Proinflammatory cytokine levels in fibromyalgia patients are independent of body mass index

Systemic pro- and anti-inflammatory profiles in acute non-specific low back pain: An exploratory longitudinal study of the relationship to six-month outcome

OBJECTIVES

Pro-inflammatory molecules are thought to underpin the development of chronic low back pain (LBP). Although research has begun to explore the association between pro-inflammatory molecules in acute LBP and long-term outcome, no study has explored the role of anti-inflammatory molecules. We aimed to explore whether levels of systemic pro- and anti-inflammatory molecules 1) changed over a period of six months from the onset of acute LBP; 2) differed between people who were recovered (N = 11) and unrecovered (N = 24) from their episode of LBP at six months; 3) baseline psychological factors were related to inflammatory molecule serum concentrations at baseline, three and six months.

METHODS

We retrospectively included participants with acute LBP included from a larger prospective trial and examined blood samples for the measurement of pro- and anti-inflammatory molecules and measures of pain, disability, and psychological factors at baseline, three and six months.

RESULTS

The serum concentrations of pro- and anti-inflammatory molecules did not differ over time when compared between participants who recovered and those who did not recover at six-month follow-up. At three months, the unrecovered group had higher interleukin (IL)-8 and IL-10 serum concentrations than the recovered group. Baseline psychological factors were not related to inflammatory molecules at any time point.

DISCUSSION

This exploratory study showed that levels of systemic inflammatory molecules did not change over the course of LBP, irrespective of whether people were recovered or unrecovered at six months. There was no relationship between acute-stage psychological factors and systemic inflammatory molecules. Further investigation is needed to elucidate the contribution of pro- and anti-inflammatory molecules to long-term LBP outcome.

Pregabalin inhibits proinflammatory cytokine release in patients with fibromyalgia syndrome

Objectives

The main goal of the study was to investigate how pregabalin (PGB) affects proinflammatory cytokine release in patients with fibromyalgia syndrome (FMS).

Patients and methods

This experimental research study was conducted with 85 female participants (mean age: 49.6±10.1 years; range, 30 to 73 years) between April 2020 and November 2020. Of the participants, 30 were FMS patients using PGB 150 mg/day for at least three months, 30 were FMS patients not using PGB, and 25 were healthy individuals. The detection of FMS was carried out according to the 2010 American College of Rheumatology diagnostic criteria. Levels of proinflammatory cytokines (interleukin [IL]-2, IL-6, IL-12, IL-17, interferon-gamma, and tumor necrosis factor-alpha) were measured by enzyme-linked immunosorbent assay.

Results

Serum concentrations of proinflammatory cytokines were remarkably decreased in FMS patients using PGB (p<0.001) and were higher in patients with FMS not using PGB than in healthy subjects (p<0.001). The highest values of proinflammatory cytokines were found in the group of FMS patients not using PGB (p<0.001).

Conclusion

These results indicate that PGB inhibits the release of proinflammatory cytokines, suggesting that it can be used as an anti-inflammatory agent in inflammatory cases.

Potential role of blood biomarkers in patients with fibromyalgia: a systematic review with meta-analysis

ABSTRACT

Fibromyalgia (FM) is a complex chronic pain condition. Its symptoms are nonspecific, and to date, no objective test exists to confirm FM diagnosis. Potential objective measures include the circulating levels of blood biomarkers. This systematic review and meta-analysis aim to review studies assessing blood biomarkers' levels in patients with FM compared with healthy controls. We systematically searched the PubMed, MEDLINE, EMBASE, and PsycINFO databases. Fifty-four studies reporting the levels of biomarkers in blood in patients with FM were included. Data were extracted, and the methodological quality was assessed independently by 2 authors. The methodological quality of 9 studies (17%) was low. The results of most studies were not directly comparable given differences in methods and investigated target immune mediators. Thus, data from 40 studies only were meta-analyzed using a random-effects model. The meta-analysis showed that patients with FM had significantly lower levels of interleukin-1 β and higher levels of IL-6, IL-8, tumor necrosis factor-alpha, interferon gamma, C-reactive protein, and brain-derived neurotrophic factor compared with healthy controls. Nevertheless, this systematic literature review and meta-analysis could not support the notion that these blood biomarkers are specific biomarkers of FM. Our literature review, however, revealed that these same individual biomarkers may have the potential role of identifying underlying pathologies or other conditions that often coexist with FM. Future research is needed to evaluate the potential clinical value for these biomarkers while controlling for the various confounding variables.

Relationship between systemic inflammation and recovery over 12 months after an acute episode of low back pain

BACKGROUND CONTEXT

Individual characteristics can influence outcomes after injury. Our previous work in individuals with early-acute low back pain (LBP) identified subgroups (clusters) with specific biopsychosocial features that recovered poorly or well by 6 months.

PURPOSE

This study extends on that work by revealing the short- and long-term trajectories of recovery and systemic inflammation of these participant clusters: (1) "inflammatory & poor sleep" (Cluster 1), "high TNF & depression" (Cluster 2), "high pain & high pain-related fear" (Cluster 3), and "low pain & low pain-related fear" (Cluster 4).

STUDY DESIGN/SETTING

Longitudinal cohort study.

PATIENT SAMPLE

Eighty-three individuals within 2 weeks of an acute episode of LBP - grouped into their a priori-defined cluster.

OUTCOME MEASURES

General participant characteristics (sex, age, body mass index, smoking history, previous LBP history); self-reported LBP (0-10 numerical rating scale, LBP-related disability (Roland-Morris Disability Questionnaire), depression (Center for Epidemiological Studies Depression Scale, pain catastrophizing (Pain Catastrophizing Scale), fear avoidance (Fear Avoidance Beliefs Questionnaire), pain self-efficacy (Pain Self-Efficacy Questionnaire), and sleep (Pittsburgh Sleep Quality Index); systemic inflammatory biomarkers (C-reactive protein [CRP], interleukin-6 [IL-6], interleukin-1β, tumor necrosis factor [TNF]).

METHODS

Participants provided blood for the measurement of CRP/cytokines, and completed questionnaires related to their pain/disability, psychological and sleep status. Blood measures were repeated 3-monthly for 9 months, and pain/disability were self-reported fortnightly for 12 months. Recovery (change in pain) and CRP/cytokines were longitudinally compared between clusters using mixed-models. Associations between baseline factors and follow-up CRP/cytokines levels were assessed with multiple regression.

RESULTS

Clusters 1 and 2 were associated, but oppositely, with recovery over the 12-months. Cluster 1 reported most recovery at every 3-monthly interval, whereas Cluster 2 reported least recovery. Cluster 1 had elevated CRP (and IL-6) at baseline that continued to decrease from 3 to 9 months. TNF was elevated early and persistently in Cluster 2. Baseline factors other than inflammation generally failed to predict follow-up inflammation.

CONCLUSIONS

Findings support the early role of CRP (and perhaps IL-6) in control of inflammation and recovery, and a pathological role of persistent TNF overexpression, which may be perpetuated by depressive-like behaviors.

Cardiac autonomic neuropathy in fibromyalgia: Revisited

BACKGROUND

Fibromyalgia (FM) is associated with widespread autonomic dysfunction where sympathetic predominance explains associated complaints such as widespread pain, sleep disorders and anxiety. Recent studies indicate a possible neurovascular autonomic interaction in the pathogenesis of FM.

OBJECTIVE

Our study paradigm included a modified Ewing's battery of autonomic function tests to find the cardiac autonomic neuropathy (CAN) in FM patients. The battery comprises some tests such as the Valsalva maneuver, which are effort-dependent, so we also aimed to identify a potential simplified test out of the whole battery as an index marker of CAN in FM patients.

METHODS

Forty-two female patients with FM were included in this study and were administered sympathetic and parasympathetic reactivity tests to explore the presence of CAN. We compared the results from each sympathetic and parasympathetic reactivity test against CAN.

RESULTS

Delta heart rate in the deep breathing test was significantly different in patients with and without CAN. Delta heart rate also exhibited best diagnostic performance (AUC = 0.769, 95% CI: 0.619-0.920, p< 0.001), with 88% sensitivity, 64% specificity, and 89% negative predictive value (NPV). The 30: 15 ratio during the lying to standing test also emerged as a suitable index; however it did not show any difference between CAN and non-CAN patients.

CONCLUSION

The delta heart rate has the best diagnostic accuracy, primarily in CAN's exclusion by its very high sensitivity and NPV.

Pioglitazone improves skeletal muscle functions in reserpine-induced fibromyalgia rat model

BACKGROUND

Fibromyalgia (FM) is characterized by musculoskeletal pain, fatigue, sleep and memory disturbance. There is no definitive cure yet for FM-related health problems. Peroxisome proliferator-activated receptor's (PPAR's) activation is associated with insulin sensitisation and improved glucose metabolism. PPAR-γ was reported to alleviate FM allodynia. Limited data are discussing its effect on motor disorders.

OBJECTIVE

To investigate the potential effect of PPAR-γ agonists (pioglitazone, as one member of thiazolidinediones (TZD)) on motor dysfunction in reserpine-induced FM in a rat model.

MATERIALS AND METHODS

Thirty-six male Wistar rats were divided into negative control (n = 9) and reserpine-induced FM (n = 27) groups. The latter was subdivided into three equal subgroups (n = 9), positive control (untreated FM model), pioglitazone-treated and GW9662-treated. We evaluated muscle functions and activity of chloramphenicol acetyltransferase, superoxide dismutase, malondialdehyde, and serum levels of interleukin-8 and monocyte chemoattractant protein-1.

RESULTS

Pioglitazone significantly relieved fatigue, improved muscle performance, reduced inflammatory cytokines and enhanced antioxidant's activity, while GW9662, a known PPAR-γ antagonist, aggravated the FM manifestations in the rat model.

CONCLUSION

PPAR-γ agonists show a promising role against FM-associated motor dysfunctions.

Is fibromyalgia associated with a unique cytokine profile? A systematic review and meta-analysis

Objectives

The aetiology of primary chronic pain syndromes (CPS) is highly disputed. We performed a systematic review and meta-analysis aiming to assess differences in circulating cytokine levels in patients with diffuse CPS (fibromyalgia) vs healthy controls (HC).

Methods

Human studies published in English from the PubMed, MEDLINE/Scopus and Cochrane databases were systematically searched from inception up to January 2020. We included full text cross-sectional or longitudinal studies with baseline cytokine measurements, reporting differences in circulating cytokine levels between fibromyalgia patients and HC. Random-effects meta-analysis models were used to report pooled effects and 95% CIs. This study is registered with PROSPERO (CRD42020193774).

Results

Our initial search yielded 324 papers and identified 29 studies (2458 participants) eligible for systematic review and 22 studies (1772 participants) suitable for meta-analysis. The systematic analysis revealed reproducible findings supporting different trends of cytokine levels when fibromyalgia patients were compared with HC, while the chemokine eotaxin, was consistently raised in fibromyalgia. Meta-analysis showed significantly increased TNF-α [standardized mean difference (SMD) = 0.36, 95% CI: 0.12, 0.60, P = 0.0034; I² = 71%, Q²P = 0.0002], IL-6 (SMD = 0.15, 95% CI: 0.003, 0.29, P = 0.045; I² = 39%, Q²P = 0.059), IL-8 (SMD = 0.26, 95% CI: 0.05, 0.47, P = 0.01; I² = 61%, Q²P = 0.005) and IL-10 (SMD = 0.61, 95% CI: 0.34, 0.89, P < 0.001; I² = 10%, Q²P = 0.34) in fibromyalgia patients compared with HC.

Conclusion

We found evidence of significant differences in the peripheral blood cytokine profiles of fibromyalgia patients compared with HC. However, the distinctive profile associated with fibromyalgia includes both pro-inflammatory (TNF-α, IL-6, IL-8) and anti-inflammatory (IL-10) cytokines in pooled analysis, as well as chemokine (eotaxin) signatures. Further research is required to elucidate the role of cytokines in fibromyalgia.

Circulating Adipokines in Predicting the Transition from Acute to Persistent Low Back Pain

OBJECTIVES

Cytokines such as tumor necrosis factor (TNF) contribute to the transition from acute to persistent pain. Despite increasing incidence of obesity and its linkage with chronic pain and inflammation, cytokines predominantly produced by adipose tissue (adipokines) have received little attention. Here we aimed to explore the longitudinal trajectory of adipokines from the onset of acute low back pain (LBP) and identify combinations of adipokines and/or other features that predict outcome.

METHODS

Individuals with acute LBP (less than two weeks after onset) who had either recovered (no pain, N = 15) or remained unrecovered (no reduction/increase in pain, N = 13) at six months and 15 controls were retrospectively selected from a larger prospective cohort. Participants provided blood for the measurement of TNF, interleukin-6 (IL-6), resistin, visfatin, adiponectin, leptin, and C-reactive protein (CRP), and completed questionnaires related to pain/disability, depression, and sleep at baseline. LBP participants repeated measurements at six months.

RESULTS

Compared with controls, acute LBP individuals had higher TNF and CRP but lower adiponectin. In LBP, unrecovered individuals had higher TNF at both time points, but lower CRP at baseline and leptin at six months. Although combined low CRP, high TNF, and depressive symptoms at baseline predicted poor recovery, the primary adipokines leptin, resistin, visfatin, and adiponectin did not.

CONCLUSIONS

Primary adipokines did not add to the prediction of poor LBP outcome that has been identified for the combination of low CRP, high TNF, and depressive symptoms in acute LBP. Whether adipokines play a role in LBP persistence in overweight/obese individuals requires investigation.

Hypothesis: Mechanisms That Prevent Recovery in Prolonged ICU Patients Also Underlie Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Here the hypothesis is advanced that maladaptive mechanisms that prevent recovery in some intensive care unit (ICU) patients may also underlie Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Specifically, these mechanisms are: (a) suppression of the pituitary gland's pulsatile secretion of tropic hormones, and (b) a "vicious circle" between inflammation, oxidative and nitrosative stress (O&NS), and low thyroid hormone function. This hypothesis should be investigated through collaborative research projects.

Significant correlation between plasma proteome profile and pain intensity, sensitivity, and psychological distress in women with fibromyalgia

Fibromyalgia (FM) is a complex pain condition where the pathophysiological and molecular mechanisms are not fully elucidated. The primary aim of this study was to investigate the plasma proteome profile in women with FM compared to controls. The secondary aim was to investigate if plasma protein patterns correlate with the clinical variables pain intensity, sensitivity, and psychological distress. Clinical variables/background data were retrieved through questionnaires. Pressure pain thresholds (PPT) were assessed using an algometer. The plasma proteome profile of FM (n = 30) and controls (n = 32) was analyzed using two-dimensional gel electrophoresis and mass spectrometry. Quantified proteins were analyzed regarding group differences, and correlations to clinical parameters in FM, using multivariate statistics. Clear significant differences between FM and controls were found in proteins involved in inflammatory, metabolic, and immunity processes. Pain intensity, PPT, and psychological distress in FM had associations with specific plasma proteins involved in blood coagulation, metabolic, inflammation and immunity processes. This study further confirms that systemic differences in protein expression exist in women with FM compared to controls and that altered levels of specific plasma proteins are associated with different clinical parameters.

Peripheral immune aberrations in fibromyalgia: A systematic review, meta-analysis and meta-regression

The objective was to identify immune alterations in patients with fibromyalgia syndrome (FMS) compared to healthy controls (HC) using meta-analysis and meta-regression. Six electronic databases were searched for suitable original articles investigating immune biomarkers in FMS in comparison to HC. We extracted outcomes and variables of interest, such as mean and SD of peripheral blood immune biomarkers, age or sex. A random-effects model with restricted maximum-likelihood estimator was used to compute effect sizes (standardized mean difference and 95% CI, Hedges' g) and meta-analysis, group meta-analysis and meta-regressions were conducted. Forty-three papers were included in this systematic review, of which 29 were suitable for meta-analysis. Interleukin (IL)-6 (g = 0.36 (0.09-0.63); I² = 85.94; p = 0.01), IL-4 (g = 0.50 (0.03-0.98); I² = 81.87; p = 0.04), and IL-17A (g = 0.53 (0.00-1.06); I² = 87.15; p = 0.05), were significantly higher in FMS compared to HC while also combinations of cytokines into relevant phenotypes were significantly upregulated including M1 macrophage (g = 0.23 (0.03-0.43); I² = 77.62; p = 0.02), and immune-regulatory (g = 0.40 (0.09-0.72); I² = 84.81; p = 0.01) phenotypes. Heterogeneity levels were very high and subgroup and meta-regression analyses showed that many covariates explained part of the heterogeneity including medication washout, sex, time of blood sampling and exclusion of patients with major depressive disorder. In conclusion, FMS is accompanied by a disbalance between upregulated pro-inflammatory (M1 and Th-17) and immune-regulatory cytokines although effect sizes are small-to-moderate. Based on our results we provide specific methodological suggestions for future research, which should assess Th-1, Th-17, chemokines, and Th-2 phenotypes while controlling for possible confounding variables specified in this study.

MCP-1 is increased in patients with CFS and FM, whilst several other immune markers are significantly lower than healthy controls

The role of the immune system in the pathogenesis of Fibromyalgia (FM) and Chronic fatigue syndrome (CFS) is not clear. We have previously reported increased levels of C-reactive protein (CRP) in these patient groups compared to healthy controls and wanted to further explore the levels of circulating immune markers in these populations. The population consisted of three groups, 58 patients with FM, 49 with CFS and 54 healthy controls. All participants were females aged 18-60. Patients were recruited from a specialised university hospital clinic and controls were recruited by advertisement among the staff and students at the hospital and university. Plasma levels of Interferon (IFN)-γ, Interleukin (IL)-1β, IL-1ra, IL-4, IL-6, IL-8, IL-10, IL-17, Interferon gamma-induced protein (IP)-10, Monocyte Chemoattractant Protein (MCP)-1, Transforming Growth Factor (TGF)-β1, TGF-β2, TGF-β3 and Tumour Necrosis Factor (TNF)-α were analysed by multiplex. Differences between the three groups CFS, FM and controls, were analysed by Kruskal Wallis tests. MCP-1 was significantly increased in both patient groups compared to healthy controls. IL-1β, Il-4, IL-6, TNF-α, TGF-β1, TGF-β2, TGF-β3, IL-10 and IL17 all were significantly lower in the patient groups than healthy controls. IFN-γ was significantly lower in the FM group. For IL-8, IL-10 and IL-1ra there were no significant difference when controlled for multiple testing. In conclusion, in our material MCP-1 seems to be increased in patients both with CFS and with FM, while several other immune markers are significantly lower in patients than controls.

Inflammation in the pathophysiology of neuropathic pain

Peripheral nerve injuries and diseases often lead to pain persisting beyond the resolution of damage, indicating an active disease-promoting process, which may result in chronic pain. This is regarded as a maladaptive mechanism resulting from neuroinflammation that originally serves to promote regeneration and healing. Knowledge on these physiological and pathophysiological processes has accumulated over the last few decades and has started to yield potential therapeutic targets. Key players are macrophages, T-lymphocytes, cytokines, and chemokines. In the spinal cord and brain, microglia and astrocytes are involved. Recently, data have been emerging on the regulation of these players. MicroRNAs and other noncoding RNAs have been discussed as potential master switches that may link nerve injury, pain, and inflammation. Clinical disorders most intensely studied in the context of neuroinflammation and pain are the complex regional pain syndrome, polyneuropathies, postherpetic neuralgia, and the fibromyalgia syndrome, in which recently a neuropathic component has been described. Research from several groups has shown an important role of both proinflammatory and anti-inflammatory cytokines in neuropathic and other chronic pain states in humans. There is ample evidence of an analgesic action of anti-inflammatory cytokines in animal models. The interplay of anti-inflammatory cytokines and the nociceptive system provides possibilities and challenges concerning treatment strategies based on this concept.

Pro-inflammatory Cytokines and Oxidized Low-Density-Lipoprotein in Patients With Fibromyalgia

Objectives

This study aims to evaluate the differences in serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), (IL-8), and oxidized low-density lipoprotein (Ox-LDL) between female fibromyalgia (FM) patients and healthy females and also to examine a possible relationship between the cytokines/biomarker and the severity of pain and clinical features of FM.

Patients and methods

This case-control study included 48 female patients (mean age 26.51±6.98 years; range, 18 to 50 years) who were diagnosed with FM according to the American College of Rheumatology criteria and 43 healthy female subjects (mean age 23.93±4.22 years; range, 18 to 50 years). Serum levels of TNF-α, IL-1β, IL-8, and Ox-LDL were measured by enzyme-linked immunosorbent assay in both groups. Fibromyalgia Impact Questionnaire, Visual Analog Scale, symptom severity scale, and widespread pain index were carried out and also their relationships with TNF-α, IL-1β, IL-8, and Ox-LDL levels were evaluated.

Results

There was no difference in levels of the serum TNF-α, IL-1β, IL-8, and Ox-LDL between FM patients and healthy controls (p>0.05). The severity of pain was significantly associated with TNF-α (r=0.338; p=0.021) and IL-8 (r=0.299; p=0.043) levels, and Ox-LDL (r=0.415; p=0.006) level was found to be related to symptom severity of FM.

Conclusion

Our results suggest that serum levels of TNF-α and IL-8 may be involved in the occurrence of pain in FM. The level of Ox-LDL may play an important role in the severity of symptoms. Future studies are needed to determine whether and how Ox-LDL plays a role in FM.

Mindfulness Meditation for Fibromyalgia: Mechanistic and Clinical Considerations

PURPOSE OF REVIEW

Fibromyalgia is a disorder characterized by widespread pain and a spectrum of psychological comorbidities, rendering treatment difficult and often a financial burden. Fibromyalgia is a complicated chronic pain condition that requires a multimodal therapeutic approach to optimize treatment efficacy. Thus, it has been postulated that mind-body techniques may prove fruitful in treating fibromyalgia. Mindfulness meditation, a behavioral technique premised on non-reactive sensory awareness, attenuates pain and improves mental health outcomes. However, the impact of mindfulness meditation on fibromyalgia-related outcomes has not been comprehensively characterized. The present review delineates the existing evidence supporting the effectiveness and hypothesized mechanisms of mindfulness meditation in treating fibromyalgia-related outcomes.

RECENT FINDINGS

Mindfulness-based interventions premised on cultivating acceptance, non-attachment, and social engagement may be most effective in decreasing fibromyalgia-related pain and psychological symptoms. Mindfulness-based therapies may alleviate fibromyalgia-related outcomes through multiple neural, psychological, and physiological processes. Mindfulness meditation may provide an effective complementary treatment approach for fibromyalgia patients, especially when combined with other reliable techniques (exercise; cognitive behavioral therapy). However, characterizing the specific analgesic mechanisms supporting mindfulness meditation is a critical step to fostering the clinical validity of this technique. Identification of the specific analgesic mechanisms supporting mindfulness-based pain relief could be utilized to better design behavioral interventions to specifically target fibromyalgia-related outcomes.

Plasma Cytokine Levels in Fibromyalgia and Their Response to 15 Weeks of Progressive Resistance Exercise or Relaxation Therapy

The aims of this study were to compare circulating cytokines between FM and healthy controls and to investigate the effect on cytokine levels by 15 weeks of progressive resistance exercise or relaxation therapy in FM. Baseline plasma cytokine levels and clinical data were analyzed in 125 women with FM and 130 age-matched healthy women. The FM women were then randomized to progressive resistance exercise (n = 49) or relaxation (n = 43). Baseline IL-2, IL-6, TNF-α, IP-10, and eotaxin were higher in FM than in healthy controls (P < 0.041), whereas IL-1β was lower (P < 0.001). There were weak correlations between cytokine levels and clinical variables. After both interventions, IL-1ra had increased (P = 0.004), while IL-1β had increased in the relaxation group (P = 0.002). Changes of IFN-γ, IL-2, IL-4, IL-6, IL-8, and IL-17A were weakly correlated with changes of PPT, but there were no significant correlations between changes of cytokine and changes in other clinical variables. The elevated plasma levels of several cytokines supports the hypothesis that chronic systemic inflammation may underlie the pathophysiology of FM even if the relation to clinical variables was weak. However, 15 weeks of resistance exercise, as performed in this study, did not show any anti-inflammatory effect on neither FM symptoms nor clinical and functional variables. This trial is registered with ClinicalTrials.govNCT01226784, registered October 21, 2010. The first patient was recruited October 28, 2010.

ISSLS PRIZE IN CLINICAL SCIENCE 2018: longitudinal analysis of inflammatory, psychological, and sleep-related factors following an acute low back pain episode-the good, the bad, and the ugly

STUDY DESIGN

Prospective longitudinal study.

OBJECTIVE

To determine whether systemic cytokines and C-reactive protein (CRP) during an acute episode of low back pain (LBP) differ between individuals who did and did not recover by 6 months and to identify sub-groups based on patterns of inflammatory, psychological, and sleep features associated with recovery/non-recovery. Systemic inflammation is observed in chronic LBP and may contribute to the transition from acute to persistent LBP. Longitudinal studies are required to determine whether changes present early or develop over time. Psychological and/or sleep-related factors may be related.

METHODS

Individuals within 2 weeks of onset of acute LBP (N = 109) and pain-free controls (N = 55) provided blood for assessment of CRP, tumor necrosis factor (TNF), interleukin-6 (IL-6) and interleukin-1β, and completed questionnaires related to pain, disability, sleep, and psychological status. LBP participants repeated measurements at 6 months. Biomarkers were compared between LBP and control participants at baseline, and in longitudinal (baseline/6 months) analysis, between unrecovered (≥pain and disability), partially recovered (reduced pain and/or disability) and recovered (no pain and disability) participants at 6 months. We assessed baseline patterns of inflammatory, psychological, sleep, and pain data using hierarchical clustering and related the clusters to recovery (% change in pain) at 6 months.

RESULTS

CRP was higher in acute LBP than controls at baseline. In LBP, baseline CRP was higher in the recovered than non-recovered groups. Conversely, TNF was higher at both time-points in the non-recovered than recovered groups. Two sub-groups were identified that associated with more ("inflammatory/poor sleep") or less ("high TNF/depression") recovery.

CONCLUSIONS

This is the first evidence of a relationship between an "acute-phase" systemic inflammatory response and recovery at 6 months. High inflammation (CRP/IL-6) was associated with good recovery, but specific elevation of TNF, along with depressive symptoms, was associated with bad recovery. Depression and TNF may have a two-way relationship. These slides can be retrieved under Electronic Supplementary Material.

Ambroxol for the treatment of fibromyalgia: science or fiction?

Fibromyalgia appears to present in subgroups with regard to biological pain induction, with primarily inflammatory, neuropathic/neurodegenerative, sympathetic, oxidative, nitrosative, or muscular factors and/or central sensitization. Recent research has also discussed glial activation or interrupted dopaminergic neurotransmission, as well as increased skin mast cells and mitochondrial dysfunction. Therapy is difficult, and the treatment options used so far mostly just have the potential to address only one of these aspects. As ambroxol addresses all of them in a single substance and furthermore also reduces visceral hypersensitivity, in fibromyalgia existing as irritable bowel syndrome or chronic bladder pain, it should be systematically investigated for this purpose. Encouraged by first clinical observations of two working groups using topical or oral ambroxol for fibromyalgia treatments, the present paper outlines the scientific argument for this approach by looking at each of the aforementioned aspects of this complex disease and summarizes putative modes of action of ambroxol. Nevertheless, at this point the evidence basis for ambroxol is not strong enough for clinical recommendation.

Systemic inflammatory profiles and their relationships with demographic, behavioural and clinical features in acute low back pain

Systemic inflammation is linked with development and persistence of many pathological pain states. Although chronic phase inflammatory responses are well reported, the acute phase has received limited attention. Here we investigated circulating pro-inflammatory cytokines and C-reactive protein (CRP), and explored their relationships with symptom severity and other factors in acute low back pain (LBP). Ninety-nine individuals within two weeks of onset of acute LBP and 55 pain-free controls completed questionnaires related to their pain (visual analogue scale, VAS) and disability, behaviour, sleep quality and psychological status. CRP, interleukin-6 (IL-6), tumor necrosis factor (TNF) and interleukin-1β (IL-1β) were measured from serum samples. Biomarkers were compared between LBP and control participants, and in a separate analysis, for those with "high-pain" (VAS ⩾4) and "low-pain" (VAS <4). The relationships between biomarkers and all other variables, including other cytokines/CRP were assessed. CRP was higher in LBP than controls and in those with high- than low-pain (p<0.01). IL-6 was higher in those with high- than low-pain (p<0.05), but not controls. Various pain and non-pain factors were associated with each biomarker differently. These findings suggest systemic CRP and IL-6 are important contributors to inflammation in the early post-onset phase of LBP and that various factors can shape these responses.

Predictors of fibromyalgia: a population-based twin cohort study

BACKGROUND

Fibromyalgia (FM) is a pain syndrome, the mechanisms and predictors of which are still unclear. We have earlier validated a set of FM-symptom questions for detecting possible FM in an epidemiological survey and thereby identified a cluster with "possible FM". This study explores prospectively predictors for membership of that FM-symptom cluster.

METHODS

A population-based sample of 8343 subjects of the older Finnish Twin Cohort replied to health questionnaires in 1975, 1981, and 1990. Their answers to the set of FM-symptom questions in 1990 classified them in three latent classes (LC): LC1 with no or few symptoms, LC2 with some symptoms, and LC3 with many FM symptoms. We analysed putative predictors for these symptom classes using baseline (1975 and 1981) data on regional pain, headache, migraine, sleeping, body mass index (BMI), physical activity, smoking, and zygosity, adjusted for age, gender, and education. Those with a high likelihood of having fibromyalgia at baseline were excluded from the analysis. In the final multivariate regression model, regional pain, sleeping problems, and overweight were all predictors for membership in the class with many FM symptoms.

RESULTS

The strongest non-genetic predictor was frequent headache (OR 8.6, CI 95% 3.8-19.2), followed by persistent back pain (OR 4.7, CI 95% 3.3-6.7) and persistent neck pain (OR 3.3, CI 95% 1.8-6.0).

CONCLUSIONS

Regional pain, frequent headache, and persistent back or neck pain, sleeping problems, and overweight are predictors for having a cluster of symptoms consistent with fibromyalgia.

Neuropeptides CRH, SP, HK-1, and Inflammatory Cytokines IL-6 and TNF Are Increased in Serum of Patients with Fibromyalgia Syndrome, Implicating Mast Cells

Fibromyalgia syndrome (FMS) is a chronic, idiopathic condition of widespread musculoskeletal pain affecting more women than men. Even though clinical studies have provided evidence of altered central pain pathways, the lack of definitive pathogenesis or reliable objective markers has hampered development of effective treatments. Here we report that the neuropeptides corticotropin-releasing hormone (CRH), substance P (SP), and SP-structurally-related hemokinin-1 (HK-1) were significantly (P = 0.026, P < 0.0001, and P = 0.002, respectively) elevated (0.82 ± 0.57 ng/ml, 0.39 ± 0.18 ng/ml, and 7.98 ± 3.12 ng/ml, respectively) in the serum of patients with FMS compared with healthy controls (0.49 ± 0.26 ng/ml, 0.12 ± 0.1 ng/ml, and 5.71 ± 1.08 ng/ml, respectively). Moreover, SP and HK-1 levels were positively correlated (Pearson r = 0.45, P = 0.002) in FMS. The serum concentrations of the inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF) were also significantly (P = 0.029 and P = 0.006, respectively) higher (2.97 ± 2.35 pg/ml and 0.92 ± 0.31 pg/ml, respectively) in the FMS group compared with healthy subjects (1.79 ± 0.62 pg/ml and 0.69 ± 0.16 pg/ml, respectively). In contrast, serum IL-31 and IL-33 levels were significantly lower (P = 0.0001 and P = 0.044, respectively) in the FMS patients (849.5 ± 1005 pg/ml and 923.2 ± 1284 pg/ml, respectively) in comparison with healthy controls (1281 ± 806.4 pg/ml and 3149 ± 4073 pg/ml, respectively). FMS serum levels of neurotensin were not different from controls. We had previously shown that CRH and SP stimulate IL-6 and TNF release from mast cells (MCs). Our current results indicate that neuropeptides could stimulate MCs to secrete inflammatory cytokines that contribute importantly to the symptoms of FMS. Treatment directed at preventing the secretion or antagonizing these elevated neuroimmune markers, both centrally and peripherally, may prove to be useful in the management of FMS.

Physiological parameters as a tool in the diagnosis of fibromyalgia syndrome in females: A preliminary study

AIMS

Although fibromyalgia (FM) syndrome is associated with many symptoms, there is as yet no specific finding or laboratory test diagnostic of this syndrome. The physical examination and laboratory tests may be helpful in figuring out this syndrome.

MATERIALS AND METHODS

The heart rate, respiration rate, body temperature (TEMP), height, body weight, hemoglobin level, erythrocyte sedimentation rate, white blood cell count, platelet count (PLT), rheumatoid factor and C-reactive protein levels and electrocardiograms (ECG) of FM patients were compared with those of control individuals. In addition, the predictive value of these tests was evaluated via receiver operating characteristic (ROC) analysis.

KEY FINDINGS

The results showed that the TEMP and the PLT were higher in the FM group compared with the control group. Also, ST heights in ECGs which corresponds to a period of ventricle systolic depolarization, showed evidence of a difference between the FM and the control groups. There was no difference observed in terms of the other parameters. According to the ROC analysis, PLT, TEMP and ST height have predictive capacities in FM.

SIGNIFICANCE

Changes in hormonal factors, peripheral blood circulation, autonomous system activity disorders, inflammatory incidents, etc., may explain the increased TEMP in the FM patients. The high PLT level may signify a thromboproliferation or a possible compensation caused by a PLT functional disorder. ST depression in FM patients may interrelate with coronary pathology. Elucidating the pathophysiology underlying the increases in TEMP and PLT and the decreases in ST height may help to explain the etiology of FM.

Prevalence of fibromyalgia and co-morbid bipolar disorder: A systematic review and meta-analysis

BACKGROUND

Fibromyalgia (FM) is a chronic disorder with high morbidity and significant health service utilization costs. Few studies have reported on the phenotypic overlap of FM and bipolar disorder (BD). The aim of this review is to qualitatively and quantitatively summarize the results and clinical implications of the extant literature on the co-occurrence of FM and BD.

METHODS

A systematic search of PubMed/Medline, Cochrane, PsycINFO, CINAHL and Embase was conducted to search for relevant articles. Articles were included if incidence and/or prevalence of BD was determined in the FM sample. Results of prevalence were pooled from all studies. Pooled odds ratio (OR) was calculated based on case-control studies using standard meta-analytic methods.

RESULTS

A total of nine studies were included. The pooled rate of BD comorbidity in samples of FM patients was 21% (n=678); however, results varied greatly as a function of study methodology. Case-controlled studies revealed a pooled OR of 7.55 of BD co-morbidity in samples of FM patients [95% Confidence Interval (CI)=3.9-14.62, FM n=268, controls n=413] with low heterogeneity (I(2)=0%).

LIMITATIONS

The current study was limited by the low number of available studies and heterogeneity of study methods and results.

CONCLUSIONS

These data strongly suggest an association between BD and FM. Future studies employing a validated diagnostic screen are needed in order to more accurately determine the prevalence of BD in FM. An adequate psychiatric assessment is recommended in FM patients with suspected symptoms consistent with BD prior to administration of antidepressants in the treatment of FM.

Comparison of the Levels of Pro-Inflammatory Cytokines Released in the Vastus Lateralis Muscle of Patients with Fibromyalgia and Healthy Controls during Contractions of the Quadriceps Muscle--A Microdialysis Study

Objective

Fibromyalgia is associated with central hyperexcitability, but it is suggested that peripheral input is important to maintain central hyperexcitability. The primary aim was to investigate the levels of pro-inflammatory cytokines released in the vastus lateralis muscle during repetitive dynamic contractions of the quadriceps muscle in patients with fibromyalgia and healthy controls. Secondarily, to investigate if the levels of pro-inflammatory cytokines were correlated with pain or fatigue during these repetitive dynamic contractions.

Material and Methods

32 women with fibromyalgia and 32 healthy women (controls) participated in a 4 hour microdialysis session, to sample IL-1β, IL-6, IL-8, and TNF from the most painful point of the vastus lateralis muscle before, during and after 20 minutes of repeated dynamic contractions. Pain (visual analogue scale; 0–100) and fatigue Borg’s Rating of Perceived Exertion Scale; 6–20) were assessed before and during the entire microdialysis session.

Results

The repetitive dynamic contractions increased pain in the patients with fibromyalgia (P < .001) and induced fatigue in both groups (P < .001). Perceived fatigue was significantly higher among patients with fibromyalgia than controls (P < .001). The levels of IL-1β did not change during contractions in either group. The levels of TNF did not change during contractions in patients with fibromyalgia, but increased in controls (P < .001) and were significantly higher compared to patients with fibromyalgia (P = .033). The levels of IL-6 and IL-8 increased in both groups alike during and after contractions (P’s < .001). There were no correlations between pain or fatigue and cytokine levels after contractions.

Conclusion

There were no differences between patients with fibromyalgia and controls in release of pro-inflammatory cytokines, and no correlations between levels of pro-inflammatory cytokines and pain or fatigue. Thus, this study indicates that IL-1β, IL-6, IL-8, and TNF do not seem to play an important role in maintenance of muscle pain in fibromyalgia.

Nitric Oxide, Inflammation, Lipid Profile, and Cortisol in Normal- and Overweight Women With Fibromyalgia

Objectives:

Research has identified many factors associated with fibromyalgia (FM), but findings have been inconsistent. This study aimed to investigate changes in levels of nitric oxide (NO), inflammatory markers, lipid profile, and cortisol in normal- and overweight patients with FM and controls. Since most patients with FM are overweight, we explored possible changes in these markers according to body mass index (BMI).

Methods:

This preliminary study was performed on serum samples of women with FM and age-matched controls, grouped according to their BMI: 12 normal-weight patients and 12 controls and 13 overweight patients and 8 controls. Ozone-based chemiluminescence assay was used to measure NO. Inflammatory mediators and cortisol were determined by immunoassay. Lipid profile was measured by a spectrophotometric procedure. Functional capacity was assessed by the fibromyalgia impact questionnaire (FIQ).

Results:

Normal-weight patients showed higher levels of C-reactive protein (CRP) and apolipoprotein B compared to controls (both p < .05). CRP, apolipoprotein B, and triglycerides were higher in overweight patients versus overweight controls (all p < .05) and in overweight versus normal-weight patients (CRP p < .01; apolipoprotein B, triglycerides p < .05). The other markers were unaffected. Apolipoprotein B ( r = .762; p < .05) and NO ( r = −.921; p < .05) levels correlated with FIQ score in normal-weight patients. CRP level correlated with FIQ ( r = .912; p < .05) in overweight patients.

Conclusions:

CRP and apolipoprotein B, biomarkers linked to cardiovascular events, may be associated with FM-related dysfunction in normal- and overweight women with FM. Their increased levels in these patients may indicate an increased risk of cardiovascular disease.

Effect of Yoga Practice on Levels of Inflammatory Markers After Moderate and Strenuous Exercise

BACKGROUND AND OBJECTIVES

To evaluate the effect of yoga practice and exercise challenge on Tumour Necrosis Factor alpha (TNF-α), Interleukin-6 (IL-6) levels and lipid profile.

MATERIALS AND METHODS

Two hundred and eighteen subjects participated in the study. One hundred and nine volunteers (51 males and 58 females) in the age group of 20 to 60 years, who practiced yoga regularly for over five years for a period of one hour daily, performed a bout of moderate exercise and a bout of strenuous exercise as per Standardized Shuttle Walk test protocol. Anthropometrically matched, age matched and gender matched subjects, who did not practice yoga (non-yoga group) were chosen as controls (non-yoga, n=109). The non-yoga group also performed similar exercises. The blood samples of both the groups were collected before and after the exercises. TNF-α and IL-6 was analysed before and after the exercise by Sandwich ELISA (Enzyme Linked Immunosorbent Assay).

RESULTS

Resting plasma TNF-α concentration was significantly higher in non-yoga group when compared to yoga group (p<0.05). There was an increase in TNF-α levels in both the groups in response to strenuous exercise. There was no gender difference in TNF-α and IL-6 levels before and after exercise in yoga and non-yoga groups.

CONCLUSION

Regular practice of yoga lowers basal TNF-α and IL-6 levels. It also reduces the extent of increase of TNF-α and IL-6 to a physical challenge of moderate exercise and strenuous exercise. There is no significant gender difference in the TNF-α and IL-6 levels. Regular practice of yoga can protect the individual against inflammatory diseases by favourably altering pro-inflammatory cytokine levels.

α1-Antitrypsin in fibromyalgia: results of a randomized, placebo-controlled, double-blind and crossover pilot trial

OBJECTIVE

To assess clinical effect of a human plasma-derived alpha-1 antitrypsin (AAT) concentrate in reducing pain severity of patients with fibromyalgia (FM).

METHODS

Thirteen subjects with FM completed a randomized, double-blind, placebo-controlled, crossover study which consisted of 9 weeks trial of AAT or placebo with a washout period of 6 weeks. Primary efficacy endpoint was change on pain severity score, assessed by a daily visual analogue scale (VAS) for pain. Other outcome measures included a tender point score, the Fibromyalgia Impact Questionnaire, (FIQ), the Medical Outcomes Study Short Form 36 (SF-36), the Health Assessment Questionnaire Disability Index (HAQ-DI), the Hospital Anxiety and Depression Scale (HADS) and tiredness score evaluated by VAS.

RESULTS

No statistically significant differences were observed in either pain severity or other secondary outcome measures in either of the treatment groups, or between treatment groups in either of the treatment periods. No carryover or order of intervention effect was observed from one treatment to the other. Both investigational interventions were generally well tolerated, and vital signs during the drug infusions were within the respective normal ranges.

CONCLUSION

Treatment with a human plasma-derived AAT concentrate did not demonstrate significant improvement over placebo on reducing pain severity and other symptoms of FM. Further research should examine other FM subpopulations and drug doses.

Lack of Circadian Pattern of Serum TNF-α and IL-6 in Patients with Fibromyalgia Syndrome

The present study was designed to test the hypothesis of a circadian variation in circulating levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in women with fibromyalgia syndrome (FMS). Serum levels of IL-6 and TNF-α were measured at 4 h intervals of the day in 50 women with FMS satisfying American College of Rheumatology criteria for FMS (age 36.68 ± 9.89) as well as 50 healthy control women (age 32.82 ± 10.53). Serum TNF-α levels were substantially increased in patients with FMS but showed no circadian variation. In contrast, no difference in the levels of IL-6 was found. Moreover, there was also no circadian variation in both the groups of patients and controls. We conclude that no circadian pattern exists in the circulating levels of serum IL-6 and TNF-α in patients with FMS, although TNF-α levels are found raised in patients with FMS.

Fibromyalgia's key symptoms in normal-weight, overweight, and obese female patients

Factors affecting the symptomatology of fibromyalgia (FM) are not fully understood. The aim of the present study was to analyze the relationship of weight status with pain, fatigue, and stiffness in Spanish female FM patients, with special focus on the differences between overweight and obese patients. The sample comprised 177 Spanish women with FM (51.3 ± 7.3 years old). We assessed tenderness (using pressure algometry), pain and vitality using the General Health Short-Form Survey (SF36), and pain, fatigue, morning tiredness, and stiffness using the Fibromyalgia Impact Questionnaire (FIQ). The international criteria for body mass index was used to classify the patients as normal weight, overweight, or obese. Thirty-two percent were normal-weight, 35% overweight, and 32% obese. Both overweight and obese patients had higher levels of pain than normal-weight patients, as assessed by FIQ and SF36 questionnaires and tender point count (p < .01). The same pattern was observed for algometer score, yet the differences were not significant. Both overweight and obese patients had higher levels of fatigue, and morning tiredness, and stiffness (p < .05) and less vitality than normal-weight patients. No significant differences were observed in any of the variables studied between overweight and obese patients. In conclusion, FM symptomatology in obese patients did not differ from overweight patients, whereas normal-weight patients significantly differed from overweight and obese patients in the studied symptoms. These findings suggest that keeping a healthy (normal) weight is not only associated with decreased risk for developing FM but might also be a relevant and useful way of improving FM symptomatology in women.

Systematic review with meta-analysis: cytokines in fibromyalgia syndrome

BACKGROUND

To perform a systematic review and meta-analysis on cytokine levels in patients with fibromyalgia syndrome (FMS).

METHODS

Through December 2010 we systematically reviewed the databases PubMed, MEDLINE, and PsycINFO and screened the reference lists of 22 review articles for suitable original articles. Original articles investigating cytokines in patients with FMS were included. Data were extracted by two independent authors. Differences of the cytokine levels of FMS patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed applying methodological scores: modified Center of Evidence Based Medicine, Newcastle-Ottawa-Scale, and Würzburg Methodological Quality Score.

RESULTS

Twenty-five articles were included investigating 1255 FMS patients and 800 healthy controls. Data of 13/25 studies entered meta-analysis. The overall methodological quality of studies was low. The results of the majority of studies were not comparable because methods, investigated material, and investigated target cytokines differed. Systematic review of the selected 25 articles revealed that FMS patients had higher serum levels of interleukin (IL)-1 receptor antagonist, IL-6, and IL-8, and higher plasma levels of IL-8. Meta-analysis of eligible studies showed that FMS patients had higher plasma IL-6 levels compared to controls (SMD = -0.34 [-0.64, -0.03] 95% CI; p = 0.03). The majority of investigated cytokines were not different between patients and controls.

CONCLUSIONS

The pathophysiological role of cytokines in FMS is still unclear. Studies of higher quality and with higher numbers of subjects are needed.