Insomnia is a risk factor for spreading of chronic pain: A Swedish longitudinal population study (SwePain)

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

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

Evidence-Based Opinions from Multidisciplinary Experts on Use of Naturopathic Herbal Remedies in Pain Management

Background

Pharmacological approaches to acute and chronic pain management, including non-steroidal anti-inflammatory drugs (NSAIDs) and opioids, are respectively associated with adverse reactions (such as gastrointestinal, cardiovascular, and renal effects) that might limit their use in patients with comorbidities and controversy related to inappropriate use. Naturopathic remedies might offer patients alternative and integrative treatments with minimal side effects.

Objective

To explore the regional variation in the acceptance and use of naturopathic remedies in pain management.

Methods

Two expert panel discussions were held by GlaxoSmithKline Consumer Healthcare (now Haleon Pte. Ltd.) over 9 and 12 hours in 2020 and 2021, respectively, and attended by multidisciplinary experts in naturopathy, Ayurvedic medicine, community pharmacy, physiotherapy, clinical pharmacy, Western medicine, academics, and naturopathic pain relief. Experts shared and discussed their experiences of naturopathic treatments and relevant clinical evidence related to different types of pain (including joint and muscle pain, migraine, sleeplessness due to pain, and general pain) and examined barriers to providing support to patients.

Results

Experts agreed on the potential for curcumin (2020, 71.4% [5/7]; 2021, 91.7% [11/12]) and fish oil (2020, 100% [7/7]) for management of osteoarthritic joint pain although these are not uniformly recommended in osteoarthritis treatment guidelines. In treatment of migraines, coenzyme Q10 and magnesium were favored by experts (2021, 90.9% [10/11] and 63.6% [7/11], respectively).

Conclusion

The need was emphasized for more and higher quality clinical studies to support naturopathic remedies, which might not be reflected in the latest treatment guidelines. The expert panel also highlighted missed opportunities for physicians and pharmacists to recommend effective naturopathic treatments.

Association of Sleep Disturbance With Catastrophizing and Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To investigate the relationship between sleep disturbance, catastrophizing, and knee pain in middle-aged and older individuals.

METHODS

Data from the Osteoarthritis Initiative cohort from months 48 to 96 were used, where month 48 was treated as baseline. Knee pain (Western Ontario and McMaster Universities Osteoarthritis Index pain scale score ≥5 [range 0-20]), catastrophizing (extracted from Coping Strategies Questionnaire score ≥3 [range 0-6]), and sleep quality (extracted from Center for Epidemiologic Studies Depression Scale [range 1-4]) were assessed annually. We described the association of sleep disturbance with the presence and risk of knee pain and catastrophizing. The mediation effect of knee pain and catastrophizing on the sleep-catastrophizing and sleep-pain association was evaluated, respectively.

RESULTS

Catastrophizing and knee pain were reported in 346 (10%) and 917 (24%) of the 3,813 participants (mean 64.9 years, 58% female) at baseline. Participants with worse sleep disturbance were more likely to have knee pain (prevalence ratio [PR] 1.4-2.0, P for trend <0.001) and catastrophizing (PR 1.4-3.1, P for trend <0.001). Sleep disturbance at baseline predicted the risk of knee pain (risk ratio [RR] 1.1, P for trend <0.001) and catastrophizing (RR 1.2-1.7, P for trend <0.001) during follow-up. No statistically significant interactions between sleep disturbance and knee pain or catastrophizing were observed. Knee pain and catastrophizing mediated the sleep-catastrophizing and sleep-pain association, respectively, at baseline, and knee pain negatively mediated the sleep-catastrophizing association longitudinally.

CONCLUSION

Sleep disturbance was associated with the presence and risk of catastrophizing and knee pain. Sleep interventions may have a universal and independent effect in preventing incident knee pain.

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.

Sleep quality as a mediator of the relation between depression and chronic pain: a systematic review and meta-analysis

BACKGROUND

Chronic pain and depression represent two global health problems with considerable economic consequences. Although existing literature reports on the relation between depression and pain conditions, meta-analytic evidence backing the mediating role of sleep disturbance as one of the main symptoms of depression is scarce. To examine the extent to which sleep disturbance mediates the depression-chronic pain association, we conducted a systematic review and meta-analysis of the associations of chronic pain, depression, and sleep quality.

METHODS

We systematically searched for literature in MEDLINE and other relevant databases and identified cohort and case-control studies on depression, sleep disturbance, and chronic pain. Forty-nine studies were eligible, with a total population of 120 489 individuals. We obtained direct and indirect path coefficients via two-stage meta-analytic structural equation modelling, examined heterogeneity via subgroup analyses, and evaluated primary studies quality.

RESULTS

We found a significant, partial mediation effect of sleep disturbance on the relation between depression and chronic pain. The pooled path coefficient (coef.) of the indirect effect was 0.03 (95% confidence interval [CI]: 0.01-0.05) and accounted for 12.5% of the total effect of depression on chronic pain. This indirect effect also existed for cohort studies (coef. 0.02; 95% CI: 0.002-0.04), European studies (coef. 0.03; 95% CI: 0.004-0.05), and studies that adjusted for confounders (coef. 0.04; 95% CI: 0.01-0.09).

CONCLUSIONS

Sleep disturbance partially mediates the association between depression and pain. Although plausible mechanisms could explain this mediation effect, other explanations, including reverse causation, must be further explored.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022338201.

Investigation of pain sensitivity following 3 nights of disrupted sleep in healthy individuals

BACKGROUND

Poor quality sleep is a common complaint among people with chronic pain. The co-occurrence of poor sleep quality and chronic pain often comes with increased pain intensity, more disability and a higher cost of healthcare. Poor sleep has been suggested to affect measures of peripheral and central pain mechanisms. To date, sleep provocations are the only models proven to affect measures of central pain mechanisms in healthy subjects. However, there are limited studies investigating the effect of several nights of sleep disruption on measures of central pain mechanisms.

METHODS

The current study implemented three nights of sleep disruption with three planned awakenings per night in 30 healthy subjects sleeping at home. Pain testing was conducted at the same time of day at baseline and follow-up for each subject. Pressure pain thresholds were assessed bilaterally on the infraspinatus and gastrocnemius muscles. Using handheld pressure algometry, suprathreshold pressure pain sensitivity and area were also investigated on the dominant infraspinatus muscle. Cuff-pressure pain detection and tolerance thresholds, temporal summation of pain and conditioned pain modulation were investigated using cuff-pressure algometry.

RESULTS

Temporal summation of pain was significantly facilitated (p = 0.022), suprathreshold pain areas (p = 0.005) and intensities (p < 0.05) were significantly increased, and all pressure pain thresholds were decreased (p < 0.005) after sleep disruption compared to baseline.

CONCLUSIONS

The current study found that three consecutive nights of sleep disruption at home induced pressure hyperalgesia and increased measures of pain facilitation in healthy subjects, which is consistent with previous findings.

SIGNIFICANCE

Poor quality of sleep is often experienced by patients with chronic pain, with the most common complaint being nightly awakenings. This exploratory study is the first to investigate changes in measures of central and peripheral pain sensitivity in healthy subjects after sleep disruptions for three consecutive nights without any restrictions on total sleep time. The findings suggest that disruptions to sleep continuity in healthy individuals can induce increased sensitivity to measures of central and peripheral pain sensitization.

The complexities of the sleep-pain relationship in adolescents: A critical review

Chronic pain is a common and disabling condition in adolescents. Disturbed sleep is associated with many detrimental effects in adolescents with acute and chronic pain. While sleep and pain are known to share a reciprocal relationship, the sleep-pain relationship in adolescence warrants further contextualization within normally occurring maturation of several biopsychological processes. Since sleep and pain disorders begin to emerge in early adolescence and are often comorbid, there is a need for a comprehensive picture of their interrelation especially related to temporal relationships and mechanistic drivers. While existing reviews provide a solid foundation for the interaction between disturbed sleep and pain in youth, we will extend this review by highlighting current methodological challenges for both sleep and pain assessments, exploring the recent evidence for directionality in the sleep-pain relationship, reviewing potential mechanisms and factors underlying the relationship, and providing direction for future investigations. We will also highlight the potential role of digital technologies in advancing the understanding of the sleep and pain relationship. Ultimately, we anticipate this information will facilitate further research and inform the management of pain and poor sleep, which will ultimately improve the quality of life in adolescents and reduce the risk of pain persisting into adulthood.

How Hospital Patients Experience Pain the Previous 24 Hours-A Prevalence Assessment of Pain in Five Hospitals in Sweden

BACKGROUND

Previous studies show that pain is common among hospital inpatients.

AIM

This study measures the prevalence of pain and the impact of pain on sleep in patients admitted to five hospitals in Sweden.

METHODS

The patients were admitted to a surgical or a medical ward. They answered on a self-reported questionnaire about their average pain intensity and how much their pain interfered with their sleep the previous 24 hours, on a 010 numerical rating scale (NRS).

RESULTS

Of the 500 patients, 308 experienced pain (62%), (NRS ≥ 3) and 111 (22%) rated their pain as NRS ≥ 7. We found no difference between surgical and medical specialty regarding pain prevalence. The results suggest that roughly the same proportion of patients with pain also experienced poor sleep due to pain265 patients (53%) reported pain interference on sleep, NRS ≥ 3.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This study shows that there is still an unacceptable high pain prevalence in inpatients and that patients experience pain as negatively impacting their sleep. Future pain care is likely to include a more comprehensive implementation strategy for the dissemination of knowledge, especially related to the complex context of today's healthcare system. That is, the possibility that anchoring new knowledge also benefits the patient is probably associated with optimization of the structural context. Future research should take this question further by examining how the organizational structure should be optimized for the dissemination of knowledge in healthcare professionals about pain and pain interference with sleep.

Bidirectional associations between chronic low back pain and sleep quality: A cohort study with schoolteachers

AIMS

Although both chronic low back pain (cLBP) and sleep problems are prevalent among active workers, the relation between these variables is not well established. This study aimed to examine the bidirectional association between cLBP and sleep in schoolteachers.

METHODS

The Pittsburgh Sleep Quality Index (PSQI) and cLBP were self-reported by 530 schoolteachers in Londrina, Brazil, at baseline and after 2 years of follow-up. Generalized estimating equations were adjusted for sociodemographic, lifestyle and mental health variables.

RESULTS

Poor sleep quality at baseline was associated with cLBP at follow-up after adjusting for sociodemographic and lifestyle variables (OR=1.61; 95% confidence interval [95% CI]=1.06, 2.47). Changes in the PSQI score over time were also associated with a higher likelihood of cLBP at follow-up (OR=1.13; 95% CI=1.07, 1.20 for each 1-point increase in the PSQI score), regardless of mental health condition. cLBP at baseline was associated with worse sleep quality at follow-up after adjusting for sociodemographic and lifestyle variables (OR=1.56; 95% CI=1.02, 2.37). The presence of cLBP also changed the PSQI score over time (ß coefficient=1.153; 95% CI=0.493, 1.814).

CONCLUSIONS

Worse sleep quality was prospectively and bidirectionally associated with cLBP. Concretely, changes in PSQI values after 2 years of follow-up increased the likelihood of reporting cLBP, and baseline cLBP was associated with sleep quality worsening (i.e., higher score in the PSQI). Mental health conditions such as self-rated health, depression and anxiety play a relevant confounding role in the bidirectional associations between sleep and chronic low back pain.

"I Don't Know Why I've Got this Pain!" Allostasis as a Possible Explanatory Model

Explaining the onset and maintenance of pain can be challenging in many clinical presentations. Allostasis encompasses the mechanisms through which humans adapt to stressors to maintain physiological stability. Due to related neuro-endocrine-immune system effects, allostasis and allostatic load (the cumulative effects on the brain and body that develop through the maintenance of physiological stability) offer the potential to explain the development and maintenance of musculoskeletal pain in certain cases. This paper outlines the concept of allostatic load, highlights the evidence for allostatic load in musculoskeletal pain conditions to date, and discusses mechanisms through which allostatic load influences pain, with particular focus on hypothalamic-pituitary-adrenal axis and sympathetic nervous system function and central, brain-driven governance of these systems. Finally, through case examples, consideration is given as to how allostatic load can be integrated into clinical reasoning and how it can be used to help explain pain to individuals and guide clinical decision-making.

IMPACT

Awareness of the concept of allostatic load, and subsequent assessment of physical and psychological stressors potentially contributing to allostatic load, may facilitate a broader understanding of the multidimensional presentations of many people with pain, both acute and persistent. This may facilitate discussion between clinicians and their patients regarding broader influences on their presentations and drive more targeted and inclusive pain management strategies.

Challenges and visions for managing pain-related insomnia in primary care using the hybrid CBT approach: a small-scale qualitative interview study with GPs, nurses, and practice managers

Background

Chronic pain and insomnia have a complex, bidirectional relationship – addressing sleep complaints alongside pain may be key to alleviating patient-reported distress and disability. Healthcare professionals have consistently reported wanting to offer psychologically informed chronic pain management at the primary care level. Research in secondary care has demonstrated good treatment efficacy of hybrid CBT for chronic pain and insomnia. However, primary care is typically the main point of treatment entry, hence may be better situated to offer treatments using a multidisciplinary approach. In this study, primary care service providers’ perception of feasibility for tackling pain-related insomnia in primary care was explored.

Methods

The data corpus originates from a feasibility trial exploring hybrid CBT for chronic pain and insomnia delivered in primary care. This formed three in-depth group interviews with primary care staff (n = 9) from different primary care centres from the same NHS locale. All interviews were conducted on-site using a semi-structured approach. Verbal data was recorded, transcribed verbatim and analysed using the thematic analysis process.

Results

Eight themes were identified – 1) Discrepant conceptualisations of the chronic pain-insomnia relationship and clinical application, 2) Mismatch between patients’ needs and available treatment offerings, 3) Awareness of psychological complexities, 4) Identified treatment gap for pain-related insomnia, 5) Lack of funding and existing infrastructure for new service development, 6) General shortage of psychological services for complex health conditions, 7) Multidisciplinary team provision with pain specialist input, and 8) Accessibility through primary care. These mapped onto four domains - Current understanding and practice, Perceived facilitators, Perceived barriers, Ideal scenarios for a new treatment service – which reflected the focus of our investigation. Taken together these provide key context for understanding challenges faced by health care professionals in considering and developing a new clinical service.

Conclusions

Primary care service providers from one locale advocate better, multidisciplinary treatment provision for chronic pain and insomnia. Findings suggest that situating this in primary care could be a feasible option, but this requires systemic support and specialist input as well as definitive trials for success.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01552-3.

Co-occurrence of chronic pain, depressive symptoms, and poor sleep quality in a health check-up population in China:A multicenter survey

OBJECTIVES

This study aimed to investigate the cooccurrence of chronic pain (CP), depressive symptoms, and poor sleep quality in terms of prevalence and associated factors in a nationwide health check-up population in China.

METHODS

This multicenter cross-sectional survey was performed in 2017. All the participants aged ≥18 years from eight health check-up institutions in 6 provinces and cities were invited to complete a self-report health questionnaire through online resources.

RESULTS

132,444 participants completed the online survey and the overall prevalence of CP and that of the three symptoms were 11.0% (95% confidence interval [95% CI]: 10.8-11.1) and 2.7% (95% CI: 2.6-2.8), respectively. The cooccurrence of all three symptoms increased with age, being higher in the female, widowed, unemployed, and lower education level groups. The respondents with multiple symptoms reported poorer self-rated health. Binary logistic regression analyses identified female sex (adjusted odds ratio [aOR]: 1.51; 95% CI: 1.42-1.62), a widowed status (aOR: 1.39; 95% CI: 1.04-1.84), a lower education level (aORs ranging from 1.46 to 2.47), and having one or more chronic diseases (aORs ranging from 1.43 to 2.02) to be significantly associated with reporting all three symptoms (all P ˂0.05). While long-term medication and regular exercise were the protective factors.

CONCLUSION

This study suggests that the cooccurrence of the three symptoms accounts for a certain proportion of the Chinese health check-up population. Integrated interventions that address CP and mental health cooccurrence may be an essential target for heath management in this population to tackle this considerable burden.