Dysregulation of lipid metabolism, energy production, and oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome, Gulf War Syndrome and fibromyalgia

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), Gulf War Syndrome (GWS), and Fibromyalgia (FM) are complex, chronic illnesses with overlapping clinical features. Symptoms that are reported across these conditions include post-exertional malaise (PEM), fatigue, and pain, yet the etiology of these illnesses remains largely unknown. Diagnosis is challenging in patients with these conditions as definitive biomarkers are lacking; patients are required to meet clinical criteria and often undergo lengthy testing to exclude other conditions, a process that is often prolonged, costly, and burdensome for patients.

The identification of reliable validated biomarkers could facilitate earlier and more accurate diagnosis and drive the development of targeted pharmacological therapies that might address the underlying pathophysiology of these diseases. Major driving forces for biomarker identification are the advancing fields of metabolomics and proteomics that allow for comprehensive characterization of metabolites and proteins in biological specimens. Recent technological developments in these areas enable high-throughput analysis of thousands of metabolites and proteins from a variety of biological samples and model systems, that provides a powerful approach to unraveling the metabolic phenotypes associated with these complex diseases.

Emerging evidence suggests that ME/CFS, GWS, and FM are all characterized by disturbances in metabolic pathways, particularly those related to energy production, lipid metabolism, and oxidative stress. Altered levels of key metabolites in these pathways have been reported in studies highlighting potential common biochemical abnormalities. The precise mechanisms driving altered metabolic pathways in ME/CFS, GWS, and FM remain to be elucidated; however, the elevated oxidative stress observed across these illnesses may contribute to symptoms and offer a potential target for therapeutic intervention.

Investigating the mechanisms, and their role in the disease process, could provide insights into disease pathogenesis and reveal novel treatment targets. As such, comprehensive metabolomic and proteomic analyses are crucial for advancing the understanding of these conditions in-order to identify both common, and unique, metabolic alterations that could serve as diagnostic markers or therapeutic targets.

Source: Davis L, Higgs M, Snaith A, Lodge TA, Strong J, Espejo-Oltra JA, Kujawski S, Zalewski P, Pretorius E, Hoerger M, Morten KJ. Dysregulation of lipid metabolism, energy production, and oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome, Gulf War Syndrome and fibromyalgia. Front Neurosci. 2025 Mar 10;19:1498981. doi: 10.3389/fnins.2025.1498981. PMID: 40129725; PMCID: PMC11931034. https://pmc.ncbi.nlm.nih.gov/articles/PMC11931034/ (Full text)

Recognizing the role of fibromyalgia in post-exertional malaise

Letter:

The recent opinion by Charlton et al. published in Trends in Endocrinology & Metabolism [] provides a thought-provoking discussion of the overlap between long coronavirus disease (long-COVID) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), emphasizing the centrality of post-exertional malaise (PEM) as a shared mechanism.

Here, we suggest that fibromyalgia should be included in the discussion, given the established role of PEM in this condition []. In addition, fibromyalgia not only shares symptomatic and mechanistic overlaps with ME/CFS, but also offers a complementary perspective on the pathophysiology of PEM. Considering that PEM is a key symptom in both fibromyalgia and long COVID, exploring skeletal muscle function in fibromyalgia could provide complementary insights into the muscle-specific alterations that contribute to this debilitating phenomenon.

Source: Giollo A, Salvato M, Doria A. Recognizing the role of fibromyalgia in post-exertional malaise. Trends Endocrinol Metab. 2025 Mar 11:S1043-2760(25)00045-1. doi: 10.1016/j.tem.2025.02.005. Epub ahead of print. PMID: 40074568. https://www.cell.com/trends/endocrinology-metabolism/abstract/S1043-2760(25)00045-1

Mitochondrial structural alterations in fibromyalgia: a pilot electron microscopy study

Abstract:

Objectives: The pathogenesis of fibromyalgia (FM), characterised by chronic widespread pain and fatigue, remains notoriously elusive, hampering attempts to develop disease modifying treatments. Mitochondria are the headquarters of cellular energy metabolism, and their malfunction has been proposed to contribute to both FM and chronic fatigue. Thus, the aim of the current pilot study, was to detect structural changes in mitochondria of peripheral blood mononuclear cells (PBMCs) of FM patients, using transmission electron microscopy (TEM).

Methods: To detect structural mitochondrial alterations in FM, we analysed PBMCs from seven patients and seven healthy controls, using TEM. Patients were recruited from a specialised Fibromyalgia Clinic at a tertiary medical centre. After providing informed consent, participants completed questionnaires including the widespread pain index (WPI), symptoms severity score (SSS), fibromyalgia impact questionnaire (FIQ), beck depression inventory (BDI), and visual analogue scale (VAS), to verify a diagnosis of FM according to ACR criteria. Subsequently, blood samples were drawn and PBMCs were collected for EM analysis.

Results: TEM analysis of PBMCs showed several distinct mitochondrial cristae patterns, including total loss of cristae in FM patients. The number of mitochondria with intact cristae morphology was reduced in FM patients and the percentage of mitochondria that completely lacked cristae was increased. These results correlated with the WPI severity. Moreover, in the FM patient samples we observed a high percentage of cells containing electron dense aggregates, which are possibly ribosome aggregates. Cristae loss and possible ribosome aggregation were intercorrelated, and thus may represent reactions to a shared cellular stress condition. The changes in mitochondrial morphology suggest that mitochondrial dysfunction, resulting in inefficient oxidative phosphorylation and ATP production, metabolic and redox disorders, and increased reactive oxygen species (ROS) levels, may play a pathogenetic role in FM.

Conclusions: We describe novel morphological changes in mitochondria of FM patients, including loss of mitochondrial cristae. While these observations cannot determine whether the changes are pathogenetic or represent an epiphenomenon, they highlight the possibility that mitochondrial malfunction may play a causative role in the cascade of events leading to chronic pain and fatigue in FM. Moreover, the results offer the possibility of utilising changes in mitochondrial morphology as an objective biomarker in FM. Further understanding the connection between FM and dysfunction of mitochondria physiology, may assist in developing both novel diagnostic tools as well as specific treatments for FM, such as approaches to improve/strengthen mitochondria function.

Source: Israel L, Furer V, Levin-Zaidman S, Dezorella N, Brontvein O, Ablin JN, Gross A. Mitochondrial structural alterations in fibromyalgia: a pilot electron microscopy study. Clin Exp Rheumatol. 2024 Jun;42(6):1215-1223. doi: 10.55563/clinexprheumatol/3l0ihz. Epub 2024 Jun 28. PMID: 38966946. https://www.clinexprheumatol.org/abstract.asp?a=21119 (Full text available as PDF file)

Mitochondrial function in patients affected with fibromyalgia syndrome is impaired and correlates with disease severity

Abstract:

Fibromyalgia is a musculoskeletal syndrome characterized by chronic widespread pain that is often associated with systemic manifestations. Since mitochondria are the main source of cellular energy, we hypothesized that fibromyalgia syndrome (FMS) could be linked to mitochondrial impairment. Aim was to study mitochondrial dysfunction in peripheral blood mononuclear cells isolated from 50 patients with primary FMS and 20 apparently healthy controls.

Although no differences in mitochondrial basal respiration were observed between patients with primary FMS and healthy controls, a lower median bioenergetic health index (BHI; – 22.1%, p = 0.03), a proxy of mitochondrial function, was found in patients. According to fibromyalgia severity score (FSS), a composite of widespread pain index and symptom severity scale, a lower median BHI (- 18.7%) was found in patients with a FSS ≥ 20 compared to those with a FSS < 20. Negative moderate correlations were found only between BHI and FSS (r = – 0.36) and widespread pain index (r = – 0.38).

We demonstrated that patients with FMS had an impaired mitochondrial function. Additionally, we found a mild correlation between the widespread pain index and the BHI, possibly indicating that the altered mitochondrial function, in these patients, narrows musculoskeletal rather than central nervous system involvement.

Source: Macchi C, Giachi A, Fichtner I, Pedretti S, Puttini PS, Mitro N, Corsini A, Ruscica M, Gualtierotti R. Mitochondrial function in patients affected with fibromyalgia syndrome is impaired and correlates with disease severity. Sci Rep. 2024 Dec 4;14(1):30247. doi: 10.1038/s41598-024-81298-x. PMID: 39632893; PMCID: PMC11618515. https://pmc.ncbi.nlm.nih.gov/articles/PMC11618515/ (Full text)

Long COVID and hypermobility spectrum disorders have shared pathophysiology

Abstract:

Hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS) are the most common joint hypermobility conditions encountered by physicians, with hypermobile and classical EDS accounting for >90% of all cases. Hypermobility has been detected in up to 30-57% of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), fibromyalgia, postural orthostatic tachycardia syndrome (POTS), and long COVID (LC) compared to the general population.

Extrapulmonary symptoms, including musculoskeletal pain, dysautonomia disorders, cognitive disorders, and fatigue, are seen in both LC and HSD. Additionally, ME/CFS has overlapping symptoms with those seen in HSD. Mast cell activation and degranulation occurring in both LC and ME/CFS may result in hyperinflammation and damage to connective tissue in these patients, thereby inducing hypermobility.

Persistent inflammation may result in the development or worsening of HSD. Hence, screening for hypermobility and other related conditions including fibromyalgia, POTS, ME/CFS, chronic pain conditions, joint pain, and myalgia is essential for individuals experiencing LC. Pharmacological treatments should be symptom-focused and geared to a patient’s presentation. Paced exercise, massage, yoga, and meditation may also provide benefits.

Source: Ganesh R, Munipalli B. Long COVID and hypermobility spectrum disorders have shared pathophysiology. Front Neurol. 2024 Sep 5;15:1455498. doi: 10.3389/fneur.2024.1455498. PMID: 39301475; PMCID: PMC11410636. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11410636/ (Full text)

Manual Therapy Improves Fibromyalgia Symptoms by Downregulating SIK1

Abstract:

Fibromyalgia (FM), classified by ICD-11 with code MG30.0, is a chronic debilitating disease characterized by widespread pain, fatigue, cognitive impairment, sleep, and intestinal alterations, among others. FM affects a large proportion of the worldwide population, with increased prevalence among women. The lack of understanding of its etiology and pathophysiology hampers the development of effective treatments.

Our group had developed a manual therapy (MT) pressure-controlled custom manual protocol on FM showing hyperalgesia/allodynia, fatigue, and patient’s quality of life benefits in a cohort of 38 FM cases (NCT04174300). With the aim of understanding the therapeutic molecular mechanisms triggered by MT, this study interrogated Peripheral Blood Mononuclear Cell (PBMC) transcriptomes from FM participants in this clinical trial using whole RNA sequencing (RNAseq) and reverse transcription followed by quantitative Polymerase Chain Reaction (RT-qPCR) technologies.

The results show that the salt-induced kinase SIK1 gene was consistently downregulated by MT in FM, correlating with improvement of patient symptoms. In addition, this study compared the findings in a non-FM control cohort subjected to the same MT protocol, evidencing that those changes in SIK1 expression with MT only occurred in individuals with FM. This positions SIK1 as a potential biomarker to monitor response to MT and as a therapeutic target of FM, which will be further explored by continuation studies.

Source: Bonastre-Férez J, Giménez-Orenga K, Falaguera-Vera FJ, Garcia-Escudero M, Oltra E. Manual Therapy Improves Fibromyalgia Symptoms by Downregulating SIK1. Int J Mol Sci. 2024 Sep 1;25(17):9523. doi: 10.3390/ijms25179523. PMID: 39273470. https://www.mdpi.com/1422-0067/25/17/9523 (Full text)

Nonpelvic comorbid symptoms of 45 patients with pain of pelvic venous origin, before and after treatment

Abstract:

Objective: To report the prevalence and severity of nonpelvic symptoms for patients with venous-origin chronic pelvic pain (VO-CPP) and to describe outcomes after pelvic vein stenting and embolization.

Methods: We retrospectively reviewed outcomes of 45 women with VO-CPP who underwent treatment with iliac vein stenting and/or embolization. Patients completed symptom-severity questionnaires before and after treatment that assessed for pelvic pain, and multiple other symptoms, including brain fog, anxiety, depression, musculoskeletal pain, fatigue, migraines and more.

Results: Patient age ranged from 18 to 65 years. The prevalence of common symptoms was as follows: migraines, 69%; brain fog, 76%; anxiety attacks, 58%; excess sweating, 64%; hip pain, 73%; diarrhea, 62%; constipation, 76%; and abdominal bloating, 82%. After treatment, most symptom scores improved by more than 50%; exceptions were excessive sweating (41% improvement) and bloating (47% improvement). Prevalence of individual symptoms that bundle into POTS ranged from 29% to 76%, where symptom improvement ranged from 23% to 59% after treatment. Overlapping individual symptoms characteristic of fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) were present in 64% to 82% of patients and all improved by 49% to 63% after treatment.

Conclusions: Pelvic venous flow abnormality is linked causally to a spectrum of interrelated symptoms, of which many can be bundled into named syndromes of unknown cause. With catheter- based treatment of pelvic venous pooling, nonpelvic symptom and syndrome scores improved.

Source: Smith SJ, Smith BH, Sichlau MJ, Chen B, Knight D, Rowe PC. Nonpelvic comorbid symptoms of 45 patients with pain of pelvic venous origin, before and after treatment. Phlebology. 2024 Aug 10:2683555241273109. doi: 10.1177/02683555241273109. Epub ahead of print. PMID: 39126670.  https://pubmed.ncbi.nlm.nih.gov/39126670/

Patients with Fibromyalgia Scored Worse in Memory, Attention, Cognitive Function

Press release:

A cross-sectional study demonstrated significant impairments in attention, memory, and higher cognitive functions among a cohort of patients with fibromyalgia and rheumatoid arthritis (RA), according to a study published in Psychology Research and Behavior Management.1

Investigators believe deficits in the fibromyalgia cohort could be explained by secondary symptoms coupled with more severe pain. A cognitive screening could help curate personalized treatment plans to improve the quality of life among patients with RA and fibromyalgia.

“Research directly comparing cognitive performance between patients with fibromyalgia and RA is still scarce. Some studies suggested deficits of similar magnitude in both patient groups,” wrote a group of investigators led by Carmen María Galvez Sánchez, PhD, associated with the Department of Personality, Evaluation and Psychological Treatment at the University of Murcia, Spain. “In response to this exigency, there is a requisite for the evaluation of cognitive impairments in individuals with chronic pain, aiming to formulate and implement interventions rooted in neuropsychological training. This approach is intended to ameliorate cognitive performance and mitigate its consequential impact on health-related quality of life.”

In certain patients with fibromyalgia, cognitive impairment was linked to clinical pain severity, depression, fatigue, insomnia, and anxiety. Similarly, these were also reported in patients with RA, although pain and emotional symptoms within the fibromyalgia cohort.2 Symptoms of fibromyalgia and RA often include depression, fatigue, insomnia, and cognitive issues.

Investigators analyzed the performance in cognitive domains between patients with RA and fibromyalgia using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Questionnaire scores were combined to determine the symptom severity factor, which was used as a control variable within the group comparisons.

A total of 64 patients with fibromyalgia, 34 patients with RA, and 32 healthy controls were included in the study. All patients were female.

Without controlling for the severity of symptoms, patients with either fibromyalgia or RA performed worse when compared with controls in terms of cognitive domains including verbal memory, visual memory, and strategic planning.

Additionally, over deficits were observed in the fibromyalgia cohort compared with RA. Patients with fibromyalgia reported more severe symptoms, such as pain intensity, total pain, anxiety, depression, insomnia, and fatigue, compared with patients with RA. After controlling for symptom severity a significant proportion of cognitive test, a large proportion of cognitive test parameters were not different between rheumatologic cohorts.

Limitations included the lack of information regarding the influence of psychotropic and pain medication on cognitive performance among rheumatic patients. Although the limitation could have been determined using subgroup analysis, the current sample size was too small to form these subgroups.

Further, no data on treatment and disease activity were collected in the RA subgroup and the analysis of the effects of clinical symptoms on cognitive performance was limited. Additionally, not all psychological factors that may impact cognition were assessed in the analysis. The generalizability of findings may be hindered as only women were included in the analysis and the recruitment of subjects was not randomly performed. Lastly, the RA and fibromyalgia diagnoses were performed by different rheumatologists, which may have introduced selection bias.

“Based on the present results, it is recommended that screening for cognitive deficits be part of routine diagnostics for fibromyalgia and RA, which may help to guide the design of personalized interventions to optimize cognitive performance of patients with fibromyalgia and RA,” investigators concluded.

Source: Lana Pine. HCP Live.

Mitochondrial Dysfunction and Coenzyme Q10 Supplementation in Post-Viral Fatigue Syndrome: An Overview

Abstract:

Post-viral fatigue syndrome (PVFS) encompasses a wide range of complex neuroimmune disorders of unknown causes characterised by disabling post-exertional fatigue, myalgia and joint pain, cognitive impairments, unrefreshing sleep, autonomic dysfunction, and neuropsychiatric symptoms. It includes myalgic encephalomyelitis, also known as chronic fatigue syndrome (ME/CFS); fibromyalgia (FM); and more recently post-COVID-19 condition (long COVID). To date, there are no definitive clinical case criteria and no FDA-approved pharmacological therapies for PVFS. Given the current lack of effective treatments, there is a need to develop novel therapeutic strategies for these disorders.
Mitochondria, the cellular organelles responsible for tissue energy production, have recently garnered attention in research into PVFS due to their crucial role in cellular bioenergetic metabolism in these conditions. The accumulating literature has identified a link between mitochondrial dysfunction and low-grade systemic inflammation in ME/CFS, FM, and long COVID. To address this issue, this article aims to critically review the evidence relating to mitochondrial dysfunction in the pathogenesis of these disorders; in particular, it aims to evaluate the effectiveness of coenzyme Q10 supplementation on chronic fatigue and pain symptoms as a novel therapeutic strategy for the treatment of PVFS.
Source: Mantle D, Hargreaves IP, Domingo JC, Castro-Marrero J. Mitochondrial Dysfunction and Coenzyme Q10 Supplementation in Post-Viral Fatigue Syndrome: An Overview. International Journal of Molecular Sciences. 2024; 25(1):574. https://doi.org/10.3390/ijms25010574 https://www.mdpi.com/1422-0067/25/1/574 (Full text)

Metabolic Fingerprinting for the Diagnosis of Clinically Similar Long COVID and Fibromyalgia Using a Portable FT-MIR Spectroscopic Combined with Chemometrics

Abstract:

Post Acute Sequelae of SARS-CoV-2 infection (PASC or Long COVID) is characterized by lingering symptomatology post-initial COVID-19 illness that is often debilitating. It is seen in up to 30–40% of individuals post-infection. Patients with Long COVID (LC) suffer from dysautonomia, malaise, fatigue, and pain, amongst a multitude of other symptoms.
Fibromyalgia (FM) is a chronic musculoskeletal pain disorder that often leads to functional disability and severe impairment of quality of life. LC and FM share several clinical features, including pain that often makes them indistinguishable. The aim of this study is to develop a metabolic fingerprinting approach using portable Fourier-transform mid-infrared (FT-MIR) spectroscopic techniques to diagnose clinically similar LC and FM.
Blood samples were obtained from LC (n = 50) and FM (n = 50) patients and stored on conventional bloodspot protein saver cards. A semi-permeable membrane filtration approach was used to extract the blood samples, and spectral data were collected using a portable FT-MIR spectrometer. Through the deconvolution analysis of the spectral data, a distinct spectral marker at 1565 cm−1 was identified based on a statistically significant analysis, only present in FM patients. This IR band has been linked to the presence of side chains of glutamate.
An OPLS-DA algorithm created using the spectral region 1500 to 1700 cm−1 enabled the classification of the spectra into their corresponding classes (Rcv > 0.96) with 100% accuracy and specificity. This high-throughput approach allows unique metabolic signatures associated with LC and FM to be identified, allowing these conditions to be distinguished and implemented for in-clinic diagnostics, which is crucial to guide future therapeutic approaches.
Source: Hackshaw KV, Yao S, Bao H, de Lamo Castellvi S, Aziz R, Nuguri SM, Yu L, Osuna-Diaz MM, Brode WM, Sebastian KR, et al. Metabolic Fingerprinting for the Diagnosis of Clinically Similar Long COVID and Fibromyalgia Using a Portable FT-MIR Spectroscopic Combined with Chemometrics. Biomedicines. 2023; 11(10):2704. https://doi.org/10.3390/biomedicines11102704 https://www.mdpi.com/2227-9059/11/10/2704 (Full text)