improvements in both groups regarding self-reported anxiety, depression and EQ5D. Sleep was improved in the intervention group but not in the control group. No statistical differences in outcomes were observed between the groups. In conclusion, adding the DAP intervention to IPRP seemed to have the potential to improve sleep among the patients, which may indicate an overall improvement regarding health outcomes from a longer perspective. The results were less clear, however, regarding the work-related outcomes of sickness absence and workability.

Eveningness is associated with persistent multisite musculoskeletal pain: a 15-year follow-up study of Northern Finns

Chronotype, a phenotype representing a person's 24-hour circadian rhythm, has been increasingly acknowledged as playing a role in musculoskeletal (MSK) pain. Most prior research on chronotype and MSK pain have been based on cross-sectional data, and no study has explored multisite MSK pain (two or more pain locations) as the outcome. We drew the study sample from the 31- and 46-year data collections (baseline and follow-up, respectively) of the Northern Finland Birth Cohort 1966 and collected self-reported data on chronotype at follow-up (morning [M]-type, intermediate [I]-type, and evening [E]-type) and longitudinal multisite MSK pain trajectories (n=3,294). Multinomial logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) in multisite MSK pain trajectories between the chronotypes. We conducted additional sensitivity analyses that 1) accounted for several confounders, and 2) examined the potential moderating role of sex, mental distress, and sleep disturbance status in the chronotype-multisite MSK pain associations. The E-types had two-and-a-half-times higher odds of multisite MSK pain at baseline and follow-up (OR 2.47, 95% CI 1.84-3.32) than the M-types. Having severe mental distress or poor sleep at baseline and follow-up, or sex did not change the strength of this association. Our examination of this longitudinal birth cohort study suggested that evening types, in comparison to morning types, are more likely to experience multisite MSK pain between ages 31 and 46 years. Chronotype should be recognized as a predictor of multisite pain and thus taken into account in the evaluation of a patient's risk for multisite pain. Perspective: This longitudinal study shows that evening types, compared to morning types, have higher odds of experiencing multisite MSK pain between ages 31 and 46 years. Chronotype should be considered while evaluating MSK patient's risk for persistent multisite pain symptoms.

Pediatric sleep and pain: etiologies, consequences, and clinical considerations

STUDY OBJECTIVES

To examine current evidence of the relationship between sleep and pain from the neonatal period through adolescence. This review serves as a critical review of the literature and of the needs for future research on pediatric sleep and pain.

METHODS

The PubMed online database was queried from January 1, 1960, to March 1, 2020, producing 149 articles applicable to pain and sleep in the pediatric population. Of those, 97 articles were cited in this review with the key articles including over 3800 participants.

RESULTS

The pediatric literature supports the relationship between poor sleep (both sleep efficiency and nighttime awakenings) and subsequent risk for pain, especially among children with chronic disease. The reverse effect of pain on sleep is not yet well delineated. The key moderating factors explored in the literature are pharmacologic and nonpharmacologic therapies, psychologic health, and the etiology of pain. There is evidence that both altered sleep and pain early in life impact neurodevelopment, as seen by changes in sleep structure in clinical studies and alterations in brain development in animal models.

CONCLUSIONS

The complicated relationship between sleep and pain is critically important during pediatric development when alterations to a normal sleep structure can have a lifelong impact. It is becoming clear that sleep deprivation and poor sleep quality exacerbate pain. Further research is needed into the complex alterations of sleep in chronic pain conditions as well as treatments to improve sleep in pediatric care.

CITATION

Morris EE, Howell MJ, Pickup E, Iber C, Wang SG. Pediatric sleep and pain: etiologies, consequences, and clinical considerations. J Clin Sleep Med. 2022;18(9):2281-2289.

Sleep deprivation and recovery sleep affect healthy male resident’s pain sensitivity and oxidative stress markers: The medial prefrontal cortex may play a role in sleep deprivation model

Sleep is essential for the body’s repair and recovery, including supplementation with antioxidants to maintain the balance of the body’s redox state. Changes in sleep patterns have been reported to alter this repair function, leading to changes in disease susceptibility or behavior. Here, we recruited healthy male physicians and measured the extent of the effect of overnight sleep deprivation (SD) and recovery sleep (RS) on nociceptive thresholds and systemic (plasma-derived) redox metabolism, namely, the major antioxidants glutathione (GSH), catalase (CAT), malondialdehyde (MDA), and superoxide dismutase (SOD). Twenty subjects underwent morning measurements before and after overnight total SD and RS. We found that one night of SD can lead to increased nociceptive hypersensitivity and the pain scores of the Numerical Rating Scale (NRS) and that one night of RS can reverse this change. Pre- and post-SD biochemical assays showed an increase in MDA levels and CAT activity and a decrease in GSH levels and SOD activity after overnight SD. Biochemical assays before and after RS showed a partial recovery of MDA levels and a basic recovery of CAT activity to baseline levels. An animal study showed that SD can cause a significant decrease in the paw withdrawal threshold and paw withdrawal latency in rats, and after 4 days of unrestricted sleep, pain thresholds can be restored to normal. We performed proteomics in the rat medial prefrontal cortex (mPFC) and showed that 37 proteins were significantly altered after 6 days of SD. Current findings showed that SD causes nociceptive hyperalgesia and oxidative stress, and RS can restore pain thresholds and repair oxidative stress damage in the body. However, one night of RS is not enough for repairing oxidative stress damage in the human body.

Predictors of neck disability among undergraduate students: A cross-sectional study

BACKGROUND: Many cross-sectional studies have examined the predictors of neck pain among adolescents and working-age populations, but there are limited studies included undergraduate students. OBJECTIVE: To investigate the predictors of neck disability among undergraduate students. METHODS: A cross-sectional study using a self-administered online survey. Students completed the survey that included socio-demographic factors, academic-related factors, health and lifestyle factors, and standardized questionnaires including Neck Disability Index (NDI), 12-Item Short-Form Health Survey (SF-12), Depression Anxiety Stress Scales (DASS-21), and Pittsburgh Sleep Quality Index (PSQI). Students who reported an NDI score higher than 15 were considered as having a neck disability. A multivariable logistic regression model was used to identify the significant predictors of neck disability. RESULTS: Of all students (n = 1292), 20.8% reported neck disability. Among all possible predictors, students’ major satisfaction (OR 1.46 [95% CI 1.06–2.01]; p = 0.019), DASS-21 anxiety score (OR 1.06 [95% CI 1.03–1.09]; p < 0.001), SF-12 total score (OR 0.89 [95% CI 0.86–92]; p < 0.001), and PSQI score (OR 1.21 [95% CI 1.15–1.28]; p < 0.001) were the only significant predictors of neck disability. CONCLUSIONS: Increased levels of academic stressors and anxiety, and decreased levels of quality of life and sleep quality are associated with increased neck disability among undergraduate students.

Clinical and psychological factors in coronary heart disease patients with statin associated muscle side-effects

Background

To compare clinical and psychological factors among patients with self-perceived statin-associated muscle symptoms (SAMS), confirmed SAMS, and refuted SAMS in coronary heart disease patients (CHD).

Methods

Data were obtained from a cross-sectional study of 1100 CHD outpatients and a study of 71 CHD outpatients attending a randomized, double-blinded, placebo-controlled, crossover study to test effects of atorvastatin 40 mg/day on muscle symptom intensity. Clinical and psychosocial factors were compared between patients with and without SAMS in the cross-sectional study, and between patients with confirmed SAMS and refuted SAMS in the randomized study.

Results

Bilateral, symmetric muscle symptoms in the lower extremities during statin treatment were more prevalent in patients with confirmed SAMS compared to patients with refuted SAMS (75% vs. 41%, p = 0.01) in the randomized study. No significant differences in psychological factors (anxiety, depression, worry, insomnia, type D personality characteristics) were detected between patients with and without self-perceived SAMS in the cross-sectional study, or between patients with confirmed SAMS and refuted SAMS, in the randomized study.

Conclusions

Patients with confirmed SAMS more often present with bilateral lower muscle symptoms compared to those with refuted SAMS. Psychological factors were not associated with self-perceived SAMS or confirmed SAMS. A careful pain history and a search for alternative causes of muscle symptoms are likely to promote communication in patients with SAMS, and may reduce the risk for statin discontinuation.

Association Between Sleep Quality and Pain Intensity in Mild Patients with COPD: A Community Study

Purpose

Poor sleep quality and pain were common and had been proved as an important influenced factor of quality of life for patients with COPD. The association of sleep quality with pain has been observed in other population but remains unclear in mild patients with COPD from a community setting.

Methods

A cross-sectional study was conducted to include eligible mild patients with COPD in Pudong New District of Shanghai. A structured questionnaire was used to collect general and clinical information for the patients. The Chinese version of Pittsburgh Sleep Quality Index (PSQI) and the short form of McGill Pain Questionnaire (SF-MPQ) was used to assess sleep quality and intensity of pain. Logistic regression was performed to test the association between sleeping quality and pain intensity.

Results

Two hundred and sixty-four patients with COPD, with an average age of 64 years (SD 5.78 years), were enrolled, and of 52% were women. Seventy-one (26.9%) participants reported at least one exacerbation during the past year. About 28.2% of the patients were classified as having poor sleep quality. Sleep quality was significantly associated with PRI score (adjusted odds ratio (ORad)=2.16, 95% CI: 1.16–4.00) and PPI rank (ORad=1.90, 95% CI: 1.08–3.34). People with daytime disturbance were more likely to have pain (ORad =2.03, 95% CI: 1.18–3.50).

Conclusion

Poor sleep quality was common in mild patients with COPD in community and was associated with higher pain intensity. Pain may involve an impairment of sleep quality.

Assessment of sleep quality in fibromyalgia syndrome and its effect on postural balance and functional status

BACKGROUND

Patients with fibromyalgia syndrome (FMS) often have sleep problems and balance disorders.

OBJECTIVE

The aim of the study was to examine sleep quality and balance disorders and the relationship between sleep quality and balance, functional status and the frequency of falls in patients with FMS.

METHODS

Fifty women with FMS and 50 healthy women were included in the study. Sleep quality was assessed with the numeric rating scale (NRS) and the Pittsburgh Sleep Quality Index (PSQI) and balance and balance self-confidence were assessed with the Berg Balance Scale (BBS) and Activities-Specific Balance Confidence (ABC) Scale, respectively. Functional status and symptom severity of patients were assessed with the Fibromyalgia Impact Questionnaire (FIQ) and the Symptom Impact Questionnaire (SIQR). The number of falls in the last six months were recorded.

RESULTS

In the patient group, sleep quality scores were significantly higher, and BBS and ABC scores were significantly lower than the control group. NRS scores were significantly correlated with the BBS, FIQ, and SIQR scores, and the PSQI scores were significantly correlated with the BBS and ABC scores and the number of falls in FMS.

CONCLUSION

This study showed that the prevalence of sleep and balance disorders is higher in FMS patients. A relationship was reported between the sleep quality and balance and functional status and frequency of falls.

Effects of Neurofeedback on Fibromyalgia: A Randomized Controlled Trial

BACKGROUND

Fibromyalgia is a chronic widespread pain condition that is associated with sleep disturbances and cognitive impairments. Neurofeedback has been demonstrated to improve pain, sleep quality, and fatigue. However, few studies have examined the effect of neurofeedback for patients with fibromyalgia.

AIM

To determine the effects of neurofeedback on pain intensity, symptom severity, sleep quality, and cognitive function in patients with fibromyalgia.

DESIGN

This study was a randomized controlled trial.

METHOD

Eighty participants were randomized to a neurofeedback group (N = 60), receiving sensorimotor and alpha rhythm feedback for 8 weeks, or a telephone support group (N = 20).

RESULTS

Results from the generalized estimating equation modelling revealed significant group-by-time interactions for Brief Pain Inventory pain severity (B = -1.35, SE = 0.46, p = .003) and pain interference (B = -1.75, SE = 0.41, p < .001), Revised Fibromyalgia Impact Questionnaire total scores (B = -16.41, SE = 3.76, p < .001), sleep onset latency (B = -25.33, SE = 9.02, p = .005), and Psychomotor Vigilance Test error (B = -1.38, SE = 0.55, p = .013) after adjustments for age, sex, duration of illness, and group differences at baseline.

CONCLUSIONS

An 8-week neurofeedback training regimen of sensorimotor rhythm and alpha brain waves significantly improved pain severity and interference, fibromyalgia symptom severity, sleep latency, and sustained attention in patients with fibromyalgia.

Chronic Severe Sleep Problems among Non-Nordic Immigrants. Data from a Population Postal Survey in Mid-Sweden

Sweden has a large population of both recent and established immigrants with high prevalence of risk factors for ill health. Here, we aimed to explore the prevalence of chronic severe sleep problems (CSSP) among non-Nordic-born persons, and to evaluate the risk for CSSP when fully adjusted for covariates. Our additional hypothesis was that lengthier time since immigration would reduce the risk for CSSP. We used data from a large-population postal survey covering life and health issues among inhabitants in mid-Sweden. Relationship between different countries of birth and CSSP was assessed in logistic analyses for more severe and longstanding pain, sex, employment, mental disability, gastrointestinal problems, and length of stay (short, middle time, and up to ten years of stay). Persons of non-Nordic birth reported significantly more often CSSP, regardless of short or long-term stay. Our findings indicate that non-Nordic birth, regardless of residence time and covariates, was an independent and significant predictor for CSSP. The findings may contribute to increasing awareness in healthcare personnel to recognize chronic sleep problems among immigrant patients. Thus, our study might contribute to developing strategies to enhance health for minorities.

Worse health status, sleeping problems, and anxiety in 16-year-old students are associated with chronic musculoskeletal pain at three-year follow-up

Background

Chronic musculoskeletal pain is common in adolescents, and it has been shown that adolescents with pain may become young adults with pain. Pain often coincides with psychosomatic symptoms in adults, but little is known about longitudinal associations and predictors of pain in adolescents. The aim was to investigate chronic musculoskeletal pain and its associations with health status, sleeping problems, stress, anxiety, depression, and physical activity in 16-year-old students at baseline, and to identify risk factors using a three-year follow-up.

Methods

This was a longitudinal study of 256 students attending a Swedish upper secondary school. Questionnaires regarding chronic musculoskeletal pain and distribution of pain (mannequin), health status (EQ-5D-3 L), sleeping problems (Uppsala Sleep Inventory), stress symptoms (single-item question), anxiety and depression (Hospital Anxiety and Depression Scale), and physical activity (International Physical Activity Questionnaire) were issued at baseline and follow-up. Student’s t-test and chi² test were used for descriptive statistics and logistic regression analyses were used to study associations between chronic pain and independent variables.

Results

Fifty-two out of 221 students at baseline (23.5%) and 39 out of 154 students at follow-up (25.3%) were categorized as having chronic musculoskeletal pain. Chronic musculoskeletal pain at follow-up was separately associated with reporting of an EQ-5D value below median (OR 4.06, 95% CI 1.83–9.01), severe sleeping problems (OR 3.63, 95% CI 1.69–7.82), and possible anxiety (OR 4.19, 95% CI 1.74–10.11) or probable anxiety (OR 3.82, 95% CI 1.17–12.48) at baseline. Similar results were found for associations between chronic musculoskeletal pain and independent variables at baseline. In multiple logistic regression analysis, chronic musculoskeletal pain at baseline was a predictor of chronic musculoskeletal pain at follow-up (OR 2.99, 95% CI 1.09–8.24, R² = 0.240).

Conclusion

Chronic musculoskeletal pain at baseline was the most important predictor for reporting chronic musculoskeletal pain at the three-year follow-up, but a worse health status, severe sleeping problems, and anxiety also predicted persistence or development of chronic musculoskeletal pain over time. Interventions should be introduced early on by the school health services to promote student health.

Best Evidence Rehabilitation for Chronic Pain Part 4: Neck Pain

Neck pain, whether from a traumatic event such as a motor vehicle crash or of a non-traumatic nature, is a leading cause of worldwide disability. This narrative review evaluated the evidence from systematic reviews, recent randomised controlled trials, clinical practice guidelines, and other relevant studies for the effects of rehabilitation approaches for chronic neck pain. Rehabilitation was defined as the aim to restore a person to health or normal life through training and therapy and as such, passive interventions applied in isolation were not considered. The results of this review found that the strongest treatment effects to date are those associated with exercise. Strengthening exercises of the neck and upper quadrant have a moderate effect on neck pain in the short-term. The evidence was of moderate quality at best, indicating that future research will likely change these conclusions. Lower quality evidence and smaller effects were found for other exercise approaches. Other treatments, including education/advice and psychological treatment, showed only very small to small effects, based on low to moderate quality evidence. The review also provided suggestions for promising future directions for clinical practice and research.

Insomnia Increases Symptom Severity and Health Care Utilization in Patients With Fibromyalgia: A Population-based Study

Supplemental Digital Content is available in the text.

Objective:

This study aimed to determine whether comorbid insomnia is associated with increased use of fibromyalgia-related medications and health resources in fibromyalgia (FM) patients.

Materials and Methods:

We analyzed data retrieved from the Longitudinal Health Insurance Database 2010, which contains claims data of 1 million beneficiaries randomly selected from Taiwan’s National Health Insurance program. Patients treated for FM (n=17,920) on 2 separate visits between 2000 and 2001 were selected and subsequently divided into 2 groups: patients with and without comorbid insomnia (n=5466 and 12,454, respectively). Insomnia was identified through diagnosis on 2 separate visits after the index FM date. FM-related pharmacotherapies and ambulatory care visits were tracked from the index date to the end of 2013.

Results:

Insomnia was associated with increased likelihood of future use of antidepressants (adjusted odds ratio [OR]=3.84, P<0.001), gabapentin (adjusted OR=1.67, P<0.001), pregabalin (adjusted OR=1.79, P=0.046), muscle relaxants (adjusted OR=3.05, P<0.001), and opioids and tramadol (adjusted OR=1.59, P<0.001) among FM patients compared with FM patients without insomnia. In addition, a diagnosis of insomnia was associated with an increased frequency of visits to ambulatory care services for both FM (β=1.79; 95% confidence interval, 1.57-2.02; P<0.001) and other conditions (β=108.51; 95% confidence interval, 103.14-113.89; P<0.001).

Discussion:

This study demonstrates the substantial burden of comorbid insomnia in patients with FM.

[Sleep disorders in chronic pain syndromes]

Sleep disorders and pain syndromes are widespread in the general population. This review presents data on comorbidity of these phenomena and possibility of their mutual influence on each other including data based on long-term prospective studies. Studies of pain syndromes and sleep disorders dynamics are analyzed in detail. Anatomical basis of sleep-pain interactions is described, and results of the emotional influence on sleep and pain associations are presented. Non-pharmacological and drug-based approaches to treatment with detailed description of the biochemical basis of their action are considered. The authors conclude that pain syndromes and sleep disorders have reciprocal relations; the improvement of sleep quality helps in various pain syndromes; sleep normalization could play a preventive role with regard to pain.

Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization

Chronic pain conditions are highly comorbid with insufficient sleep. While the mechanistic relationships between the 2 are not understood, chronic insufficient sleep may be 1 pathway through which central pain-modulatory circuits deteriorate, thereby contributing to chronic pain vulnerability over time. To test this hypothesis, an in-laboratory model of 3 weeks of restricted sleep with limited recovery (5 nights of 4-hour sleep per night followed by 2 nights of 8-hour sleep per night) was compared with 3 weeks of 8-hour sleep per night (control protocol). Seventeen healthy adults participated, with 14 completing both 3-week protocols. Measures of spontaneous pain, heat-pain thresholds, cold-pain tolerance (measuring habituation to cold over several weeks), and temporal summation of pain (examining the slope of pain ratings during cold water immersion) were assessed at multiple points during each protocol. Compared with the control protocol, participants in the sleep-restriction protocol experienced mild increases in spontaneous pain (P < 0.05). Heat-pain thresholds decreased after the first week of sleep restriction (P < 0.05) but normalized with longer exposure to sleep restriction. By contrast, chronic exposure to restricted sleep was associated with decreased habituation to, and increased temporal summation in response to cold pain (both P < 0.05), although only in the past 2 weeks of the sleep-restriction protocol. These changes may reflect abnormalities in central pain-modulatory processes. Limited recovery sleep did not completely resolve these alterations in pain-modulatory processes, indicating that more extensive recovery sleep is required. Results suggest that exposure to chronic insufficient sleep may increase vulnerability to chronic pain by altering processes of pain habituation and sensitization.

Sleep problems and fatigue as predictors for the onset of chronic widespread pain over a 5- and 18-year perspective

BACKGROUND

Previous research suggests that sleep problems may be an important predictor for chronic widespread pain (CWP). With this study we investigated both sleep problems and fatigue as predictors for the onset of CWP over a 5-year and an 18-year perspective in a population free from CWP at baseline.

METHODS

To get a more stable classification of CWP, we used a wash-out period, including only individuals who had not reported CWP at baseline (1998) and three years prior baseline (1995). In all, data from 1249 individuals entered the analyses for the 5-year follow-up and 791 entered for the 18-year follow-up. Difficulties initiating sleep, maintaining sleep, early morning awakening, non-restorative sleep and fatigue were investigated as predictors separately and simultaneously in binary logistic regression analyses.

RESULTS

The results showed that problems with initiating sleep, maintaining sleep, early awakening and non-restorative sleep predicted the onset of CWP over a 5-year (OR 1.85 to OR 2.27) and 18-year (OR 1.54 to OR 2.25) perspective irrespective of mental health (assessed by SF-36) at baseline. Also fatigue predicted the onset of CWP over the two-time perspectives (OR 3.70 and OR 2.36 respectively) when adjusting for mental health. Overall the effect of the sleep problems and fatigue on new onset CWP (over a 5-year perspective) was somewhat attenuated when adjusting for pain at baseline but remained significant for problems with early awakening, non-restorative sleep and fatigue. Problems with maintaining sleep predicted CWP 18 years later irrespective of mental health and number of pain regions (OR 1.72). Reporting simultaneous problems with all four aspects of sleep was associated with the onset of CWP over a five-year and 18-yearperspective, irrespective of age, gender, socio economy, mental health and pain at baseline. Sleep problems and fatigue predicted the onset of CWP five years later irrespective of each other.

CONCLUSION

Sleep problems and fatigue were both important predictors for the onset of CWP over a five-year perspective. Sleep problems was a stronger predictor in a longer time-perspective. The results highlight the importance of the assessment of sleep quality and fatigue in the clinic.

Undercover Dogs: Pet Dogs in the Sleep Environment of Patients with Chronic Pain

(1) Background: Chronic pain is a significant and prevalent condition in many industrialized nations. Pain and sleep’s reciprocal nature suggests that interventions to improve sleep may decrease pain symptoms. Little attention has been paid to the influence that owning a pet dog has on the pain/sleep relationship. Typical advice to remove pets from the bedroom negates the possible positive benefit of human-animal co-sleeping. Aim: To investigate pain patients’ perceived impact of pet dog ownership on sleep. (2) Methods: We carried out a content analysis of interview data focused on the impact of pet dog ownership on sleep. The qualitative dataset comes from a subgroup of participants in a larger study examining the pain patient/canine relationship. This subgroup of participants from the larger study was asked, “Does your dog have a positive or negative impact on your sleep?” The data were thematically coded using an iterative approach. (3) Findings: Codes included: companionship; physical presence/’cuddles’; routine/schedule; distraction from anxiety/worry at night; reassuring/protective presence; active intervention to keep participant safe; daytime activity to promote sleeping at night; and reciprocal concern for the sleep of the pet dog. (4) Conclusions: Pet dogs may play important roles in helping people with chronic pain achieve sleep onset and maintenance. Removing the dog to improved sleep could be counter-productive and lead to additional sleep-related issues.

A prospective study of work-private life conflict and number of pain sites: moderated mediation by sleep problems and support

The objective of the current study was to elucidate how work-private life conflict prospectively affects musculoskeletal pain complaints by exploring possible mediation through sleep problems. In addition, the study determined whether support from coworkers and superior moderate this mediated relationship. The study incorporated a two-wave full panel design and participants included 4681 Norwegian working men and women. Path analyses were performed to study direct and indirect effects of work-private life conflict on sleep problems and multisite musculoskeletal pain, moderated by support. This study suggested time-lagged relationships of work-private life conflict with number of pain sites. Furthermore, sleep problems may mediate the effects of work-private life conflict on number of pain sites. While support has been found to affect the direct relationship between work-private life conflict and number of pain sites, it does not significantly moderate the indirect mediation effect, i.e. no moderated mediation effect of support was established. Findings from the present study suggest sleep may be one explaining factor in the complex work-pain mechanism, and this may aid the development of theories on work-private life conflict and pain. Since both work-private life conflict and support are modifiable work factors, primary workplace interventions by the employer aiming to reduce sleep problems and musculoskeletal pain in employees could target these specific work factors, and help prevent work-related pain complaints.

Effects of sleep changes on pain-related health outcomes in the general population: A systematic review of longitudinal studies with exploratory meta-analysis

Emerging longitudinal research has highlighted poor sleep as a risk factor of a range of adverse health outcomes, including disabling pain conditions. In establishing the causal role of sleep in pain, it remains to be clarified whether sleep deterioration over time is a driver of pain and whether sleep improvement can mitigate pain-related outcomes. A systematic literature search was performed using PubMed MEDLINE, Ovid EMBASE, and Proquest PsycINFO, to identify 16 longitudinal studies involving 61,000 participants. The studies evaluated the effect of sleep changes (simulating sleep deterioration, sleep stability, and sleep improvement) on subsequent pain-related outcomes in the general population. A decline in sleep quality and sleep quantity was associated with a two- to three-fold increase in risk of developing a pain condition, small elevations in levels of inflammatory markers, and a decline in self-reported physical health status. An exploratory meta-analysis further revealed that deterioration in sleep was associated with worse self-reported physical functioning (medium effect size), whilst improvement in sleep was associated with better physical functioning (small effect size). The review consolidates evidence that changes in sleep are prospectively associated with pain-related outcomes and highlights the need for further longitudinal investigations on the long-term impact of sleep improvements.

Insomnia Really Hurts: Effect of a Bad Night's Sleep on Pain Increases With Insomnia Severity

Insomnia and chronic pain are highly prevalent conditions and are often comorbid. Somatic complaints other than pain are also often observed in insomnia. Poor sleep and pain are known to mutually reinforce each other. However, it is unknown whether the habitual severity of insomnia modulates the acute effect of a particularly bad night's sleep on the next day's pain severity, and whether it modulates the acute effect of pain on the following night's sleep quality. Using data from 3,508 volunteers (2,684 female, mean age 50.09 y), we addressed these questions in addition to the associations between the habitual severity of insomnia, somatic complaints, and pain. Results indicated that people suffering from more severe habitual insomnia showed stronger mutual acute within-day reactivity of pain and poor sleep quality. The same increased reactivity was found in people with more severe habitual pain. Interestingly, the acute within-day mutual reactivity of pain and sleep quality showed consistent asymmetry. Pain worsened more after a particularly bad night's sleep than it improved after a particularly good night's sleep. Likewise, sleep worsened more after a day with more-than-usual pain than it improved after a day with less-than-usual pain. Future interventions may profit from addressing this asymmetric mutual reactivity especially in people with severe comorbid insomnia and chronic pain.

A novel clinical framework: The use of dispositions in clinical practice. A person centred approach

This paper explores a novel clinical framework that is underpinned by a specific philosophical perspective of causation and its utility in clinical practice. A dispositional theory of causation may overcome challenges that clinicians face in complex clinical presentations including those that are medically unexplained. Dispositionalism identifies causes not as regular events necessitating an effect but rather phenomena, which are highly complex, context-sensitive, and which tend toward an effect. Diagnostic uncertainty and causal explanation are significant challenges in terms of clinical reasoning, communication, and the overall therapeutic outcome. This novel framework aims to facilitate improved collaborative clinical reasoning, enhanced patient-practitioner interaction, and supported treatment planning. The paper uses a real case study of a patient with nonspecific spinal pain to demonstrate the clinical framework as used in clinical practice.

Sleep disturbances in fibromyalgia: A meta-analysis of case-control studies

OBJECTIVE

Sleep disturbances are common in fibromyalgia, but the features of sleep disturbances are not well understood. We performed a systematic review and meta-analysis of case-control studies to compare the sleep outcomes of individuals with fibromyalgia and healthy controls.

METHODS

We systematically searched eight databases (PubMed, Ovid MEDLINE, Embase, CINAHL, PsycINFO, Web of Science, Airiti Library and Wanfang Data) for articles published before April 2016.

RESULTS

Twenty-five case-controlled studies and a total of 2086 participants were included in the meta-analysis. Sleep was assessed using polysomnography and the Pittsburgh Sleep Quality Index. When sleep was assessed using polysomnography (19 studies), significant differences were observed in wake time after sleep onset (g=0.81, 95% confidence interval [CI] 0.21-1.41), total sleep time (g=-0.78, 95% CI=-1.34 to -0.15), sleep efficiency (g=-0.78, 95% CI=-1.23 to -0.32), percentage of stage 1 sleep (g=0.55, 95% CI=0.15-0.95), and percentage of slow-wave sleep (g=-0.66, 95% CI=-1.21 to -0.12) between participants with fibromyalgia and healthy controls. When sleep was assessed using the Pittsburgh Sleep Quality Index (7 studies), significant differences were observed in global scores (g=2.19, 95% CI 1.58-2.79), sleep onset latency (g=1.75, 95% CI 0.80-2.70), and sleep efficiency (g=-1.08, 95% CI -1.65 to -0.51) between participants with fibromyalgia and healthy controls.

CONCLUSION

Individuals with fibromyalgia experience lower sleep quality and sleep efficiency; longer wake time after sleep onset, short sleep duration, and light sleep when objectively assessed and more difficulty in initiating sleep when subjectively assessed. Sleep difficulties in fibromyalgia appear to be more when reported subjectively than when assessed objectively.

COMPLIANCE WITH ETHICAL STANDARDS

This study received no funding from any source. All authors declare that they have no conflict of interest. This article does not contain any studies with human participants performed by any of the authors.

Back Complaints in the Elders in Brazil and the Netherlands: a cross-sectional comparison

Background

although back pain is most prevalent in older adults, there is a paucity of studies investigating back pain in older people. Our objective was to characterize and compare Brazilian and Dutch older adults presenting to primary care with a new episode of back pain. We also aimed to investigate whether socio-demographic characteristics were associated with pain severity and disability.

Methods

we sourced data on 602 Brazilian and 675 Dutch participants aged ≥55 years with a new episode of back pain from the Back Complaints in the Elders consortium. We analyzed country differences in participants' characteristics, and associations between socio-demographic/clinical characteristics and pain severity and pain-related disability.

Results

the two populations differed in most characteristics. More Dutch participants were smokers, heavy drinkers, and reported back stiffness. More Brazilian participants were less educated, had higher prevalence of comorbidities; higher levels of pain intensity, disability and psychological distress. When controlling for the effect of country, being female and having altered quality of sleep were associated with higher pain intensity. Altered quality of sleep, having two or more comorbidities and physical inactivity were associated with higher disability. Higher educational levels were negatively associated with both pain and disability outcomes.

Conclusions

back pain is disabling in the older population. Our country comparison has shown that country of residence is an important determinant of higher disability and pain in older people with back pain. Irrespective of country, women with poor sleep quality, comorbidities, low education and who are physically inactive report more severe symptoms.

Racial/ethnic differences in sleep quality among older adults with osteoarthritis

OBJECTIVE

To examine racial/ethnic differences in sleep quality and the pain-sleep association among older adults with osteoarthritis of the knee.

DESIGN

Baseline interview followed by a 7-day microlongitudinal study using accelerometry and self-reports.

SETTING

Participants were community residents in western Alabama and Long Island, NY.

PARTICIPANTS

Ninety-six African Americans (AAs) and 128 non-Hispanic whites (NHWs) with physician-diagnosed knee osteoarthritis, recruited from a variety of clinical and community settings.

MEASUREMENTS

Self-reports yielded demographics, body mass index, physical health problems, and depressive symptoms. Sleep quality was measured for 3 to 7 nights using wrist-worn accelerometers; pain was self-reported daily over the same period.

RESULTS

With demographics and health controlled, AAs displayed poorer sleep efficiency, greater time awake after sleep onset and sleep fragmentation, and marginally more awakenings during the night, but no differences in total sleep time. AAs also showed greater night-to-night variability in number of awakenings and sleep fragmentation, and marginally greater variability in total sleep time and sleep efficiency. Sleep quality was not associated with pain either the day before sleep or the day after. Average daily pain interacted with race, whereas AAs displayed no effect of pain on sleep efficiency, NHWs exhibited better sleep efficiency at higher levels of average pain.

CONCLUSIONS

These data corroborate previous studies documenting poorer sleep among AAs vs NHWs. The findings of greater night-to-night variability in sleep among AAs, as well as a negative association of pain with sleep quality among NHWs, are unique. Further study is needed to elucidate these findings.

Reliability of Actigraphy and Subjective Sleep Measurements in Adults: The Design of Sleep Assessments

STUDY OBJECTIVES

The aim of the study was to investigate how many nights of measurement are needed for a reliable measure of sleep in a working population including adult women and men.

METHODS

In all, 54 individuals participated in the study. Sleep was assessed for 7 consecutive nights using actigraphy as an objective measure, and the Karolinska sleep diary for a subjective measure of quality. Using intra-class correlation and the Spearman-Brown formula, calculations of how many nights of measurements were required for a reliable measure were performed. Differences in reliability according to whether or not weekend measurements were included were investigated. Further, the correlation between objectively (actigraphy) measured sleep and subjectively measured sleep quality was studied over the different days of the week.

RESULTS/CONCLUSIONS

The results concerning actigraphy sleep measures suggest that data from at least 2 nights are to be recommended when assessing sleep percent and at least 5 nights when assessing sleep efficiency. For actigraphy-measured total sleep time, more than 7 nights are needed. At least 6 nights of measurements are required for a reliable measure of self-reported sleep. Fewer nights (days) are required if measurements include only week nights. Overall, there was a low correlation between the investigated actigraphy sleep parameters and subjective sleep quality, suggesting that the two methods of measurement capture different dimensions of sleep.

Pain extent and function in youth with physical disabilities

Background

The aim of this study was to increase our understanding of the role that spatial qualities of pain (location and extent) play in functioning, among youths with disabilities and chronic pain.

Methods

One-hundred and fifteen youths (mean age 14.4 years; SD ±3.3 years) with physical disabilities and chronic pain were interviewed and were asked to provide information about pain locations and their average pain intensity in the past week, and to complete measures of pain interference, psychological function and disability. Most of the participants in this sample were males (56%), Caucasian (68%), and had a cerebral palsy (34%) or muscular dystrophy (25%) problem. Most participants did not report high levels of disability ( X¯=12.7, SD ±9.5, range 0–60) or global pain intensity ( X¯=3.2, SD ±2.4, range 0–10).

Results

Pain at more than one body site was experienced by 91% of participants. There were positive associations between pain extent with pain interference (r = 0.30) and disability (r = 0.30), and a negative association with psychological function (r = –0.38), over and above average pain intensity. Additionally, pain intensity in the back (as opposed to other locations) was associated with more pain interference (r = 0.29), whereas pain intensity in the shoulders was associated with less psychological function (r = –0.18), and pain intensity in the bottom or hips was associated with more disability (r = 0.29).

Conclusion

The findings support the need to take into account pain extent in the assessment and treatment of youths with physical disabilities and chronic pain, call our attention about the need to identify potential risk factors of pain extent, and develop and evaluate the benefits of treatments that could reduce pain extent and target pain at specific sites.

Sleep disturbances predict future sickness absence among individuals with lower back or neck-shoulder pain: a 5-year prospective study

BACKGROUND

Musculoskeletal pain is one of the most common causes of sickness absence. Sleep disturbances are often co-occurring with pain, but the relationship between sleep and pain is complex. Little is known about the importance of self-reported sleep, when predicting sickness absence among persons with musculoskeletal pain. This study aims to study the association between self-reported sleep quality and sickness absence 5 years later, among individuals stratified by presence of lower back pain (LBP) and neck and shoulder pain (NSP).

METHODS

The cohort (n = 2286) in this 5-year prospective study (using data from the MUSIC-Norrtälje study) was stratified by self-reported pain into three groups: no LBP or NSP, solely LBP or NSP, and concurrent LBP and NSP. Odds ratios (ORs) for the effect of self-reported sleep disturbances at baseline on sickness absence (> 14 consecutive days), 5 years later, were calculated.

RESULTS

Within all three pain strata, individuals reporting the most sleep problems showed a significantly higher OR for all-cause sickness absence, 5 years later. The group with the most pronounced sleep problems within the concurrent LBP and NSP stratum had a significantly higher OR (OR 2.00; CI 1.09-3.67) also for long-term sickness absence (> 90 days) 5 years later, compared to the group with the best sleep. CONCLUSIONS Sleep disturbances predict sickness absence among individuals regardless of co-existing features of LBP and/or NSP. The clinical evaluation of patients should take possible sleep disturbances into account in the planning of treatments.