Endocrine and immunologic parameters indicative of 6-month prognosis after the onset of low back pain or neck/shoulder pain

Job demands and DHEA-S levels: a study on healthcare workers

BACKGROUND

The intricate interplay between work-related stress and its physiological impact has drawn extensive research attention. Dehydroepiandrosterone sulphate (DHEA-S) emerges as a potential biomarker reflecting stress-related endocrine changes.

AIMS

This cross-sectional study aimed to examine the association between job demands and DHEA-S levels among healthcare workers. The study also explored potential correlations between DHEA-S levels and psychophysical symptoms commonly linked to work-related stress.

METHODS

A sample of 488 healthcare workers from a local health authority participated. Job demands were measured using the Demands scale of the Health and Safety Management Standards Indicator Tool. DHEA-S levels and symptom prevalence were assessed through serum analysis and questionnaires, respectively.

RESULTS

Workers exposed to high job demands exhibited significantly lower DHEA-S levels compared to those with low job demands. Psychophysical symptoms, including sleep disorders, depression, and headache, were more prevalent in the high-demands group. DHEA-S levels showed significant negative correlations with the prevalence of all considered symptoms.

CONCLUSIONS

The study shows the inverse relationship between job demands and DHEA-S levels among healthcare workers, indicating that high job demands correlate with reduced DHEA-S secretion and increased symptom prevalence. The findings suggest DHEA-S as a potential biomarker for assessing the physiological consequences of work-related stress. Proactive interventions in managing job demands are crucial for promoting employee well-being and productivity in demanding work environments. By recognizing DHEA-S as a stress biomarker, organizations can effectively address stress-related health risks and implement targeted interventions for enhancing employees' overall health and work performance.

How Can We Get to Equitable and Effective Postpartum Pain Control?

Postpartum pain is common, yet patient experiences and clinical management varies greatly. In the United States, pain-related expectations and principles of adequate pain management have been framed within established norms of Western clinical medicine and a biomedical understanding of disease processes. Unfortunately, this positioning of postpartum pain and the corresponding coping strategies and pain treatments is situated within cultural biases and systemic racism. This paper summarizes the history and existing literature that examines racial inequities in pain management to propose guiding themes and suggestions for innovation. This work is critical for advancing ethical practice and establishing more effective care for all patients.

Effects of Tai Chi on beta endorphin and inflammatory markers in older adults with chronic pain: an exploratory study

The purpose of this exploratory study was to examine the effects of Tai Chi on blood levels of beta endorphin (β-endorphin) and inflammatory markers in older adults with chronic pain. Forty community-dwelling older adults with chronic pain were randomized to Tai Chi or light physical exercise, and each offered twice weekly for 12 weeks. Following the 12-week intervention, neither Tai Chi nor light physical exercise changed levels of β-endorphin and inflammatory markers. However, in older adults who completed 70% or more classes, Tai Chi significantly lowered levels of β-endorphin (p < 0.05), whereas light physical exercise did not change levels of β-endorphin. The results suggest that Tai Chi may reduce levels of β-endorphin in older adults with chronic pain. Future studies are needed to better understand the role of the opioid analgesic system and immune system in regulating pain with aging and the long-term effects of Tai Chi on pain-related biomarkers.

Photobiomodulation Therapy is Able to Modulate PGE2 Levels in Patients With Chronic Non-Specific Low Back Pain: A Randomized Placebo-Controlled Trial

BACKGROUND AND OBJECTIVES

Non-specific low back pain (LBP) is responsible for triggering increased biomarkers levels. In this way, photobiomodulation therapy (PBMT) may be an interesting alternative to treat these patients. One of the possible biological mechanisms of PBMT involved to decrease pain intensity in patients with musculoskeletal disorders is modulation of the inflammatory mediators' levels. The aim of this study was to evaluate the effects of PBMT compared with placebo on inflammatory mediators' levels and pain intensity in patients with chronic non-specific LBP.

STUDY DESIGN/MATERIALS AND METHODS

A prospectively registered, randomized triple-blinded (volunteers, therapists, and assessors), placebo-controlled trial was performed. Eighteen patients with chronic non-specific LBP were recruited and treated with a single session of active PBMT or placebo PBMT. The primary outcome of the study was serum prostaglandin E₂ levels and the secondary outcomes were tumor necrosis factor-α, interleukin-6 levels, and pain intensity. All outcomes were measured before and after 15 minutes of treatment session.

RESULTS

PBMT was able to decrease prostaglandin E₂ levels at post-treatment compared with placebo, with a mean difference of -1470 pg/ml, 95% confidence interval -2906 to -33.67 in patients with LBP. There was no difference between groups in the other measured outcomes. Patients did not report any adverse events.

CONCLUSION

Our results suggest that PBMT was able to modulate prostaglandin E₂ levels, indicating that this may be one of the mechanisms involved in the analgesic effects of PBMT in patients with LBP. Trial registration number (ClinicalTrials.gov): NCT03859505. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.

Can Beta-Endorphin Be Used as a Biomarker for Chronic Low Back Pain? A Meta-analysis of Randomized Controlled Trials

Background

Chronic low back pain (CLBP) is usually quantified using the visual analog scale (VAS). However, the VAS is a subjective measure and prone to reporting bias, therefore making it difficult to differentiate patients with true pain from those seeking to obtain secondary gain. This study aimed to evaluate the feasibility of using plasma β-endorphin as an objective biomarker for CLBP.

Methods

We searched PubMed, Embase, and the Cochrane Library for randomized trials that compared treatment vs sham procedures for patients with CLBP. Changes in VAS and β-endorphin levels between baseline and final evaluations were assessed for the treatment and control groups. A meta-regression model was developed to evaluate the association between the β-endorphin level and VAS.

Results

We included data from seven trials involving 375 patients. There was no significant difference in VAS scores and β-endorphin levels between both groups at baseline. At final evaluation, the treatment group demonstrated significantly greater improvements in VAS scores and an increased β-endorphin level compared with the control group. The change in the plasma β-endorphin level may be a surrogate marker of treatment response for patients with CLBP (explanatory power: 80%). The plasma β-endorphin level might be rarely affected by sham procedures. For patients with CLBP, the baseline β-endorphin level may reflect the intensity of CLBP (explanatory power: 66%).

Conclusions

A change in plasma β-endorphin level may be a surrogate marker of the treatment response for patients with CLBP. Advancements in β-endorphin measurements may help us better quantify pain intensity.

Effects of photobiomodulation therapy on inflammatory mediators in patients with chronic non-specific low back pain: Protocol for a randomized placebo-controlled trial

INTRODUCTION

Low back pain (LBP) is ranked as one of the most prevalent health conditions. It is likely that some inflammatory mediators could be associated with pain and disability in these patients. Photobiomodulation therapy (PBMT) is a non-pharmacological therapy often used in patients with LBP and one of the possible mechanisms of action of therapy is modulate inflammatory mediators. However, to date there are no studies that evaluated the effects of PBMT on the levels of inflammatory mediators in patients with LBP. The aim of this study is to evaluate the acute effects of PBMT on systemic levels of inflammatory mediators and pain intensity in patients with chronic non-specific low back pain.

METHODS AND ANALYSIS

This is a prospectively registered, two-arm randomized placebo-controlled trial with blinded patients, assessors and therapists. Eighteen patients with chronic non-specific LBP will be randomized into 2 groups: placebo or active PBMT. The treatment will be provided in a single session. The primary outcome will be levels of prostaglandin E2 (PGE2). The secondary outcomes will be levels of necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and pain intensity. Biochemical and clinical outcomes will be measured at baseline and 15 minutes after the single treatment session.

DISCUSSION

Despite PBMT be used in musculoskeletal disorders such as LBP, to the best of our knowledge this is the first study that will investigate a possible biological mechanism behind the positive clinical effects of PBMT on non-specific chronic low back pain.

ETHICS AND DISSEMINATION

The study was approved by the Regional Research Ethics Committee. The results will be disseminated through publication in peer-reviewed international journal and conferences.

TRIAL REGISTRATION NUMBER

NCT03859505.

Sarcopenia in elderly patients with chronic low back pain

Objectives

The prevalence of chronic low back pain (CLBP) increases with age and several mechanisms are involved in the development of CLBP, including osteoporosis; however, no associations with sarcopenia have yet been identified.

Methods

In total, 100 patients with CLBP and 560 patients without CLBP (nCLBP) aged over 65 years were studied. Skeletal muscle mass index (SMI) and percentage of body fat were evaluated using whole-body dual-energy X-ray absorptiometry. Sarcopenia was diagnosed when the relative SMI was more than 2 standard deviations below the mean in young adults. Thus, the cutoff value for sarcopenia was defined according to Sanada's Japanese population data. Paraspinal muscle cross-sectional areas of the lumbar multifidus and the erector spinae muscles were calculated using magnetic resonance imaging.

Results

Forty patients (40.0%) from the CLBP group and 149 (26.6%) from the nCLBP group met the criteria of sarcopenia. SMI was significantly lower and the body fat ratio was significantly higher in the CLBP group compared with the nCLBP group. Sarcopenic obesity was significantly observed in the CLBP group. Lumbar multifidus and the erector spinae muscle cross sectional area were significantly lower in the CLBP group.

Conclusions

Elderly patients with CLBP have significantly lower skeletal muscle mass, and age-related mechanisms in sarcopenia are considered to be associated with chronic pain. Therapeutic procedures that are used to treat elderly aging muscle, including muscle strengthening and performance training, can possibly be a treatment for or used to prevent elderly CLBP.

Inflammatory Mediators and Pain in the First Year After Acute Episode of Low-Back Pain in Elderly Women: Longitudinal Data from Back Complaints in the Elders-Brazil

OBJECTIVE

The aims of this study were to determine the course of plasma levels of inflammatory mediators (interleukin 6 [IL-6], tumor necrosis factor α [TNF-α], soluble TNF receptor 1 [sTNF-R1]) and the severity of low-back pain (LBP) over 6 to 12 months after an acute episode of LBP in elderly women and to establish an association between inflammatory mediators and LBP recovery.

DESIGN

This was a longitudinal study of a subsample (155 elderly women with acute LBP, aged ≥65 years) of the international Back Complaints in the Elders cohort study. Plasma levels of IL-6, TNF-α, and sTNF-R1 were measured using enzyme-linked immunosorbent assays and pain severity using the numerical pain scale.

RESULTS

There was a decrease in the severity of LBP (P = 0.033) and in the levels of IL-6 and TNF-α (P < 0.001) and an increase in sTNF-R1 (P < 0.001) in the first year after an acute episode of LBP. The probability of occurrence of pain relief at the 12-month follow-up was 2.22 times higher in elderly women who had low levels of IL-6 (<1.58 pg/mL) at baseline.

CONCLUSIONS

Our findings showed a relationship between inflammation and LBP by establishing that low IL-6 plasma levels preceded outcome (LBP recovery), supporting the concept that proinflammatory cytokines promote pain.

Allostatic load and pain severity in older adults: Results from the English Longitudinal Study of Ageing

Pain is common in older adults, is frequently experienced as stressful, and is associated with increased morbidity and mortality. Stress regulatory systems are adaptive to challenge and change, allostasis, until demands exceed the adaptive capacity contributing to dysregulation, resulting in a high allostatic load. A high allostatic load is associated with increased risk of morbidity and mortality. Pain severity, based on the average intensity of frequent pain, was hypothesized to be positively associated with AL. Four formulations of AL were investigated. Cross-sectional data from Wave 4 (2008-2009) of the English Longitudinal Study of Aging (ELSA) were analyzed. Covariates in the model included age, sex, education, smoking status, alcohol consumption, activity level, depression and common comorbid health conditions. A total of 5341 individuals were included; mean age 65.3(±9.2) years, 55% female, 62.4% infrequent or no pain, 12.6% mild pain, 19.1% moderate pain, and 5.9% severe pain. Severe pain was associated with greater AL defined by all four formulations. The amount of variance explained by pain severity and the covariates was highest when allostatic load was defined by the high risk quartile (12.9%) and by the clinical value (11.7%). Findings indicate a positive relationship between pain severity and AL. Further investigation is needed to determine if there is a specific AL signature for pain that differs from other health conditions.

Investigating the Burden of Chronic Pain: An Inflammatory and Metabolic Composite

Background. Chronic pain is associated with increased morbidity and mortality, predominated by cardiovascular disease and cancer. Investigating related risk factor measures may elucidate the biological burden of chronic pain. Objectives. We hypothesized that chronic pain severity would be positively associated with the risk factor composite. Methods. Data from 12,982 participants in the 6th Tromsø study were analyzed. Questionnaires included demographics, health behaviors, medical comorbidities, and chronic pain symptoms. The risk factor composite was comprised of body mass index, fibrinogen, C-reactive protein, and triglycerides. Chronic pain severity was characterized by frequency, intensity, time/duration, and total number of pain sites. Results. Individuals with chronic pain had a greater risk factor composite than individuals without chronic pain controlling for covariates and after excluding inflammation-related health conditions (p < 0.001). A significant "dose-response" relationship was demonstrated with pain severity (p < 0.001). In individuals with chronic pain, the risk factor composite varied by health behavior, exercise, lower levels and smoking, and higher levels. Discussion. The risk factor composite was higher in individuals with chronic pain, greater with increasing pain severity, and influenced by health behaviors. Conclusions. Identification of a biological composite sensitive to pain severity and adaptive/maladaptive behaviors would have significant clinical and research utility.

Association Between the Plasma Levels of Mediators of Inflammation With Pain and Disability in the Elderly With Acute Low Back Pain: Data From the Back Complaints in the Elders (BACE)-Brazil Study

STUDY DESIGN

Cross-sectional study with subsample of elderly women with acute low back pain (LBP), from Back Complaints in the Elders-Brazil (BACE-Brazil)

OBJECTIVE

To investigate the association between plasma levels of mediators of inflammation (interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor alpha (TNF-α), and soluble TNF receptor 1 (sTNF-R1)) with pain and disability experienced by elderly women with acute LBP.

SUMMARY OF BACKGROUND DATA

Among the elderly, LBP is a complaint of great importance and can lead to disability. Inflammatory cytokines are elevated in painful conditions, and may promote pain.

METHODS

We included 155 community-dwelling elderly women (age ≥ 65 yr), who presented with a new (acute) episode of LBP. Enzyme-linked immunosorbent assays were used to measure TNF-α, sTNF-R1, IL-1β, and IL-6. Disability was assessed using the Roland Morris Disability Questionnaire; pain was assessed using the McGill Pain Questionnaire. Linear regression models were fit with each pain and disability outcome as dependent variables: Present Pain Intensity; Qualities of pain; Severity of pain in the last week; LBP frequency and disability.

RESULTS

Depressive symptoms and IL-6 were associated and explained 20.9% of "qualities of pain" variability. TNF-α, sTNFR1, education, body mass index, and depressive symptoms explained 8.4% of "Severity of pain in the past week" variability. TNF-α, education, BMI, depressive symptoms, present pain intensity, qualities of pain, and LBP frequency explained 48.6% of "disability." No associations between inflammatory cytokines and "present pain intensity" and "LBP frequency" were found.

CONCLUSION

Our results demonstrate associations between inflammatory markers (TNF-α and sTNFR1) and pain severity, IL-6 was associated with the qualities of pain, and TNF-α was also associated with disability. These inflammatory mediators represent new markers to be considered in the assessment and treatment of elderly patients with LBP.

LEVEL OF EVIDENCE

5.

Perceived stress at work is associated with lower levels of DHEA-S

BACKGROUND

It is known that long-term psychosocial stress may cause or contribute to different diseases and symptoms and accelerate aging. One of the consequences of prolonged psychosocial stress may be a negative effect on the levels of dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEA-S). The aim of this study is to investigate whether levels of DHEA and DHEA-S differ in individuals who report perceived stress at work compared to individuals who report no perceived stress at work.

METHODS

Morning fasting DHEA-S and DHEA levels were measured in serum in a non-stressed group (n = 40) and a stressed group (n = 41). DHEA and DHEA-S levels were compared between the groups using ANCOVA, controlling for age.

RESULTS

The mean DHEA-S levels were 23% lower in the subjects who reported stress at work compared to the non-stressed group. Statistical analysis (ANCOVA) showed a significant difference in DHEA-S levels between the groups (p = 0.010). There was no difference in DHEA level between the groups.

CONCLUSIONS

This study indicates that stressed individual have markedly lower levels of DHEA-S. Given the important and beneficial functions of DHEA and DHEA-S, lower levels of DHEA-S may constitute one link between psychosocial stress, ill health and accelerated ageing.

Psychosocial and physiological correlates of self-reported hearing problems in male and female musicians in symphony orchestras

Experimental and epidemiological research indicate an association between long-term stress and hearing problems, yet the mechanisms underlying these disorders are not yet fully established. Thus, in order to better understand the pathogenesis of stress-related hearing problems, the present study explored the symptoms and general physiological and psychosocial status of musicians in symphony orchestras. Orchestral musicians are an ideal group to study since physical, psychosocial, work-environmental and acoustic stressors are highly prevalent. The subjects where obtained from two different studies. The first group included 250 participants from 12 orchestras and is entitled "the epidemiological study". The second group, entitled "the longitudinal study", included 47 musicians who were assessed at five occasions (every half year) during two years. Thirty-one of the 47 participants were selected for sampling of physiological variables, i.e. 24-hour ECG to assess heart rate variability to evaluate the synergistic action of the autonomic system as well as saliva cortisol and testosterone levels. The results indicate that self-reported hearing problems are associated with perceived poorer psychosocial environment, as well as mental health symptoms and stress. High-frequency power of heart rate variability (parasympathetic activity) showed a negative relationship to hearing problems, implying a poorer ability to "unwind" from stress. Cortisol levels were not correlated to hearing problems whereas testosterone levels showed a tendency to be lower in subjects with hearing problems than in others. These findings provide evidence for a relationship between long-term stress and self-reported hearing problems and demonstrate a protective role of parasympathetic and anabolic activity on hearing status.

Stress biomarkers' associations to pain in the neck, shoulder and back in healthy media workers: 12-month prospective follow-up

Physiological and psychological mechanisms have been proposed to link stress and musculoskeletal pain (MSP), and a number of stress biomarkers in patients with chronic pain have shown to be associated with stress-related disorders as well as health and recovery. The aim was to study if similar results might be found in a working population, in stress and computer intensive occupations with mild/moderate pain in neck, shoulder and back. The questions were if there are: (1) associations between self rated neck, shoulder and back pain (VAS) on one hand and stress-related (catabolic), recovery related (anabolic) variables, cardiovascular/lifestyle factors and immune markers on the other hand. (2) associations between long term changes in pain and stress marker values (6 month period). (3) predictive values in stress biomarkers for pain (12 month period) A study group with 121 media workers, 67 males (average 45 years) and 53 females (average 43 years), at three news departments of a media company was recruited. Pain occurrence and pain level in neck, shoulder, upper and low back were self-rated at three times with a 6-month interval towards the last month. Stress biomarker sampling was performed, at the same intervals. An additional similar questionnaire with momentary ratings focusing on "at present" i.e. within the same hour as stress biomarker sampling was performed. There were no changes in medicine intake or computer working hours during the 12 month study period. The total pain level and prevalence of pain decreased between baseline and 12 months follow-up. The rate of participation was 95%. Cross-sectional analyses on differences in stress biomarkers in groups of "no pain" and "pain" showed less beneficial stress biomarker levels (P < 0.05) in the "pain" group after age and gender adjustments in: S-DHEA-S and P-endothelin, S-insulin and P-fibrinogen. Analyses of each gender separately, adjusted for age, revealed in males differences in S-insulin, saliva cortisol 3, and P-endothelin. Furthermore, tendencies were seen in BMI, P-fibrinogen, and S-testosterone. In the female "pain" group a less beneficial P-BNP level was found. Longitudinal analysis of changes in pain levels and stress biomarkers within an interval of 6 months showed beneficial changes in the following stress markers: P-NPY, S-albumin, S-growth hormone and S-HDL when pain decreased, and vice versa when pain increased. Linear regression analyses showed statistically significant predicting values at the initial test instance for pain 12 months later in lower S-DHEA-S and S-albumin and higher B-HbA1c and P-fibrinogen. In stepwise regression and after age and gender adjustments, the associations with S-DHEA-S remained statistically significant. The present study shows that individuals in working life with a high level of regenerative/anabolic activity have less pain than other subjects, and that decreased regenerative/anabolic activity is associated with increasing pain. The levels of NPY, albumin, GH and HDL increased when pain decreased and vice versa. Low DHEA-S predicted pain 12 months later. These findings might contribute to increased knowledge about strategies to prevent further progression of neck/shoulder/back pain in persons who are "not yet in chronic pain".

Estimation of individual reference intervals in small sample sizes

In occupational health studies, the study groups most often comprise healthy subjects performing their work. Sampling is often planned in the most practical way, e.g., sampling of blood in the morning at the work site just after the work starts. Optimal use of reference intervals requires that the population, on which the reference interval is based, is representative for the study group in question. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommends estimating reference interval on at least 120 subjects. It may be costly and difficult to gain group sizes of that order of magnitude for all topics in question. Therefore, new methods to estimate reference intervals for small sample sizes are needed. We present an alternative method based on variance component models. The models are based on data from 37 men and 84 women taking into account biological variation from various variables such as gender, age, BMI, alcohol, smoking, and menopause. The reference intervals were compared to reference intervals calculated using IFCC recommendations. Where comparable, the IFCC calculated reference intervals had a wider range compared to the variance component models presented in this study. The presented method enables occupational health researchers to calculate reference intervals for specific groups, i.e. smokers versus non-smokers, etc. In conclusion, the variance component models provide an appropriate tool to estimate reference intervals based on small sample sizes.