Stress biomarkers in individuals with fibromyalgia syndrome: a systematic review with meta-analysis

Childhood maltreatment and chronic "all over" body pain in adulthood: a counterfactual analysis using UK Biobank

ABSTRACT

Evidence linking adverse childhood experiences and chronic pain in adulthood is largely cross-sectional, potentially subject to recall bias and does not allow exploration of mediating pathways. We analysed a large population-based cohort (UK Biobank) using a causal framework, to determine if childhood maltreatment is related to chronic "all over" body pain in adulthood. We used doubly robust estimation with inverse probability weights to estimate the difference in risk of chronic pain "all over" between those exposed/not exposed to childhood maltreatment (abuse or neglect). In addition, we looked at interaction with adult stressful life events and examined mediation using inverse odds weighting in a generalized linear model. Using cases with complete data (n = 118,347), the risk of chronic "all over" body pain was higher in the exposed (6.3%, 95% confidence interval [CI] 6.0%-6.5%) than in the unexposed (4.0%; 95% CI 3.8%-4.2%). This difference remained in analyses stratified by sex. Conversely, when analyses were repeated with a negative control exposure, childhood sunburn, risk differences were 0.8% in women (95% CI 0.3%-1.3%) and 0.5% in men (95% CI 0.1%-0.9%). Childhood maltreatment and adult life events had similar effects, and there was a supra-additive risk (1.2%; 95% CI 0.6-1.7) when experiencing both. In mediation analyses, the total effect was a relative risk of 1.57 (95% CI 1.49-1.66), while the estimated indirect effect via all mediators was relative risk 1.16 (95% CI 1.14-1.18). Reducing childhood maltreatment would likely prevent cases of chronic widespread pain in adulthood. Stressful adult events and mediators may offer opportunities for intervention.

Quantitative Sensory Testing in Fibromyalgia Syndrome: A Scoping Review

Background/Objectives: Quantitative sensory testing (QST) is one of the most reliable methods for assessing Fibromyalgia Syndrome (FMS). Despite its importance, there are still controversies regarding the correct interpretation of evoked responses, as they may vary depending on the protocol, individual characteristics, disease severity, and other factors. This study aims to examine how QST has been applied as an outcome measure in FMS. Methods: We considered three databases (Medline, Embase, and Web of Science) until June 2024. From a total of 2512 studies, 126 (39 RCTs and 87 non-RCTs) were selected for full reading after assessment for risk of bias and eligibility criteria. These criteria included at least one type of QST and a clear diagnosis of fibromyalgia (FMS). Results: The results highlighted a lack of standardization in QST, as no reported protocols were followed and there was no specific number of tender points tested for FMS. Additionally, there was inconsistency in the selection of sites and types of tests conducted. Conclusions: This heterogeneity in methodology may affect the comparability and interpretation of results, underscoring the urgent need for standardized guidelines for conducting QST in fibromyalgia studies. A clear understanding of how QST has been measured could prompt a reevaluation of current approaches to FMS assessment, leading to more accurate interpretations and, ultimately, improved management of this complex condition.

Early-life adversity as a predictor of fibromyalgia syndrome: the central role of perceived stress over endocrine stress indicators

ABSTRACT

This study investigates the associations between early childhood adversities, stress perception, and fibromyalgia syndrome (FMS). Although the interconnection between dysregulated stress systems and FMS is well documented, the interconnection between early adversities and FMS remains less understood. This study explores the relationship of early-life stress and FMS by examining its mediation through perceived stress, and acute and chronic endocrine stress indicators. Stress was assessed using the perceived stress scale, as well as using salivary and hair cortisol as endocrine indicators of acute and chronic stress, respectively. The sample consisted of 99 individuals with FMS and 50 pain-free controls. A structural equation model was used to assess the mediating effects of stress indicators between early adversities and the severity of FMS. Compared with controls, individuals with FMS had notably higher early adversity scores (d = 0.63) and greater occurrence of exposure to adversity (78.8% vs 66%). Structural equation modeling indicated that the influence of early adversities on FMS symptoms is mediated by perceived stress levels, with no direct effect observed. Our findings indicate that early-life adversity is a significant determinant of the development of FMS, with the relationship between these factors mediated by perceived stress rather than by endocrine stress indicators. These results underscore the critical role of stress perception in the development and management of FMS, suggesting that perceived stress may serve as a valuable therapeutic target. Incorporating trauma-informed and stress-targeted care into treatment strategies could significantly improve outcomes for individuals with FMS, emphasizing the importance of addressing psychological factors alongside physical symptoms.

A Comprehensive Analysis of Fibromyalgia and the Role of the Endogenous Opioid System

Fibromyalgia represents a chronic pain disorder characterized by musculoskeletal pain, fatigue, and cognitive impairments. The exact mechanisms underlying fibromyalgia remain undefined; as a result, diagnosis and treatment present considerable challenges. On the other hand, the endogenous opioid system is believed to regulate pain intensity and emotional responses; hence, it might be expected to play a key role in the enhanced sensitivity experienced by fibromyalgia patients. One explanation for the emergence of disrupted pain modulation in individuals with fibromyalgia is a significant reduction in opioid receptor activity or an imbalance in the levels of endogenous opioid peptides. Further research is essential to clarify the complex details of the mechanisms underlying this abnormality. This complexity arises from the notion that an improved understanding could contribute to the development of innovative therapeutic strategies aimed at targeting the endogenous opioid system in the context of fibromyalgia. Although progress is being made, a complete understanding of these complexities remains a significant challenge. This paradigm has the potential to revolutionize the complex management of fibromyalgia, although its implementation may experience challenges. The effectiveness of this approach depends on multiple factors, but the implications could be profound. Despite the challenges involved in this transformation, the potential for improving patient care is considerable, as this condition has long been inadequately treated.

Perceived and endocrine acute and chronic stress indicators in fibromyalgia syndrome

Fibromyalgia syndrome (FMS) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue and tenderness and closely associated with high levels of stress. FMS is therefore often considered a stress-related disease. A comparative study was conducted with 99 individuals diagnosed with FMS and a control group of 50 pain-free individuals. Stress indicators were classified into three categories: perceived stress assessed using the Perceived Stress Scale, and daily average salivary cortisol and hair cortisol concentrations as indicators of acute and chronic stress levels related to the hypothalamic-pituitary-adrenal axis. Analysis of variance and covariance were used to identify group differences and the influence of covariates age, sex, and body mass index. Correlational analyses further elucidated the relationship between stress indicators and clinical symptoms. Participants with FMS reported significantly higher perceived stress levels than controls (p < .001, ηp2 = 0.3), which were positively correlated with symptom burden (r = .41, p < .001). In contrast, there were no significant differences in the endocrinological stress indicators salivary and hair cortisol between the groups (p > .05), nor were these indicators associated with clinical symptoms. The study highlights the central role of perceived stress in FMS, whereas endocrinological indicators did not differentiate FMS from controls. This finding calls for a nuanced approach to clinical assessment and therapeutic interventions tailored to patients with FMS, emphasizing the management of perceived stressors.

Glucocorticoid treatment during COVID-19 infection: does it affect the incidence of long COVID?

BACKGROUND

Long COVID (LC) is a frequent complication of COVID infection. It usually results in cognitive impairment, myalgia, headache and fatigue. No effective treatment has been found yet. We aimed to explore the effect of glucocorticoid (GC) treatment during COVID-19 infection on the later development of LC.

METHODS

We examined electronic health records from Clalit Health Services for documentation of COVID-19, GC treatment, and LC frequency. Background diagnoses, demographic data, hospitalization rates, and the use of anti-COVID drugs were recorded.

RESULTS

1,322,599 cases of COVID-19 infection met the inclusion criteria; 13,530 patients (1.02%) received GC treatment. 149,272 patients, 11.29% of COVID-19 patients were diagnosed with LC. Age and female gender were prognostic risk factors for LC (OR 1.06 for age, OR 1.4 for female gender; p value < 0.0001). Background psychiatric diagnoses, migraine, backache and irritable bowel syndrome were predisposing conditions for LC (OR 2.7, p value < .0001). Higher BMI was associated with a greater probability of LC (OR of 1.25 for obese population). COVID patients who received GC were diagnosed with LC more frequently: 2294 cases (16.95%) compared to 146,978 cases (11.23%) in the non-GC group; (adjusted OR of 1.28 ± 0.07, 95% CI, p < 0.0001).

CONCLUSIONS

GC treatment during COVID-19 is correlated with the development of LC. In vivo and animal models may be used to explore the mechanism of this correlation. Future directions include prospective studies as well.

Relationship of Pain, Depression, Fatigue, and Sleep Problems with Functional Capacity, Balance, and Fear of Falling in Women with Fibromyalgia: Cross-Sectional Study

(1) Background: Fibromyalgia (FM) is a syndrome marked by chronic widespread pain, fatigue, sleep issues, and other symptoms. Interventions like physical exercise can potentially enhance physical function in individuals with FM. This study aimed to assess physical function, perceived physical fitness, balance confidence, and fear of falling in women with FM based on their levels of pain, depression, fatigue, and sleep problems. (2) Methods: Participants underwent a series of tests and questionnaires to evaluate physical and perceptual aspects. These included the Time Up and Go, Four Step Square Test, 6-Minute Walking Test, Maximum Handgrip Strength, Back Scratch, International Fitness Scale, Activities-Specific Balance Confidence Scale, and Fall Efficacy Scale-International. Participants were categorised by the severity of their pain, depression, fatigue, and sleep problems (mild, moderate, severe). A Kruskal-Wallis test assessed intergroup differences, while Spearman's rho evaluated correlations between the study variables and symptom levels. (3) Results: Perceived physical condition varied significantly with symptom severity. Symptoms and sleep problems were notably linked to fear of falling, though no significant differences emerged in the physical tests. (4) Conclusions: In women with fibromyalgia, symptom severity was primarily related to perceptual and subjective aspects of physical condition and fall safety.

How to understand the overlap of long COVID, chronic fatigue syndrome/myalgic encephalomyelitis, fibromyalgia and irritable bowel syndromes

Long COVID should be limited to patients with multiple, persistent symptoms not related to well-defined organ damage. Once redefined, a focused review of long COVID demonstrates striking similarity to chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), fibromyalgia (FM) and irritable bowel syndrome (IBS). Research in long COVID has revealed similar findings to those noted in CFS/ME and FM, characterized by central nervous system organ dysfunction. Long COVID, like CFS/ME, FM and IBS, is best understood as a bidirectional mind-body, neuroimmune illness.

Could TREM-1 be a novel marker in the diagnosis of fibromyalgia?: A cross-sectional study

Triggering receptors expressed on myeloid cells-1 (TREM-1) are transmembrane molecules expressed in cells of the immune system. Activation of TREM-1 leads to the release of pro-inflammatory mediators, which act as amplifiers of inflammation and thereby contribute to the pathogenesis of various diseases, whether inflammatory or not. This study explored the role of TREM-1 in the etiopathogenic context of fibromyalgia syndrome (FMS) and its association with disease activity. This randomized controlled and observational study included 45 patients diagnosed with FMS according to the 2016 American College of Rheumatology criteria. Serum TREM-1 levels were assessed using ELISA, and disease activity was measured using various scales such as the fibromyalgia impact questionnaire (FIQ). Patients were divided into 2 groups according to disease severity based on the FIQ score. Compared to a control group of 46 healthy individuals, patients with FMS exhibited significantly elevated concentrations of TREM-1 (mean ± SD = 216.97 pg/mL ± 16.04), P < .05. The FIQ, Pittsburgh sleep quality index, hospital anxiety and depression scale, fatigue severity scale, and visual analog scale, which confirm symptoms such as pain, disease severity, sleep disturbance, depression, anxiety, and fatigue seen in FMS was significantly correlated with TREM-1 level (P < .001). The optimal threshold value for TREM-1 to disease activity was determined to be 182.250, showing (area under the curve) (CI (95%)): [0.940] (0.887-0.993), a sensitivity of 97% and a specificity of 89% according to the receiver operating characteristic analysis. The positive correlation of TREM-1 with various symptom severity scales and hematological inflammatory indices may be a suitable biomarker for the diagnosis of FMS and a potential therapeutic target.

Fibromyalgia: A Review of the Pathophysiological Mechanisms and Multidisciplinary Treatment Strategies

Fibromyalgia is a syndrome characterized by chronic widespread musculoskeletal pain, which may or may not be associated with muscle or joint stiffness, accompanied by other symptoms such as fatigue, sleep disturbances, anxiety, and depression. It is a highly prevalent condition globally, being considered the third most common musculoskeletal disorder, following lower back pain and osteoarthritis. It is more prevalent in women than in men, and although it can occur at any age, it is more common between the ages of thirty and thirty-five. Although the pathophysiology and etiopathogenesis remain largely unknown, three underlying processes in fibromyalgia have been investigated. These include central sensitization, associated with an increase in the release of both excitatory and inhibitory neurotransmitters; peripheral sensitization, involving alterations in peripheral nociceptor signaling; and inflammatory and immune mechanisms that develop concurrently with the aforementioned processes. Furthermore, it has been determined that genetic, endocrine, psychological, and sleep disorders may influence the development of this pathology. The accurate diagnosis of fibromyalgia remains challenging as it lacks specific diagnostic biomarkers, which are still under investigation. Nonetheless, diagnostic approaches to the condition have evolved based on the use of scales and questionnaires for pain identification. The complexity associated with this pathology makes it difficult to establish a single effective treatment. Therefore, treatment is multidisciplinary, involving both pharmacological and non-pharmacological interventions aimed at alleviating symptoms. The non-pharmacological treatments outlined in this review are primarily related to physiotherapy interventions. The effectiveness of physical exercise, both on land and in water, as well as the application of electrotherapy combined with transcranial therapy and manual therapy has been highlighted. All of these interventions aim to improve the quality of life of patients highly affected by fibromyalgia.

Proteomics in Patients with Fibromyalgia Syndrome: A Systematic Review of Observational Studies

PURPOSE OF REVIEW

Fibromyalgia syndrome (FMS) is a disease of unknown pathophysiology, with the diagnosis being based on a set of clinical criteria. Proteomic analysis can provide significant biological information for the pathophysiology of the disease but may also reveal biomarkers for diagnosis or therapeutic targets. The present systematic review aims to synthesize the evidence regarding the proteome of adult patients with FMS using data from observational studies.

RECENT FINDINGS

An extensive literature search was conducted in MEDLINE/PubMed, CENTRAL, and clinicaltrials.gov from inception until November 2022. The study protocol was published in OSF. Two independent reviewers evaluated the studies and extracted data. The quality of studies was assessed using the modified Newcastle-Ottawa scale adjusted for proteomic research. Ten studies fulfilled the protocol criteria, identifying 3328 proteins, 145 of which were differentially expressed among patients with FMS against controls. The proteins were identified in plasma, serum, cerebrospinal fluid, and saliva samples. The control groups included healthy individuals and patients with pain (inflammatory and non-inflammatory). The most important proteins identified involved transferrin, α-, β-, and γ-fibrinogen chains, profilin-1, transaldolase, PGAM1, apolipoprotein-C3, complement C4A and C1QC, immunoglobin parts, and acute phase reactants. Weak correlations were observed between proteins and pain sensation, or quality of life scales, apart from the association of transferrin and a2-macroglobulin with moderate-to-severe pain sensation. The quality of included studies was moderate-to-good. FMS appears to be related to protein dysregulation in the complement and coagulation cascades and the metabolism of iron. Several proteins may be dysregulated due to the excessive oxidative stress response.

Correlation of Psychological Factors, Obesity, Serum Cortisol, and C-Reactive Protein in Patients with Fibromyalgia Diagnosed with Obstructive Sleep Apnea and Other Comorbidities

BACKGROUND

Fibromyalgia (FM) is a chronic pain disorder and is associated with disability, and high levels of pain and suffering. FM is known to co-occur with obesity and obstructive sleep apnea (OSA). Individuals with FM often experience symptoms of pain, depression and anxiety, sleep disturbances, and fatigue. These symptoms may be exacerbated by OSA and contribute to the symptoms' severity in FM. Obesity is a common comorbidity in OSA patients, and as FM and OSA are related in some patients, obesity also may contribute to FM symptom severity. For healthcare providers to effectively manage FM patients, a better understanding of the co-occurrence between these FM comorbidities and psychological factors is needed.

METHODS

This study was approved by IRB and conducted using a retrospective EPIC chart review. To identify FM, the following ICD-9 codes were used: (729.1) and ICD-10 (M79.7) codes. To identify patients with OSA, the following ICD-9 codes were used: (327.23) and ICD-10 (G47.33). Body Mass Index (BMI), the total number of medical diagnoses, and psychiatric conditions were documented for each patient. The prevalence of psychiatric conditions including depression and anxiety was compared between patients with and without obesity (BMI > 30), and patients with fewer than 25 medical diagnoses and those with 25 or more diagnoses. A chart review was conducted to identify patients with fibromyalgia with prior serum cortisol testing within the last ten years. Cortisol levels were compared and patients were divided into six groups: 1. FM without identified psychiatric conditions; 2. FM with psychiatric diagnosis of adjustment disorders and insomnia; 3. FM with psychiatric diagnosis of depressive disorders; 4. FM with psychiatric diagnosis of bipolar disorders; 5. FM with psychiatric diagnosis of mixed anxiety and depression; 6. FM with psychiatric diagnosis of anxiety disorders. Available C-reactive protein (CRP) values were gathered.

RESULTS

The total FM and OSA population was N = 331. The mean age of the patient population was 63.49 years old, with 297 being female. The diagnoses mean was 31.79 ± 17.25 and the mean total psychiatric diagnoses was 2.80 ± 1.66. The mean BMI was 36.69 ± 8.86, with obesity present in 77.95% of the patients. A total of 66.99% of patients had comorbid anxiety and depression with 25 or more medical problems vs. 33.01% of patients who had fewer than 25 medical problems (odds ratio = 1.50). Patients with a BMI < 30 (N = 71) had rates of anxiety and depression at 64.79% and a mean total of 2.79 ± 1.66 psychiatric diagnoses, whereas patients with a BMI > 30 (N = 258) had rates of anxiety and depression at 61.63% (odds ratio = 1.28) and a mean total of 2.80 ± 1.66 psychiatric diagnoses. The most common other psychiatric conditions among FM/OSA patients included hypersomnia and substance use disorders. Cortisol data: Available cortisol results: FM n = 64, female: 59, male: 5, mean age: 63, average BMI: 38.8. The averages for serum cortisol alone for groups 1-6, respectively, are 9.06, 5.49, 13.00, 14.17, 12.25, and 16.03 μg/dL. These results indicate a relatively upward cortisol serum value by the addition of several psychiatric conditions, with the most notable being anxiety for patients with FM. CRP values were available for 53 patients with an average CRP of 4.14.

DISCUSSION

Higher rates of anxiety and depression were present in FM patients with 25 or more diagnoses. The odds ratios indicate that a patient with 25 or more medical problems was 1.5 times more likely to have anxiety and depression than those with fewer diagnoses. Additionally, those with a BMI > 30 were 1.3 times more likely to have anxiety and depression than those with a normal BMI.

CONCLUSION

addressing psychological factors in FM and OSA is important as high healthcare utilization is common in patients with FM and OSA.

Global trends and hotspots in pain associated with bipolar disorder in the last 20 years: a bibliometric analysis

Purpose

The prevalence of comorbid pain and Bipolar Disorder in clinical practice continues to be high, with an increasing number of related publications. However, no study has used bibliometric methods to analyze the research progress and knowledge structure in this field. Our research is dedicated to systematically exploring the global trends and focal points in scientific research on pain comorbidity with bipolar disorder from 2003 to 2023, with the goal of contributing to the field.

Methods

Relevant publications in this field were retrieved from the Web of Science core collection database (WOSSCC). And we used VOSviewer, CiteSpace, and the R package "Bibliometrix" for bibliometric analysis.

Results

A total of 485 publications (including 360 articles and 125 reviews) from 66 countries, 1019 institutions, were included in this study. Univ Toront and Kings Coll London are the leading research institutions in this field. J Affect Disorders contributed the largest number of articles, and is the most co-cited journal. Of the 2,537 scholars who participated in the study, Stubbs B, Vancampfort D, and Abdin E had the largest number of articles. Stubbs B is the most co-cited author. "chronic pain," "neuropathic pain," "psychological pain" are the keywords in the research.

Conclusion

This is the first bibliometric analysis of pain-related bipolar disorder. There is growing interest in the area of pain and comorbid bipolar disorder. Focusing on different types of pain in bipolar disorder and emphasizing pain management in bipolar disorder are research hotspots and future trends. The study of pain related bipolar disorder still has significant potential for development, and we look forward to more high-quality research in the future.

Night time heart rate predicts next-day pain in fibromyalgia and primary back pain

Introduction

Primary chronic pain is pain that persists for over 3 months without associated measurable tissue damage. One of the most consistent findings in primary chronic pain is its association with autonomic hyperactivation. Yet whether the autonomic hyperactivation causes the pain or results from it is still unclear. It is also unclear to what extent autonomic hyperactivation is related to experienced pain intensity in different subtypes or primary chronic pain.

Objectives

Our first aim was to test lagged relationships between the markers of autonomic activation (heart rate) and pain intensity to determine its directionality. The main question here was whether autonomic biomarkers predict pain intensity or whether pain intensity predicts autonomic biomarkers. The second aim was to test whether this relationship is different between people with primary back pain and people with fibromyalgia.

Methods

Sixty-six patients with chronic pain were observed over an average of 81 days. Sleep heart rate and heart rate variability were measured with a wearable sensor, and pain intensity was assessed from daily subjective reports.

Results

The results showed a predictive relationship between sleep heart rate and next-day pain intensity (P < 0.05), but not between daily pain intensity and next night heart rate. There was no interaction with the type of chronic pain.

Conclusions

These findings suggest that autonomic hyperactivation, whether stress-driven or arising from other causes, precedes increases in primary chronic pain. Moreover, the present results suggest that autonomic hyperactivation is a common mechanism underlying the pain experience in fibromyalgia and chronic back pain.

Applying Lessons From Rheumatology to Better Understand Long COVID

Long COVID can sometimes be attributed to organ damage and well-characterized pathophysiology, but more often there is no evidence of organ damage or abnormal biomarkers. This is most evident in patients with mild to moderate initial SARS-CoV-2 infection who were not hospitalized. Their persistent symptoms are strikingly similar to those of fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome, including fatigue, post-exertional malaise, myalgias/arthralgias, and sleep and cognitive disturbances in 50% to 100% of cases. Analogous pathophysiologic pathways in fibromyalgia (FM), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and long COVID include host-microbial interactions in the absence of direct tissue invasion and absence of systemic autoimmunity, with evidence for immune dysregulation as well as autonomic, peripheral, and central nervous system dysfunction. Current treatment of long COVID has been based on multidisciplinary management recommended for FM and ME/CFS and has been formalized and made widely available by funding for nationwide long COVID clinics. Long COVID and its treatment should be distinguished by the presence or absence of organ damage. The acknowledged role of patient engagement in research and open dialogue regarding work and disability noted in long COVID may have meaningful impact on patients with FM and ME/CFS. Hopefully, advances in basic long COVID research will aid in understanding FM and ME/CFS, and rheumatologists should thus be involved in such research and patient care.

Elevated high sensitive C-reactive protein in fibromyalgia

Introduction

Fibromyalgia syndrome (FMS) is a complex chronic pain condition characterized by widespread pain and tenderness, fatigue, and sleep disturbances. Currently, factors contributing to FMS are considered to be multifactorial, and the involvement of inflammatory processes is a question of debate.

Objective

The aims of this study were (1) to assess whether serum concentrations of high-sensitivity C-reactive protein (hsCRP) differ between individuals diagnosed with FMS and pain-free controls, (2) to determine whether these differences are associated with clinical symptoms, and (3) to explore whether the observed differences can be explained by specific covariates such as age, weight, and smoking status.

Methods

An ANOVA was applied to identify differences of hsCRP levels between FMS and pain-free controls and an analysis of covariance (ANCOVA) was performed to investigate the dependencies of hsCRP with respect to covariates. To assess the reliability of our findings, we also utilized a Bayesian robust estimation model to determine the level of confidence associated with our results.

Results

The results showed that individuals with FMS had higher hsCRP levels compared to healthy controls [F(1,106) = 8.802, p < 0.001] and that higher hsCRP levels were significant correlated with a higher symptom burden (r = 0. 287, p = 0.008) and more tender points (r = 0.307, p = 0.005). Further, hsCRP levels were significantly associated with weight (η2 = 0.154, p < 0.001), but independent of age (η2 = 0.005, p = 0.42), smoking status (η2 = 0.002, p = 0.623), or gender (η2 = 0.0045, p = 0.437), which resulted in an insignificant group effect between FMS and controls (η2 = 0.029, p = 0.052), even after controlling for covariates.

Conclusion

In conclusion, this study provides evidence that sub-inflammatory processes correlate with clinical symptoms, which can be partly attributed to differences in weight, but cannot be fully explained by them. Further research is needed to elucidate the mechanisms underlying the association between hsCRP and FMS and to explore the potential therapeutic implications of targeting hsCRP in the management of FMS.