Reliability of physiological, psychological, and cognitive variables in chronic fatigue syndrome

Abstract:

The purpose of this study was to assess the reliability of specific physiological, psychological, and cognitive variables in 31 chronic fatigue syndrome (CFS) subjects and 31 matched control subjects. All variables were assessed weekly over a 4-week period and reliability was determined using an intraclass correlation coefficient (ICC). Results ranged from moderately to highly reliable for all variables assessed, except for mental and physical fatigue, which were of questionable reliability in both groups (ICC = 0.61 and 0.65, respectively, for the CFS group; 0.62 and 0.52 for the control group).

A Pearson product-moment correlation analysis that compared exercise performance with all psychological variables assessed, demonstrated a significant relationship between exercise performance and depression (r = .41, P = .02) in week 3 only, suggesting minimal association between objective performance and psychological responses. These correlation results support a central, as opposed to a peripheral, basis to the sensation of fatigue in CFS.

 

Source: Wallman KE, Morton AR, Goodman C, Grove R. Reliability of physiological, psychological, and cognitive variables in chronic fatigue syndrome. Res Sports Med. 2005 Jul-Sep;13(3):231-41. http://www.ncbi.nlm.nih.gov/pubmed/16392538

 

In chronic fatigue syndrome, the decreased levels of omega-3 poly-unsaturated fatty acids are related to lowered serum zinc and defects in T cell activation

Abstract:

There is now evidence that major depression is accompanied by decreased levels of omega3 poly-unsaturated fatty acids (PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). There is a strong comorbidity between major depression and chronic fatigue syndrome (CFS). The present study has been carried out in order to examine PUFA levels in CFS.

In twenty-two CFS patients and 12 normal controls we measured serum PUFA levels using gas chromatography and mass spectrometry. We found that CFS was accompanied by increased levels of omega6 PUFAs, i.e. linoleic acid and arachidonic acid (AA), and mono-unsaturated fatty acids (MUFAs), i.e. oleic acid. The EPA/AA and total omega3/omega6 ratios were significantly lower in CFS patients than in normal controls. The omega3/omega6 ratio was significantly and negatively correlated to the severity of illness and some items of the FibroFatigue scale, i.e. aches and pain, fatigue and failing memory.

The severity of illness was significantly and positively correlated to linoleic and arachidonic acid, oleic acid, omega9 fatty acids and one of the saturated fatty acids, i.e. palmitic acid. In CFS subjects, we found significant positive correlations between the omega3/omega6 ratio and lowered serum zinc levels and the lowered mitogen-stimulated CD69 expression on CD3+, CD3+ CD4+, and CD3+ CD8+ T cells, which indicate defects in early T cell activation. The results of this study show that a decreased availability of omega3 PUFAs plays a role in the pathophysiology of CFS and is related to the immune pathophysiology of CFS.

The results suggest that patients with CFS should respond favourably to treatment with–amongst other things–omega3 PUFAs, such as EPA and DHA.

 

Source: Maes M, Mihaylova I, Leunis JC. In chronic fatigue syndrome, the decreased levels of omega-3 poly-unsaturated fatty acids are related to lowered serum zinc and defects in T cell activation. Neuro Endocrinol Lett. 2005 Dec;26(6):745-51. http://www.ncbi.nlm.nih.gov/pubmed/16380690

 

Orthostatic instability in a population-based study of chronic fatigue syndrome

Abstract:

PURPOSE: Autonomic nervous system dysfunction has been suggested as involved in the pathophysiology of chronic fatigue syndrome. This population-based case control study addressed the potential association between orthostatic instability (one sign of dysautonomia) and chronic fatigue syndrome.

SUBJECTS AND METHODS: Fifty-eight subjects who fulfilled criteria of the 1994 chronic fatigue syndrome research case definition and 55 healthy controls participated in a 2-day inpatient evaluation. Subjects had been identified during a 4-year population-based chronic fatigue syndrome surveillance study in Wichita, Kan. The present study evaluated subjects’ current medical and psychiatric status, reviewed past medical/psychiatric history and medication use, used a stand-up test to screen for orthostatic instability, and conducted a head-up tilt table test to diagnose orthostatic instability.

RESULTS: No one manifested orthostatic instability in the stand-up test. The head-up tilt test elicited orthostatic instability in 30% of eligible chronic fatigue syndrome subjects (all with postural orthostatic tachycardia) and 48% of controls (50% with neurally mediated hypotension); intolerance was present in only nonfatigued (n=7) subjects. Neither fatigue nor illness severity were associated with outcome.

CONCLUSIONS: Orthostatic instability was similar in persons with chronic fatigue syndrome and nonfatigued controls subjects recruited from the general Wichita population. Delayed responses to head-up tilt tests were common and may reflect hydration status. These findings suggest reappraisal of primary dysautonomia as a factor in the pathogenesis of chronic fatigue syndrome.

Comment in: Orthostatic intolerance in chronic fatigue syndrome. [Am J Med. 2007]

 

Source: Jones JF, Nicholson A, Nisenbaum R, Papanicolaou DA, Solomon L, Boneva R, Heim C, Reeves WC. Orthostatic instability in a population-based study of chronic fatigue syndrome. Am J Med. 2005 Dec;118(12):1415. http://www.ncbi.nlm.nih.gov/pubmed/16378795

 

Aetiology and pathogenesis of chronic fatigue syndrome: a review

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disease of uncertain aetiology that is characterised by unexplained, severe fatigue associated with a number of typical symptoms. This paper reviews the scientific literature related to current theories about the aetiology and pathogenesis of CFS by focussing on what appear to be the four most significant aspects in the development and perpetuation of this disease: the role of infectious agents as well as immunological, neuroendocrine, and psychiatric factors. A multifactorial model for the aetiology of CFS, which includes and draws together these four aspects, is proposed; and suggestions are offered regarding approaches to the diagnosis and treatment of this disease.

 

Source: Mihrshahi R, Beirman R. Aetiology and pathogenesis of chronic fatigue syndrome: a review. N Z Med J. 2005 Dec 16;118(1227):U1780. http://www.ncbi.nlm.nih.gov/pubmed/16372029

 

Social support and chronic fatigue syndrome

Abstract:

The role of social support was examined in Chronic Fatigue Syndrome (CFS). Social support has been shown to affect illness outcome in medical disorders, likely due in part to communication between patient and support giver on illness-related concerns. Forty-one participants, 25 of whom had a primary support giver, completed the Beck Depression Inventory, the Perceived Stress Scale, the Profile of Mood States, and the Inventory of Socially Supportive Behaviors (ISSB); the primary support giver completed a modified version of the ISSB indicating the level of support he or she provided and a questionnaire assessing beliefs about CFS.

Results indicated that there were no differences among individuals with CFS with or without support on measures of mood and perceived stress. Individuals with CFS and their support givers agreed on the amount of support offered, and extent of support was independent of beliefs concerning etiology. Exploratory analyses revealed that verbal emotional-cognitive support generally was more predictive of mental health than was tangible, less communicative support. The lack of positive effect of social support is discussed in relation to the degree of support offered, and implications for future research are discussed.

 

Source: Kelly KS, Soderlund K, Albert C, McGarrahan AG. Social support and chronic fatigue syndrome. Health Commun. 1999;11(1):21-34. http://www.ncbi.nlm.nih.gov/pubmed/16370968

 

Chronic fatigue syndrome–a clinically empirical approach to its definition and study

Abstract:

BACKGROUND: The lack of standardized criteria for defining chronic fatigue syndrome (CFS) has constrained research. The objective of this study was to apply the 1994 CFS criteria by standardized reproducible criteria.

METHODS: This population-based case control study enrolled 227 adults identified from the population of Wichita with: (1) CFS (n = 58); (2) non-fatigued controls matched to CFS on sex, race, age and body mass index (n = 55); (3) persons with medically unexplained fatigue not CFS, which we term ISF (n = 59); (4) CFS accompanied by melancholic depression (n = 27); and (5) ISF plus melancholic depression (n = 28). Participants were admitted to a hospital for two days and underwent medical history and physical examination, the Diagnostic Interview Schedule, and laboratory testing to identify medical and psychiatric conditions exclusionary for CFS. Illness classification at the time of the clinical study utilized two algorithms: (1) the same criteria as in the surveillance study; (2) a standardized clinically empirical algorithm based on quantitative assessment of the major domains of CFS (impairment, fatigue, and accompanying symptoms).

RESULTS: One hundred and sixty-four participants had no exclusionary conditions at the time of this study. Clinically empirical classification identified 43 subjects as CFS, 57 as ISF, and 64 as not ill. There was minimal association between the empirical classification and classification by the surveillance criteria. Subjects empirically classified as CFS had significantly worse impairment (evaluated by the SF-36), more severe fatigue (documented by the multidimensional fatigue inventory), more frequent and severe accompanying symptoms than those with ISF, who in turn had significantly worse scores than the not ill; this was not true for classification by the surveillance algorithm.

CONCLUSION: The empirical definition includes all aspects of CFS specified in the 1994 case definition and identifies persons with CFS in a precise manner that can be readily reproduced by both investigators and clinicians.

 

Source: Reeves WC, Wagner D, Nisenbaum R, Jones JF, Gurbaxani B, Solomon L, Papanicolaou DA, Unger ER, Vernon SD, Heim C. Chronic fatigue syndrome–a clinically empirical approach to its definition and study. BMC Med. 2005 Dec 15;3:19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1334212/ (Full article)

 

Primary healthcare provision and Chronic Fatigue Syndrome: a survey of patients’ and General Practitioners’ beliefs

Abstract:

BACKGROUND: The current study was conducted as part of a research project into the evaluation and assessment of healthcare provision and education in Chronic Fatigue Syndrome (CFS). One aim of the study was the development of informative and educational literature for both General Practitioners (GP) and sufferers. Issues such as diagnosis, management and treatment of the syndrome should be included in information booklets written by healthcare professionals. It was important to begin the process by assessing the level of specialist knowledge that existed in typical GP surgeries. This data would then be compared to data from CFS patients.

METHOD: 197 survey booklets were sent to CFS sufferers from an existing research panel. The patients approached for the purpose of the study had been recruited onto the panel following diagnosis of their illness at a specialised CFS outpatient clinic in South Wales. A further 120 booklets were sent to GP surgeries in the Gwent Health Authority region in Wales.

RESULTS: Results from the study indicate that the level of specialist knowledge of CFS in primary care remains low. Only half the GP respondents believed that the condition actually exists.

CONCLUSION: Steps are recommended to increase the knowledge base by compiling helpful and informative material for GPs and patient groups.

 

Source: Thomas MA, Smith AP. Primary healthcare provision and Chronic Fatigue Syndrome: a survey of patients’ and General Practitioners’ beliefs. BMC Fam Pract. 2005 Dec 13;6:49. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325235/ (Full article)

 

Chronic fatigue syndrome of childhood. Comparative study with emotional disorders

Abstract:

OBJECTIVE: To examine clinical specificity in chronic fatigue syndrome (CFS) of childhood, by comparing clinical features in childhood CFS and in emotional disorders (ED).

METHOD SAMPLE: 28 children with CFS; 27 with ED.

MEASURES: History of disorder; K-SADS psychiatric interviews; self-esteem and physical symptoms questionnaires; premorbid history, behavioural and personality assessments.

RESULTS: There were high levels of comorbid emotional disorders in children with CFS, and the two groups were comparable on self-esteem, but CFS children endorsed more fatigue and other somatic symptoms. The two groups were comparable on age at illness onset, but parents of children with CSF reported more biological illness precipitants, more pre-morbid recurrent medical problems and infections. The CFS group had fewer pre-morbid psychological problems and less psychiatric comorbidity than the ED group.

CONCLUSION: There is considerable clinical overlap between CFS and ED of childhood, but there are also differences in clinical presentation between these disorders.

 

Source: Garralda ME, Rangel L. Chronic fatigue syndrome of childhood. Comparative study with emotional disorders. Eur Child Adolesc Psychiatry. 2005 Dec;14(8):424-30. http://www.ncbi.nlm.nih.gov/pubmed/16341498

 

Lower serum zinc in Chronic Fatigue Syndrome (CFS): relationships to immune dysfunctions and relevance for the oxidative stress status in CFS

Abstract:

The present study examines serum zinc concentrations in patients with chronic fatigue syndrome (CFS) versus normal volunteers. Serum zinc levels were determined by means of an atomic absorption method.

We found that serum zinc was significantly lower in the CFS patients than in the normal controls. There was a trend toward a significant negative correlation between serum zinc and the severity of CFS and there was a significant and negative correlation between serum zinc and the subjective experience of infection. We found that serum zinc was significantly and negatively correlated to the increase in the alpha2 protein fraction and positively correlated to decreases in the expression of mitogen-induced CD69+ (a T cell activation marker) on CD3+ as well as CD3+CD8+ T cells.

These results show that CFS is accompanied by a low serum zinc status and that the latter is related to signs of inflammation and defects in early T cell activation pathways. Since zinc is a strong anti-oxidant, the present results further support the findings that CFS is accompanied by increased oxidative stress. The results of these reports suggest that some patients with CFS should be treated with specific antioxidants, including zinc supplements.

 

Source: Maes M, Mihaylova I, De Ruyter M. Lower serum zinc in Chronic Fatigue Syndrome (CFS): relationships to immune dysfunctions and relevance for the oxidative stress status in CFS. J Affect Disord. 2006 Feb;90(2-3):141-7. Epub 2005 Dec 9. http://www.ncbi.nlm.nih.gov/pubmed/16338007

 

Do support groups help people with chronic fatigue syndrome and fibromyalgia? A comparison of active and inactive members

Abstract:

OBJECTIVE: To examine the benefits and problems of a chronic fatigue syndrome (CFS) and fibromyalgia (FM) support organization as reported by its participants.

METHODS: Active members (n = 32) and inactive members or dropouts (n = 135) of a regional support organization for people with CFS and FM completed a 26 item questionnaire by telephone interview or by self-completion and postal return.

RESULTS: The most frequently endorsed benefits of membership were illness legitimization (67.8%), finding out helpful new information (66.4%), and feeling understood by others (62.2%). Lower frequency endorsements were given to: helped to find (35.0%) or deal with (38.5%) doctors, and helped to improve my illness (36.4%). The most frequently reported reasons for dropping out were inconvenient location (37.8%) or time (37.0%), too much negative talk or complaining (33.3%), too sick to attend (28.8%), and illness or coping improvement (29.6% each). The active-member group showed significantly higher (p < 0.04) symptom severity scores and less illness improvement (p < 0.01) in comparison to the inactive/dropout group.

CONCLUSION: This cross-sectional study suggests that support groups for CFS are viewed as helpful by participants on a number of illness related issues. On the other hand, active members reported greater symptom severity and less illness improvement than inactive members or dropouts.

 

Source: Friedberg F, Leung DW, Quick J. Do support groups help people with chronic fatigue syndrome and fibromyalgia? A comparison of active and inactive members. J Rheumatol. 2005 Dec;32(12):2416-20. http://www.ncbi.nlm.nih.gov/pubmed/16331774