Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study

Abstract:

Chronic fatigue syndrome (CFS) is a disabling condition characterized by unexplained chronic fatigue that impairs normal activities. Although immunological and psychological aspects are present, symptoms related to skeletal muscles, such as muscle soreness, fatigability and increased lactate accumulation, are prominent in CFS patients.

In this case-control study, the phenotype of the same biopsy samples was analyzed by determining i) fibre-type proportion using myosin isoforms as fibre type molecular marker and gel electrophoresis as a tool to separate and quantify myosin isoforms, and ii) contractile properties of manually dissected, chemically made permeable and calcium-activated single muscle fibres.

The results showed that fibre-type proportion was significantly altered in CSF samples, which showed a shift from the slow- to the fast-twitch phenotype. Cross sectional area, force, maximum shortening velocity and calcium sensitivity were not significantly changed in single muscle fibres from CSF samples. Thus, the contractile properties of muscle fibres were preserved but their proportion was changed, with an increase in the more fatigue-prone, energetically expensive fast fibre type.

Taken together, these results support the view that muscle tissue is directly involved in the pathogenesis of CSF and it might contribute to the early onset of fatigue typical of the skeletal muscles of CFS patients.

 

Source: Pietrangelo T, Toniolo L, Paoli A, Fulle S, Puglielli C, Fanò G, Reggiani C. Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study. Int J Immunopathol Pharmacol. 2009 Apr-Jun;22(2):427-36. https://www.ncbi.nlm.nih.gov/pubmed/19505395

 

Gene expression in peripheral blood leukocytes in monozygotic twins discordant for chronic fatigue: no evidence of a biomarker

Abstract:

BACKGROUND: Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes.

METHODS: Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue. Biological sampling conditions were standardized and RNA stabilizing media were used. These methodological features provide rigorous control for bias resulting from case-control mismatched ancestry and experimental error. Individual gene expression profiles were assessed using Affymetrix Human Genome U133 Plus 2.0 arrays.

FINDINGS: There were no significant differences in gene expression for any transcript.

CONCLUSIONS: Contrary to our expectations, we were unable to identify a biomarker for chronic fatiguing illness in the transcriptome of peripheral blood leukocytes suggesting that positive findings in prior studies may have resulted from experimental bias.

 

Source: Byrnes A, Jacks A, Dahlman-Wright K, Evengard B, Wright FA, Pedersen NL, Sullivan PF. Gene expression in peripheral blood leukocytes in monozygotic twins discordant for chronic fatigue: no evidence of a biomarker. PLoS One. 2009 Jun 5;4(6):e5805. doi: 10.1371/journal.pone.0005805. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2688030/ (Full article)

 

Promising outcomes of an adolescent chronic fatigue syndrome inpatient programme

Abstract:

INTRODUCTION: Chronic fatigue syndrome (CFS) is a condition of prolonged and disabling fatigue, which is accompanied by characteristic constitutional and neuropsychiatric symptoms. In children and adolescents, this condition occurring at a developmentally vulnerable time adds to the disability affecting self-concept, autonomy, body image, socialisation, sexuality and academic problems. This case series looks at the effects of a graded exercise programme on physical outcomes, fatigue and mental state in an adolescent population.

METHODS: Data sets from 16 adolescents who completed combined exercise training as part of the 4-week inpatient intensive CFS programme at the Austin Hospital, Melbourne were analysed. All patients completed an exercise assessment and three questionnaires before beginning any training. A paediatrician (LL) confirmed the diagnosis according to the Fukuda criteria in all patients. Exercise was carefully supervised and prescribed daily by an exercise physiologist (BG) according to each individual’s ability and response with the basic aim of increasing exercise tolerance and improving muscle strength and endurance.

RESULTS: There was an 18% improvement in volitional time to fatigue (P= 0.02) and 17% improvement in peak oxygen uptake (VO(2peak)) (P= 0.01). Upper body strength and function improved with a remarkable 70% increase in the number of push-ups. Fatigue severity was reported to improve by 13% (P= 0.01) and depression index improved significantly by 42% (P= 0.02).

CONCLUSIONS: The significance of these improvements cannot be underestimated as an improvement in physical capacity through increased time to fatigue and less severe fatigue allows adolescents to resume school, social and family activities.

Source: Gordon B, Lubitz L. Promising outcomes of an adolescent chronic fatigue syndrome inpatient programme. J Paediatr Child Health. 2009 May;45(5):286-90. doi: 10.1111/j.1440-1754.2009.01493.x. https://www.ncbi.nlm.nih.gov/pubmed/19493121

Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is an illness characterised by pervasive physical and mental fatigue without specific identified pathological changes. Many patients with CFS show reduced physical activity which, though quantifiable, has yielded little information to date. Nonlinear dynamic analysis of physiological data can be used to measure complexity in terms of dissimilarity within timescales and similarity across timescales. A reduction in these objective measures has been associated with disease and ageing. We aimed to test the hypothesis that activity patterns of patients with CFS would show reduced complexity compared to healthy controls.

METHODS: We analysed continuous activity data over 12 days from 42 patients with CFS and 21 matched healthy controls. We estimated complexity in two ways, measuring dissimilarity within timescales by calculating entropy after a symbolic dynamic transformation of the data and similarity across timescales by calculating the fractal dimension using allometric aggregation.

RESULTS: CFS cases showed reduced complexity compared to controls, as evidenced by reduced dissimilarity within timescales (mean (SD) Renyi(3) entropy 4.05 (0.21) vs. 4.30 (0.09), t = -6.6, p < 0.001) and reduced similarity across timescales (fractal dimension 1.19 (0.04) vs. 1.14 (0.04), t = 4.2, p < 0.001). This reduction in complexity persisted after adjustment for total activity.

CONCLUSION: Patients with CFS show evidence of reduced complexity of activity patterns. Measures of complexity applied to activity have potential value as objective indicators for CFS.

 

Source: Burton C, Knoop H, Popovic N, Sharpe M, Bleijenberg G. Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study. Biopsychosoc Med. 2009 Jun 2;3:7. doi: 10.1186/1751-0759-3-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2697171/ (Full article)

 

Modulation of antigen-induced chronic fatigue in mouse model of water immersion stress by naringin, a polyphenolic antioxidant

Abstract:

It is believed that physical stress, infection and oxidative stress are involved in the development of chronic fatigue syndrome. There is little evidence stating the beneficial role of nutritional supplements in chronic fatigue syndrome. Based on this, this study was designed to evaluate the effect of naringin, a natural polyphenol, in a mouse model of immunologically-induced fatigue, wherein purified lipopolysaccharide (LPS) as well as Brucella abortus (BA) antigen was used as immunogens.

The assessment of chronic fatigue syndrome was based on chronic water-immersion stress test for 10 mins as well as measurement of hyperalgesia for 19 days. Immobility time and tail withdrawal latency as well as oxidative stress were taken as the markers of fatigue. Mice challenged with LPS or BA for 19 days showed significant increase in the immobility time, hyperalgesia and oxidative stress on 19th day. Serum tumor necrosis factor-alpha (TNF-alpha) levels markedly increased with LPS or BA challenge.

Concurrent treatment with naringin resulted in the significant decrease in the immobility time as well as hyperalgesia. There was significant attenuation of oxidative stress as well as in TNF-alpha levels. Present findings strongly suggest the role of oxidative stress and immunological activation in the pathophysiology of chronic fatigue syndrome, and treatment with naringin can be a valuable option in chronic fatigue syndrome.

 

Source: Vij G, Gupta A, Chopra K. Modulation of antigen-induced chronic fatigue in mouse model of water immersion stress by naringin, a polyphenolic antioxidant. Fundam Clin Pharmacol. 2009 Jun;23(3):331-7. doi: 10.1111/j.1472-8206.2009.00675.x. Epub 2009 Mar 11. https://www.ncbi.nlm.nih.gov/pubmed/19469804

 

Chronic fatigue syndrome: illness severity, sedentary lifestyle, blood volume and evidence of diminished cardiac function

Abstract:

The study examined whether deficits in cardiac output and blood volume in a CFS (chronic fatigue syndrome) cohort were present and linked to illness severity and sedentary lifestyle. Follow-up analyses assessed whether differences in cardiac output levels between CFS and control groups were corrected by controlling for cardiac contractility and TBV (total blood volume).

The 146 participants were subdivided into two CFS groups based on symptom severity data, severe (n=30) and non-severe (n=26), and two healthy non-CFS control groups based on physical activity, sedentary (n=58) and non-sedentary (n=32). Controls were matched to CFS participants using age, gender, ethnicity and body mass. Echocardiographic measures indicated that the severe CFS participants had 10.2% lower cardiac volume (i.e. stroke index and end-diastolic volume) and 25.1% lower contractility (velocity of circumferential shortening corrected by heart rate) than the control groups. Dual tag blood volume assessments indicated that the CFS groups had lower TBV, PV (plasma volume) and RBCV (red blood cell volume) than control groups. Of the CFS subjects with a TBV deficit (i.e. > or = 8% below ideal levels), the mean+/-S.D. percentage deficit in TBV, PV and RBCV were -15.4+/-4.0, -13.2+/-5.0 and -19.1+/-6.3% respectively. Lower cardiac volume levels in CFS were substantially corrected by controlling for prevailing TBV deficits, but were not affected by controlling for cardiac contractility levels.

Analyses indicated that the TBV deficit explained 91-94% of the group differences in cardiac volume indices. Group differences in cardiac structure were offsetting and, hence, no differences emerged for left ventricular mass index. Therefore the findings indicate that lower cardiac volume levels, displayed primarily by subjects with severe CFS, were not linked to diminished cardiac contractility levels, but were probably a consequence of a co-morbid hypovolaemic condition. Further study is needed to address the extent to which the cardiac and blood volume alterations in CFS have physiological and clinical significance.

Comment in: Chronic fatigue syndrome: comments on deconditioning, blood volume and resulting cardiac function. [Clin Sci (Lond). 2009]

 

Source: Hurwitz BE, Coryell VT, Parker M, Martin P, Laperriere A, Klimas NG, Sfakianakis GN, Bilsker MS. Chronic fatigue syndrome: illness severity, sedentary lifestyle, blood volume and evidence of diminished cardiac function. Clin Sci (Lond). 2009 Oct 19;118(2):125-35. doi: 10.1042/CS20090055. https://www.ncbi.nlm.nih.gov/pubmed/19469714

 

Chronic fatigue syndrome combines increased exercise-induced oxidative stress and reduced cytokine and Hsp responses

Abstract:

OBJECTIVES: As heat shock proteins (Hsp) protect the cells against the deleterious effects of oxidative stress, we hypothesized that Hsp expression might be reduced in patients suffering from chronic fatigue syndrome (CFS) who present an accentuated exercise-induced oxidative stress.

DESIGN: This case-control study compared nine CFS patients to a gender-, age- and weight-matched control group of nine healthy sedentary subjects.

INTERVENTIONS: All subjects performed an incremental cycling exercise continued until exhaustion. We measured ventilation and respiratory gas exchange and evoked compound muscle potential (M-wave) recorded from vastus lateralis. Repetitive venous blood sampling allowed measurements of two markers of oxidative stress [thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA)], two cytokines (IL-6 and TNF-alpha) and two Hsp (Hsp27 and Hsp70) at rest, during maximal exercise and the 60-min recovery period.

RESULTS: Compared with controls, resting CFS patients had low baseline levels of RAA and Hsp70. Their response to maximal exercise associated (i) M-wave alterations indicating reduced muscle membrane excitability, (ii) early and accentuated TBARS increase accompanying reduced changes in RAA level, (iii) absence of significant increase in IL-6 and TNF-alpha, and (iv) delayed and marked reduction of Hsp27 and Hsp70 variations. The post-exercise increase in TBARS was accentuated in individuals having the lowest variations of Hsp27 and Hsp70.

CONCLUSIONS: The response of CFS patients to incremental exercise associates a lengthened and accentuated oxidative stress, which might result from delayed and insufficient Hsp production.

 

Source: Jammes Y, Steinberg JG, Delliaux S, Brégeon F.Chronic fatigue syndrome combines increased exercise-induced oxidative stress and reduced cytokine and Hsp responses. J Intern Med. 2009 Aug;266(2):196-206. doi: 10.1111/j.1365-2796.2009.02079.x. Epub 2009 May 19. https://www.ncbi.nlm.nih.gov/pubmed/19457057

 

Anxiety in children with CFS/ME

Abstract:

Anxiety symptoms are commonly described in children with chronic fatigue syndrome or myalgic encephalopathy (CFS/ME) but to date there has been little information on the type of anxiety children experience or the relationship between anxiety and school attendance, disability or fatigue.

The aim of this study was to first describe the prevalence and type of anxiety symptoms in children with CFS/ME compared with a normal European population, and secondly to investigate the association of anxiety symptoms with age, gender, school attendance, fatigue, and physical function in paediatric CFS/ME.

Data were prospectively collected on children and young people with CFS/ME referred to a large specialist CFS/ME service. One hundred and sixty-four children with CFS/ME had complete data for the Spence Children’s Anxiety Scale. Teenage girls had the highest rates of total anxiety symptoms with 38% (95% CI 27-49) over the cut off (top 10% of normal European population) and significantly higher rates of symptoms in each subscale.

Younger girls were more likely to score over the cut off in separation anxiety (37%, 19-40) and social phobia (39%, 25-47). There was no evidence of association between total anxiety symptoms and: time at school, time to assessment, pain or age. Associations with fatigue and physical function were attenuated when adjusted for other variables. Although anxiety symptoms are high in CFS/ME, particularly in teenage girls, it does not appear to be associated with school attendance or other measures of disability. Separation anxiety and social phobia were the most clearly elevated in paediatric CFS/ME.

 

Source: Crawley E, Hunt L, Stallard P. Anxiety in children with CFS/ME. Eur Child Adolesc Psychiatry. 2009 Nov;18(11):683-9. doi: 10.1007/s00787-009-0029-4. Epub 2009 May 19. https://www.ncbi.nlm.nih.gov/pubmed/19452195

 

An investigation into the cognitive deficits associated with chronic fatigue syndrome

Abstract:

This study addresses, among other things, the debate as to whether cognitive deficits do occur with a diagnosis of Chronic Fatigue Syndrome (CFS). Previous studies have indicated a potential mismatch between subjective patient ratings of impairment and clinical assessment.

In an attempt to tackle some of the methodological problems faced by previous research in this field, this study recruited a large sample of CFS patients where adequate diagnosis had been made and administered an extensive battery of measures. In doing so this study was able to replicate previous published evidence of clear cognitive impairment in this group and demonstrate also that these deficits occurred independent of psychopathology.

The conclusion drawn is that cognitive impairments can be identified if appropriate measures are used. Furthermore, the authors have shown that performance changes in these measures have been used to assess both efficacy of a treatment regime and rates of recovery.

 

Source: Thomas M, Smith A. An investigation into the cognitive deficits associated with chronic fatigue syndrome. Open Neurol J. 2009 Feb 27;3:13-23. doi: 10.2174/1874205X00903010013. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2682840/ (Full article)

 

A comparison of patients with chronic fatigue syndrome in two “ideologically” contrasting clinics

Abstract:

Aim of the present study was to compare chronic fatigue syndrome (CFS) patients, attending 2 “ideologically” contrasting clinics for CFS, on various patient and illness characteristics. Fifty-nine CFS patients of each clinic, located in Leuven and Brussels (Belgium), participated. Patients did not differ with regard to age, levels of fatigue, psychopathology, and self-efficacy. However, patients from the psychosocially-oriented clinic had a lower level of education, reported more progressive illness onset, and attributed their illness more to psychological causes.

Patients in the biologically-oriented clinic reported more pain, and showed higher levels of social functioning, motivation and vitality, as well as fewer limitations related to emotional problems. It is concluded that CFS patients attending the 2 clinics could not be distinguished along dualistic biological/psychosocial lines, but those reporting sudden illness onset and making somatic attributions were more likely to be represented in the biologically-oriented clinic.

 

Source: Van Houdenhove B, Van Hoof E, Becq K, Kempke S, Luyten P, De Meirleir K.A comparison of patients with chronic fatigue syndrome in two “ideologically” contrasting clinics. J Nerv Ment Dis. 2009 May;197(5):348-53. doi: 10.1097/NMD.0b013e3181a2081f. https://www.ncbi.nlm.nih.gov/pubmed/19440108