Exercise testing in children and adolescents with chronic fatigue syndrome

Abstract:

The objective of this study was to evaluate exercise capacity in children and adolescents diagnosed with Chronic Fatigue Syndrome (CFS). We examined 20 patients (12 girls and 8 boys; mean age 14.9 +/- 3.7 years) diagnosed with CFS.

Exercise capacity was measured using a maximal exercise test on a bicycle ergometer and an expired gas analysis system. Fatigue was assessed using a questionnaire and a daily activity diary was used to describe activities for three days. Z-scores were calculated using age- and sex-matched reference values. Z-scores in children and adolescents with CFS were – 0.33 +/- 1.0 (p = 0.17) for peak oxygen uptake, – 1.13 +/- 1.41 (p = 0.002) for relative peak oxygen uptake [ml/kg/min] and – 0.93 +/- 1.29 (p = 0.07) for maximal work load. Both heart rate and blood pressure at peak performance were significantly reduced compared to reference values.

Fatigue levels were significantly positively associated with age and negatively with blood pressure at peak exercise (p < 0.05). In conclusion maximum exercise testing was feasible in young people with CFS. Maximal exercise capacity was only reduced in a minority of the patients and was related to current physical activity levels.

 

Source: Takken T, Henneken T, van de Putte E, Helders P, Engelbert R. Exercise testing in children and adolescents with chronic fatigue syndrome. Int J Sports Med. 2007 Jul;28(7):580-4. Epub 2007 Mar 15. https://www.ncbi.nlm.nih.gov/pubmed/17357961

 

Personality and chronic fatigue syndrome: methodological and conceptual issues

Abstract:

Among clinical psychologists, consulting physicians, scientific researchers and society in general an image has emerged of patients with chronic fatigue syndrome (CFS) as perfectionist, conscientious, hardworking, somewhat neurotic and introverted individuals with high personal standards, a great desire to be socially accepted and with a history of continuously pushing themselves past their limits.

The aim of this article is to (a) give a concise review of the main recent studies on personality and CFS, (b) address the major methodological problems in the study of personality in CFS and (c) discuss some of the conceptual assumptions that seem to limit the research on personality and CFS.

The results of the reviewed studies range from no evidence of major differences between the personalities of patients with CFS and controls, to evidence of severe psychopathology and personality disorder in patients with CFS. Although personality seems to play a role in CFS, it is difficult to draw general conclusions on the relation between personality and CFS. It is argued that this is partially due to the diversity and heterogeneity in study methods, patient populations, control groups and CFS case definitions.

Personality should be regarded as an important factor to be studied in CFS. However, additional studies are needed, not focusing exclusively on personality disorder, or personality considered on a general trait level. In recent developments in personality research, the continually evolving life narrative that makes sense of, and gives direction to, an individual’s life is also regarded as an important aspect of personality. New insights into personality and CFS might be gained by systematically studying the self-narratives of patients with the syndrome.

 

Source: van Geelen SM, Sinnema G, Hermans HJ, Kuis W. Personality and chronic fatigue syndrome: methodological and conceptual issues. Clin Psychol Rev. 2007 Dec;27(8):885-903. Epub 2007 Jan 27. https://www.ncbi.nlm.nih.gov/pubmed/17350740

 

Can submaximal exercise variables predict peak exercise performance in women with chronic fatigue syndrome?

Abstract:

This study aimed at examining whether physiological exercise variables at the submaximal level, defined as 75% of the age-predicted target heart rate, are able to predict peak exercise performance in women with chronic fatigue syndrome (CFS) (n=222). Subjects performed a bicycle ergometric test against a graded increase in workload until exhaustion with continuous monitoring of electrocardiographic and ventilatory variables. Oxygen uptake at the submaximal level (VO2SUBMAX) correlated strongly with peak oxygen uptake (VO2PEAK) (r=0.70). For the prediction of VO2PEAK, linear regression analysis determined the line of best fit as: VO2PEAK=0.95xVO2SUBMAX+372.3. Using this equation, the mean error in the prediction was 14.6+/-11.2% (range 0.1-63.7%). It is concluded that the prediction of VO2PEAK based on VO2SUBMAX might be useful for analyzing group differences or treatment effects but not for individual (clinical) purposes.

Source: Nijs J, Demol S, Wallman K. Can submaximal exercise variables predict peak exercise performance in women with chronic fatigue syndrome? Arch Med Res. 2007 Apr;38(3):350-3. Epub 2007 Jan 30. https://www.ncbi.nlm.nih.gov/pubmed/17350488

Incidence, prognosis, and risk factors for fatigue and chronic fatigue syndrome in adolescents: a prospective community study

Abstract:

OBJECTIVE: The objective of this study was to describe the incidence, prevalence, risk factors, and prognosis of fatigue, chronic fatigue, and chronic fatigue syndrome in 11- to 15-year-olds.

METHODS: A random general population sample (n = 842) of British adolescents and their parents were assessed at baseline and 4 to 6 months later. The main outcomes were fatigue, chronic fatigue, and chronic fatigue syndrome, operationally defined.

RESULTS: The incidence over 4 to 6 months was 30.3% for fatigue, 1.1% for chronic fatigue, and 0.5% for chronic fatigue syndrome. The point prevalence was 34.1% and 38.1% for fatigue, 0.4% and 1.1% for chronic fatigue, and 0.1% and 0.5% for chronic fatigue syndrome at time 1 and time 2, respectively. Of participants who were fatigued at time 1, 53% remained fatigued at time 2. The 3 cases of chronic fatigue and 1 case of chronic fatigue syndrome at time 1 had recovered by time 2. Higher risk for development of chronic fatigue at time 2 was associated with time 1 anxiety or depression, conduct disorder, and maternal distress; in multivariate analysis, baseline anxiety or depression remained a significant predictor of chronic fatigue. Increased risk for development of fatigue at time 2 was associated with time 1 anxiety or depression, conduct disorder, and older age; in multivariate analyses, these factors and female gender all were significant predictors of fatigue.

CONCLUSIONS: The incidence rates for chronic fatigue and chronic fatigue syndrome in this adolescent sample were relatively high, but the prognosis for these conditions was good. This prospective study provides evidence for an association between emotional/behavioral problems and subsequent onset of fatigue/chronic fatigue.

 

Source: Rimes KA, Goodman R, Hotopf M, Wessely S, Meltzer H, Chalder T. Incidence, prognosis, and risk factors for fatigue and chronic fatigue syndrome in adolescents: a prospective community study. Pediatrics. 2007 Mar;119(3):e603-9. https://www.ncbi.nlm.nih.gov/pubmed/17332180

 

Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) present a disordered sleep pattern and frequently undergo polysomnography to exclude a primary sleep disorder. Such studies have shown reduced sleep efficiency, a reduction of deep sleep, prolonged sleep initiation, and alpha-wave intrusion during deep sleep. Deregulation of the 2-5A synthetase/RNase L antiviral pathway and a potential acquired channelopathy are also found in a subset of CFS patients and could lead to sleep disturbances. This article compiles a large sleep study database on CFS patients and correlates these data with a limited number of immune parameters as it has been thought that RNase L could be associated with these sleep disturbances.

METHODS: Forty-eight patients who fulfilled 1994 Centers for Disease Control and Prevention criteria for CFS underwent extensive medical evaluation, routine laboratory testing, and a structured psychiatric interview. Subjects then completed a complaint checklist and a two-night polysomnographic investigation. RNase L analysis was performed by gel electrophoresis using a radiolabeled 2′,5′-oligoadenylate trimer. Basic descriptive statistical parameters were calculated.

RESULTS: Patients experienced a prolonged sleep latency, showed a low sleep efficiency index, and had a low percentage of slow wave sleep. The present alpha-delta intrusion correlated with anxiety; no correlations appeared, however, between alpha-delta sleep and immunologic parameters, including RNase L.

CONCLUSIONS: The main findings are 1) validation of sleep latency problems and other sleep disturbances as already suggested by several authors; 2) alpha-delta intrusion seems associated with anxiety; and 3) elevated RNase L did not correlate with alpha-delta sleep.

 

Source: Van Hoof E, De Becker P, Lapp C, Cluydts R, De Meirleir K. Defining the occurrence and influence of alpha-delta sleep in chronic fatigue syndrome. Am J Med Sci. 2007 Feb;333(2):78-84. https://www.ncbi.nlm.nih.gov/pubmed/17301585

 

Fibromylagia, chronic fatigue, and adult attention deficit hyperactivity disorder in the adult: a case study

Abstract:

Adult attention deficit hyperactivity disorder (ADHD) may share common features with fibromyalgia syndrome (FMS) and chronic fatigue syndrome(CFS). In an outpatient psychiatric clinic, a number of adult patients who presented primarily with symptoms of ADHD, predominately inattentive type, also reported unexplained fatigue, widespread musculoskeletal pain or a pre-existing diagnosis of CFS or FMS.

As expected, ADHD pharmacotherapy usually attenuated the core ADHD symptoms of inattention, distractibility, hyperactivity, and impulsivity. Less expected was the observation that some patients also reported amelioration of pain and fatigue symptoms. The utility of ADHD medications in FMS and CFS states may be their innate arousal and enhanced filtering properties.

This model supposes that FMS and CFS are central processing problems rather than peripheral disorders of muscles and joints.

 

Source: Young JL, Redmond JC. Fibromylagia, chronic fatigue, and adult attention deficit hyperactivity disorder in the adult: a case study. Psychopharmacol Bull. 2007;40(1):118-26. https://www.ncbi.nlm.nih.gov/pubmed/17285103

 

An ‘overwhelming illness’: women’s experiences of learning to live with chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

The processes through which people learn to live with CFS/ME are poorly understood and have not been rigorously explored within the literature. Semi-structured interviews were conducted with eight women and analysed using interpretative phenomenological analysis. Participants initially described being ‘overwhelmed’ by CFS/ME. Attempts at seeking help were unsatisfactory and participants described feeling let down and disbelieved.

Participants reacted to this by identifying types of ‘self-help’ and assertively taking more responsibility for their illness and its treatment. Acquiring social support and greater knowledge were key mediating factors in the emergence of control and acceptance. The relevance of the themes to existing research and the implications for clinical practice are considered.

 

Source: Edwards CR, Thompson AR, Blair A. An ‘overwhelming illness’: women’s experiences of learning to live with chronic fatigue syndrome/myalgic encephalomyelitis. J Health Psychol. 2007 Mar;12(2):203-14. https://www.ncbi.nlm.nih.gov/pubmed/17284485

 

Enhanced feedback sensitivity to prednisolone in chronic fatigue syndrome

Abstract:

OBJECTIVE: Enhancement of negative feedback control of the HPA axis in patients with chronic fatigue syndrome (CFS) has been reported using the low dose dexamethasone suppression test. We have developed the use of prednisolone (5mg) as a more physiologically appropriate alternative to dexamethasone in the investigation of mild degrees of glucocorticoid resistance or supersensitivity. The objective of the study was to use this test to look for alterations in negative feedback control of the HPA axis in CFS patients.

METHODS: Fifteen patients with CFS were recruited after fulfilling strict criteria including the absence of comorbid psychiatric diagnosis. They collected urine between 0900 and 1800h and saliva at 0900h pre-prednisolone. At midnight, they took prednisolone (5mg) orally and then collected urine and saliva at the same intervals the following day.

RESULTS: Salivary cortisol was lower in CFS subjects pre-prednisolone than controls. Urinary cortisol metabolites were lower in CFS subjects pre-prednisolone, but did not reach significance. Both measures were significantly lower in CFS subjects post-dose. Mean percentage suppression of both salivary cortisol and urinary cortisol metabolites was significantly higher in CFS compared to controls.

CONCLUSION: There is enhanced sensitivity of the HPA axis to negative feedback in CFS as demonstrated using the prednisolone suppression test. This provides further evidence of alterations in the control of the HPA axis in patients with established CFS.

 

Source: Jerjes WK, Taylor NF, Wood PJ, Cleare AJ. Enhanced feedback sensitivity to prednisolone in chronic fatigue syndrome. Psychoneuroendocrinology. 2007 Feb;32(2):192-8. Epub 2007 Feb 5. https://www.ncbi.nlm.nih.gov/pubmed/17276605

 

Activation of human herpesviruses 6 and 7 in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Human herpesvirus 6 (HHV-6) and 7 (HHV-7) have been suggested as possible triggering agents for chronic fatigue syndrome(CFS).

OBJECTIVES: To determine the possible association of HHV-6 and HHV-7 infections with CFS.

STUDY DESIGN: The prevalence of latent/persistent and active viral infections by nPCR, characteristic of HHV-6 variants using restriction endonuclease analysis and changes of lymphocyte subsets in peripheral blood by laser flow-cytometry in 17 CFS patients was examined. In addition, 12 patients with unexplained chronic fatigue and 20 blood donors (BD) were studied.

RESULTS: No difference in prevalence of latent/persistent single viral infections between the patients and BD was found but dual infection rate was significantly higher in CFS patients. Active HHV-6 and dual (HHV-6 + HHV-7) infections were detected in CFS patients only and frequency of HHV-7 reactivation was also significantly higher in these patients. HHV-6 variant B was predominant in CFS patients (12/13). The changes of immunological parameters in CFS patients with active dual infection were characterized by significant decrease of CD3+ and CD4+ T cells, significant increase of CD95+ cells and decrease of CD4+/CD8+ ratio.

CONCLUSIONS: HHV-6 and HHV-7 may be involved in the pathogenesis of CFS and reactivation of both viruses may provoke changes in the phenotype of circulating lymphocytes.

 

Source: Chapenko S, Krumina A, Kozireva S, Nora Z, Sultanova A, Viksna L, Murovska M. Activation of human herpesviruses 6 and 7 in patients with chronic fatigue syndrome. J Clin Virol. 2006 Dec;37 Suppl 1:S47-51. https://www.ncbi.nlm.nih.gov/pubmed/17276369

 

Is human herpesvirus-6 a trigger for chronic fatigue syndrome?

Abstract:

Chronic fatigue syndrome (CFS) is an illness currently defined entirely by a combination of non-specific symptoms. Despite this subjective definition, CFS is associated with objective underlying biological abnormalities, particularly involving the nervous system and immune system.

Most studies have found that active infection with human herpesvirus-6 (HHV-6)–a neurotropic, gliotropic and immunotropic virus–is present more often in patients with CFS than in healthy control and disease comparison subjects, yet it is not found in all patients at the time of testing. Moreover, HHV-6 has been associated with many of the neurological and immunological findings in patients with CFS.

Finally, CFS, multiple sclerosis and seizure disorders share some clinical and laboratory features and, like CFS, the latter two disorders also are being associated increasingly with active HHV-6 infection. Therefore, it is plausible that active infection with HHV-6 may trigger and perpetuate CFS in a subset of patients.

 

Source: Komaroff AL. Is human herpesvirus-6 a trigger for chronic fatigue syndrome? J Clin Virol. 2006 Dec;37 Suppl 1:S39-46. https://www.ncbi.nlm.nih.gov/pubmed/17276367