Chronic low back pain, sleep disturbance, and interleukin-6

The change of inflammatory cytokines after antidepressant treatment and correlation with depressive symptoms

BACKGROUND

The objective of this study was to explore the serum levels of IL-1, IL-6, IL-10, TNF-a, and high-sensitivity C-reactive protein (hs-CRP) in patients with depression before and after treatment and their correlation with the clinical symptoms of depression.

METHODS

Fifty depression patients newly diagnosed and untreated in the Fourth People's Hospital of Wuhu were chosen as the depression group, while 50 healthy individuals from the same period served as the control group. We contrasted the serum levels of these markers of inflammation in both groups. After 8 weeks of SSRI antidepressant therapy, changes in inflammatory cytokines, hs-CRP, and HAMD-17 scores were evaluated in the depression group.

RESULTS

The levels of serum inflammatory cytokines and hs-CRP in patients with depression were higher than the healthy control group significantly (P < 0.05). After treatment, the levels of serum inflammatory cytokines and hs-CRP in patients with depression decreased significantly (P < 0.05). The total score of HAMD-17 and the scores of sleep, cognitive impairment, inhibition, and anxiety somatization factors in the depression group were decreased than those before treatment (P < 0.01). The serum IL-1 concentration in the depression group inversely related to the decrease in the HAMD-17 inhibition factor (R = -0.359,P = 0.011); The serum IL-6 concentration change rate positively correlated with the reduction rate of the cognitive impairment factor of HAMD-17 (R = 0.426,P = 0.017); the change rate of hs-CRP concentration was positively correlated with the reduction rate of the anxiety somatization factor of HAMD-17 (R = 0.343,P = 0.015).

CONCLUSION

Antidepressant treatment affects the levels of serum inflammatory cytokines and hs-CRP significantly, and is correlated with changes in clinical symptoms.

Sleep Status and Chronotype in University Athletes with and without Chronic Low Back Pain: A Cross-Sectional Study

Objective  This study aimed to evaluate the status of sleep, chronotype, and related variables of university athletes with and without chronic low back pain (CLBP), to find the correlation between CLBP, sleep difficulty score (SDS), and chronotype, and to determine if SDS and chronotype predict CLBP. Methods  Ninety-two university athletes [46 with CLBP (Age: 22.08±2.74 years) and 46 healthy athletes (Age: 22.32±3.11 years) completed the athlete sleep screening questionnaire (ASSQ), also, their demographic, anxiety, depression, and sports-related details were collected. A Pearson correlation and logistic regression models (univariate and multivariate) were used for the statistical analysis. Results  The results demonstrated a higher SDS and evening type preference in CLBP athletes, a significant negative correlation between CLBP and chronotype (r = -0.40, p <0.01), a significant correlation between SDS and CLBP (r = 0.25, p  = 0.01). SDS and chronotype were not found to be significant independent predictors of CLBP. Conclusion  This study concludes that there exists a correlation of CLBP, SDS, and chronotype However, despite the relationship, SDS and chronotype cannot predict CLBP.

Advances in modern Balneology: new evidence-based indications from recent studies

Balneotherapy (BT) is a therapeutic approach that utilizes various forms of water-based treatments to promote health and well-being. BT possesses a rich historical heritage and has garnered recognition from esteemed institutions such as the World Health Organization (WHO). Recent scientific research enables the identification of relevant diseases (obesity, metabolic diseases, sleep disorders, mental health conditions, Long-COVID-19, and cancer rehabilitation) that could potentially benefit from balneo-therapeutic treatments, thereby presenting new avenues of opportunity for SPA ("Salus per Aquam") medicine. These conditions exemplify the potential benefits of BT for ailments beyond the traditional scope of treatment associated with BT (most commonly osteoarthritis, fibromyalgia, rheumatic back pain, and chronic inflammatory respiratory or skin disorders). Overall, the current scientific evidence suggests that BT holds significant potential for enhancing both individual wellbeing and public health. However, further high-quality clinical trials are essential to corroborate these preliminary findings and to provide critical insights into the therapeutic benefits of BT, paving the way for its broader integration into healthcare practices and public health initiatives.

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.

Moving toward affective immunology: Legacy and future directions

The term "affective immunology" has recently been used to denote a field focused on the interplay between affective processes (including mood states, specific emotions, and regulatory processes) and various aspects of immune function. The overarching goals of this commentary are a) to provide historical underpinnings of this field with a focus on the profound impact of the work of Janice Kiecolt-Glaser, who is further honored in this special issue, b) to review important off-shoots of her legacy work in this domain, and c) to highlight important future directions for the field. Kiecolt-Glaser's work laid much of the foundation for affective immunology, with groundbreaking research related to depression, hostility and dyadic interactions, loneliness, and other affective patterns, often in the context of holistic models, novel experimental designs, and interventions. Her former mentees (and many of their mentees) have carried on her legacy in these domains, in ways that continue to advance appreciation of how affective processes relate to immune function. There are numerous remaining questions for the field to pursue, including better understanding of the role of emotion regulation, emotional reactivity and recovery, restorative processes, affective variability, and developmental and dynamic social processes. Such work will require greater use of longitudinal and within-person approaches and/or examination of processes in daily life, as well as models that account for interactive and reciprocal processes and which integrate behavior, social context, sociocultural factors, individual differences, and other aspects of health. As more work in these domains continues, building on Kiecolt-Glaser's rich legacy, we move toward the emergence of affective immunology as an important subfield in the domain of psychoneuroimmunology, one which will offer more nuanced understanding of the role of affective processes in immune health.

Manual therapy and exercise effects on inflammatory cytokines: a narrative overview

Background

Matching disease and treatment mechanisms is a goal of the Precision Medicine Initiative. Pro- and anti-inflammatory cytokines (e.g., Tumor Necrosis Factor-alpha, Transforming Growth Factor-beta, and Interleukin-2, 10, and 12) have gained a significant amount of interest in their potential role in persistent pain for musculoskeletal (MSK) conditions. Manual therapy (MT) and exercise are two guideline-recommended approaches for treating MSK conditions. The objective of this narrative overview was to investigate of the effects of MT and exercise on pro- and anti-inflammatory cytokines and determine the factors that lead to variability in results.

Methods

Two reviewers evaluated the direction and variabilities of MT and exercise literature. A red, yellow, and green light scoring system was used to define consistencies.

Results

Consistencies in responses were seen with acute and chronic exercise and both pro- and anti-inflammatory cytokines. Chronic exercise is associated with a consistent shift towards a more anti-inflammatory cytokine profile (Transforming Growth Factor-beta, and Interleukin-2 and 13, whereas acute bouts of intense exercise can transiently increase pro-inflammatory cytokine levels. The influence of MT on cytokines was less commonly studied and yielded more variable results.

Conclusion

Variability in findings is likely related to the subject and their baseline condition or disease, when measurement occurs, and the exercise intensity, duration, and an individual's overall health and fitness.

Efficacy of balneotherapy on pain, function, and sleep quality in patients with chronic low-back pain: a prospective observational study

The aim of this prospective observational study was to evaluate the efficacy of a cycle of sulfate-arsenical-ferruginous mud bath therapy on pain, function, and sleep quality in patients with chronic low-back pain (CLBP). One hundred twenty-three patients treated at Levico Spa Center (Italy) with 12 daily local mud packs and generalized thermal baths were included in this experience. General medical assessments were performed before starting the therapy, at the end of the treatment, and 3 months later. Pain intensity and stiffness were measured by a 0 to 10 cm visual analogue scale (VAS); the range of mobility of the lumbar spine was evaluated using the Schober test and functional disability by the Roland-Morris Disability Questionnaire (RMDI). The Pittsburgh Sleep Quality Index (PSQI) was used to assess the sleep quality. The VAS score for pain and stiffness showed a significant reduction (p < 0.0001) at the end of the treatment persisting for 3 months of follow-up. Similarly, a significant improvement was found for the Schober test and RMDQ. Finally, we showed a significant decrease of PSQI score at the end of the cycle of mud bath and at 3 months of follow-up. The Spearman analysis showed a significant positive correlation between the score of PSQI and VAS pain, VAS stiffness, and RMDQ. In conclusion, this preliminary study confirms the beneficial and long-term efficacy of balneotherapy on pain and function and, for the first one, shows the positive effect on quality of sleep in patients with CLBP treated with a cycle of mud bath therapy.

Clinically relevant differences in spinal mobility related to daytime performance in patients with axial spondyloarthritis

OBJECTIVE

Patients with axial spondyloarthritis (axSpA) suffer from clinical symptoms like morning stiffness and back pain. Mobility of patients with axSpA is often impaired. The aim of this study is to compare the performance of patients with axSpA regarding mobility measures including performance-based tests and objective electronic assessments with the Epionics SPINE device (ES) at different times of the day compared with healthy controls (HC).

METHODS

Observational trial, consecutive inpatients with axSpA (n=100) and 20 HCs were examined in the morning (V1: before 10:00 am) and in the afternoon (V2: after 02:00 pm) by the Bath Ankylosing Spondylitis Metrology Index (BASMI), the AS physical performance index (ASPI), the Short Physical Performance Battery (SPPB) and ES measurements, including range of motion (RoM) and range of kinematics (RoK).

RESULTS

The assessments of patients with axSpA performed in the morning clearly differed from those in the afternoon, especially regarding performance-based tests. Significant improvements were seen for BASMI (4.0±3.8 to 3.8±1.9; p<0.001), ASPI (36.2±18.3 to 28.8±11.9 s; p<0.001), SPPB (10.1±1.5 to 10.7±1.4 points; p<0.001) and for ES measures of speed (RoK; p<0.018) but not for RoM, except for lateral flexion (13.3±7.4 to 14.7±8.2°; p=0.002). This time of assessment-related variability was not observed in HC.

CONCLUSION

The spinal mobility of patients with axSpA was worse in the morning but significantly improved in the afternoon. This was captured best by performance-based measures and was not seen in HC. The diurnal variation of mobility has implications for clinical studies, suggesting that the time of assessments needs to be standardised.

Composite Biomarkers, Behavioral Symptoms, and Comorbidities in Axial Low Back Pain: A Systematic Review

PURPOSE

Proinflammatory cytokines play a critical role in chronic inflammation and pain and contribute to behavioral symptoms (depressive symptoms, anxiety, fatigue, sleep disturbance) and comorbidities (diabetes, cardiac diseases, cancer). Evidence is lacking on the specific proinflammatory cytokines associated with these behavioral symptoms/comorbidities co-occurring with axial low back pain (aLBP). This review aimed to systematically analyze the following: (1) specific proinflammatory cytokines associated with aLBP in adults, (2) associations among proinflammatory cytokines and behavioral symptoms in aLBP, and (3) relationships among proinflammatory cytokines and comorbidities in aLBP, to develop a new clinical framework for future diagnostic and intervention targets for patients with aLBP.

METHODS

Electronic databases, including PubMed/MEDLINE, ProQuest Nursing & Allied Health Source, and CINAHL Complete (EBSCO) were searched for the period January 2012 to February 2023. Eligible studies included cross-sectional, case-control, longitudinal, and cohort studies in which proinflammatory cytokines were reported in adults above 18 years with aLBP. Intervention studies and randomized controlled trails were excluded. The Joanna Briggs Institute (JBI) criteria were used for quality evaluation.

RESULTS

Findings from 11 studies showed 3 proinflammatory cytokines associated with pain intensity in adult patients with aLBP: C-Reactive Protein (CRP), Tumor Necrosis Factor (TNF-α), and Interleukin (IL-6). Some studies assessed associations between proinflammatory cytokines and depressive symptoms; none explored the association of proinflammatory cytokines with fatigue, anxiety, sleep disturbance, or comorbidities (diabetes, cardiac diseases, and cancer) in aLBP.

CONCLUSIONS

Proinflammatory cytokines in aLBP can serve as composite biomarkers for pain, associated symptoms, and comorbidities and may serve as a target for future interventions. There is need for well-designed studies assessing associations among chronic inflammation, behavioral symptoms, and comorbidities.

The importance of inflammatory biomarkers in non-specific acute and chronic low back pain: a systematic review

OBJECTIVE

The purpose of this study was to systematically review the evidence on inflammatory biomarkers as analytic predictors of non-specific low back pain (NsLBP). Low back pain (LBP) is the number one cause of disability globally, posing a major health problem that causes an enormous social and economic burden, and there is an increasing interest on the importance of biomarkers in quantifying and even emerge as potential therapeutic tools to LBP.

METHODS

A systematic search was conducted on July 2022 in Cochrane Library, MEDLINE and Web of Science for all the available literature. Cross-sectional, longitudinal cohort or case-control studies that evaluated the relationship between inflammatory biomarkers collected from blood samples and low back pain in humans were considered eligible for inclusion, as well as prospective and retrospective studies.

RESULTS

The systematic database search resulted in a total of 4016 records, of which 15 articles were included for synthesis. Sample size comprised a total of 14,555 patients with LBP (acute LBP (n = 2073); chronic LBP (n = 12482)) and 494 controls. Most studies found a positive correlation between classic pro-inflammatory biomarkers and NsLBP, namely C-reactive protein (CRP), interleukin 1 (IL-1) and IL-1β, interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). On the other hand, anti-inflammatory biomarker interleukin 10 (IL-10) demonstrated a negative association with NsLBP. Four studies have made direct comparisons between ALBP and CLBP groups regarding their inflammatory biomarkers profile.

CONCLUSIONS

This systematic review found evidence of increased levels of pro-inflammatory biomarkers CRP, IL-6 and TNF-α and decreased levels of anti-inflammatory biomarker IL-10 in patients with LBP. Hs-CRP was not correlated with LBP. There is insufficient evidence to associate these findings with the degree of pain severity or the activity status of the lumbar pain over time.

Analysis of intervertebral disc CCR6 and IL-6 gene levels with short-term postoperative low back pain after spinal fusion in lumbar degenerative disease

Background

Previous studies have reported that specific pro-inflammatory cytokines or chemokines are more highly expressed in painful than in nonpainful intervertebral discs (IVDs). However, few studies have investigated their correlation with postsurgical outcomes or the relationship between postoperative pain and inflammatory cytokines in IVDs. Thus, the present study examined the correlation among the gene expression levels of pro-inflammatory cytokines and chemokines in IVD tissues removed during surgery and low back pain (LBP), leg pain (LP), and leg numbness (LN) at one year after spinal fusion surgery in patients with a lumbar degenerative disease (LDD).

Methods

Chemokine and cytokine gene expression levels were measured in IVD samples from 48 patients with LDD. The associations between chemokine and cytokine gene expression levels and pain intensity (numeric rating scale [NRS]) were also analyzed. A correlation analysis was performed between gene expression in each IVD and preoperative and postoperative pain intensity.

Results

In the preoperative analysis, CCR6 was associated with NRSLBP (r = -0.291, P = 0.045). Postoperative pain analysis revealed correlations between postoperative NRSLBP and CCR6 (r = -0.328, P = 0.023) and between postoperative NRSLBP and IL-6 (r = -0.382, P = 0.007). Furthermore, patients with high postoperative LBP intensity (NRSLBP ≥ 7) also had high LBP intensity (NRSLBP ≥ 6) before surgery, and a correlation was observed (r = 0.418, P = 0.003). None of the gene mRNAs correlated with NRSLP or NRSLN, respectively.

Conclusions

CCR6 and IL-6 gene expression in the IVD was associated with postoperative LBP intensity and may indicate a need for postoperative pain management.

Biomarkers of sleep disturbance in adults with chronic illness: A scoping review

OBJECTIVES

The purpose of this scoping review was to identify which biomarkers for sleep disturbance were the most prevalent and significant in the literature across chronic illnesses.

METHODS

A scoping review was conducted, following Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, to provide a map of the existing literature on the biomarkers of sleep disturbance in adults with chronic illness. Peer-reviewed articles published between 2010-2020 were included if they measured a biomarker and discussed sleep deprivation, disturbance, or dysfunction secondary to a chronic illness.

RESULTS

A total of 21 articles were included and synthesized using data charting. There were 24 different biomarkers identified, most commonly collected through serum. Biomarkers were grouped, then biomarkers and correlations with sleep were identified and mapped.

DISCUSSION

Overall, the most common biomarkers studied were interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), c-reactive protein (CRP), and interleukin-1 beta (IL-1β). Cytokines were the most commonly studied biomarkers, with a majority of studies focusing on pro-inflammatory cytokines. Based on the results of this review, CRP, IL-6, TNF-α, and erythrocyte sedimentation rate (ESR) showed themost significant correlations with sleep across all chronic illnesses. Future research is still needed to identify an ideal biomarker for sleep disturbance that can be used across chronic illnesses.

A nationwide study on pain manifestations and sleep problems in community-dwelling older adults: findings from ELSI-Brazil

PURPOSE

Sleep problems are common and affect approximately 36-70% of older adults worldwide and can be associated with negative outcomes such as pain. There is believed to be a bidirectional relationship between sleep problems and pain, modulated by inflammation and stress. The objective was to investigate the association between self-reported sleep problems and pain manifestations.

METHODS

A cross-sectional study using data from the second wave of the Brazilian Longitudinal Study of Aging (2019-2021) was conducted. The exposure variables were self-reported sleep problems: poor sleep quality, insomnia (initial, intermediate, and final), and daytime sleepiness. The outcomes were self-reported pain manifestations: frequent pain, moderate/intense/strong pain, and pain-related disability. Logistic regressions were performed to verify the association between exposures and outcomes.

RESULTS

A total of 6875 community-dwelling older adults participated in this study (71.1 ± 8.3 years; 54.4% female). Older adults with self-reported poor sleep quality, initial, intermediate and final insomnia, and daytime sleepiness had, respectively, 1.99 (95% CI 1.57-2.53), 1.47 (95% CI 1.11-1.97), 1.65 (95% CI 1.27-2.14), 1.69 (95% CI 1.29-2.22), and 1.76 (95% CI 1.35-2.29) greater odds of reporting frequent pain. The odds of moderate/intense/strong pain were higher in older adults that reported poor sleep quality (OR: 2.21; 95% CI 1.08-4.51). Older adults with self-reported poor sleep quality, initial, intermediate and final insomnia, and daytime sleepiness had, respectively, 1.84 (95% CI 1.11-3.02), 1.73 (95% CI 1.14-2.62), 1.80 (95% CI 1.19-2.73), 1.58 (95% CI 1.07-2.34), and 1.63 (95% CI 1.11-2.39) greater odds of reporting pain-related disability.

CONCLUSION

Self-reported sleep problems are associated with pain manifestations in older adults. The results may help in the proposition of programs and public health policies.

Modulation of TRPV4 protects against degeneration induced by sustained loading and promotes matrix synthesis in the intervertebral disc

While it is well known that mechanical signals can either promote or disrupt intervertebral disc (IVD) homeostasis, the molecular mechanisms for transducing mechanical stimuli are not fully understood. The transient receptor potential vanilloid 4 (TRPV4) ion channel activated in isolated IVD cells initiates extracellular matrix (ECM) gene expression, while TRPV4 ablation reduces cytokine production in response to circumferential stretching. However, the role of TRPV4 on ECM maintenance during tissue-level mechanical loading remains unknown. Using an organ culture model, we modulated TRPV4 function over both short- (hours) and long-term (days) and evaluated the IVDs' response. Activating TRPV4 with the agonist GSK101 resulted in a Ca²⁺ flux propagating across the cells within the IVD. Nuclear factor (NF)-κB signaling in the IVD peaked at 6 h following TRPV4 activation that subsequently resulted in higher interleukin (IL)-6 production at 7 days. These cellular responses were concomitant with the accumulation of glycosaminoglycans and increased hydration in the nucleus pulposus that culminated in higher stiffness of the IVD. Sustained compressive loading of the IVD resulted in elevated NF-κB activity, IL-6 and vascular endothelial growth factor A (VEGFA) production, and degenerative changes to the ECM. TRPV4 inhibition using GSK205 during loading mitigated the changes in inflammatory cytokines, protected against IVD degeneration, but could not prevent ECM disorganization due to mechanical damage in the annulus fibrosus. These results indicate TRPV4 plays an important role in both short- and long-term adaptations of the IVD to mechanical loading. The modulation of TRPV4 may be a possible therapeutic for preventing load-induced IVD degeneration.

Potential mechanisms underlying the accelerated cognitive decline in people with chronic low back pain: A scoping review

A growing body of evidence has shown that people with chronic low back pain (CLBP) demonstrate significantly greater declines in multiple cognitive domains than people who do not have CLBP. Given the high prevalence of CLBP in the ever-growing aging population that may be more vulnerable to cognitive decline, it is important to understand the mechanisms underlying the accelerated cognitive decline observed in this population, so that proper preventive or treatment approaches can be developed and implemented. The current scoping review summarizes what is known regarding the potential mechanisms underlying suboptimal cognitive performance and cognitive decline in people with CLBP and discusses future research directions. Five potential mechanisms were identified based on the findings from 34 included studies: (1) altered activity in the cortex and neural networks; (2) grey matter atrophy; (3) microglial activation and neuroinflammation; (4) comorbidities associated with CLBP; and (5) gut microbiota dysbiosis. Future studies should deepen the understanding of mechanisms underlying this association so that proper prevention and treatment strategies can be developed.

The effect of mindfulness on the inflammatory, psychological and biomechanical domains of adult patients with low back pain: A randomized controlled clinical trial

Objective

This study aims to study the effect of mindfulness-based program on the psychological, biomechanical and inflammatory domains of patients with chronic low back pain.

Methods

A multicentre randomized and controlled clinical trial of parallel groups in patients with chronic low back pain between March 2019 to March 2020. Participants with no experience in mindfulness based intervention, were randomized to receive (36 patients) or not (34 patients) mindfulness-based stress reduction program for chronic back pain (MBSR-CBP). The program was performed in 9 sessions. Patients with chronic low back pain due to symptomatic discopathy (degenerative disc disease or herniated disc) were included. The principal outcome was changes in the blood level of cortisol and cytokines (tumor necrosis factor- α (TNF- α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-17 (IL-17)). Secondary outcomes (psychological factors, pain, and quality of life) were measured by validated questionnaires.

Results

Of the 96 randomized patients, 70 who completed the study were included in the analysis (mean [range] age: 53 [33–73] years; 66% females). MBSR-CBP stopped the increase in cortisol, and reduced pro-inflammatory cytokine IL-1β (p = 0.05). It reduced depression (p = 0.046) and stress (p = 0.0438), perceived pain (p < 0.0001), and limitations related to health (p < 0.0001). It also increased the physical function (p = 0.002) and sleep quality (p = 0.05). Furthermore, it significantly increased life satisfaction (0.006), well-being (p = 0.001) and vitality (p < 0.0001). It also increased self-compassion (p < 0.0001) and significantly reduced the overidentification (p<0.0001) and catastrophization (p = 0.002).

Conclusions

MBSR-CBP could be part of a multidisciplinary approach in the management of patients suffering from chronic low back pain.

Immune-inflammatory and hypothalamic-pituitary-adrenal axis biomarkers are altered in patients with non-specific low back pain: A systematic review

This systematic review aimed to investigate immune-inflammatory and hypothalamic-pituitary-adrenal (HPA) axis biomarkers in individuals with non-specific low back pain (NSLBP) compared to healthy control. The search was performed in five databases until 4 November 2021. Two reviewers independently conducted screenings, data extraction, risk of bias, and methodological quality assessment of 14 unique studies. All studies reported the source of the fluid analyzed: nine studies used serum, two used plasma, one used serum and plasma, and two studies used salivary cortisol. We found preliminary and limited evidence (only one study for each biomarker) of increased levels in growth differentiation factor 15 (GDF-15), interleukin-23 (IL-23), transforming growth factor–beta (TGF-β), and soluble tumor necrosis factor receptor 1 (sTNF-R1) in NSLBP. Inconsistent and limited evidence was identified for interleukin-10 (IL-10). Although C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor–alpha (TNF-α) levels appear to increase in NSLBP, only one study per each biomarker reported statistically significant differences. Interleukin-1 beta (IL-1β), interleukin-17 (IL-17), interferon gamma (IFN-γ), and high-sensitivity CRP (hsCRP) showed no significant differences. Regarding cortisol, one study showed a significant increase and another a significant decrease. More robust evidence between GDF-15, IL-23, TGF-β, and sTNF-R1 with NSLBP is needed. Moreover, contrary to the findings reported in previous studies, when comparing results exclusively with healthy control, insufficient robust evidence for IL-6, TNF-α, and CRP was found in NSLBP. In addition, cortisol response (HPA-related biomarker) showed a dysregulated functioning in NSLBP, with incongruent evidence regarding its directionality. Therefore, our effort is to find adjusted evidence to conclude which immune-inflammatory and HPA axis biomarkers are altered in NSLBP and how much their levels are affected.

Knowledge and attitudes of physiotherapists toward sleep: A survey study

BACKGROUND: Sleep has been considered as a critical brain state that affects various body functions relevant to physiotherapy (PTs) practice such as motor learning and relearning, pain management, and cognitive function. Despite the importance of sleep for successful rehabilitation outcomes, sleep is often overlooked by PTs. OBJECTIVE: The purpose of this study was to assess the attitude and perception of PTs on the need to assess sleep and provide education about sleep for their patients, as well as the perceived need for PTs to be educated on sleep topics. METHODS: A survey questionnaire to assess physical therapist’s perceptions and attitudes about sleep was utilized in this study. RESULTS: 90 PTs fill out the survey. All respondents agreed that poor sleep is important to people’s health, 93% agreed that PTs should assess patients’ sleep habits and sleep quality and 88% agreed that addressing sleep issues may impact PTs outcomes. The majority did not receive education about sleep during PT education (75%) or following graduation (86%). Most respondents (95%) think PTs should receive education about sleep. CONCLUSIONS: our findings indicated that PTs recognize that sleep impacts their outcomes and patients’ sleep should be assessed, as well as the need to receive education about sleep. Therefore, PT education programs may consider incorporating education about sleep, and the development of continuing education courses is also needed.

SYSTEMIC CYTOKINE LEVEL DIFFERENCES IN PATIENTS WITH CHRONIC MUSCULOSKELETAL SPINAL PAIN COMPARED TO HEALTHY CONTROLS AND ITS ASSOCIATION WITH PAIN SEVERITY: A SYSTEMATIC REVIEW

OBJECTIVE

Although there has been increasing interest in the role of systemic cytokines in chronic spinal pain (CSP), the evidence on their potential contribution is still unclear. Therefore, the current study systematically reviewed the evidence on systemic cytokine level differences between people with CSP compared to healthy controls (HCs) and the potential associations with pain severity.

METHODS

An electronic search was conducted on PubMed, Web of Science and Embase. All included studies were classified as observational studies, exploring the comparison between a CSP group and a HC group, and the association between systemic cytokine levels and pain severity.

RESULTS

Nine articles were included with a total sample of 400 CSP patients suffering from chronic whiplash associated disorder (CWAD) or chronic low back pain (CLBP). In CLBP, moderate evidence was found for elevated tumor necrosis factor (TNF) α, interleukin (IL) 6, IL-1 receptor antagonist (IL-1RA), and soluble TNF receptor (sTNF-R) type 2, for normal interferon (IFN) γ and IL-2 levels, and for reduced IL-10 levels. No association was found between pain severity and these cytokines in CLBP. In CWAD, moderate evidence was found for elevated CRP and evidence for changes in TNF-α was inconclusive. Evidence for the association between pain severity and CRP was limited, and there is probably no association between pain severity and TNF-α with limited evidence in CWAD.

CONCLUSIONS

Moderate evidence indicates the presence of systemic inflammation in CSP. Evidence regarding the association between pain severity and systemic cytokines is inconclusive and limited.

Sleep, Positive Affect, and Circulating Interleukin-6 in Women With Temporomandibular Joint Disorder

OBJECTIVE

Systemic inflammation is commonly observed in idiopathic chronic pain conditions, including temporomandibular joint disorder (TMD). Trait positive affect (PA) is associated with lower inflammation in healthy controls, but those effects may be threatened by poor sleep. The associations between PA with proinflammatory cytokine activity and potential moderation by sleep in chronic pain are not known. We thus investigated the association between PA and circulating interleukin-6 (IL-6) and moderation of that association by sleep in a sample of women with TMD and sleep difficulties.

METHODS

Participants (n = 110) completed the insomnia severity index and provided blood samples at five intervals throughout an evoked pain testing session. They then completed a 14-day diary assessing sleep and affect, along with wrist actigraphy.

RESULTS

There was not a significant main effect of PA on resting or pain-evoked IL-6 (b = 0.04, p = .33). Diary total sleep time (b = -0.002, p = .008), sleep efficiency (b = -0.01, p = .005), sleep onset latency (b = 0.006, p = .010), and wake after sleep onset (b = 0.003, p = .033) interacted with PA to predict IL-6, such that PA inversely predicted IL-6 at higher levels of total sleep time and sleep efficiency and at lower levels of sleep onset latency and wake after sleep onset. Surprisingly, when sleep was poor, PA predicted greater IL-6.

CONCLUSIONS

The potential salutary effects of PA on resting IL-6 erode when sleep is poor, underscoring the importance of considering sleep in conceptual and intervention models of TMD.

Are Morphometric and Biomechanical Characteristics of Lumbar Multifidus Related to Pain Intensity or Disability in People With Chronic Low Back Pain After Considering Psychological Factors or Insomnia?

INTRODUCTION

Lumbar multifidus muscle (LMM) dysfunction is thought to be related to pain and/or disability in people with chronic low back pain (CLBP). Although psychosocial factors play a major role in pain/disability, they are seldom considered as confounders in analyzing the association between LMM and CLBP.

OBJECTIVES

This study aimed to determine: (1) differences in psychological factors, insomnia, and LMM characteristics between people with and without CLBP; (2) associations between psychological factors, insomnia, or LMM characteristics and low back pain (LBP) intensity or LBP-related disability in people with CLBP; and (3) whether LMM characteristics are related to LBP symptoms in people with CLBP after considering confounders.

METHODS

Seventy-eight volunteers with CLBP and 73 without CLBP provided sociodemographic information, filled the 11-point numeric pain rating scale and Roland-Morris disability questionnaire (RMDQ). They completed the Hospital Anxiety and Depression Scale (HADS), Pain Catastrophizing Scale (PCS), Fear Avoidance Belief Questionnaire (FAB), and Insomnia Severity Index Scale (ISI). Resting and contracted thickness of LMM at L4-S1 levels were measured from brightness-mode ultrasound images. Percent thickness changes of LMM at L4-S1 levels during contraction were calculated. Resting LMM stiffness at L4-S1 was measured by shear wave elastography. Associations among LMM, psychosocial or insomnia parameters and clinical outcomes were analyzed by univariate and multivariate analyses.

RESULTS

People with CLBP demonstrated significantly higher LBP-intensity, RMDQ, HADS, FAB, PCS, and ISI scores than asymptomatic controls (p < 0.05). The former also had significantly smaller percent thickness changes of LMM at L4/L5 during contraction. LBP-intensity was positively related to scores of PCS-total, PCS-helplessness, FAB-total, FAB-work, and ISI in people with CLBP (p < 0.05). RMDQ scores were positively associated with the scores of HADS-total, HADS-depression, PCS-total, FAB-total, FAB-physical activity, PCS-helplessness, and ISI in people with CLBP (p < 0.05). FAB-work and ISI scores together explained 24% of LBP-intensity. FAB-total scores alone explained 34% of variance of LBP-related disability in people with CLBP.

CONCLUSION

More fear-avoidance belief or insomnia is related to greater LBP-intensity and/or LBP-related disability in people with CLBP. Although people with CLBP were thought to have aberrant LMM morphometry/function, no LMM characteristics were related to LBP-intensity or LBP-related disability after considering other confounders.

Are Changes in Sleep Quality/Quantity or Baseline Sleep Parameters Related to Changes in Clinical Outcomes in Patients With Nonspecific Chronic Low Back Pain?: A Systematic Review

OBJECTIVES

Sleep disturbance is prevalent among patients with chronic low back pain (CLBP). This systematic review aimed to summarize the evidence regarding the: (1) temporal relations between changes in sleep quality/quantity and the corresponding changes in pain and/or disability; and (2) role of baseline sleep quality/quantity in predicting future pain and/or disability in patients with CLBP.

METHODS

Four databases were searched from their inception to February 2021. Two reviewers independently screened the abstract and full text, extracted data, assessed the methodological quality of the included studies, and evaluated the quality of evidence of the findings using the Grading of Recommendations Assessment Development and Evaluation (GRADE).

RESULTS

Of 1995 identified references, 6 articles involving 1641 participants with CLBP were included. Moderate-quality evidence substantiated that improvements in self-reported sleep quality and total sleep time were significantly correlated with the corresponding LBP reduction. Low-quality evidence showed that self-reported improvements in sleep quality were related to the corresponding improvements in CLBP-related disability. There was conflicting evidence regarding the relation between baseline sleep quality/quantity and future pain/disability in patients with CLBP.

DISCUSSION

This is the first systematic review to accentuate that improved self-reported sleep quality/quantity may be associated with improved pain/disability, although it remains unclear whether baseline sleep quality/quantity is a prognostic factor for CLBP. These findings highlight the importance of understanding the mechanisms underlying the relation between sleep and CLBP, which may inform the necessity of assessing or treating sleep disturbance in people with CLBP.

The role of mindfulness and relaxation in improved sleep quality following a mind-body and activity program for chronic pain

Objectives

Poor sleep quality is prevalent among individuals with chronic pain and contributes to increased physical and emotional dysfunction. However, treatments that improve sleep quality among individuals with chronic pain are scant. A previously developed mind-body activity program for chronic pain has been shown to be feasible and associated with improvements in pain and physical and emotional function. Using secondary data-analysis, the purpose of this study was to understand whether participants also experienced significant and sustained improvements in sleep quality over time and whether these improvements were explained by change in two core treatment targets, relaxation and mindfulness.

Methods

Participants with heterogenous chronic pain (N = 82) were randomized to a mind-body activity intervention with (GetActive-Fitbit; n=41) or without (GetActive; n=41) a Fitbit device. Sleep quality was measured with the PSQI, mindfulness with the CAMS-R, and relaxation with the relaxation subscale of the MOCS-A. Mediation was tested via mixed-models analysis.

Results

Both intervention groups experienced significant and comparable improvements in sleep quality from baseline to post-treatment, which were sustained through a 3-month follow-up. Mindfulness and relaxation also improved significantly over time and these improvements were associated with improved sleep quality. Mindfulness and relaxation fully mediated improvement in sleep quality (medium to large effect sizes).

Conclusions

Results suggest that, despite not targeting sleep explicitly, the two mind-body activity programs hold promise for sustainably improving sleep quality among patients with chronic pain. Targeting mindfulness and relaxation may facilitate these improvements.

Serum Levels of TNF-α Are Increased in Patients with Rotator Cuff Tear and Sleep Disturbance

The purpose of this study was to determine serum levels of sleep-related cytokines in patients with rotator cuff tear (RCT) who were experiencing pain-related sleep disturbance. Peripheral blood samples before surgery were collected from 63 study participants and divided into three groups: RCT with sleep disturbance group; SD group (n = 21), RCT with normal sleep group; NS group (n = 21), and patients with chronic shoulder instability; control group (n = 21). Serum concentration levels of interleukin-1α (IL-1α), IL-1β, IL-2, IL-6, IL-8, IL-10, and tumor necrosis factor-α (TNF-α) were measured via ELISA. The associations between serum levels of sleep-related cytokines and clinical scores and the Pittsburgh Sleep Quality Index (PSQI) were analyzed. Serum concentration levels of TNF-α were significantly higher in the SD group compared with those of the NS and control groups (p = < 0.001 and 0.05). Serum levels of IL-8 and IL-10 were significantly higher in the SD group compared with those of control group (p = 0.01 and = 0.05), but did not differ significantly from that of the NS group. There were no associations between serum levels of sleep-related cytokines and all clinical scores. The current findings suggest that TNF-α may be associated with sleep disturbance in patients with RCT.

Association Between Sleep Duration and Functional Disability in Inpatient Stroke Rehabilitation: A Pilot Observational Study

Objective

To describe the change in sleep duration during inpatient rehabilitation and to determine if sleep quality and sleep duration is associated with functional disability for individuals after stroke. It was hypothesized that participants who experienced optimal sleep during inpatient rehabilitation would have greater functional ability at discharge.

Design

Longitudinal observation study.

Setting

Inpatient rehabilitation unit at a large, urban hospital.

Participants

Thirty-seven individuals with acute stroke (N=37; mean age, 62.5±11.8y, male=20, female=17) were recruited from September 2018 to September 2019. Participants were invited to participate in the study by clinical personnel associated with their usual care as they were admitted to inpatient rehabilitation.

Interventions

Not applicable.

Main Outcome Measures

Participants were asked to wear an actigraph for the duration of their rehabilitation program to assess sleep. The first 3 nights of actigraphy data were averaged to obtain total sleep time (TST) and sleep efficiency (SE) at admission, and the last 3 nights were averaged for TST and SE at discharge. Functional disability (primary outcome was FIM) at admission and discharge was gathered from the participants’ medical records. One-way analysis of variance and chi-square analyses assessed for group differences, and regression modeling was used to determine if sleep was associated with functional ability at discharge.

Results

Sixteen participants (43%) were categorized as “good sleepers” and 21 (57%) were “poor sleepers” based on their TST at admission. Of the poor sleepers, 14 participants (66%) remained short duration sleepers (<7h at admission and discharge). Sleep outcomes did not significantly predict FIM score at discharge.

Conclusions

Most participants had less than optimal sleep duration during inpatient rehabilitation. Efforts may be warranted to optimize sleep during inpatient rehabilitation.

The Association between Sleep and Chronic Spinal Pain: A Systematic Review from the Last Decade

Chronic spinal pain, including both neck and low back pain, is a common disabling disorder in which sleep problems are frequently reported as a comorbidity. The complex processes of both sleep and chronic pain seem to have overlapping mechanisms, which may explain their often established bidirectional relationship. This systematic review aims to investigate the assumed association between sleep and chronic spinal pain by providing an overview of the literature from the last decade. Eligible studies were obtained by searching four databases (PubMed, Embase, Web of Science, and PsycARTICLES). Articles were found relevant if they included a human adult population and investigated the possible association between sleep parameters and chronic spinal pain. Only studies published after January 2009 were included, as this review aimed to provide an update of a previous literature overview on this topic. The quality of the studies was assessed by risk of bias and level of evidence. A total of twenty-seven studies (6 cohort, 5 case-control, and 16 cross-sectional studies) were included in this systematic review. The methodological quality of these studies was low to moderate. The majority of studies reported weak to moderate evidence for an association between sleep parameters and chronic spinal pain, with more severe pain accompanied by more disturbed sleep. Addressing frequently reported sleep problems in chronic spinal pain patients therefore appears to be a necessary complement to pain management to achieve optimal treatment outcomes.

Identifying the most important confounders when assessing the association between low-grade systemic inflammation and musculoskeletal pain: A modified Delphi study

Objective

The association between low-grade systemic inflammation and musculoskeletal pain may be influenced by multiple factors. However, little is known about the relative importance of these factors, and few studies account for them. This Delphi study aimed to reach consensus on the most important confounders which influence the association between low-grade systemic inflammation and musculoskeletal pain.

Methods

The panel consisted of 48 experts. In Round 1, the experts proposed what they believed were important confounders. In Round 2, the experts indicated for each confounder whether they believed it was important (yes/no). At least 50% of experts had to indicate the confounder was important to be considered in the final round. In Round 3, the experts rated the importance of each confounder on a 7-point Likert scale. Consensus was reached if ≥75% of the experts considered the factor either extremely or moderately important.

Results

In Round 1, 120 confounders were proposed, which were synthesized into 38 distinct factors. In Round 2, 33 confounders met the criterion to be considered important. In Round 3, consensus was reached for 14 confounders: acute illness/trauma, immune disease, medication use, endocrine, nutritional, or metabolic disease, other musculoskeletal conditions, age, handling of blood samples, sex, cancer, body composition, pregnancy, cardiovascular disease, physical activity, and pain characteristics.

Conclusions

These findings provide insight in the complexity of the association between low-grade systemic inflammation and musculoskeletal pain. Some factors currently listed as confounders may be re-classified as moderators or mediators as insights progress.

Social Support is Inversely Associated with Sleep Disturbance, Inflammation, and Pain Severity in Chronic Low Back Pain

BACKGROUND

Chronic low back pain (CLBP) is a significant cause of disability, lost wages, and health care costs. Inflammatory mediators, such as interleukin 6 (IL-6), have been associated with LBP severity. Patients with CLBP commonly experience sleep disturbance, and poor sleep has been shown to increase pain severity and inflammation. In contrast, social support may benefit patients with chronic low back by reducing pain intensity and inflammation.

OBJECTIVES

The purpose of this study was to examine the influence of social support on the relationships among sleep disturbance, inflammation, and pain severity in patients with CLBP.

METHODS

In a cross-sectional study, men and women with CLBP were enrolled from an outpatient pain clinic. Participants completed psychometric instruments for social support, sleep quality, and pain severity. Blood samples were obtained for measurement of the pro-inflammatory cytokine, IL-6, by enzyme-linked immunoassay.

RESULTS

Linear regression revealed greater sleep disturbance predicted greater pain severity. In contrast, participants who reported higher social support had lower sleep disturbance and lower pain severity. Mediation analysis revealed sleep disturbance to mediate the relationship between social support and pain, such that sleep disturbance reduced the benefit of social support on pain severity. Further, greater sleep disturbance and lower social support predicted increased IL-6. However, IL-6 did not mediate the relationship between social support and pain.

DISCUSSION

The findings suggest that increased social support is associated with lower sleep disturbance, lower inflammation, and lower pain severity in patients with CLBP. Assessing the extent of social support and fostering social support as part of a comprehensive pain management program may benefit patients with CLBP. Interventions to strengthen social support systems and cultivate support from family and/or informal social networks may reduce symptom burden and improve quality of life.

Therapeutic Effectiveness of AxioBionics Wearable Therapy Pain Management System in Patients with Chronic Lower Back Pain

Chronic lower back pain is one of the most common medical conditions leading to a significant decrease in quality of life. This study retrospectively analyzed whether the AxioBionics Wearable Therapy Pain Management (WTPM) System, a customized and wearable electrical stimulation device, alleviated chronic lower back pain, and improved muscular function. This study assessed self-reported pain levels using the visual analog scale before and during the use of the AxioBionics WTPM System when performing normal activities such as sitting, standing, and walking (n = 69). Results showed that both at-rest and activity-related pain were significantly reduced during treatment with the AxioBionics WTPM System (% reduction in pain: 64% and 60%, respectively; P < .05). Thus, this study suggests that the AxioBionics WTPM System is efficacious in treating chronic lower back pain even when other therapies have failed to sufficiently decrease reported pain levels.

Behavioral Symptom Clusters, Inflammation, and Quality of Life in Chronic Low Back Pain

BACKGROUND

Chronic low back pain is a prevalent condition, often involving an inflammatory process. Behavioral symptoms, including depressed mood, fatigue, and sleep disturbance, intensifies pain and reduces quality of life.

AIMS

The objectives of this pilot study were to identify behavioral symptom clusters (depressive mood, fatigue, poor sleep) in individuals with chronic low back pain, and to determine whether there are differences in pain, quality of life and inflammation (plasma IL-6) based on cluster membership.

DESIGN AND SETTINGS

A cross-sectional study was conducted in a pain clinic.

PARTICIPANTS/ SUBJECTS

Participants between ages 21 to 70 years (N=69) were enrolled if they had chronic low back pain for at least six months.

METHODS

Participants completed instruments measuring, pain, depressive mood, fatigue, sleep, and demographic form. Blood (10ml) was obtained. Latent class analysis was used to identify clusters.

RESULTS AND CONCLUSIONS

Findings revealed a two-class model, with Class 1 characterized by more depressive mood, fatigue, and sleep disturbance compared to Class 2. Class 1 participants reported worse quality of life than those in Class 2. Pain severity and pain interference were not significantly different between the classes. Levels of IL-6 were significantly greater in Class 1 participants compared to Class 2 with higher levels of IL-6 correlating with greater pain severity and sleep disturbances. Logistic regression revealed higher levels of IL-6 predicted Class 1 membership. Behavioral symptoms cluster exist in chronic low back pain patients and impact quality of life. Inflammation may contribute to relationship between behavioral symptoms and pain severity.

Chronic musculoskeletal pain prospectively predicts insomnia in older people, not moderated by age, gender or co-morbid illnesses

The study evaluated if chronic musculoskeletal (MSK) pain predicts the severity of insomnia, and whether the effect is moderated by age, gender, and number of comorbid diseases in older people. An 18-month prospective study was performed within the framework of a community health program in Hong Kong. A total of 498 older people aged ≥ 60 with multimorbidity were recruited. The predictors included the presence of chronic MSK pain, pain measured by the Brief Pain Inventory (BPI), insomnia measured by baseline Insomnia Severity Index (ISI), and number of co-morbid diseases, age, and gender. The outcome was ISI repeated at 18 months. The moderators included age, gender, and number of comorbid diseases. Multivariate linear regression and moderation analysis were conducted. We found that the presence of chronic MSK pain (β = 1.725; 95% CI, 0.607-2.842; P < 0.01) predicted the severity of ISI, after controlling for age, gender, BMI, and the number of comorbid diseases. Participants with chronic MSK pain throughout the period had worse trend of improvement in ISI compared to those who were "pain-free" (β = 2.597; 95% CI, 1.311-3.882; P < 0.001). Age, gender, and number of comorbid diseases did not moderate the longitudinal relationship. We propose that pain management should prioritized in the prevention of insomnia.

Beyond the mechanical lens: Systemic inflammatory responses to repetitive lifting under varying loads and frequencies

OBJECTIVE

Currently, low back disorder (LBD) research focuses primarily on mechanical variables to assess whether task demands exceed tissue capacity; however, it is important to assess how other nonmechanical variables affect tissue capacity in a time-dependent manner. The current investigation sought to explore physiological responses to an acute lifting task, as lifting has been implicated as a risk factor in the development of LBDs.

METHODS

Twelve participants completed two sessions of 2 h of repetitive symmetrical lifting from floor to knuckle height under two conditions, matched for total external work (Low Force High Repetition (LFHR) and High Force Low Repetition (HFLR)). Full-body kinematics and ground reaction forces were measured throughout. Interleukin 6 (IL-6) and interleukin 8 (IL-8), markers of systemic inflammation, were assessed from blood sampling at Baseline, 0, 4 and 24 h post-lifting on both days. Dual x-ray absorptiometry (DEXA) scans were also performed on participants to quantify body composition.

RESULTS

Significant load (HFLR and LFHR) * time (Baseline, 0, 4, 24 h) interaction effects were found for both IL-6 and IL-8, where the LFHR condition resulted in greater responses at 0 and 4 h post-lifting.

CONCLUSIONS

This was the first study of its kind to concurrently measure peak and cumulative spinal moments and their relationship to systemic inflammation in both sexes, while strictly controlling for confounding variables (e.g. physical activity, caloric intake, body composition, etc.). Greater levels of IL-6 and IL-8 were seen in the LFHR condition, likely due to the greater cumulative spinal moments in this condition.

Association of Serum Minerals, Vitamin D, Total Protein, and Inflammatory Mediators and Severity of Low Back Pain

BACKGROUND

Low back pain (LBP) is a multifactorial disorder with multiple etiologies, which are not fully understood. In this study, we aimed to evaluate the relationship between serum levels of minerals, total protein, vitamin D (vit D), and inflammatory mediators with LBP and its severity.

MATERIALS AND METHODS

This case-control study was derived from the study nested in the Fasa Cohort Study. Overall, 148 individuals with LBP were compared with 150 individuals without LBP. Blood samples were evaluated for serum protein, iron (Fe), aluminum (Al), copper (Cu), phosphorus, vit D, IL-1B, IL-6, high-sensitive C-reactive protein (HS-CRP), and TNF-alpha. Severity of pain was measured with the McGill and Oswestry questionnaires.

RESULTS

The mean age of participants in the case and control groups was 49.2 ± 6.1 and 47.57 ± 5.85 years, respectively. In the case group, 61 patients (48.8%) were male. The mean serum levels of Fe, Al, vit D, Cu, IL-1B, IL-6, HS-CRP, and TNF-alpha were significantly different between case and control groups (P≤0.05). However, there were no significant differences between studied groups in the term of sex and serum phosphorus (P>0.05). Regarding pain severity, age was correlated with McGill score (r=0.18), body mass index with Oswestry (r=0.21), Fe with McGill (r=-0.15) and Oswestry (r=-0.13), protein with McGill (r=0.32) and Oswestry (r=-0.32), Al with McGill (r=0.56) and Oswestry (r=0.45), IL-1B with McGill (r=0.19) and Oswestry (r=0.13), TNF-alpha with McGill (r=0.34) and Oswestry (r=0.26), IL-6 with Oswestry (r=0.13), HS-CRP with McGill (r=0.60) and Oswestry (r=0.46), and vit D was correlated with McGill (r=0.21) and Oswestry scores (r=0.17). Higher Fe (odds ratio [OR]: 0.99), protein (OR: 0.47), Al (OR: 0.11), and vit D levels (OR: 0.97) were protective against LBP (P<0.001). Higher IL-1B (OR: 1.01), TNF-alpha (OR: 1.03), and HS-CRP (OR: 1.0003) presented as risk factors for LBP (P<0.001).

CONCLUSION

Our study revealed except phosphorous, all the serum levels minerals and inflammatory markers was significantly different in LBP patients compared to healthy individuals. Also, in the LBP patients, serum levels of Fe, total protein, Al, and vit D aside to inflammatory mediators (i.e., IL-1B, TNF-alpha, and HS-CRP) shows a marked association with severity of LBP.

Sex Differences in Interleukin-6 Responses Over Time Following Laboratory Pain Testing Among Patients With Knee Osteoarthritis

Epidemiological studies suggest that women are not only at a higher risk for developing knee osteoarthritis (KOA), but also report greater symptom severity compared to men. One potential underlying mechanism of these sex differences may be exaggerated inflammatory responses to pain among women compared to men. The present study examined sex differences in interleukin-6 (IL-6) response over time following experimental pain testing. We hypothesized that women, when compared to men, would show greater IL-6 reactivity when exposed to acute pain in a human laboratory setting. Eighty-four participants (36 men and 48 women) with KOA scheduled for total knee arthroplasty underwent a quantitative sensory testing (QST) battery. A total of seven IL-6 measurements were taken, twice at baseline, once immediately after QST, and every 30 minutes up to 2 hours after QST. Consistent with our hypothesis, women, when compared to men, showed accelerated increases in IL-6 levels following laboratory-evoked pain, even after controlling for body mass index, marital status, clinical pain, evoked pain sensitivity, and situational pain catastrophizing. Given that KOA is a chronic condition, and individuals with KOA frequently experience pain, these sex differences in IL-6 reactivity may contribute to the maintenance and/or exacerbation of KOA symptoms. PERSPECTIVES: The present study demonstrates that women, when compared to men, exhibit greater IL-6 reactivity after exposure to laboratory-evoked pain. Such sex differences may explain the mechanisms underlying women's higher chronic pain risk and pain perception, as well as provide further insight in developing personalized pain interventions.

A systematic review of the role of inflammatory biomarkers in acute, subacute and chronic non-specific low back pain

Background

Low back pain (LBP) is one of the greatest contributors to disability in the world and there is growing interest on the role of biomarkers in LBP. To purpose of this review was to analyze available evidence on the relationship between inflammatory biomarkers, clinical presentation, and outcomes in patients with acute, subacute and chronic non-specific low back pain (NSLBP).

Methods

A search was performed in Medline, Embase, Cinahl and Amed databases. Studies which measured levels of inflammatory biomarkers in participants with NSLBP were included. Two reviewers independently screened titles and abstracts, full-texts, and extracted data from included studies. Methodological quality was assessed using the Newcastle Ottawa Quality Assessment Scale. Level of evidence was assessed using the modified GRADE approach for prognostic studies.

Results

Seven primary studies were included in this review. All results assessed using the modified GRADE demonstrated low to very low quality evidence given the small number of studies and small sample. Three studies examined C-reactive protein (CRP), one of which found significantly higher CRP levels in an acute NSLBP group than in controls and an association between high pain intensity and elevated CRP. Three studies examined tumor necrosis factor alpha (TNF-α), two of which found elevated TNF-α in chronic NSLBP participants compared to controls. Two studies examined interleukin 6 (IL-6), none of which found a significant difference in IL-6 levels between NSLBP groups and controls. Two studies examined interleukin 1 beta (IL-β), none of which found a significant difference in IL-β levels between NSLBP groups and controls.

Conclusions

This review found evidence of elevated CRP in individuals with acute NSLBP and elevated TNF-Α in individuals with chronic NSLBP. There are a limited number of high-quality studies evaluating similar patient groups and similar biomarkers, which limits the conclusion of this review.

Clinical Pain-related Outcomes and Inflammatory Cytokine Response to Pain Following Insomnia Improvement in Adults With Knee Osteoarthritis

OBJECTIVES

Clinical insomnia is known to affect pain, but mechanisms are unclear. Insomnia can dysregulate inflammatory pathway, and inflammation plays a mediating role in pain. It is unclear whether insomnia-related alterations in inflammation can be modified with insomnia improvement, and if such alterations parallel improvement in pain. The current study objective was to provide proof of concept for the role of insomnia in inflammation and pain by testing whether improving insomnia would reduce pain and related physical function, and, concurrently, modulate inflammatory responses.

MATERIALS AND METHODS

Thirty adults with osteoarthritis knee pain and insomnia (Insomnia Severity Index >10) provided baseline measures of osteoarthritis and laboratory pain, and serial blood samples for inflammatory biomarkers, interleukin 6, and tumor necrosis factor α, before and after pain testing. To manipulate insomnia, participants were randomly assigned to a 6-week cognitive-behavioral therapy for insomnia (n=16); or wait-list control (n=14). At 8-weeks (time 2), all measures were repeated. To directly test insomnia improvement effects, participants were grouped by insomnia status at time 2 after confirming baseline equivalency on all outcomes.

RESULTS

Compared with those maintaining insomnia at time 2 (Insomnia Severity Index ≥8; n=18), those whose insomnia improved at time 2 (n=12) had significantly improved physical functioning, decline in knee pain during transfer activities, and attenuated increase in interleukin 6 and less decrease in tumor necrosis factor α across the pain testing session.

DISCUSSION

These findings suggest further exploration of inflammatory pathways linking clinical insomnia, and its improvement, to chronic pain.

The Effects Induced by Spinal Manipulative Therapy on the Immune and Endocrine Systems

Background and Objectives: Spinal manipulations are interventions widely used by different healthcare professionals for the management of musculoskeletal (MSK) disorders. While previous theoretical principles focused predominantly on biomechanical accounts, recent models propose that the observed pain modulatory effects of this form of manual therapy may be the result of more complex mechanisms. It has been suggested that other phenomena like neurophysiological responses and the activation of the immune-endocrine system may explain variability in pain inhibition after the administration of spinal manipulative therapy (SMT). The aim of this paper is to provide an overview of the available evidence supporting the biological plausibility of high-velocity, low-amplitude thrust (HVLAT) on the immune-endocrine system. Materials and Methods: Narrative critical review. An electronic search on MEDLINE, ProQUEST, and Google Scholar followed by a hand and "snowballing" search were conducted to find relevant articles. Studies were included if they evaluated the effects of HVLAT on participants' biomarkers Results: The electronic search retrieved 13 relevant articles and two themes of discussion were developed. Nine studies investigated the effects of SMT on cortisol levels and five of them were conducted on symptomatic populations. Four studies examined the effects of SMT on the immune system and all of them were conducted on healthy individuals. Conclusions: Although spinal manipulations seem to trigger the activation of the neuroimmunoendocrine system, the evidence supporting a biological account for the application of HVLAT in clinical practice is mixed and conflicting. Further research on subjects with spinal MSK conditions with larger sample sizes are needed to obtain more insights about the biological effects of spinal manipulative therapy.

The association between pro-inflammatory biomarkers and nonspecific low back pain: a systematic review

BACKGROUND CONTEXT

About 85% of the patients with low back pain seeking medical care have nonspecific low back pain (NsLBP), implying that no definitive cause can be identified. Nonspecific low back pain is defined as low back pain and disability which cannot be linked to an underlying pathology, such as cancer, spinal osteomyelitis, fracture, spinal stenosis, cauda equine, ankylosing spondylitis, and visceral-referred pain. Many pain conditions are linked with elevated serum levels of pro-inflammatory biomarkers. Outcomes of interest are NsLBP and the level of pro-inflammatory biomarkers.

PURPOSE

To unravel the etiology and get better insight in the prognosis of NsLBP, the aim of this study was to assess the association between pro-inflammatory biomarkers and the presence and severity of NsLBP.

STUDY DESIGN

A systematic literature search was made in Embase, Medline, Cinahl, Webof-science, and Google scholar up to January 19th 2017.

METHODS

Included were cross-sectional and cohort studies reporting on patients aged over 18 years with NsLBP, in which one or more pro-inflammatory biomarkers were measured in blood plasma. The methodological quality of the included studies was assessed using the Newcastle Ottawa Scale. A best-evidence synthesis was used to summarize the results from the individual studies, meaning that the included studies were ranked according to the consistency of the findings and according to their methodological quality score using the Newcastle Ottawa Scale.

RESULTS

Included were 10 studies which assessed four different pro-inflammatory biomarkers. For the association between the presence of NsLBP and C-reactive protein (CRP), interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α limited, conflicting and moderate evidence, respectively, was found. For the association between the severity of NsLBP and CRP and IL-6, moderate evidence was found. For the association between the severity of NsLBP and TNF-α and RANTES Regulated on Activation, Normal T Cell Expressed and Secreted conflicting and limited evidence, respectively, was found.

CONCLUSIONS

This study found moderate evidence for (i) a positive association between the pro-inflammatory biomarkers CRP and IL-6 and the severity of NsLBP, and (ii) a positive association between TNF-α and the presence of NsLBP. Conflicting and limited evidence was found for the association between TNF-α and Regulated on Activation, Normal T Cell Expressed and Secreted and severity of NsLBP, respectively.

Effects of Sleep Fragmentation and Induced Mood on Pain Tolerance and Pain Sensitivity in Young Healthy Adults

Background: Experimental research exploring the sleep/pain-relationship has typically focused on total or partial sleep deprivation, hereby failing to reproduce the mere fragmented sleep pattern typically observed in patients with chronic pain. Further, little research is done on how affect moderates the sleep–pain relationship after sleep fragmentation. The present study sought to clarify the relationship between pain, sleep and positive and negative affect.

Methods: In an experimental counterbalanced crossover design, 35 healthy young adults were subjected to several pain measures after one night of fragmented sleep, compared to one control night of normal sleep, both conducted in their own homes, and respectively, positive and negative affect induction using validated film clips and facial feedback procedures. Sleep was monitored using sleep diaries.

Results: Increased pain sensitivity after one night of experimentally induced sleep fragmentation was found, compared to after one control night of undisturbed sleep. No main effects of induced affect on pain were found, and sleep x induced affect interaction was not significant.

Conclusion: The present study supports the adverse effect of sleep fragmentation on pain sensitivity, however, affect was not found to be a moderator in the sleep–pain relationship. The results underline the need for further research within this field.

Evidence that dry eye is a comorbid pain condition in a U.S. veteran population

A retrospective review of 3,265,894 veterans seen over a 5-year period demonstrates dry eye is associated with numerous chronic pain conditions implying shared mechanisms.

Introduction:

Recent evidence suggests that dry eye (DE) may be comorbid with other chronic pain conditions.

Objectives:

To evaluate DE as a comorbid condition in the U.S. veteran population.

Methods:

Retrospective review of veterans seen in the Veterans Administration Healthcare System (Veteran Affairs) between January 1, 2010, and December 31, 2014. Dry eye and nonocular pain disorders were ascertained by International Classification of Diseases, Ninth Revision (ICD-9) codes. Dry eye was further separated into ICD-9 codes representing tear film dysfunction or ocular pain. χ² and logistic regression analyses were used to examine frequency and risk of DE, ocular pain, and tear film dysfunction by pain disorders.

Results:

Of 3,265,894 veterans, 959,881 had a DE diagnosis (29.4%). Dry eye frequency increased with the number of pain conditions reported (P < 0.0005). Ocular pain was most strongly associated with headache (odds ratio [OR] 2.98; 95% confidence interval [CI] 2.95–3.01), tension headache (OR 2.64; 95% CI 2.58–2.71), migraine (OR 2.58; 95% CI 2.54–2.61), temporomandibular joint dysfunction (OR 2.39; 95% CI 2.34–2.44), pelvic pain (OR 2.30; 95% CI 2.24–2.37), central pain syndrome (OR 2.24; 95% CI 1.94–2.60), and fibromyalgia/muscle pain (OR 2.23; 95% CI 2.20–2.26), all P < 0.0005. Tear film dysfunction was most closely associated with osteoarthritis (OR 1.97; 95% CI 1.96–1.98) and postherpetic neuralgia (OR 1.95; 95% CI 1.90–2.00), both P < 0.0005.

Conclusions:

Dry eye, including both ocular pain and tear film dysfunction, is comorbid with pain conditions in this nationwide population, implying common mechanisms.

Sleep Health Promotion: Practical Information for Physical Therapists

Sleep disturbances occur in one third of the US population, and the Centers for Disease Control and Prevention's National Center for Injury Prevention and Control has deemed insufficient sleep to be a public health problem. Knowledge about sleep and skills to screen sleep disorders and to promote sleep health have been recommended for physical therapists. Furthermore, in survey studies, physical therapists overwhelmingly agree that sleep is important for health and poor sleep impairs function. Sleep is critical for the proper functioning of the body, including immune function, tissue healing, pain modulation, cardiovascular health, cognitive function, and learning and memory. Sleep disruptions occur across the life span and in individuals with various conditions that are typically treated by physical therapists. Therefore, the purpose of this perspective paper is to (1) discuss the relevance of sleep to physical therapist practice, (2) recommend tools to screen for the 3 most common sleep disorders, and (3) provide suggestions for how therapists can integrate sleep health in prevention, health promotion, and wellness interventions.