Tag: stress

Plasma neuropeptide Y: a biomarker for symptom severity in chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a complex, multi-symptom illness with a multisystem pathogenesis involving alterations in the nervous, endocrine and immune systems.Abnormalities in stress responses have been identified as potential triggers or mediators of CFS symptoms. This study focused on the stress mediator neuropeptide Y (NPY). We hypothesized that NPY would be a useful biomarker for CFS.

METHODS: The CFS patients (n = 93) were from the Chronic Fatigue and Related Disorders Clinic at the University of Miami and met the 1994 case definition of Fukuda and colleagues. Healthy sedentary controls (n = 100)) were from NIH or VA funded studies. Another fatiguing, multi-symptom illness, Gulf War Illness (GWI), was also compared to CFS. We measured NPY in plasma using a radioimmunoassay (RIA). Psychometric measures, available for a subset of CFS patients included: Perceived Stress Scale, Profile of Mood States, ATQ Positive & Negative Self-Talk Scores, the COPE, the Beck Depression Inventory, Fatigue Symptom Inventory, Cognitive Capacity Screening Examination, Medical Outcomes Survey Short Form-36, and the Quality of Life Scale.

RESULTS: Plasma NPY was elevated in CFS subjects, compared to controls (p = .000) and to GWI cases (p = .000). Receiver operating characteristics (ROC) curve analyses indicated that the predictive ability of plasma NPY to distinguish CFS patients from healthy controls and from GWI was significantly better than chance alone. In 42 patients with CFS, plasma NPY had significant correlations (<0.05) with perceived stress, depression, anger/hostility, confusion, negative thoughts, positive thoughts, general health, and cognitive status. In each case the correlation (+ or -) was in the anticipated direction.

CONCLUSIONS: This study is the first in the CFS literature to report that plasma NPY is elevated compared to healthy controls and to a fatigued comparison group, GWI patients. The significant correlations of NPY with stress, negative mood, general health, depression and cognitive function strongly suggest that this peptide be considered as a biomarker to distinguish subsets of CFS.

 

Source: Fletcher MA, Rosenthal M, Antoni M, Ironson G, Zeng XR, Barnes Z, Harvey JM, Hurwitz B, Levis S, Broderick G, Klimas NG. Plasma neuropeptide Y: a biomarker for symptom severity in chronic fatigue syndrome. Behav Brain Funct. 2010 Dec 29;6:76. doi: 10.1186/1744-9081-6-76. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024290/ (Full article)

 

No differences in cardiovascular autonomic responses to mental stress in chronic fatigue syndrome adolescents as compared to healthy controls

Abstract:

Chronic fatigue syndrome (CFS) is a disabling disease with unknown etiology. There is accumulating evidence of altered cardiovascular autonomic responses to different somatic stressors, in particular orthostatic stress, whereas autonomic responses to mental stress remain to be investigated. In this study, we explored cardiovascular autonomic responses to a simple mental stress test in CFS patients and healthy controls.

A consecutive sample of 13 patients with CFS, aged 12 to 18 years, and a volunteer sample of 53 healthy control subjects of equal age and gender distribution were included. Blood pressure, heart rate and acral skin blood flow were continuously recorded during an arithmetic exercise.

At baseline, heart rate was significantly higher among CFS patients than controls (p = 0.02). During the arithmetic exercise, however, there were no significant differences in the responses between the two groups.

In conclusion, CFS patients have unaltered autonomic responses to simple mental stress as compared to healthy control subjects.

 

Source: Egge C, Wyller VB. No differences in cardiovascular autonomic responses to mental stress in chronic fatigue syndrome adolescents as compared to healthy controls. Biopsychosoc Med. 2010 Dec 14;4:22. doi: 10.1186/1751-0759-4-22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3012010/ (Full article)

 

The increase of alpha-melanocyte-stimulating hormone in the plasma of chronic fatigue syndrome patients

Abstract:

BACKGROUND: Despite extensive research, no reliable biological marker for chronic fatigue syndrome (CFS) has yet been identified. However, hyperactivation of melanotrophs in the pituitary gland and increased levels of plasma alpha-melanocyte-stimulating hormone (alpha-MSH) have recently been detected in an animal model of chronic stress. Because CFS is considered to be caused partly by chronic stress events, increased alpha-MSH plasma levels may also occur in CFS patients. We therefore examined alpha-MSH levels in CFS patients.

METHODS: Fifty-five CFS patients, who were previously diagnosed within 10 years of with the disease, were enrolled in this study. Thirty healthy volunteers were studied as controls. Fasting bloods samples were collected in the morning and evaluated for their plasma levels of alpha-MSH, adrenocorticotropic hormone (ACTH), serum cortisol and dehydroepiandrosterone sulfate (DHEA-S). Mean levels of alpha-MSH were compared between the CFS and control groups using Welch’s t test.

RESULTS: The mean plasma alpha-MSH concentration in the CFS group (17.9 +/- 1.0 pg/mL) was significantly higher than that in healthy controls (14.5 +/- 1.0 pg/mL, p = 0.02). However, there was a wide range of values in the CFS group. The factors correlated with the plasma alpha-MSH values were analyzed using Spearman’s rank correlation. A negative correlation was found between the duration of the CFS and the plasma alpha-MSH values (p = 0.04, rs = -0.28), but no correlations with ACTH, cortisol or DHEA-S levels were identified (p = 0.55, 0.26, 0.33, respectively). The CFS patients were divided into two groups: patients diagnosed for <or= 5 years’ duration, and those diagnosed for 5-10 years’ duration. They were compared with the healthy controls using one-way ANOVA and Tukey-Kramer multiple comparison tests. The mean alpha-MSH concentration in the <or= 5 years group was 20.8 +/- 1.2 pg/mL, which was significantly higher than that in the healthy controls (p < 0.01). There was no significant difference between the 5-10 year group (15.6 +/- 1.4 pg/mL) and the healthy controls.

CONCLUSIONS:CFS patients with a disease duration of <or= 5 years had significantly higher levels of alpha-MSH in their peripheral blood. alpha-MSH could be a potent biological marker for the diagnosis of CFS, at least during the first 5 years after onset of the disease.

 

Source: Shishioh-Ikejima N, Ogawa T, Yamaguti K, Watanabe Y, Kuratsune H, Kiyama H. The increase of alpha-melanocyte-stimulating hormone in the plasma of chronic fatigue syndrome patients. BMC Neurol. 2010 Aug 23;10:73. doi: 10.1186/1471-2377-10-73. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933583/ (Full article)

 

Neuroendocrine and immune contributors to fatigue

Abstract:

Central fatigue, a persistent and subjective sense of tiredness, generally correlates poorly with traditional markers of disease. It is frequently associated with psychosocial factors, such as depression, sleep disorder, anxiety, and coping style, which suggest that dysregulation of the body’s stress systems may serve as an underlying mechanism in the maintenance of chronic fatigue (CF).

This article addresses the endocrine, neural, and immune factors that contribute to fatigue and describes research regarding the role of these factors in chronic fatigue syndrome as a model for addressing the biology of CF. In general, hypoactivity of the hypothalamic-pituitary-adrenal axis, autonomic nervous system alterations characterized by sympathetic overactivity and low vagal tone, as well as immune abnormalities, may contribute to the expression of CF. Noninvasive methods for evaluating endocrine, neural, and immune function are also discussed.

Simultaneous evaluation of neuroendocrine and immune systems with noninvasive techniques will help elucidate the underlying interactions of these systems, their role in disease susceptibility, and progression of stress-related disorders.

Copyright (c) 2010 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

 

Source: Silverman MN, Heim CM, Nater UM, Marques AH, Sternberg EM. Neuroendocrine and immune contributors to fatigue. PM R. 2010 May;2(5):338-46. doi: 10.1016/j.pmrj.2010.04.008. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2933136/ (Full article)

 

Assessment of Cellular Bioenergetics in Chronic Fatigue Syndrome

Introduction: Abnormalities in bioenergetic function have been cited as one possible cause for chronic fatigue syndrome (CFS). One hypothesis to explain this suggests that CFS may be caused, at least in part, by an acquired mitochondrial dysfunction.

Extracellular flux analysers make real-time, in vitro assessment of cellular energy pathways possible. Using this technology, mitochondrial function can be measured in a variety of cell types in real-time thus increasing our understanding of the role of metabolism in CFS.

Objectives: This project aims to utilise extracellular flux detection technology in order to investigate the cellular bioenergetics of different cell types obtained from CFS patients and healthy controls.

Methods: Mitochondrial stress tests were conducted using skeletal muscle cells and peripheral blood mononuclear cells (PBMCs) derived from CFS patients and controls. During this test mitochondrial complexes are inhibited in turn to modulate respiration so mitochondrial function can be evaluated. The oxygen consumption rate of cells is measured which allows keys parameters of mitochondrial function to be measured and calculated in a single experiment, providing an overall assessment of mitochondrial function. Parameters measured are: basal respiration, maximal respiration and non-mitochondrial respiration. Proton leak, ATP-production and spare respiratory capacity are subsequently able to be calculated using the three measured parameters. CFS patients whose samples were used in these studies were diagnosed using the Fukuda definition.

Results: Results using skeletal muscle cells obtained from CFS patients (n=3) and controls (n=5), indicate that there is no difference in the energy profiles of the skeletal muscle cells of CFS patients in any of the parameters investigated.

Mitochondrial stress test results using PBMCs show CFS PBMCs (n=7) to be significantly lower than control cells (n=10) in all parameters investigated (p≤0.016). Importantly, these results suggest that CFS PBMCs perform closer to their maximum under normal conditions. This means that when CFS PBMCs come under stress they are less able to increase their respiration rate to compensate for the increase in stress.

Conclusions: These findings provide an interesting starting point for investigations into cellular bioenergetics in CFS.

Cara Jasmine Tomas; First year medical science PhD student; Institute of Cellular Medicine, Level 1, William Leech Building, Medical School, Newcastle University, Newcastle Upon-Tyne, NE2 4HH, England; c.j.tomas@ncl.ac.uk
This work was funded by the Medical Research Council and Newcastle University.

 

Source: Cara Tomas, Julia Newton, Audrey Brown, Gina Rutherford, Philip Manning
Newcastle University, UK. Assessment of Cellular Bioenergetics in Chronic Fatigue Syndrome. Poster presentation, IACFS/ME 2016 conference.

Chronic fatigue syndrome and high allostatic load: results from a population-based case-control study in Georgia

Abstract:

OBJECTIVE: To confirm the association of chronic fatigue syndrome (CFS) with high allostatic load (AL) level, examine the association of subsyndromal CFS with AL level, and investigate the effect of depression on these relationships and the association of AL with functional impairment, fatigue, symptom severity, fatigue duration, and type of CFS onset. AL represents the cumulative physiologic effect of demands to adapt to stress.

METHODS: Population-based case-control study of 83 persons with CFS, 202 persons with insufficient symptoms or fatigue for CFS (ISF), and 109 well controls living in Georgia. Unconditional logistic regression was used to generate odds ratios (ORs) as measures of the association of AL with CFS.

RESULTS: Relative to well controls, each 1-point increase in allostatic load index (ALI) was associated with a 26% increase in likelihood of having CFS (OR(adjusted) = 1.26, 95% Confidence Interval (CI) = 1.00, 1.59). This association remained in the presence and absence of depression (OR(adjusted) = 1.35, CI = 1.07, 1.72; OR(adjusted) = 1.35, CI = 1.10, 1.65). Compared with the ISF group, each 1-point increase in ALI was associated with a 10% increase in likelihood of having CFS (OR(adjusted) = 1.10, CI = 0.93, 1.31). Among persons with CFS, the duration of fatigue was inversely correlated with ALI (r = -.26, p = .047).

CONCLUSIONS: Compared with well controls, persons with CFS were significantly more likely to have a high AL. AL increased in a gradient across well, ISF, and CFS groups.

 

Source: Maloney EM, Boneva R, Nater UM, Reeves WC. Chronic fatigue syndrome and high allostatic load: results from a population-based case-control study in Georgia. Psychosom Med. 2009 Jun;71(5):549-56. doi: 10.1097/PSY.0b013e3181a4fea8. Epub 2009 May 4. https://www.ncbi.nlm.nih.gov/pubmed/19414615 (Full article)

 

Does hypothalamic-pituitary-adrenal axis hypofunction in chronic fatigue syndrome reflect a ‘crash’ in the stress system?

Abstract:

The etiopathogenesis of chronic fatigue syndrome (CFS) remains poorly understood. Although neuroendocrine disturbances – and hypothalamic-pituitary-adrenal (HPA) axis hypofunction in particular – have been found in a large proportion of CFS patients, it is not clear whether these disturbances are cause or consequence of the illness.

After a review of the available evidence we hypothesize that that HPA axis hypofunction in CFS, conceptualized within a system-biological perspective, primarily reflects a fundamental and persistent dysregulation of the neurobiological stress system. As a result, a disturbed balance between glucocorticoid and inflammatory signaling pathways may give rise to a pathological cytokine-induced sickness response that may be the final common pathway underlying central CFS symptoms, i.e. effort/stress intolerance and pain hypersensitivity.

This comprehensive hypothesis on HPA axis hypofunction in CFS may stimulate diagnostic refinement of the illness, inform treatment approaches and suggest directions for future research, particularly focusing on the neuroendocrine-immune interface and possible links between CFS, early and recent life stress, and depression.

 

Source: Van Houdenhove B, Van Den Eede F, Luyten P. Does hypothalamic-pituitary-adrenal axis hypofunction in chronic fatigue syndrome reflect a ‘crash’ in the stress system? Med Hypotheses. 2009 Jun;72(6):701-5. doi: 10.1016/j.mehy.2008.11.044. Epub 2009 Feb 23. https://www.ncbi.nlm.nih.gov/pubmed/19237251

 

Can sustained arousal explain the Chronic Fatigue Syndrome?

Abstract:

We present an integrative model of disease mechanisms in the Chronic Fatigue Syndrome (CFS), unifying empirical findings from different research traditions. Based upon the Cognitive activation theory of stress (CATS), we argue that new data on cardiovascular and thermoregulatory regulation indicate a state of permanent arousal responses – sustained arousal – in this condition.

We suggest that sustained arousal can originate from different precipitating factors (infections, psychosocial challenges) interacting with predisposing factors (genetic traits, personality) and learned expectancies (classical and operant conditioning).

Furthermore, sustained arousal may explain documented alterations by establishing vicious circles within immunology (Th2 (humoral) vs Th1 (cellular) predominance), endocrinology (attenuated HPA axis), skeletal muscle function (attenuated cortical activation, increased oxidative stress) and cognition (impaired memory and information processing). Finally, we propose a causal link between sustained arousal and the experience of fatigue.

The model of sustained arousal embraces all main findings concerning CFS disease mechanisms within one theoretical framework.

 

Source: Wyller VB, Eriksen HR, Malterud K. Can sustained arousal explain the Chronic Fatigue Syndrome? Behav Brain Funct. 2009 Feb 23;5:10. doi: 10.1186/1744-9081-5-10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654901/ (Full article)

 

Hyperventilation in patients with chronic fatigue syndrome: the role of coping strategies

Abstract:

Hyperventilation has been suggested as a concomitant and possible maintaining factor that may contribute to the symptom pattern of chronic fatigue syndrome (CFS). Because patients accepting the illness and trying to live with it seem to have a better prognosis than patients chronically fighting it, we investigated breathing behavior during different coping response sets towards the illness in patients with CFS (N=30, CDC criteria).

Patients imagined a relaxation script (baseline), a script describing a coping response of hostile resistance, and a script depicting acceptance of the illness and its (future) consequences. During each imagery trial, end-tidal PCO2 (Handheld Capnograph, Oridion) was measured. After each trial, patients filled out a symptom checklist. Results showed low resting values of PetCO2 overall, while only imagery of hostile resistance triggered a decrease and deficient recovery of PetCO2. Also, more hyperventilation complaints and complaints of other origin were reported during hostile resistance imagery compared with acceptance and relaxation.

In conclusion, hostile resistance seems to trigger both physiological and symptom perception processes contributing to the clinical picture of CFS.

 

Source: Bogaerts K, Hubin M, Van Diest I, De Peuter S, Van Houdenhove B, Van Wambeke P, Crombez G, Van den Bergh O. Hyperventilation in patients with chronic fatigue syndrome: the role of coping strategies. Behav Res Ther. 2007 Nov;45(11):2679-90. Epub 2007 Jul 20. https://www.ncbi.nlm.nih.gov/pubmed/17719001

 

Premorbid predictors of chronic fatigue

Abstract:

CONTEXT: Chronic fatigue syndrome is a disabling problem characterized by persistent fatigue lasting at least 6 months with a number of ancillary symptoms. Although the etiology of chronic fatiguing illness is unknown, some evidence suggests that stress may confer increased risk for development of the disorder. Moreover, subjects with chronic fatiguing illness may have distinctive personality traits, although this finding could reflect confounding by other mechanisms.

OBJECTIVE: To assess the prospective association of premorbid self-reported stress and personality with chronic fatigue-like illness.

DESIGN: Prospective nested case-control study in a population-based sample.

SETTING: General community.

PARTICIPANTS: From the Swedish Twin Registry, 19,192 twins born between January 1, 1935, and December 31, 1958.

MAIN OUTCOME MEASURES: Information about current chronic fatiguing illnesses was obtained from computer-assisted telephone interviews conducted between 1998 and 2002. Self-reported stress (based on a single question) and personality scales (emotional instability and extraversion in the Eysenck Personality Inventory) were measured from 1972 to 1973 by a mailed questionnaire. Relative risks were estimated with case-control analyses (matched for age and sex) and co-twin control analyses (comparing discordant pairs).

RESULTS: Higher emotional instability and self-reported stress in the premorbid period were associated with higher risk for chronic fatigue-like illness in matched case-control analyses (odds ratios, 1.72 and 1.64, respectively). In co-twin control analyses, relative risk of emotional instability decreased to 1.02 whereas that of stress increased considerably to 5.81. There was no association between extraversion and fatigue.

CONCLUSIONS: Elevated premorbid stress is a significant risk factor for chronic fatigue-like illness, the effect of which may be buffered by genetic influences. Emotional instability assessed 25 years earlier is associated with chronic fatigue through genetic mechanisms contributing to both personality style and expression of the disorder. These findings suggest plausible mechanisms for chronic fatiguing illness.

 

Source: Kato K, Sullivan PF, Evengård B, Pedersen NL. Premorbid predictors of chronic fatigue. Arch Gen Psychiatry. 2006 Nov;63(11):1267-72. https://www.ncbi.nlm.nih.gov/pubmed/17088507