Category: Pathophysiology

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 and mitochondrial dysfunction

Abstract:

This study aims to improve the health of patients suffering from chronic fatigue syndrome (CFS) by interventions based on the biochemistry of the illness, specifically the function of mitochondria in producing ATP (adenosine triphosphate), the energy currency for all body functions, and recycling ADP (adenosine diphosphate) to replenish the ATP supply as needed.

Patients attending a private medical practice specializing in CFS were diagnosed using the Centers for Disease Control criteria. In consultation with each patient, an integer on the Bell Ability Scale was assigned, and a blood sample was taken for the “ATP profile” test, designed for CFS and other fatigue conditions. Each test produced 5 numerical factors which describe the availability of ATP in neutrophils, the fraction complexed with magnesium, the efficiency of oxidative phosphorylation, and the transfer efficiencies of ADP into the mitochondria and ATP into the cytosol where the energy is used. With the consent of each of 71 patients and 53 normal, healthy controls the 5 factors have been collated and compared with the Bell Ability Scale.

The individual numerical factors show that patients have different combinations of biochemical lesions. When the factors are combined, a remarkable correlation is observed between the degree of mitochondrial dysfunction and the severity of illness (P<0.001). Only 1 of the 71 patients overlaps the normal region.

The “ATP profile” test is a powerful diagnostic tool and can differentiate patients who have fatigue and other symptoms as a result of energy wastage by stress and psychological factors from those who have insufficient energy due to cellular respiration dysfunction. The individual factors indicate which remedial actions, in the form of dietary supplements, drugs and detoxification, are most likely to be of benefit, and what further tests should be carried out.

 

Source: Myhill S, Booth NE, McLaren-Howard J. Chronic fatigue syndrome and mitochondrial dysfunction. Int J Clin Exp Med. 2009;2(1):1-16. Epub 2009 Jan 15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680051/ (Full article)

 

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)

 

Risk markers for both chronic fatigue and irritable bowel syndromes: a prospective case-control study in primary care

Abstract:

BACKGROUND: Fatigue syndromes and irritable bowel syndrome (IBS) often occur together. Explanations include being different manifestations of the same condition and simply sharing some symptoms.

METHOD: A matched case-control study in UK primary care, using data collected prospectively in the General Practice Research Database (GPRD). The main outcome measures were: health-care utilization, specific symptoms and diagnoses. Risk markers were divided into distant (from 3 years to 1 year before diagnosis) and recent (1 year before diagnosis).

RESULTS: A total of 4388 patients with any fatigue syndrome were matched to two groups of patients: those attending for IBS and those attending for another reason. Infections were specific risk markers for both syndromes, with viral infections being a risk marker for a fatigue syndrome [odds ratios (ORs) 2.3-6.3], with a higher risk closer to onset, and gastroenteritis a risk for IBS (OR 1.47, compared to a fatigue syndrome). Chronic fatigue syndrome (CFS) shared more distant risk markers with IBS than other fatigue syndromes, particularly other symptom-based disorders (OR 3.8) and depressive disorders (OR 2.3), but depressive disorders were a greater risk for CFS than IBS (OR 2.4). Viral infections were more of a recent risk marker for CFS compared to IBS (OR 2.8), with gastroenteritis a greater risk for IBS (OR 2.4).

CONCLUSIONS: Both fatigue and irritable bowel syndromes share predisposing risk markers, but triggering risk markers differ. Fatigue syndromes are heterogeneous, with CFS sharing predisposing risks with IBS, suggesting a common predisposing pathophysiology.

 

Source: Hamilton WT, Gallagher AM, Thomas JM, White PD. Risk markers for both chronic fatigue and irritable bowel syndromes: a prospective case-control study in primary care. Psychol Med. 2009 Nov;39(11):1913-21. doi: 10.1017/S0033291709005601. Epub 2009 Apr 15. https://www.ncbi.nlm.nih.gov/pubmed/19366500

 

Visible and near-infrared spectral changes in the thumb of patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) patients show a persistent fatigue condition with muscle pain and impairment of concentration, memory, and sleep. Presently, the physiological basis of CFS remains unclear. In this study, spectroscopic differences in the thumb were compared between 103 CFS patients and 122 healthy controls to examine possible changes of levels of oxygenated or deoxygenated hemoglobin.

METHODS: Visible and near-infrared (Vis-NIR) spectroscopy was used to examine possible changes in the region of 600-1100 nm.

RESULTS: Vis-NIR spectra showed sharp peaks at 694, 970 and 1060 nm and broad peaks in the regions of 740-760 and 830-850 nm. As these peaks are possibly related to oxyhemoglobin, cytochrome c oxidase and water, levels of these factors were compared between the two groups. Statistical analysis of the absorbance of Vis-NIR spectra showed a significant decrease in water content, a significant increase in oxyhemoglobin content, and a significant increase in the oxidation of heme a+a(3) and copper in cytochrome c oxidase in CFS patients.

CONCLUSIONS: These changes imply accelerated blood flow and energy metabolism in the thumbs of CFS patients.

 

Source: Sakudo A, Kato YH, Tajima S, Kuratsune H, Ikuta K. Visible and near-infrared spectral changes in the thumb of patients with chronic fatigue syndrome. Clin Chim Acta. 2009 May;403(1-2):163-6. doi: 10.1016/j.cca.2009.02.010. Epub 2009 Feb 25. https://www.ncbi.nlm.nih.gov/pubmed/19248775

 

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)

 

Secondary structural changes of proteins in fingernails of chronic fatigue syndrome patients from Fourier-transform infrared spectra

Abstract:

BACKGROUND: Generally, nails can be an index of health, with abnormalities sometimes found under diseased conditions. Fatigue is also supposed to affect the condition of nails. Possible differences in infrared (IR) spectra of nail plates of chronic fatigue syndrome(CFS) patients compared to healthy control subjects were investigated in this study.

METHODS: Using an attenuated total reflection (ATR)-Fourier-transform infrared (FTIR) spectrophotometer, spectra in the region of 4000-600 cm(-1) were obtained. The amide I region was then separated by Fourier deconvolution and curve fitting based on the Gauss and Lorentz formula and revealed differences in the secondary structural content of proteins compared to healthy donors.

RESULTS: The specific secondary structural pattern commonly observed in nails of male and female CFS patients in the absence and presence of medication indicated a decreased alpha-helix content and increased beta-sheet content, suggesting reduced levels of normal elements of the nail plate.

CONCLUSIONS: This provides the first evidence of alterations in the fingernails of CFS patients which could be detected by IR spectroscopy. Possible explanations for the alterations will be discussed.

 

Source: Sakudo A, Kuratsune H, Kato YH, Ikuta K. Secondary structural changes of proteins in fingernails of chronic fatigue syndrome patients from Fourier-transform infrared spectra. Clin Chim Acta. 2009 Apr;402(1-2):75-8. doi: 10.1016/j.cca.2008.12.020. Epub 2008 Dec 30. https://www.ncbi.nlm.nih.gov/pubmed/19150612

 

Inflammatory and oxidative and nitrosative stress pathways underpinning chronic fatigue, somatization and psychosomatic symptoms

Abstract:

PURPOSE OF REVIEW: The aim of this paper is to review recent findings on inflammatory and oxidative and nitrosative stress (IO&NS) pathways in chronic fatigue and somatization disorder.

RECENT FINDINGS: Activation of IO&NS pathways is the key phenomenon underpinning chronic fatigue syndrome (CFS): intracellular inflammation, with an increased production of nuclear factor kappa beta (NFkappabeta), cyclo-oxygenase-2 (COX-2) and inducible NO synthase (iNOS); and damage caused by O&NS to membrane fatty acids and functional proteins. These IO&NS pathways are induced by a number of trigger factors, for example psychological stress, strenuous exercise, viral infections and an increased translocation of LPS from gram-bacteria (leaky gut). The ‘psychosomatic’ symptoms experienced by CFS patients are caused by intracellular inflammation (aches and pain, muscular tension, fatigue, irritability, sadness, and the subjective feeling of infection); damage caused by O&NS (aches and pain, muscular tension and fatigue); and gut-derived inflammation (complaints of irritable bowel). Inflammatory pathways (monocytic activation) are also detected in somatizing disorder.

SUMMARY: ‘Functional’ symptoms, as occurring in CFS and somatization, have a genuine organic cause, that is activation of peripheral and central IO&NS pathways and gut-derived inflammation. The development of new drugs, aimed at treating those disorders, should target these IO&NS pathways.

 

Source: Maes M. Inflammatory and oxidative and nitrosative stress pathways underpinning chronic fatigue, somatization and psychosomatic symptoms. Curr Opin Psychiatry. 2009 Jan;22(1):75-83. https://www.ncbi.nlm.nih.gov/pubmed/19127706

 

Kindling and Oxidative Stress as Contributors to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) is one of the more complex illnesses involving multiple systems within the body. Onset of ME/CFS frequently occurs quickly, and many patients report a prior exposure to a viral infection. This debilitating illness can affect the immune, neuroendocrine, autonomic, and neurologic systems.

Abnormal biological findings among some patients have included aberrant ion transport and ion channel activity, cortisol deficiency, sympathetic nervous system hyperactivity, EEG spike waves, left ventricular dysfunction in the heart, low natural killer cell cytotoxicity, and a shift from Th1 to Th2 cytokines. We propose that the kindling and oxidative stress theories provide a heuristic template for better understanding the at times conflicting findings regarding the etiology and pathophysiology of this illness.

 

Source: Jason LA, Porter N, Herrington J, Sorenson M, Kubow S. Kindling and Oxidative Stress as Contributors to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. J Behav Neurosci Res. 2009 Jan 1;7(2):1-17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3022475/ (Full article)