Cellular bioenergetics is impaired in patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a highly debilitating disease of unknown aetiology. Abnormalities in bioenergetic function have been cited as one possible cause for CFS. Preliminary studies were performed to investigate cellular bioenergetic abnormalities in CFS patients.

A series of assays were conducted using peripheral blood mononuclear cells (PBMCs) from CFS patients and healthy controls. These experiments investigated cellular patterns in oxidative phosphorylation (OXPHOS) and glycolysis. Results showed consistently lower measures of OXPHOS parameters in PBMCs taken from CFS patients compared with healthy controls. Seven key parameters of OXPHOS were calculated: basal respiration, ATP production, proton leak, maximal respiration, reserve capacity, non-mitochondrial respiration, and coupling efficiency.

While many of the parameters differed between the CFS and control cohorts, maximal respiration was determined to be the key parameter in mitochondrial function to differ between CFS and control PBMCs due to the consistency of its impairment in CFS patients found throughout the study (p≤0.003). The lower maximal respiration in CFS PBMCs suggests that when the cells experience physiological stress they are less able to elevate their respiration rate to compensate for the increase in stress and are unable to fulfil cellular energy demands. The metabolic differences discovered highlight the inability of CFS patient PBMCs to fulfil cellular energetic demands both under basal conditions and when mitochondria are stressed during periods of high metabolic demand.

Source: Cara Tomas, Audrey Brown, Victoria Strassheim, Joanna Elson, Julia Newton, Philip Manning. Cellular bioenergetics is impaired in patients with chronic fatigue syndrome. PLoS One. 2017 Oct 24;12(10):e0186802. doi: 10.1371/journal.pone.0186802. eCollection 2017. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186802 (Full article)

Are current chronic fatigue syndrome criteria diagnosing different disease phenotypes?

Abstract:

Importance: Chronic fatigue syndrome (CFS) is characterised by a constellation of symptoms diagnosed with a number of different polythetic criteria. Heterogeneity across these diagnostic criteria is likely to be confounding research into the as-yet-unknown pathophysiology underlying this stigmatised and debilitating condition and may diagnose a disease spectrum with significant implications for clinical management. No studies to date have objectively investigated this possibility using a validated measure of CFS symptoms–the DePaul Symptom Questionnaire (DSQ).

Objective: To examine whether current CFS diagnostic criteria are identifying different disease phenotypes using the DSQ.

Design: Case control study.

Setting: Clinical Research Facility of the Royal Victoria Infirmary, Newcastle upon Tyne, UK.

Participants: 49 CFS subjects and ten matched, sedentary community controls, excluded for co-morbid depression.

Main outcomes and measures: Self-reported autonomic and cognitive features were assessed with the Composite Autonomic Symptom Score (COMPASS) and Cognitive Failures Questionnaire (COGFAIL) respectively. Objective autonomic cardiovascular parameters were examined using the Task Force® Monitor and a battery of neuropsychological tests administered for objective cognitive assessment.

Results: Self-reported autonomic and cognitive symptoms were significantly greater in CFS subjects compared to controls. There were no statistically significant differences in objective autonomic measures between CFS and controls. There were clinically significant differences between DSQ subgroups on objective autonomic testing. Visuospatial memory, verbal memory and psychomotor speed were significantly different between DSQ subgroups.

Conclusions and relevance: The finding of no significant differences in objective autonomic testing between CFS and control subjects may reflect the inclusion of sedentary controls or exclusion for co-morbid depression. Consistent exclusion criteria would enable better delineation of these two conditions and their presenting symptoms. Findings across CFS subgroups suggest subjects have a different disease burden on subjective and objective measures of function, autonomic parameters and cognitive impairment when categorised using the DSQ. Different CFS criteria may at best be diagnosing a spectrum of disease severities and at worst different CFS phenotypes or even different diseases. This complicates research and disease management and may contribute to the significant stigma associated with the condition.

Source: Laura Maclachlan, Stuart Watson, Peter Gallagher, Andreas Finkelmeyer, Leonard A. Jason, Madison Sunnquist, Julia L. Newton. Are current chronic fatigue syndrome criteria diagnosing different disease phenotypes? PLoS ONE. Published: October 20, 2017https://doi.org/10.1371/journal.pone.0186885   http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186885 (Full article)

Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study

Abstract:

OBJECTIVE: Investigate global and regional grey and white matter volumes in patients with Chronic Fatigue Syndrome (CFS) using magnetic resonance imaging (MRI) and recent voxel-based morphometry (VBM) methods.

METHODS: Forty-two patients with CFS and thirty healthy volunteers were scanned on a 3-Tesla MRI scanner. Anatomical MRI scans were segmented, normalized and submitted to a VBM analysis using randomisation methods. Group differences were identified in overall segment volumes and voxel-wise in spatially normalized grey matter (GM) and white matter (WM) segments.

RESULTS: Accounting for total intracranial volume, patients had larger GM volume and lower WM volume. The voxel-wise analysis showed increased GM volume in several structures including the amygdala and insula in the patient group. Reductions in WM volume in the patient group were seen primarily in the midbrain, pons and right temporal lobe.

CONCLUSION: Elevated GM volume in CFS is seen in areas related to processing of interoceptive signals and stress. Reduced WM volume in the patient group partially supports earlier findings of WM abnormalities in regions of the midbrain and brainstem.

Source: Finkelmeyer A, He J, Maclachlan L, Watson S, Gallagher P, Newton JL, Blamire AM. Grey and white matter differences in Chronic Fatigue Syndrome – A voxel-based morphometry study. Neuroimage Clin. 2017 Sep 28;17:24-30. doi: 10.1016/j.nicl.2017.09.024. ECollection 2018. https://www.ncbi.nlm.nih.gov/pubmed/29021956

Clinical criteria versus a possible research case definition in chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

Background: The Institute of Medicine (IOM) recently developed clinical criteria for what had been known as chronic fatigue syndrome. Given the broad nature of the clinical IOM criteria, there is a need for a research definition that would select a more homogenous and impaired group of patients than the IOM clinical criteria. At the present time, it is unclear what will serve as the research definition.

Purpose: The current study focused on a research definition which selected homebound individuals who met the four IOM criteria, excluding medical and psychiatric co-morbidities.

Methods: Our research criteria were compared to those participants meeting the IOM criteria. Those not meeting either of these criteria sets were placed in a separate group defined by six or more months of fatigue. Data analyzed were from the DePaul Symptom Questionnaire and the 36-item Short-Form Health Survey (SF-36). Due to unequal sample sizes and variances, Welch’s F tests and Games-Howell post-hoc tests were conducted.

Results: Using a large database of over 1000 patients from several countries, we found that those meeting a more restrictive research definition were even more impaired and more symptomatic than those meeting criteria for the other two groups.

Conclusion: Deciding on a particular research case definition would allow researchers to select more comparable patient samples across settings, and this would represent one of the most significant methodologic advances for this field of study.

 

Source: Leonard A. Jason, Stephanie McManimen, Madison Sunnquist, Julia L. Newton & Elin Bolle Strand. Clinical criteria versus a possible research case definition in chronic fatigue syndrome/myalgic encephalomyelitis. Fatigue: Biomedicine, Health & Behavior. Published online: 06 Mar 2017

 

Assessing current functioning as a measure of significant reduction in activity level

Abstract:

BACKGROUND: Myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) have case definitions with varying criteria, but almost all criteria require an individual to have a substantial reduction in activity level. Unfortunately, a consensus has not been reached regarding what constitutes substantial reductions. One measure that has been used to measure substantial reduction is the Medical Outcomes Study Short Form-36 Health Survey (SF-36).[1].

PURPOSE: The current study examined the relationship between the SF-36, a measure of current functioning, and a self-report measure of the percent reduction in hours spent on activities.

RESULTS: Findings indicated that select subscales of the SF-36 accurately measure significant reductions in functioning. Further, this measure significantly differentiates patients from controls.

CONCLUSION: Determining what constitutes a significant reduction in activity is difficult because it is subjective to the individual. However, certain subscales of the SF-36 could provide a uniform way to accurately measure and define substantial reductions in functioning.

 

Source: Thorpe T, McManimen S, Gleason K, Stoothoff J, Newton JL, Strand EB, Jason LA. Assessing current functioning as a measure of significant reduction in activity level. Fatigue. 2016;4(3):175-188. doi: 10.1080/21641846.2016.1206176. Epub 2016 Jul 19. https://www.ncbi.nlm.nih.gov/pubmed/28217427

 

Reduced cardiac volumes in chronic fatigue syndrome associate with plasma volume but not length of disease: a cohort study

Abstract:

OBJECTIVES: To explore potential mechanisms that underpin the cardiac abnormalities seen in chronic fatigue syndrome (CFS) using non-invasive cardiac impedance, red cell mass and plasma volume measurements.

METHODS: Cardiac MR (MR) examinations were performed using 3 T Philips Intera Achieva scanner (Best, NL) in participants with CFS (Fukuda; n=47) and matched case-by-case controls. Total volume (TV), red cell volume (RCV) and plasma volume (PV) measurements were performed (41 CFS and 10 controls) using the indicator dilution technique using simultaneous 51-chromium labelling of red blood cells and 125-iodine labelling of serum albumin.

RESULTS: The CFS group length of history (mean±SD) was 14±10 years. Patients with CFS had significantly reduced end-systolic and end-diastolic volumes together with reduced end-diastolic wall masses (all p<0.0001). Mean±SD RCV was 1565±443 mL with 26/41 (63%) having values below 95% of expected. PV was 2659±529 mL with 13/41 (32%) <95% expected. There were strong positive correlations between TV, RCV and PV and cardiac end-diastolic wall mass (all p<0.0001; r(2)=0.5). Increasing fatigue severity correlated negatively with lower PV (p=0.04; r(2)=0.2). There were no relationships between any MR or volume measurements and length of history, suggesting that deconditioning was unlikely to be the cause of these abnormalities.

CONCLUSIONS: This study confirms an association between reduced cardiac volumes and blood volume in CFS. Lack of relationship between length of disease, cardiac and plasma volumes suggests findings are not secondary to deconditioning. The relationship between plasma volume and severity of fatigue symptoms suggests a potential therapeutic target in CFS.

 

Source: Newton JL, Finkelmeyer A, Petrides G, Frith J, Hodgson T, Maclachlan L, MacGowan G, Blamire AM. Reduced cardiac volumes in chronic fatigue syndrome associate with plasma volume but not length of disease: a cohort study. Open Heart. 2016 Jun 24;3(1):e000381. doi: 10.1136/openhrt-2015-000381. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932290/ (Full article)

 

Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome

Abstract:

OBJECTIVES: The objective of this study was to examine individuals with myalgic encephalomyelitis and chronic fatigue syndrome who are confined to their homes due to severe symptomatology. The existing literature fails to address differences between this group, and less severe, nonhousebound patient populations.

METHODS: Participants completed the DePaul Symptom Questionnaire, a measure of myalgic encephalomyelitis and chronic fatigue syndrome symptomology, and the SF-36, a measure of health impact on physical/mental functioning. ANOVAs and, where appropriate, MANCOVAS were used to compare housebound and nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome across areas of functioning, symptomatology, and illness onset characteristics.

RESULTS: Findings indicated that the housebound group represented one quarter of the sample, and were significantly more impaired with regards to physical functioning, bodily pain, vitality, social functioning, fatigue, postexertional malaise, sleep, pain, neurocognitive, autonomic, neuroendocrine, and immune functioning compared to individuals who were not housebound.

DISCUSSION: Findings indicated that housebound patients have more impairment on functional and symptom outcomes compared to those who were not housebound. Understanding the differences between housebound and not housebound groups holds implications for physicians and researchers as they develop interventions intended for patients who are most severely affected by this chronic illness.

© The Author(s) 2016.

 

Source: Pendergrast T, Brown A, Sunnquist M, Jantke R, Newton JL, Strand EB, Jason LA. Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome. Chronic Illn. 2016 Dec;12(4):292-307. Epub 2016 Apr 28. https://www.ncbi.nlm.nih.gov/pubmed/27127189

 

The Relationship between Age and Illness Duration in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating illness, but it is unclear if patient age and illness duration might affect symptoms and functioning of patients.

In the current study, participants were categorized into four groups based upon age (under or over age 55) and illness duration (more or less than 10 years). The groups were compared on functioning and symptoms.

Findings indicated that those who were older with a longer illness duration had significantly higher levels of mental health functioning than those who were younger with a shorter or longer illness duration and the older group with a shorter illness duration. The results suggest that older patients with an illness duration of over 10 years have significantly higher levels of mental health functioning than the three other groups.

For symptoms, the younger/longer illness duration group had significantly worse immune and autonomic domains than the older/longer illness group. In addition, the younger patients with a longer illness duration displayed greater autonomic and immune symptoms in comparison to the older group with a longer illness duration.

These findings suggest that both age and illness duration need to be considered when trying to understand the influence of these factors on patients.

 

Source: Kidd E, Brown A, McManimen S, Jason LA, Newton JL, Strand EB. The Relationship between Age and Illness Duration in Chronic Fatigue Syndrome. Diagnostics (Basel). 2016 Apr 22;6(2). pii: E16. doi: 10.3390/diagnostics6020016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931411/ (Full article)

 

Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains

Abstract:

The present study attempted to identify critical symptom domains of individuals with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Using patient and control samples collected in the United States, Great Britain, and Norway, exploratory factor analysis (EFA) was used to establish the underlying factor structure of ME and CFS symptoms.

The EFA suggested a four-factor solution: post-exertional malaise, cognitive dysfunction, sleep difficulties, and a combined factor consisting of neuroendocrine, autonomic, and immune dysfunction symptoms. The use of empirical methods could help better understand the fundamental symptom domains of this illness.

 

Source: Jason LA, Sunnquist M, Brown A, Furst J, Cid M, Farietta J, Kot B, Bloomer C, Nicholson L, Williams Y, Jantke R, Newton JL, Strand EB. Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains. J Neurol Neurobiol. 2015 Sep;1(4). doi: 10.16966/2379-7150.114. Epub 2015 Sep 17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4830389/ (Full article)