Biomarkers for chronic fatigue

Preliminary investigation of anti-fatigue effects and potential mechanisms of meiju oral liquid in mouse and zebrafish models

Meiju Oral Liquid (MOL), a representative medicinal formula in China, stems from the traditional use of specific Chinese medicinal herbs known for their anti-fatigue properties, including rose, jujube, chicory, and wolfberry. While these individual herbs have been recognized for their benefits, the formulation of MOL itself has not been extensively studied. This study was designed to evaluate the potential anti-fatigue effects of MOL, prepared from these natural herbs, and to explore its underlying mechanisms. In this research, both mouse and zebrafish models were utilized to investigate the anti-fatigue effects of MOL. Chemical characterization of MOL and identification of bioactive compounds in serum were conducted using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The results demonstrated that MOL significantly prolonged the weight-bearing swimming time in mice, increased hepatic and muscle glycogen content, and reduced serum levels of blood urea nitrogen, blood lactate, and inflammatory markers (IL-1β, IL-6, TNF-α, and NO). Furthermore, MOL down-regulated the expression of NOX4 and TNF-α proteins while up-regulating p-PI3K and p-AKT proteins in the liver tissues of fatigued mice. In zebrafish models, MOL exhibited protective effects against sodium sulfite-induced lethality, enhanced high-speed motion trajectories, and increased movement distances in both normal and fatigued zebrafish. Additionally, MOL downregulated IL-1β, IL-6, TNF-α, and TNF-β mRNA levels while up-regulating PI3K and AKT1 mRNA levels in fatigued zebrafish. These findings suggested that the anti-fatigue effects of MOL may be mediated through the activation of the PI3K/AKT signaling pathway as well as the inhibition of TNF-α and NOX4 expression. In addition, a total of ninety-four chemical components were identified in MOL, with twenty-three migration compounds detected in mouse serum. These migration compounds are likely the primary active agents, contributing to the reduction of metabolite accumulation, enhancement of glycogen synthesis, and suppression of inflammatory responses. Taken together, our findings underscore the potential anti-fatigue effects of MOL, warranting further investigation into its therapeutic applications and the specific roles of its bioactive compounds.

Jingfang Granule promotes the tricarboxylic acid cycle to improve chronic fatigue syndrome by increasing the expression of Idh1 and Idh2

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic fatigue syndrome (CFS), as a complex, multisystemic, and multisystemic disorder affecting multiple organs and systems, often accompanies by symptoms such as post-exercise discomfort, sleep disorders, cognitive difficulties, and orthostatic intolerance. Jingfang Granule (JFG) is a traditional Chinese medicine that have significant protective effects on CFS, but the mechanism is still vague.

AIM OF STUDY

This study was designed to evaluate the protective mechanism of JFG on mice with CFS.

MATERIALS AND METHODS

The combined stimuli method was used to establish the mice CFS model, and JFG was orally administered. The body weight, exhaustion swimming training and tail suspension test were assayed every 7 days to evaluate the improvement of JFG on CFS. Lactic acid, adenosine triphosphate (ATP), malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS), IL-1β, TNF-α, IL-6 in serum and liver glycogen, muscle glycogen in muscle were analyzed. Transmission electron microscopy was used to detect mitochondrial morphology. The regulatory networks were investigated by proteomics and central carbon metabolomics, which were verified by Western blot.

RESULTS

JFG reversed the loss of weight and reduce of exhaust swimming time (P < 0.05) induced by CFS in mice, and increased the tail suspension time (P < 0.05), indicating that JFG has an improving effect on CFS. Meanwhile, JFG increased the spleen index (P < 0.05), decreased the thymus index (P < 0.05) and cardiac index (P < 0.05), inhibited the secretion of Lactic acid (P < 0.05), and increased the content of liver glycogen (P < 0.05), muscle glycogen (P < 0.05), and ATP (P < 0.05), and improved mitochondrial morphology in mice with CFS. JFG also inhibited the release of TNF-α (P < 0.05), IL-1β (P < 0.05) and IL-6 (P < 0.05) in serum by inhibiting TLR4/NF-κB signaling pathway and NLRP3 inflammasome signaling pathway, and inhibited oxidative stress by activating Nrf2/HO-1/NQO1 axis. Integrated central carbon metabolomics, proteomics and Western blot showed that JFG intervened in CFS by increasing the expression of Idh1 (P < 0.05) and Idh2 (P < 0.01) to promote tricarboxylic acid (TCA) cycle.

CONCLUSIONS

This study confirmed that JFG promoted the TCA cycle by increasing the expression of Idh1 and Idh2, and then inhibited inflammation and oxidative stress to prevent CFS injury, which provided a potential drug candidate for CFS treatment.

Anti-fatigue effect of an enzymatically derived deer velvet extract through muscle damage recovery and improvement of antioxidant levels

ETHNOPHARMACOLOGICAL RELEVANCE

Deer velvet (DV) has been extensively used in traditional Oriental medicine to treat various diseases. Its pharmacological spectrum encompasses tonicity, longitudinal bone growth of adolescence, blood retention, hemopoiesis facilitation, enhancement of organ function, physical function improvement, and augmentation of physical vitality. Among its myriad effects, DV notably exhibits anti-fatigue properties; however, its specific mode of action is yet to be fully elucidated.

AIM OF THE STUDY

This study was undertaken to investigate the anti-fatigue and exercise performance-enhancing effects of YC-1101(HENKIV®), an enzymatically derived DV extract, in C2C12 cell lines and forced swimming mouse models.

MATERIALS AND METHODS

The effect of YC-1101 on increasing cell growth and lowering lactate dehydrogenase (LDH) activity was assessed in C2C12. The antioxidative effects of YC-1101 and its mechanistic underpinnings were also evaluated in C2C12 cells. Moreover, mice were subjected to an exhaustive swimming test subsequent to 3 weeks of YC-1101 extract administration. Fatigue-associated biochemical parameters, such as LDH activity and lactate, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels, were measured in serum and muscle tissues.

RESULTS

YC-1101 significantly promoted myoblast growth and reduced LDH activity, indicative of a cell-proliferative effect. Notably, free radical scavenging assays and analysis of reactive oxygen species production and antioxidant-related mRNA expression corroborated the significant involvement of YC-1101 in antioxidation, an important mechanism in anti-fatigue processes. Furthermore, animal experiments demonstrated prolonged swimming endurance and inhibition of muscle LDH accumulation in forced swimming mouse models. Serum biochemical analysis further revealed significant modulation of the expression of anti-fatigue-related biomarkers. Various bioactive low-molecular-weight DV peptides were enriched in YC-1101 compared to YHC-BE-2038 (a DV extract without enzymatic digestion). The anti-fatigue effect of YC-1101 was significantly stronger than that of YHC-BE-2038.

CONCLUSIONS

These findings suggest the potential of YC-1101 as a nutraceutical adjunct in ameliorating fatigue, concurrently facilitating muscle damage recovery, and exerting antioxidant effects via the nuclear factor E2-related factor 2-Kelch-like ECH-associated protein-1 pathway. It can be assumed that the complex action of low-molecular-weight DV peptides produced during the enzymatic degradation process was effective, and the further research is needed.

Concussion and the Autonomic, Immune, and Endocrine Systems: An Introduction to the Field and a Treatment Framework for Persisting Symptoms

A significant proportion of patients who sustain a concussion/mild traumatic brain injury endorse persisting, lingering symptoms. The symptoms associated with concussion are nonspecific, and many other medical conditions present with similar symptoms. Medical conditions that overlap symptomatically with concussion include anxiety, depression, insomnia, chronic pain, chronic fatigue, fibromyalgia, and cervical strain injuries. One of the factors that may account for these similarities is that these conditions all present with disturbances in the optimal functioning of the autonomic nervous system and its intricate interactions with the endocrine system and immune system-the three primary regulatory systems in the body. When clinicians are working with patients presenting with persisting symptoms after concussion, evidence-based treatment options drawn from the literature are limited. We present a framework for the assessment and treatment of persisting symptoms following concussion based on the available evidence (treatment trials), neuroanatomical principles (research into the physiology of concussion), and clinical judgment. We review the research supporting the premise that behavioral interventions designed to stabilize and optimize regulatory systems in the body following injury have the potential to reduce symptoms and improve functioning in patients. Foundational concussion rehabilitation strategies in the areas of sleep stabilization, fatigue management, physical exercise, nutrition, relaxation protocols, and behavioral activation are outlined along with practical strategies for implementing intervention modules with patients.

The effects of chronic fatigue and chronic stress on alterations in immune cell responses to acute psychosocial stress

Fatigue is a common and debilitating symptom of a broad spectrum of diseases. Previous research has shown that individuals suffering from chronic forms of fatigue experience significantly more stress compared to healthy individuals, suggesting that stress is a potential pathophysiological factor in the onset and maintenance of chronic fatigue. Individually, chronic experiences of fatigue and stress have been associated with disruptions in adaptive immunity. However, how chronic fatigue and chronic stress together affect immune regulation is not fully understood. Here, we investigated the unique and combined contribution of chronic fatigue and chronic stress on immune cell redistribution in response to, and recovery from, acute psychosocial stress. Eighty women with high or low levels of chronic fatigue and varying levels of chronic stress were exposed to a psychosocial laboratory stressor. Blood samples were collected 10 min before and then at 10, 40, and 100 min after the end of stress. The main lymphocyte subpopulations (CD3+, CD3 + CD4+, CD3 + CD8+, CD16 + CD56+, and CD19 + cells) were enumerated via flow cytometry. Acute stress resulted in an increase in CD8 + and CD16+/CD56 + cells, a decline in CD4 + cells, and no effects on CD19 + B lymphocytes. Importantly, the magnitude of immune cell redistribution during stress reactivity (CD3+, CD4+, CD16+/CD56 + ) and recovery (CD3 + ) was contingent on fatigue and chronic stress levels of individuals. Notably, in contrast to low-fatigued individuals, who showed steeper changes in cell populations, increasing levels of chronic stress did not impact immune cell migration responses in high-fatigued individuals. Our findings demonstrate the compounded blunting effects of fatigue and chronic stress on adaptive immune functioning, highlighting a potential pathway for vulnerability and detrimental effects on long-term health.

Joint modeling of longitudinal health-related quality of life during concurrent chemoradiotherapy period and long-term survival among patients with advanced nasopharyngeal carcinoma

BACKGROUND

To investigate the prognosis of longitudinal health-related quality of life (HRQOL) during concurrent chemoradiotherapy (CCRT) on survival outcomes in patients with advanced nasopharyngeal carcinoma (NPC).

METHODS

During 2012-2014, 145 adult NPC patients with stage II-IVb NPC were investigated weekly using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire core 30 (EORCT QLQ-C30) during their CCRT period. The effects of longitudinal trends of HRQOL on survival outcomes were estimated using joint modeling, and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were reported as a 10-point increase in HRQOL scores.

RESULTS

After a median follow-up of 83.4 months, the multivariable models showed significant associations of longitudinal increasing scores in fatigue and appetite loss during the CCRT period with distant metastasis-free survival: 10-point increases in scores of fatigue and appetite loss domains during CCRT period were significantly associated with 75% (HR: 1.75, 95% CI: 1.01, 3.02; p = 0.047) and 59% (HR: 1.59, 95% CI: 1.09, 2.59; p = 0.018) increase in the risk of distant metastasis, respectively. The prognostic effects of the longitudinal HRQOL trend on overall survival and progress-free survival were statistically non-significant.

CONCLUSION

Increases in fatigue and appetite loss of HRQOL during the CCRT period are significantly associated with high risks of distant metastasis in advanced NPC patients. Nutritional support and psychological intervention are warranted for NPC patients during the treatment period.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: the biology of a neglected disease

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating disease characterised by a wide range of symptoms that severely impact all aspects of life. Despite its significant prevalence, ME/CFS remains one of the most understudied and misunderstood conditions in modern medicine. ME/CFS lacks standardised diagnostic criteria owing to variations in both inclusion and exclusion criteria across different diagnostic guidelines, and furthermore, there are currently no effective treatments available. Moving beyond the traditional fragmented perspectives that have limited our understanding and management of the disease, our analysis of current information on ME/CFS represents a significant paradigm shift by synthesising the disease's multifactorial origins into a cohesive model. We discuss how ME/CFS emerges from an intricate web of genetic vulnerabilities and environmental triggers, notably viral infections, leading to a complex series of pathological responses including immune dysregulation, chronic inflammation, gut dysbiosis, and metabolic disturbances. This comprehensive model not only advances our understanding of ME/CFS's pathophysiology but also opens new avenues for research and potential therapeutic strategies. By integrating these disparate elements, our work emphasises the necessity of a holistic approach to diagnosing, researching, and treating ME/CFS, urging the scientific community to reconsider the disease's complexity and the multifaceted approach required for its study and management.

Can inflammatory plasma proteins predict Long COVID or Fatigue severity after SARS-CoV-2 infection?

OBJECTIVE

To investigate whether specific immune response plasma proteins can predict an elevated risk of developing Long COVID symptoms or fatigue severity after SARS-CoV-2 infection.

METHODS

This study was based on 257 outpatients with test-confirmed SARS-CoV-2 infection between February 2020 and January 2021. At least 12 weeks after the acute infection, 92 plasma proteins were measured using the Olink Target 96 immune response panel (median time between acute infection and venous blood sampling was 38.8 [IQR: 24.0-48.0] weeks). The presence of Long COVID symptoms and fatigue severity was assessed 115.8 [92.5-118.6] weeks after the acute infection by a follow-up postal survey. Long COVID (yes/no) was defined as having one or more of the following symptoms: fatigue, shortness of breath, concentration or memory problems. The severity of fatigue was assessed using the Fatigue Assessment Scale (FAS). In multivariable-adjusted logistic and linear regression models the associations between each plasma protein (exposure) and Long COVID (yes/no) or severity of fatigue were investigated.

RESULTS

Nine plasma proteins were significantly associated with Long COVID before, but not after adjusting for multiple testing (FDR-adjustment): DFFA, TRIM5, TRIM21, HEXIM1, SRPK2, PRDX5, PIK3AP1, IFNLR1 and HCLS1. Moreover, a total of 10 proteins were significantly associated with severity of fatigue before FDR-adjustment: SRPK2, ITGA6, CLEC4G, HEXIM1, PPP1R9B, PLXNA4, PRDX5, DAPP1, STC1 and HCLS1. Only SRPK2 and ITGA6 remained significantly associated after FDR-adjustment.

CONCLUSIONS

This study demonstrates that certain immune response plasma proteins might play an important role in the pathophysiology of Long COVID and severity of fatigue after SARS-CoV-2 infection.

Respiratory dysfunction in persistent somatic symptoms: A systematic review of observational studies

OBJECTIVE

This systematic review aims to analyze the existing literature investigating respiratory functioning in people with Persistent Somatic Symptoms (PSS) compared to healthy controls, to identify patterns of respiratory disturbances by symptom or syndrome, and describe any respiratory outcomes consistent across diagnoses.

METHODS

A systematic review following PRISMA guidelines was conducted. A comprehensive search was carried out across five databases (PubMed (NCBI), PsycArticles (Ovid), Web of Science (Core Collection), Embase, and Scopus) using two customised search strings for persistent somatic symptoms and objective respiratory parameters. Title/abstract screening and data extraction were carried out independently by two reviewers. The modified Newcastle-Ottawa Scale was used for quality assessment of the studies. Studies investigating baseline respiratory functioning in adult patients with PSS compared to healthy controls, using at least one objective respiratory were included.

RESULTS

18 studies met the inclusion criteria for the review, with a pooled sample size of n = 3245. Chronic pain conditions were found to be the most prevalent subset of diagnoses of interest, comprising six of the studies. 10 studies included measures of lung capacity, flow and/or volume, nine studies reported measures of ventilation, and four studies investigated respiratory muscle functioning. 13 of the included studies reported significant differences in at least one objective respiratory measure between groups (at rest). Scores on self-reported measures of dysnpea and breathlessness were higher in patients compared to healthy controls, while objective respiratory outcomes were varied.

CONCLUSION

The current systematic review is consistent with previous literature suggesting more pronounced experiences of breathlessness in patients with PSS, and significant disparities between reported dyspnea and objective respiratory outcomes. Research investigating the uncoupling between subjective and objective respiratory outcomes is needed to understand the mechanisms behind breathing disturbances in PSS.

The anti-fatigue and sleep-aiding effects vary significantly among different recipes containing Ganoderma lucidum extracts

Aims

This study aims to delve into the anti-fatigue and sleep-aiding effects of various formulations containing Ganoderma lucidum extracts.

Materials and methods

PGB [incorporating Ganoderma lucidum extract (GE), broken Ganoderma lucidum spore powder (GB) and Paecilomyces hepiali mycelium (PH)] and GBS [composed of GE, GB, and Ganoderma sinense powder (GS)] were chosen as representative recipes for this study. Mice were treated with these recipes or key components of Ganoderma lucidum for 14 consecutive days. Subsequently, a weight-bearing swimming experiment was conducted to assess the mice's exhaustion time and evaluate the anti-fatigue properties of the recipes. Sleep-aiding effects were analyzed by measuring the sleep latency and duration. Furthermore, levels of blood lactic acid, serum urea nitrogen, hepatic glycogen, muscle glycogen, and malondialdehyde (MDA) were measured in the livers and muscles.

Key findings

The anti-fatigue abilities of the tested mice were significantly improved after treatment with PGB and their sleep quality improved as well with GBS treatment. PGB treatment for 14 days could significantly prolong the exhaustion time in weight-bearing swimming (from 10.1 ± 0.5 min to 15.2 ± 1.3 min). Meanwhile, glycogen levels in the livers and muscles were significantly increased, while the levels of serum lactic acid, serum urea nitrogen, and MDA in the livers and muscles were significantly decreased. In contrast, mice treated with GBS for 14 days experienced significant improvements in sleep quality, with shortened sleep latency (from 6.8 ± 0.7 min to 4.2 ± 0.4 min), extended sleep duration (from 88.3 ± 1.4 min to 152.5 ± 9.3 min), and decreased muscle MDA levels. These results indicated that Ganoderma lucidum extracts can be used for anti-fatigue and or aid in sleeping, depending on how they are prepared and administered.

Significance

This study provides experimental evidence and theoretical basis for the development of Ganoderma lucidum recipes that are specifically designed to help with anti-fatigue and sleep.

The German Multicenter Registry for ME/CFS (MECFS-R)

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisystemic disease characterized by a complex, incompletely understood etiology. Methods: To facilitate future clinical and translational research, a multicenter German ME/CFS registry (MECFS-R) was established to collect comprehensive, longitudinal, clinical, epidemiological, and laboratory data from adults, adolescents, and children in a web-based multilayer-secured database. Results: Here, we present the research protocol and first results of a pilot cohort of 174 ME/CFS patients diagnosed at two specialized tertiary fatigue centers, including 130 (74.7%) adults (mean age 38.4; SD 12.6) and 43 (25.3%) pediatric patients (mean age 15.5; SD 4.2). A viral trigger was identified in 160/174 (92.0%) cases, with SARS-CoV-2 in almost half of them. Patients exhibited severe functional and social impairment, as reflected by a median Bell Score of 30.0 (IQR 30.0 to 40.0) and a poor health-related quality of life assessed with the Short Form-36 health survey, resulting in a mean score of 40.4 (SD 20.6) for physical function and 59.1 (SD 18.8) for mental health. Conclusions: The MECFS-R provides important clinical information on ME/CFS to research and healthcare institutions. Paired with a multicenter biobank, it facilitates research on pathogenesis, diagnostic markers, and treatment options. Trial registration: ClinicalTrials.gov NCT05778006.

Ninjin'yoeito reduces fatigue-like conditions by alleviating inflammation of the brain and skeletal muscles in aging mice

Fatigue can lead to several health issues and is particularly prevalent among elderly individuals with chronic inflammatory conditions. Ninjin'yoeito, a traditional Japanese herbal medicine, is used to address fatigue and malaise, anorexia, and anemia. This study aimed to examine whether relieving inflammation in the brain and skeletal muscle of senescence-accelerated mice prone 8 (SAMP8) could reduce fatigue-like conditions associated with aging. First, SAMP8 mice were divided into two groups, with and without ninjin'yoeito treatment. The ninjin'yoeito-treated group received a diet containing 3% ninjin'yoeito for a period of 4 months starting at 3 months of age. At 7 months of age, all mice underwent motor function, treadmill fatigue, and behavioral tests. They were then euthanized and the skeletal muscle weight, muscle cross-sectional area, and concentration of interleukin (IL)-1β and IL-1 receptor antagonist (IL-1RA) in both the brain and skeletal muscle were measured. The results showed that the ninjin'yoeito-treated group had higher motor function and spontaneous locomotor activity than the untreated group did and ran for significantly longer in the treadmill fatigue test. Moreover, larger muscle cross-sectional area, lower IL-1β concentrations, and higher IL-1RA concentrations were observed in both the brain and skeletal muscle tissues of the ninjin'yoeito-treated group than in the untreated group. The results suggest that ninjin'yoeito improves age-related inflammatory conditions in both the central and peripheral tissues and reduces fatigue.

Differences in psychiatric comorbidity patterns in patients diagnosed with chronic stress-induced exhaustion disorder and depression - A cohort study in the total population of Region Stockholm

The high prevalence of stress-related disorders and depression underscores the urgent need to unravel their impact on individual well-being. This study aim to investigate common psychiatric and stress-related diagnoses, along with postviral fatigue, in individuals with prior stress-induced exhaustion disorder (SED) and prior depression compared to those without prior SED or depression, and to study whether the psychiatric comorbidity patterns differ. The study includes individuals in Region Stockholm who, in 2011, did not have a diagnosis of SED or depression. ICD-10 diagnosis of SED, depression, or both, recorded in 2012-2013, were compared to individuals without prior SED or depression in a cohort (n = 1,362,886), aged 18 to 65. Odds ratios (OR) with 99 % confidence intervals, adjusted for age and neighborhood socioeconomic status, were calculated for psychiatric disorders and post-viral fatigue in 2014-2022. Patients with prior SED showed associations primarily with stress related diagnoses, including acute stress reaction, reaction to severe stress, as well as post-COVID-19 and post-viral fatigue syndrome. These ORs were all larger for SED than depression. Depression was primarily associated with post-traumatic stress disorder (PTSD), alcohol related and substance use disorders, schizophrenia, schizotypal disorders, delusional disorders, manic episode, bipolar affective disorder, persistent mood disorder, neurotic disorder, borderline personality disorder, autistic disorder, Asperger's syndrome, attention -deficit hyperactivity disorder, attention-deficit disorders ADHD/ADD), and suicide attempt. These ORs were all higher for depression, although autistic disorders, ADHD/ADD and PTSD were also highly associated with prior SED (OR > 3.5). The divergent psychiatric comorbidity patterns suggest different underlying mechanisms and clinical prognosis.

Mast cells in the autonomic nervous system and potential role in disorders with dysautonomia and neuroinflammation

Mast cells (MC) are ubiquitous in the body, and they are critical for not only in allergic diseases but also in immunity and inflammation, including having potential involvement in the pathophysiology of dysautonomias and neuroinflammatory disorders. MC are located perivascularly close to nerve endings and sites such as the carotid bodies, heart, hypothalamus, the pineal gland, and the adrenal gland that would allow them not only to regulate but also to be affected by the autonomic nervous system (ANS). MC are stimulated not only by allergens but also many other triggers including some from the ANS that can affect MC release of neurosensitizing, proinflammatory, and vasoactive mediators. Hence, MC may be able to regulate homeostatic functions that seem to be dysfunctional in many conditions, such as postural orthostatic tachycardia syndrome, autism spectrum disorder, myalgic encephalomyelitis/chronic fatigue syndrome, and Long-COVID syndrome. The evidence indicates that there is a possible association between these conditions and diseases associated with MC activation. There is no effective treatment for any form of these conditions other than minimizing symptoms. Given the many ways MC could be activated and the numerous mediators released, it would be important to develop ways to inhibit stimulation of MC and the release of ANS-relevant mediators.

Camellia oil exhibits anti-fatigue property by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice

Camellia seed oil (CO) has high nutritional value and multiple bioactivities. However, the specific anti-fatigue characteristics and the implied mechanism of CO have not yet been fully elucidated. Throughout this investigation, male C57BL/6J mice, aged 8 weeks, underwent exhaustive exercise with or without CO pretreatment (2, 4, and 6 mL/kg BW) for 28 days. CO could extend the rota-rod and running time, reduce blood urea nitrogen levels and serum lactic acid, and increase muscle and hepatic glycogen, adenosine triphosphate, and anti-oxidative indicators. Additionally, CO could upregulate the mRNA and Nrf2 protein expression levels, as well as enhance the levels of its downstream antioxidant enzymes and induce the myofiber-type transformation from fast to slow and attenuate the gut mechanical barrier. Moreover, CO could ameliorate gut dysbiosis by reducing Firmicutes to Bacteroidetes ratio at the phylum level, increasing the percentage of Alistipes, Alloprevotella, Lactobacillus, and Muribaculaceae, and decreasing the proportion of Dubosiella at the genus level. In addition, specific bacterial taxa, which were altered by CO, showed a significant correlation with partial fatigue-related parameters. These findings suggest that CO may alleviate fatigue by regulating antioxidant capacity, muscle fiber transformation, gut mechanical barrier, and gut microbial composition in mice. PRACTICAL APPLICATION: Our study revealed that camellia seed oil (CO) could ameliorate exercise-induced fatigue in mice by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice. Our results promote the application of CO as an anti-fatigue functional food that targets oxidative stress, myofiber-type transformation, and microbial community.

Review of studies on polysaccharides, lignins and small molecular compounds from three Polygonatum Mill. (Asparagaceae) spp. in crude and processed states

Since ancient times, Polygonatum Mill. (Asparagaceae) has been utilized as a medicinal and culinary resource in China. Its efficacy in treating various illnesses has been well documented. Traditional processing involves the Nine-Steam-Nine-Bask method, which results in a reduction of toxicity and enhanced effectiveness of Polygonatum. Many substances, such as polysaccharides, lignins, saponins, homoisoflavones, alkaloids, and others, have been successfully isolated from Polygonatum. This review presents the research progress on the chemical composition of three crude and processed Polygonatum, including Polygonatum sibiricum Redouté (P. sibiricum), Polygonatum kingianum Collett & Hemsl (P. kingianum), and Polygonatum cyrtonema Hua (P. cyrtonema). The review also includes the pharmacology of Polygonatum, specifically on the pharmacology of polysaccharides both before and after processing. Its objective is to provide a foundation for uncovering the significance of the processing procedure, and to facilitate the development and utilization of Polygonatum in clinical practice.

[Association of inflammation and chronic fatigue syndrome in patients with Parkinson's disease]

OBJECTIVE

To study the prevalence of chronic fatigue syndrome (CFS) and association of CFS with other clinical and neuropsychological manifestations of Parkinson's disease (PD) as well as with serum inflammatory markers and genetic polymorphisms.

MATERIAL AND METHODS

The study included 533 patients with PD. All patients underwent clinical, neurological examination and neuropsychological testing using validated questionnaires: MoCA test, HADS, BDI-II, the Fatigue Severity Scale (FSS). Serum concentrations of inflammatory markers (slCAM-1, sVCAM-1, NCAM, CCL5, PAI-1 and MPO) were assessed in 144 patients using xMAP technology. A case-control study of CCL5 (rs2107538) and PAI-1 (rs2227631) gene polymorphisms was performed in connection with PD development and in groups differing in the presence/absence of CFS in PD. In addition, the relationship of these polymorphisms with variability in the levels of the corresponding proteins in the blood serum of patients was studied. Genotyping of CCL5 (rs2107538) and PAI-1 (rs2227631) polymorphisms was performed using real-time PCR with TaqMan probes.

RESULTS

CFS is common in 66.7% of patients in the PD group. In addition, non-motor symptoms (emotional-affective, cognitive, autonomic disorders and pain) were more common in patients with CFS. A strong correlation has been established between the severity of CFS assessed with FSS and serum concentrations of CCL5, sVCAM-1, NCAM and slCAM-1. In newly diagnosed patients with PD who were not taking antiparkinsonian drugs at the time of the study and had CFS, higher correlations were noted between inflammatory markers and the severity of CFS manifestations. When comparing the distribution of genotypes and alleles of CCL5 (rs2107538) and PAI-1 (rs2227631) polymorphisms, some differences were found between the groups of patients with PD and controls (p<0.05). However, these polymorphisms did not affect the variability of serum protein levels CCL5 and PAI-1, respectively, nor did they affect the development of CFS in patients with PD.

CONCLUSION

CFS is common in PD, and patients with PD and CFS are characterized by elevated levels of serum markers CCL5, sVCAM-1, slCAM-1 and NCAM, suggesting the importance of the inflammatory component in the development of neurodegenerative disease. In addition, the clinical course of PD in patients with CFS is aggravated by other non-motor manifestations, including emotional-affective, cognitive, autonomic disorders and pain. These results highlight the potential contribution of an inflammatory component to the development of fatigue associated with PD, starting from the earliest clinical stages of the disease.

Increased SARS-CoV-2 reactive low avidity T cells producing inflammatory cytokines in pediatric post-acute COVID-19 sequelae (PASC)

BACKGROUND

A proportion of the convalescent SARS-CoV-2 pediatric population presents nonspecific symptoms, mental health problems, and a reduction in quality of life similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID-19 symptomatic. However, data regarding its clinical manifestation and immune mechanisms are currently scarce.

METHODS

In this study, we perform a comprehensive clinical and immunological profiling of 17 convalescent COVID-19 children with post-acute COVID-19 sequelae (PASC) manifestation and 13 convalescent children without PASC manifestation. A detailed medical history, blood and instrumental tests, and physical examination were obtained from all patients. SARS-CoV-2 reactive T-cell response was analyzed via multiparametric flow cytometry and the humoral immunity was addressed via pseudovirus neutralization and ELISA assay.

RESULTS

The most common PASC symptoms were shortness of breath/exercise intolerance, paresthesia, smell/taste disturbance, chest pain, dyspnea, headache, and lack of concentration. Blood count and clinical chemistry showed no statistical differences among the study groups. We detected higher frequencies of spike (S) reactive CD4+ and CD8+ T cells among the PASC study group, characterized by TNFα and IFNγ production and low functional avidity. CRP levels are positively correlated with IFNγ producing reactive CD8+ T cells.

CONCLUSIONS

Our data might indicate a possible involvement of a persistent cellular inflammatory response triggered by SARS-CoV-2 in the development of the observed sequelae in pediatric PASC. These results may have implications on future therapeutic and prevention strategies.

Effects of lactotripeptide ingestion and physical activity intervention on the fatigue status of middle-aged and older adults: a randomized controlled trial

This randomized controlled trial aimed to investigate the effects of eight weeks of lactotripeptide (LTP) ingestion, physical activity (PA) intervention, and combined intervention on the fatigue status of middle-aged and older adults. A total of 78 middle-aged and older adults (63 ± 8 years of age) were randomly assigned to four groups: placebo, LTP, placebo with PA intervention (placebo + PA), and LTP with PA intervention (LTP + PA). All participants ingested the placebo or LTP tablets daily (three tablets/day). The placebo + PA and LTP + PA groups participated in a weekly supervised exercise class and were instructed to increase their moderate- to vigorous-intensity PA at home. The visual analog scale, Brief Fatigue Inventory, Profile of Mood States second edition (POMS2), and Beck Depression Inventory second edition (BDI-II) were administered before and after the intervention. No significant interactions or main effects were observed between LTP ingestion and PA intervention on any of the fatigue scales. The main-effect analyses revealed that the PA intervention improved the total mood disturbance score of the POMS2 (F = 5.22, P = 0.03) and BDI-II score (F = 4.81, P = 0.03). After the post hoc paired comparisons, the total mood disturbance and BDI-II scores improved more with the combined intervention than with the PA intervention alone (percentage difference between the effect of combined intervention and PA intervention alone was 3.7% for total mood disturbance score and 13.7% for BDI-II score). The present study suggests that eight weeks of LTP ingestion and PA intervention did not have a significant effect on fatigue status. However, the PA intervention improved mood status and depressive symptoms, and these effects were enhanced by LTP ingestion.

Reduced ex vivo TNFα synthesis upon whole blood stimulation with endotoxin predicts post-stroke fatigue

OBJECTIVE

Fatigue is a common, debilitating syndrome after stroke. Peripheral inflammation plays a role in the pathogenesis of fatigue of different origin, but its contribution to post-stroke fatigue (PSF) remains unclear. We aimed to determine if there is any association between ex vivo synthesized and circulating cytokines, and risk of PSF.

METHODS

We included 174 patients with ischemic stroke. We stimulated in vitro blood taken on day 3 after stroke with endotoxin. We measured ex vivo released (TNFα, IP-10, IL-1β, IL-6, IL-8, IL-10, IL-12p70) and plasma (TNFα, IL-6, sIL-6R, IL-1Ra) cytokines. We assessed fatigue at month 3 using Fatigue Severity Scale (FSS). We used logistic regression to assess the relationship between cytokines and fatigue scores.

RESULTS

Compared with patients with lower fatigue at month 3 (FSS < 36), patients with higher fatigue (FSS ≥ 36) had lower endotoxin-stimulated TNFα release after 24 h (median: 429 vs 581 pg/mL, P = 0.05). Plasma TNFα tended to be higher in patients who developed fatigue (median: 0.8 vs 0.6 pg/mL, P = 0.06). Other cytokines did not differ between groups. After adjusting for pre-stroke fatigue and depressive symptoms, TNFα release <559.7 pg/mL after 24 h was associated with an increased risk of PSF (OR: 2.61, 95%CI: 1.22-5.57, P = 0.01). Plasma TNFα >0.76 pg/mL was associated with higher risk of PSF in univariable (OR: 2.41, 95%CI: 1.13-5.15, P = 0.02), but not multivariable analysis (OR: 2.41, 95%CI: 0.96-6.00, P = 0.06).

CONCLUSION

Reduced ex vivo TNFα synthesis upon whole blood stimulation with endotoxin in the acute phase of stroke predicted PSF.

Dose-effect of long-snake-like moxibustion for chronic fatigue syndrome: a randomized controlled trial

BACKGROUND

The dose-effect relationship of Long-snake-like moxibustion for chronic fatigue syndrome (CFS) remains poorly understood. In order to address this gap, we designed this trial to assess the association between different treatment duration of Long-snake-like moxibustion and its effects on CFS based on the combination measurements of the subjective patient-reported scales with objective medical infrared imaging technology─Thermal Texture Maps (TTM).

METHODS

From December 2020 to January 2022, 60 female CFS patients were recruited and equally allocated to two groups: Group A, receiving 60-min Long-snake-like moxibustion per treatment, and Group B, receiving 30-min Long-snake-like moxibustion per treatment. The treatment was administered 3 times per week for a total of 4 weeks. The primary outcome was defined as the improvement of symptoms measured by the Fatigue scale-14 (FS-14), and secondary outcomes were designated as the improvement in Symptoms Scale of Spleen-Kidney Yang Deficiency, Self-rating depression scale, and Self-rating anxiety scale. TTM scanning was employed twice for CFS patients (before and after 4-week treatment) and once for Healthy control subjects (HCs).

RESULTS

At week 4, the scores of FS-14 and Symptoms Scale of Spleen-Kidney Yang Deficiency in Group A were significantly lower than those in Group B (physical fatigue: 5.00 vs. 6.00, with 95%CI - 2.00 to 0.00, p = 0.003; FS-14 total score: 8.00 vs. 9.00, with 95%CI - 3.00 to 0.00, p = 0.012; total score of Symptoms Scale of Spleen-Kidney Yang Deficiency: 9.80 vs. 13.07, with 95%CI - 5.78 to - 0.76, P = 0.012). All thermal radiation values of the two groups increased, and statistical differences in ΔTs between Group A and HCs were not obtained. More significant correlations between symptoms improvements and ΔT changes were observed in Group A, and its ΔT changes in Upper Jiao, Shenque (CV8), Zhongwan (CV12), Danzhong (CV17), Zhiyang (GV9), Dazhui (GV14), upper arm, thoracic segments, lumbar segments, renal region, popliteal fossa strongly correlated with the improvement of Spleen-Kidney Yang Deficiency symptoms.

CONCLUSIONS

In the same course of treatment, the positive dose-effect relationship was found between the treatment duration of Long-snake-like moxibustion and CFS effect assessment. 60-min Long-snake-like moxibustion per treatment were associated with optimal clinical response and TTM improvement.

TRIAL REGISTRATION

Chinese Clinical Trail Registry (No. ChiCTR2000041000, date of registration: 16 December 2020), http://www.chictr.org.cn/showproj.aspx?proj=62488.

Sleep and fatigue among youth with sickle cell disease: A daily diary study

Youth with sickle cell disease (SCD) experience disease effects including vaso-occlusive pain crises, poor sleep quality, and fatigue. The present study examines how sleep quality and pain medications impact fatigue in youth with SCD. Daily diaries assessing pain, fatigue, sleep quality, mood, and use of pain medications from 25 youth with SCD ages 11 to 18 years were collected for eight consecutive weeks. Poor sleep quality predicted increases in next-day fatigue levels while controlling for pain and mood. Sleep quality did not moderate the existing temporal relationship between pain and next-day fatigue established by Reinman et al. (2019) as predicted. Non-opioid medications affected ratings of next-day fatigue but opioid medications did not. Sleep quality appears to play an important role in predicting next-day fatigue levels and may be an important target for intervention. Pain medication use did not substantially contribute to prospective fatigue levels among youth, but requires further study.

Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia

Although the predominant symptom in fibromyalgia (FM) is muscle pain, and fatigue in chronic fatigue syndrome (CFS), differential diagnosis is very difficult. This research investigates the psychoneuroimmunoendocrine disorders of FM patients and ascertains whether a previous CFS diagnosis affected them. Through accelerometry objective parameters, physical activity/sedentarism levels in relation to fatigue are studied, as well as whether perceived levels of stress, anxiety, and pain correspond to objective biomarkers, all of these with respect to a reference group (RG) of women without FM. FM patients have a worse psychological state and perceived quality of life than those with RG. These perceived outcomes are consistent with impaired objective levels of a sedentary lifestyle, higher systemic levels of cortisol and noradrenaline, and lower levels of serotonin. However, FM patients with a previous CFS diagnosis had lower systemic levels of IL-8, cortisol, oxytocin, and higher levels of adrenaline and serotonin than FM patients without diagnosed CFS. In conclusion, while perceived health parameters do not detect differences, when objective neuroimmunoendocrine parameters related to stress, inflammation, pain, and fatigue are used, people with CFS could be overdiagnosed with FM. This reinforces the need for objective biomarker assessment of these patients for better diagnostic discrimination between both syndromes.

Bringing the patient's perspectives forward in drug development and health-care evaluation

INTRODUCTION

For many years, psychologists and other social scientists have been pushing for the individual patient's perspective - priorities, needs, feelings, and functioning - to be incorporated into drug development. This is usually achieved through the use of patient-reported outcome measures (PROMs) in clinical trials.

AREAS COVERED

This paper discusses some key issues in the use of PROM data as the sole method of generating information about the patient's perspective and outlines the relevance of narrative evidence to enhance understanding and interpretation of PROM data.

EXPERT OPINION

The development and use of PROMs situates them at the vertex of two very different trends in medicine: patient-centered care and standardization. Indeed, the application of PROMs - which pull in the direction of standardization - results in a narrow conception of evidence by overriding the subjectivity of individual experiences, beliefs, and judgments. Without additional context, PROM data cannot easily support individual patient-level care. When collected systematically and with an interpretive phenomenological approach, narrative data can contain valuable information about the patient experience that numerical ratings from PRO measures do not capture.

Anti-fatigue Effect of Traditional Chinese Medicines: A Review

A third of the world's population suffers from unexplained fatigue, hugely impacting work learning, efficiency, and health. The fatigue development may be a concomitant state of a disease or the side effect of a drug, or muscle fatigue induced by intense exercise. However, there are no authoritative guides or clinical medication recommendations for various fatigue classifications. Traditional Chinese medicines (TCM) are used as dietary supplements or healthcare products with specific anti-fatigue effects. Thus, TCM may be a potential treatment for fatigue. In this review, we outline the pathogenesis of fatigue, awareness of fatigue in Chinese and western medicine, pharmacodynamics mechanism, and substances. Additionally, we offer a comprehensive summary of fatigue and forecast the potential effect of novel herbal-based medicines against fatigue.

Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome

Long-COVID syndrome is associated with high healthcare costs, but its pathophysiology is not yet fully understood. Inflammation, renal impairment or disturbance of the NO system emerge as potential pathogenetic factors. We aimed to investigate the relationship between symptoms of long-COVID syndrome and serum levels of cystatin-c (CYSC), orosomucoid (ORM), l-arginine, symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA). A total of 114 patients suffering from long-COVID syndrome were included in this observational cohort study. We found that serum CYSC was independently associated with the anti-spike immunoglobulin (S-Ig) serum level (OR: 5.377, 95% CI: 1.822-12.361; p = 0.02), while serum ORM (OR: 9.670 (95% CI: 1.34-9.93; p = 0.025) independently predicted fatigue in patients with long-COVID syndrome, both measured at baseline visit. Additionally, the serum CYSC concentrations measured at the baseline visit showed a positive correlation with the serum SDMA levels. The severity of abdominal and muscle pain indicated by patients at the baseline visit showed a negative correlation with the serum level of L-arginine. In summary, serum CYSC may indicate subclinical renal impairment, while serum ORM is associated with fatigue in long-COVID syndrome. The potential role of l-arginine in alleviating pain requires further studies.

Association between fatigue and cytokine profiles in patients with ischemic stroke

Background

Chronic fatigue is a common symptom after a stroke. Studies suggested that chronic fatigue is caused by inflammatory or immunological processes but data are limited and contradictory. Thus, the present study aimed to identify specific biomarkers associated with fatigue in post-stroke patients and replicated the findings in a population-based study.

Methods

We investigated associations between 39 circulating biomarkers of inflammation and fatigue in 327 patients after an ischemic stroke included in the Stroke Cohort Augsburg (SCHANA) study and the "Metabolism, Nutrition and Immune System in Augsburg" (MEIA) study (n = 140). The Fatigue Assessment Scale (FAS) was used to assess the severity of fatigue. The serum concentrations of the biomarkers were measured using the Bio-Plex Pro™ Human Cytokine Screening Panel (Bio-Rad, USA). Multiple linear regression models adjusted for possible confounders were used to examine associations.

Results

In patients with stroke, SCGFb was inversely associated [-1.67, 95% confidence interval (CI) (-3.05; -0.29) p = 0.018], and in healthy subjects, G-CSF was positively associated [1.56, 95% CI (0.26; 2.87), p = 0.020] with an increasing FAS-score, while SCF was positively related in both samples [1.84, 95% CI (0.27; 3.42), p = 0.022 and 1.40, 95% CI (0.29; 2.52), p = 0.015]. However, after correction for multiple testing, all of these associations lost statistical significance.

Conclusion

The present findings suggested an association between the growth factor SCF and fatigue. Future research on cytokines as possible markers of fatigue should focus on a longitudinal design including a sufficiently large number of study participants to enable testing associations between certain cytokines and sub-groups of chronic fatigue.

A Multi-Dimensional Model of Fatigue in Old Age: Implications for Brain Aging

As the most reported symptom in old age, fatigue is understudied in terms of both mechanisms and measures. Population heterogeneity and methodological inconsistency makes understanding the relationship between fatigue and brain aging challenging. The present article comprehensively reviews existing conceptual and operational frameworks of fatigue, as well as mechanistic heterogeneities of fatigue that exist in the aging literature. Then, I propose a Multi-Dimensional Model of fatigue to provide theoretical cohesion to the study of fatigue in old age, along with a "fatigue circuit" addressing brain profiles across dimensions of fatigue. The potential relationships between fatigue dimensions, the fatigue circuit, and brain aging are discussed to inform the direction of future research.

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in Adolescents: Practical Guidance and Management Challenges

This paper reviews the current understanding of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and whether any treatment strategies have been effective. ME/CFS is a condition of as yet unknown etiology that commonly follows an infective process. It includes a new onset of fatigue (of more than 3-6 month duration and not relieved by rest), post-exertional malaise, cognitive difficulties and unrefreshing sleep, and frequently orthostatic intolerance, somatic symptoms and pain. Long COVID has renewed interest in the condition and stimulated research with findings suggestive of a multisystem neuroimmune disease. There are no definitively effective treatments. Despite earlier recommendations regarding graded exercise therapy and cognitive behavior therapy, the current recommendations are managing symptoms, with lifestyle management and supportive care. This paper provides an outline of strategies that young people and their families have reported as helpful in managing a chronic illness that impacts their life socially, physically, emotionally, cognitively and educationally. As the illness frequently occurs at a time of rapid developmental changes, reducing these impacts is reported to be as important as managing the physical symptoms. Young people face a mean duration of 5 years illness (range 1-16 years) with a likely residual 20% having significant restrictions after 10 years. Their feedback has suggested that symptom management, self-management strategies, advocacy and educational liaison have been the most helpful. They value professionals who will listen and take them seriously, and after excluding alternative diagnoses, they explain the diagnosis, are supportive and assist in monitoring their progress. Remaining engaged in education was the best predictor of later functioning. This allowed for social connections, as well as potential independence and fulfilling some aspirations. The need to consider the impact of this chronic illness on all aspects of adolescent development, as part of management, is highlighted.

Effects of Pregnant Fatigue on the Development of Offspring in Rats

AIM

To explore the correlation between pregnant fatigue and intrauterine physical and neural development of offspring in rats.

METHODS

Sprague-Dawley pregnant rats were randomly divided into a normal control group, a mild fatigue group (stand in water for 6 hours/day), and a severe fatigue group (stand in water for 15 h/day). The levels of lactic acid, 5-Hydroxytryptamine and Interleukin-6 in cardiac serum of rats were used to evaluate the fatigue. The expression of S100β in the telencephalon, Insulin-like growth factor-1 (IGF-1) in the liver and Cyclooxygenage-2 (COX-2) in the small intestine tissues of fetal rats were examined. Frozen sections were taken from the telencephalon of rat pups to observe morphological changes in the hippocampal primordium.

RESULTS

Pregnant fatigue led to a decrease in food intake (F = 37.586, p = 0.000) and water intake (F = 23.608, p = 0.000) in rats. The IGF-1 mRNA expression of fetal rats in the severe fatigue group was lower than that in the control group (p = 0.0003). The expression of S100β mRNA (p = 0.000) and COX-2 mRNA (p = 0.0002) of fetal rats were higher in the severe fatigue group than in the control group. HE staining of the telencephalon of fetal rats in the pregnant fatigue group revealed sparse and irregular cell arrangement and increased gaps in the hippocampal primordial site.

CONCLUSION

Pregnant fatigue rats had both physical fatigue and mental fatigue. Fatigue during pregnancy affects physical development and neurodevelopment of offspring. Further research should elucidate the mechanisms of pregnant fatigue and its effects on offspring.

The association of job fatigue with mental disorders among bus drivers

OBJECTIVE

Mental disorders are a global problem with growing importance. However, the contribution of work factors to the development of mental disorders is inconclusive. This study aimed to assess the impact of fatigue and job stress on mental disorders in a prospective cohort of bus drivers.

METHODS

The Taiwan Bus Driver Cohort Study (TBDCS) recruited 1652 bus drivers from a bus company in 2005. Participants self-completed a structured questionnaire in 2007, which included the Demand-Control-Support (DCS) model questions and the Swedish Occupational Fatigue Inventory-Chinese (SOFI-C). Psychiatric care visits and admissions were obtained from the National Health Insurance Research Dataset (NHIRD) from 2003 to 2016 for as a proxy for psychiatric diagnoses. Drivers with a history of psychiatric disorders before the questionnaire survey time were excluded (N=69). During the follow-up period, a new diagnosis with a psychiatric disorder was defined as an event. Cox proportional hazards model was used to estimate the hazard ratio (HR) for new one-set psychiatric disorders, adjusting for age, body mass index, marital status, education, alcohol consumption, smoking, exercise, bus driving experience, shift work, and chronic diseases.

RESULTS

Among the 896 bus drivers retained for analysis, 85 were newly diagnosed with a psychiatric disorders. DCS score was not associated with the risk of developing a psychiatric disorders, but bus drivers with high SOFI-C scores (≥5) had an elevated risk for anxiety or mood disorders (HR 3.35, 95% confidence interval 1.23-9.09).

CONCLUSIONS

Among bus drivers, occupational fatigue, as indicated by high a SOFI-C score, might result in an elevated risk of anxiety or mood disorders. Health service organizations should provide recommendations and guidance for drivers with high fatigue levels to avoid anxiety or mood disorders.

Exosome-associated mitochondrial DNA from patients with myalgic encephalomyelitis/chronic fatigue syndrome stimulates human microglia to release IL-1β

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease that presents with fatigue, sleep disturbances, malaise, and cognitive problems. The pathogenesis of ME/CFS is presently unknown, and serum levels of potential biomarkers have been inconsistent. Here, we show that mitochondrial DNA (mtDNA) associated with serum exosomes, is increased in ME/CFS patients only after exercise. Moreover, exosomes isolated from patients with ME/CFS stimulate significant release of IL-1β from cultured human microglia. These results provide evidence that activation of microglia by serum-derived exosomes may serve as a potential novel pathogenetic factor and target for treatment of ME/CFS.

Genetics of COVID-19 and myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review

COVID‐19 and ME/CFS present with some similar symptoms, especially physical and mental fatigue. In order to understand the basis of these similarities and the possibility of underlying common genetic components, we performed a systematic review of all published genetic association and cohort studies regarding COVID‐19 and ME/CFS and extracted the genes along with the genetic variants investigated. We then performed gene ontology and pathway analysis of those genes that gave significant results in the individual studies to yield functional annotations of the studied genes using protein analysis through evolutionary relationships (PANTHER) VERSION 17.0 software. Finally, we identified the common genetic components of these two conditions. Seventy‐one studies for COVID‐19 and 26 studies for ME/CFS were included in the systematic review in which the expression of 97 genes for COVID‐19 and 429 genes for ME/CFS were significantly affected. We found that ACE, HLA‐A, HLA‐C, HLA‐DQA1, HLA‐DRB1, and TYK2 are the common genes that gave significant results. The findings of the pathway analysis highlight the contribution of inflammation mediated by chemokine and cytokine signaling pathways, and the T cell activation and Toll receptor signaling pathways. Protein class analysis revealed the contribution of defense/immunity proteins, as well as protein‐modifying enzymes. Our results suggest that the pathogenesis of both syndromes could involve some immune dysfunction.

Use of 1-MNA to Improve Exercise Tolerance and Fatigue in Patients after COVID-19

COVID-19 is not only a short-term infection, as patients (pts) recovering from SARS-CoV-2 infection complain of persisting symptoms, which may lead to chronic fatigue syndrome. There is currently no evidence that nutritional supplements can assist in the recovery of pts with chronic fatigue syndrome. 1-Methylnicotinamide (1-MNA) is an endogenic substance that is produced in the liver when nicotinic acid is metabolized. 1-MNA demonstrates anti-inflammatory and anti-thrombotic properties. Therefore, we investigated whether 1-MNA supplements could improve exercise tolerance and decrease fatigue among patients recovering from SARS-CoV-2.

METHODS

The study population was composed of 50 pts who had recovered from symptomatic COVID-19. The selected pts were randomized into two groups: Gr 1 (NO-1-MNA)-without supplementation; Gr 2 (1-MNA) with 1-MNA supplementation. At the beginning of the study (Phase 0), in both groups, a 6-minute walk test (6MWT) was carried out and fatigue assessment was performed using the Fatigue Severity Scale (FSS). Both FSS and 6MWT were repeated after 1 month.

RESULTS

A significant improvement in the mean distance covered in the 6MWT was noted at follow-up in Gr 1-MNA, compared with Gr NO-1-MNA. We also noted that in Gr 1-MNA, the 6MWT distance was significantly higher after 1 month of supplementation with 1-MNA, compared with the beginning of the study (515.18 m in Phase 0 vs. 557.8 m in Phase 1; p = 0.000034). In Gr 1-MNA, significantly more pts improved their distance in the 6MWT (23 out of 25 pts, equal to 92%), by a mean of 47 m, compared with Gr NO-1-MNA (15 of 25 pts, equal to 60%) (p = 0.0061). After one month, significantly more patients in the group without 1-MNA had severe fatigue (FSS ≥ 4) compared with the group with supplementation (Gr 1-MNA = 5 pts (20%) vs. Gr NO-1-MNA = 14pts (56%); p = 0.008).

CONCLUSIONS

1-MNA supplementation significantly improved physical performance in a 6-min walk test and reduced the percentage of patients with severe fatigue after COVID-19. The comprehensive action of 1-MNA, including anti-inflammatory and anticoagulant effects, may be beneficial for the recovery of patients with persistent symptoms of fatigue and low tolerance to exercise after COVID-19.

Anti-fatigue effect from Ginseng Radix et Rhizoma: a suggestive and promising treatment for long COVID

Two years after the coronavirus disease 2019 (COVID-19) outbreak, an increasing number of patients continue to suffer from long COVID (LC), persistent symptoms, and/or delayed or long-term complications beyond the initial 4 weeks from the onset of symptoms. Constant fatigue is one of the most common LC symptoms, leading to severely reduced quality of life among patients. Ginseng Radix et Rhizoma-known as the King of Herbs in traditional Chinese medicine-has shown clinical anti-fatigue effects. In this review, we summarize the underlying anti-fatigue mechanisms of Ginseng Radix et Rhizoma extracts and their bioactive compounds, with a special focus on anti-viral, immune remodeling, endocrine system regulation, and metabolism, suggesting that Ginseng Radix et Rhizoma is a potentially promising treatment for LC, especially in regard to targeting fatigue.

Post-COVID-19 Fatigue and SARS-CoV-2 Specific Humoral and T-Cell Responses in Male and Female Outpatients

Background

Information on the clinical characteristics and pathophysiological mechanisms underlying post-COVID-19 fatigue are scarce. The main objective of this study was to evaluate sex-specific humoral and T-cell responses associated with post-COVID-19 fatigue in a sample of individuals treated as outpatients.

Methods

At a median time of 279 (179;325) days after the acute infection, a total of 281 individuals (45.9% men) aged 18-87 years old were included in the analysis. The participants were examined at the University Hospital of Augsburg, Southern Germany. Fatigue was assessed using the Fatigue Assessment Scale (FAS). Levels of anti-SARS-CoV2-spike IgG antibodies were measured by an enzyme-linked immunosorbent assay (ELISA), and for exploration of the SARS-CoV2-specific T-cell response, ex vivo ELISpot/FLUOROspot assays were conducted using an interferon-γ (IFN-γ) and interleukin-2 (IL-2) SARS-CoV-iSpot kit.

Results

Women more significantly suffered from post-COVID-19 fatigue in comparison to men (47.4% versus 25.6%, p=0.0002). Females but not males with fatigue showed a significantly lower number of T-cells producing IFN-γ, IL-2 or both IL-2 and IFNγ in comparison with females without fatigue. In both sexes, serum levels of anti-SARS-CoV2-spike IgG antibodies did not differ significantly between participants with or without fatigue.

Conclusions

Development of fatigue after acute COVID-19 disease might be associated with SARS-CoV-2-specific T-cell responses in women, but not men after a mild infection course treated outpatient.

Lasting Immunological Imprint of Primary Epstein-Barr Virus Infection With Associations to Chronic Low-Grade Inflammation and Fatigue

Background

Epstein-Barr virus (EBV) causes infectious mononucleosis (IM) that can lead to chronic fatigue syndrome. The CEBA-project (Chronic fatigue following acute EBV infection in Adolescents) has followed 200 patients with IM and here we present an immunological profiling of adolescents with IM related to clinical characteristics.

Methods

Patients were sampled within 6 weeks of debut of symptoms and after 6 months. Peripheral blood mononuclear cells (PBMC) were cultured and stimulated in vitro (n=68), and supernatants analyzed for cytokine release. Plasma was analyzed for inflammatory markers (n=200). The Chalder Fatigue Questionnaire diagnosed patients with and without chronic fatigue at 6 months (CF+ and CF- group, respectively) (n=32 and n=91, in vitro and plasma cohorts, respectively.

Results

Broad activation of PBMC at baseline, with high levels of RANTES (Regulated on activation, normal T-cell expressed and secreted) in the CF+ group, and broad inflammatory response in plasma with high levels of T-cell markers was obeserved. At 6 months, there was an increased β-agonist response and RANTES was still elevated in cultures from the CF+ group. Plasma showed decrease of inflammatory markers except for CRP which was consistently elevated in the CF+ group.

Conclusion

Patients developing chronic fatigue after IM have signs of T-cell activation and low-grade chronic inflammation at baseline and after 6 months.

Clinical Trial Registration

https://clinicaltrials.gov/, identifier NCT02335437.

A Natural History of Disease Framework for Improving the Prevention, Management, and Research on Post-viral Fatigue Syndrome and Other Forms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

We propose a framework for the treatment, rehabilitation, and research into Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) using a natural history of disease approach to outline the distinct disease stages, with an emphasis on cases following infection to provide insights into prevention. Moving away from the method of subtyping patients based on the various phenotypic presentations and instead reframing along the lines of disease progression could help with defining the distinct stages of disease, each of which would benefit from large prospective cohort studies to accurately describe the pathological mechanisms taking place therein. With a better understanding of these mechanisms, management and research can be tailored specifically for each disease stage. Pre-disease and early disease stages call for management strategies that may decrease the risk of long-term morbidity, by focusing on avoidance of further insults, adequate rest to enable recovery, and pacing of activities. Later disease stages require a more holistic and tailored management approach, with treatment-as this becomes available-targeting the alleviation of symptoms and multi-systemic dysfunction. More stringent and standardised use of case definitions in research is critical to improve generalisability of results and to create the strong evidence-based policies for management that are currently lacking in ME/CFS.

Chemical Characterization and Preliminary Evaluation of the Efficacy and Tolerability of a Food Supplement Based on Pomegranate Extract, B Vitamins, and Vitamin C against Prolonged Fatigue in Healthy Consumers

Fatigue, characterized by periods of exhaustion that interfere with normal activities and negatively affect quality of life, can be classified as prolonged fatigue (or short-term fatigue, SF) or chronic fatigue. Vitamin deficiency and chronic inflammation seem to be possible causes of fatigue. Due to the unavailability of effective remedies that attenuate fatigue and provide consumer satisfaction, the aim of this investigation is to assess whether a commercial food supplement consisting of pomegranate extract with known anti-inflammatory activity, B vitamins, and vitamin C can help fight SF. To this end, the chemical composition of whole fruit pomegranate dry extract was determined through a RP-UHPLC–HRMS method, which indicated the presence of ellagitannins, gallotannins, and organic and phenolic acids. In a survey of consumers of food supplements aimed at reducing fatigue, 78 subjects (21 men and 57 women) were recruited for one month to evaluate the efficacy and tolerability of this food supplement through validated questionnaires for assessing fatigue level and quality of life. The consumers reported a significant improvement in their conditions without adverse effects over this time period. Although further studies are needed, these preliminary data suggest the capacity of a combination of pomegranate extract and hydrosoluble vitamins to alleviate SF.

Observational study on the benefit of a nutritional supplement, supporting immune function and energy metabolism, on chronic fatigue associated with the SARS-CoV-2 post-infection progress

Background & aims

Recent studies have verified that the SARS-CoV-2 infection (from December 2019 has affected 123 million people throughout the world and more than 3 million people in Italy), can have medium-term and long-term effects, collectively referred to as “post-Covid syndrome” or “long-Covid” characterized by chronic fatigue, followed by muscle weakness, dyspnea and headache. Chronic fatigue or chronic tiredness is a persistent symptom both in patients who have experienced a severe infection and in those who have experienced a mild form of infection. Studies conducted on both patients discharged from hospital and patients managed at home showed that there was no association between the severity of the Coronavirus disease (Covid-19) and the subsequent chronic fatigue symptom. The aim of this study was to evaluate the ability of a nutritional supplement based on vitamins, minerals, amino acids and plant extracts (Apportal®) intake, to ameliorate the general health status in particular the chronic fatigue symptom in subjects after SARS-CoV-2 negativity.

Methods

Participants were advised to take one sachet daily of Apportal® for 28 consecutive days. At the beginning (T0), after 14 days (T1) and after 28 days (T2) of supplementation, general fatigue, mental fatigue and Quality of Life indexes were evaluated through specific questionnaires. The assessment of quality of life and health status were measured through the EuroQoL-5D questionnaire, chronic fatigue using the FACIT-Fatigue questionnaire and mental fatigue using the modified Chalder questionnaire.

Results

201 subjects were enrolled for the study; results showed a significant improvement in all indexes analyzed after 14 and 28 days of supplementation. The main significant improvement was observed after the first 14 days and it was further confirmed at 28 days as well. The RTE (Relative Treatment Effect) trend about quality of life, health status, FACIT-Fatigue and mental fatigue in the three questionnaires was statistically significant (Wald Statistic, p < 0.0001). The data of FACIT-questionnaire showed an improvement of at least 1 unit in 76.62% of subjects after 14 days and in 90.05% of subjects after 28 days. An improvement of 10-unit was found in about one third of subjects after 14 days and in half of the subjects after 28 days.

Conclusions

This study shows that Apportal® can reduce chronic fatigue and improve quality of life and health status in subjects after SARS-CoV-2 negativity due to the synergistic effect of its components.

Clinical characterization and cytokine profile of fatigue in hematologic malignancy patients with chronic graft-versus-host disease

Limited information is available regarding clinical and biological properties of fatigue in patients with chronic graft-versus-host disease (cGvHD). Patients with moderate-to-severe cGvHD per NIH criteria were enrolled on a cross-sectional study and categorized as "fatigued" if SF-36 vitality score was <40. Clinical and laboratory parameters of fatigued (n = 109) and nonfatigued patients (n = 72) were compared. In univariate analysis, walk velocity, NIH joint-fascia score, human activity profile, and SF-36 physical and mental health self-report scales were correlates of fatigue. No cGvHD biomarkers were associated with fatigue. NIH joint score, Lee sleep and depression questions, and PG-SGA activities and function score jointly predicted fatigue. Though higher rates of depression and insomnia were reported in the fatigued group, antidepressant or sleep aid use did not differ between groups. Survival ratio was not significantly different by fatigue status. Pathophysiology of fatigue in patients with cGvHD is complex and may involve mechanisms unrelated to disease activity. Patients with cGvHD experiencing fatigue had higher rates of untreated depression and insomnia, highlighting the need to focus clinical management of these conditions to improve health-related quality of life.

Analysis of Gender Differences in HRV of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Mobile-Health Technology

In a previous study using mobile-health technology (mHealth), we reported a robust association between chronic fatigue symptoms and heart rate variability (HRV) in female patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This study explores HRV analysis as an objective, non-invasive and easy-to-apply marker of ME/CFS using mHealth technology, and evaluates differential gender effects on HRV and ME/CFS core symptoms. In our methodology, participants included 77 ME/CFS patients (32 men and 45 women) and 44 age-matched healthy controls (19 men and 25 women), all self-reporting subjective scores for fatigue, sleep quality, anxiety, and depression, and neurovegetative symptoms of autonomic dysfunction. The inter-beat cardiac intervals are continuously monitored/recorded over three 5-min periods, and HRV is analyzed using a custom-made application (iOS) on a mobile device connected via Bluetooth to a wearable cardiac chest band. Male ME/CFS patients show increased scores compared with control men in all symptoms and scores of fatigue, and autonomic dysfunction, as with women in the first study. No differences in any HRV parameter appear between male ME/CFS patients and controls, in contrast to our findings in women. However, we have found negative correlations of ME/CFS symptomatology with cardiac variability (SDNN, RMSSD, pNN50, LF) in men. We have also found a significant relationship between fatigue symptomatology and HRV parameters in ME/CFS patients, but not in healthy control men. Gender effects appear in HF, LF/HF, and HFnu HRV parameters. A MANOVA analysis shows differential gender effects depending on the experimental condition in autonomic dysfunction symptoms and HF and HFnu HRV parameters. A decreased HRV pattern in ME/CFS women compared to ME/CFS men may reflect a sex-related cardiac autonomic dysfunction in ME/CFS illness that could be used as a predictive marker of disease progression. In conclusion, we show that HRV analysis using mHealth technology is an objective, non-invasive tool that can be useful for clinical prediction of fatigue severity, especially in women with ME/CFS.

Insights into Metabolite Diagnostic Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without infectious or neuropsychiatric symptoms, and with a minimum duration of 6 consecutive months. Its pathogenesis is not fully understood. There are no firmly established diagnostic biomarkers or treatment, due to incomplete understanding of the etiology of ME/CFS and diagnostic uncertainty. Establishing a biomarker for the objective diagnosis is urgently needed to treat a lot of patients. Recently, research on ME/CFS using metabolome analysis methods has been increasing. Here, we overview recent findings concerning the metabolic features in patients with ME/CFS and the animal models which contribute to the development of diagnostic biomarkers for ME/CFS and its treatment. In addition, we discuss future perspectives of studies on ME/CFS.

Are there subgroups of chronic fatigue syndrome? An exploratory cluster analysis of biological markers

BACKGROUND

Chronic fatigue syndrome (CFS) is defined according to subjective symptoms only, and several conflicting case definition exist. Previous research has discovered certain biological alterations. The aim of the present study was to explore possible subgroups based on biological markers within a widely defined cohort of adolescent CFS patients and investigate to what extent eventual subgroups are associated with other variables.

METHODS

The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL) has previously performed detailed investigation of immunological, autonomic, neuroendocrine, cognitive and sensory processing functions in an adolescent group of CFS patients recruited according to wide diagnostic criteria. In the present study, hierarchical cluster analyses (Ward's method) were performed using representative variables from all these domains. Associations between clusters and constitutional factors (including candidate genetic markers), diagnostic criteria, subjective symptoms and prognosis were explored by standard statistical methods.

RESULTS

A total of 116 patients (26.7% males, mean age 15.4 years) were included. The final cluster analyses revealed six clusters labelled pain tolerant & good cognitions, restored HPA dynamics, orthostatic intolerance, low-grade inflammation, pain intolerant & poor cognitions, and high vagal (parasympathetic) activity, respectively. There was substantial overlap between clusters. The pain intolerant & poor cognitions-cluster was associated with low functional abilities and quality of life, and adherence to the Canada 2003 diagnostic criteria for CFS. No other statistically significant cluster associations were discovered.

CONCLUSION

Within a widely defined cohort of adolescent CFS patients, clusters could be delineated, but no distinct subgroups could be identified. Associations between clusters and constitutional factors, subjective symptoms and prognosis were scarce. These results question the clinical usefulness of searching for CFS subgroups, as well as the validity of the most "narrow" CFS diagnostic criteria.

TRIAL REGISTRATION

Clinical Trials NCT01040429.

Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and debilitating disease with no molecular diagnostics and no treatment options. To identify potential markers of this illness, we profiled 48 patients and 52 controls for standard laboratory tests, plasma metabolomics, blood immuno-phenotyping and transcriptomics, and fecal microbiome analysis. Here, we identified a set of 26 potential molecular markers that distinguished ME/CFS patients from healthy controls. Monocyte number, microbiome abundance, and lipoprotein profiles appeared to be the most informative markers. When we correlated these molecular changes to sleep and cognitive measurements of fatigue, we found that lipoprotein and microbiome profiles most closely correlated with sleep disruption while a different set of markers correlated with a cognitive parameter. Sleep, lipoprotein, and microbiome changes occur early during the course of illness suggesting that these markers can be examined in a larger cohort for potential biomarker application. Our study points to a cluster of sleep-related molecular changes as a prominent feature of ME/CFS in our Japanese cohort.

Persistent fatigue following SARS-CoV-2 infection is common and independent of severity of initial infection

Fatigue is a common symptom in those presenting with symptomatic COVID-19 infection. However, it is unknown if COVID-19 results in persistent fatigue in those recovered from acute infection. We examined the prevalence of fatigue in individuals recovered from the acute phase of COVID-19 illness using the Chalder Fatigue Score (CFQ-11). We further examined potential predictors of fatigue following COVID-19 infection, evaluating indicators of COVID-19 severity, markers of peripheral immune activation and circulating pro-inflammatory cytokines. Of 128 participants (49.5 ± 15 years; 54% female), more than half reported persistent fatigue (67/128; 52.3%) at median of 10 weeks after initial COVID-19 symptoms. There was no association between COVID-19 severity (need for inpatient admission, supplemental oxygen or critical care) and fatigue following COVID-19. Additionally, there was no association between routine laboratory markers of inflammation and cell turnover (leukocyte, neutrophil or lymphocyte counts, neutrophil-to-lymphocyte ratio, lactate dehydrogenase, C-reactive protein) or pro-inflammatory molecules (IL-6 or sCD25) and fatigue post COVID-19. Female gender and those with a pre-existing diagnosis of depression/anxiety were over-represented in those with fatigue. Our findings demonstrate a significant burden of post-viral fatigue in individuals with previous SARS-CoV-2 infection after the acute phase of COVID-19 illness. This study highlights the importance of assessing those recovering from COVID-19 for symptoms of severe fatigue, irrespective of severity of initial illness, and may identify a group worthy of further study and early intervention.

The Effect of Fermented Porcine Placental Extract on Fatigue-Related Parameters in Healthy Adults: A Double-Blind, Randomized, Placebo-Controlled Trial

Background: Fatigue is one of the major health conditions induced by excessive stress or abnormal immune function or defective antioxidant systems. Placental extract has been reported to have various effects such as immune modulation and cellular regeneration. Fermented porcine placenta (FPP) is a safe nontoxic material, which is highly valuable as a functional food. The aim of this study was to investigate the anti-fatigue effects of FPP supplementation compared with a placebo product. Methods: In this double-blind, parallel, randomized, and placebo-controlled trial 84 healthy males and females, aged between 30 and 60 years were randomized to 320 mg of FPP once daily or placebo. The main outcome measures included efficacy of fatigue-inducing treadmill exercise on physical fatigue and fatigue-related parameters based on the questionnaire administered. Results: The IL-1β mRNA expression and fatigue severity scale were changed significantly after 8 weeks of treatment with fermented porcine placenta compared with placebo (p < 0.05). Cortisol levels were significantly improved in participants younger than 45 years following treatment with FPP compared with placebo. Furthermore, the lactate and myoglobin levels were improved significantly in participants with BMI ≥ 23 kg/m² (p = 0.045 and p = 0.011, respectively) following treatment with FPP versus placebo. Conclusions: Our study showed that FPP supplementation significantly ameliorated fatigue-related parameters and subjective symptoms in healthy adults. Therefore, our results indicate that FPP supplementation induced anti-fatigue effect by regulating the inflammatory response.

How Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Progresses: The Natural History of ME/CFS

We propose a framework for understanding and interpreting the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) that considers wider determinants of health and long-term temporal variation in pathophysiological features and disease phenotype throughout the natural history of the disease. As in other chronic diseases, ME/CFS evolves through different stages, from asymptomatic predisposition, progressing to a prodromal stage, and then to symptomatic disease. Disease incidence depends on genetic makeup and environment factors, the exposure to singular or repeated insults, and the nature of the host response. In people who develop ME/CFS, normal homeostatic processes in response to adverse insults may be replaced by aberrant responses leading to dysfunctional states. Thus, the predominantly neuro-immune manifestations, underlined by a hyper-metabolic state, that characterize early disease, may be followed by various processes leading to multi-systemic abnormalities and related symptoms. This abnormal state and the effects of a range of mediators such as products of oxidative and nitrosamine stress, may lead to progressive cell and metabolic dysfunction culminating in a hypometabolic state with low energy production. These processes do not seem to happen uniformly; although a spiraling of progressive inter-related and self-sustaining abnormalities may ensue, reversion to states of milder abnormalities is possible if the host is able to restate responses to improve homeostatic equilibrium. With time variation in disease presentation, no single ME/CFS case description, set of diagnostic criteria, or molecular feature is currently representative of all patients at different disease stages. While acknowledging its limitations due to the incomplete research evidence, we suggest the proposed framework may support future research design and health care interventions for people with ME/CFS.