Tag: chronic fatigue vs chronic fatigue syndrome

Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue

Abstract:

Fatigue is a common reason that patients seek medical care. Only a fraction of these patients meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To determine if ME/CFS is just a more extreme form of fatigue, or a qualitatively different condition, we assessed whether risk factors for ME/CFS and for Severe Fatigue were similar.

An email questionnaire that inquired about symptoms of Severe Fatigue and ME/CFS was completed by 41,802 US female nurses from whom detailed medical and lifestyle information had been collected since 1989: 102 met criteria for ME/CFS, 522 had Severe Fatigue, and 41,178 individuals were without significant chronic fatigue.

We used Cox proportional hazards regression to estimate the Hazard Ratio (HR) of Severe Fatigue and of ME/CFS with each of several potential risk factors, according to the level of exposure to each risk factor. The risk of Severe Fatigue was significantly increased among participants who were older, had a higher BMI in adulthood, used hormone therapy, had increased alcohol intake and decreased caffeine intake.

In contrast, these risk factor associations were not seen in people with ME/CFS. A self-reported past history of acute infectious mononucleosis was associated with a non-significantly increased Hazard Ratio of later ME/CFS (HR 1.77, 0.87–3.61) and, to a lesser extent, of Severe Fatigue (HR 1.28, 0.98–1.66). The different contribution of various risk factors to Severe Fatigue and ME/CFS suggests that ME/CFS has a qualitatively different underlying biology from the more common state of Severe Fatigue.

Source: Palacios, N., Molsberry, S., Fitzgerald, K.C. et al. Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue. Sci Rep 13, 2469 (2023). https://doi.org/10.1038/s41598-023-29329-x https://www.nature.com/articles/s41598-023-29329-x (Full text)

The Invisible Burden of Chronic Fatigue in the Community: a Narrative Review

Abstract:

PURPOSE OF REVIEW: Unexplained fatigue is commonly reported in the general population, with varying severity. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) sits at the extreme of the fatigue continuum, yet more individuals experience unexplained prolonged fatigue (1-6-month duration) or chronic fatigue (> 6 months) that, although debilitating, does not fulfil ME/CFS criteria. This review examines the empirical literature comparing symptoms for those with prolonged fatigue, chronic fatigue and ME/CFS.

RECENT FINDINGS: Substantial overlap of self-reported psychological, physical and functional impairments exists between chronic fatigue and ME/CFS. The conversion rate from prolonged or chronic fatigue to ME/CFS is not understood. Current research has failed to uncover factors accounting for differences in fatigue trajectories, nor incorporate comprehensive, longitudinal assessments extending beyond self-reported symptoms. Distinguishing factors between prolonged fatigue, chronic fatigue and ME/CFS remain poorly understood, highlighting a need for longitudinal studies integrating biopsychosocial approaches to inform early management and targeted rehabilitation strategies.

Source: Fatt SJ, Cvejic E2,, Lloyd AR, Vollmer-Conna U, Beilharz JE. The Invisible Burden of Chronic Fatigue in the Community: a Narrative Review. Curr Rheumatol Rep. 2019 Feb 11;21(2):5. doi: 10.1007/s11926-019-0804-2.

Mortality in a cohort of chronically fatigued patients

Abstract:

BACKGROUND: Comprehensive studies of mortality among patients with chronic fatigue (CF) and chronic fatigue syndrome (CFS) have not been published, but several sources suggest that CFS is associated with an elevated risk for suicide.

METHOD: Data on 1201 chronically fatigued patients followed in a university-affiliated tertiary-care clinic for up to 14 years were submitted to the Center for Disease Control and Prevention (CDC) National Death Index (NDI) to evaluate all-cause and suicide-caused death rates against standardized mortality rates (SMRs). We used Life Table Analysis to examine the influence of sex and diagnoses of CFS and depression.

RESULTS: All-cause mortality in chronically fatigued patients was no higher than expected, but suicide-caused death rates were more than eight times higher than in the US general population. The significant elevation in the SMR of suicide was restricted to those who did not meet criteria for CFS [SMR(CF)=14.2, 95% confidence interval (CI) 5.7-29.3 versus SMR(CFS)=3.6, 95% CI 0.4-12.9]. Among chronically fatigued patients who did not meet CFS criteria, those with a lifetime history of major depression (MD) had higher suicide-caused death rates than among their non-depressed counterparts (SMR(MD)=19.1, 95% CI 7.0-41.5 versus SMR(NMD)=5.6, 95% CI 0.1-31.4), although the difference was not significant.

CONCLUSIONS: CFS does not appear to be associated with increased all-cause mortality or suicide rates. Clinicians, however, should carefully evaluate patients with CF for depression and suicidality.

 

Source: Smith WR, Noonan C, Buchwald D. Mortality in a cohort of chronically fatigued patients. Psychol Med. 2006 Sep;36(9):1301-6. https://www.ncbi.nlm.nih.gov/pubmed/16893495

 

The definition of disabling fatigue in children and adolescents

Abstract:

BACKGROUND: Disabling fatigue is the main illness related reason for prolonged absence from school. Although there are accepted criteria for diagnosing chronic fatigue in adults, it remains uncertain as to how best to define disabling fatigue and Chronic Fatigue Syndrome (CFS) in children and adolescents. In this population-based study, the aim was to identify children who had experienced an episode of disabling fatigue and examine the clinical and demographic differences between those individuals who fulfilled a narrow definition of disabling fatigue and those who fulfilled broader definitions of disabling fatigue.

METHODS: Participants (aged 8-17 years) were identified from a population-based twin register. Parent report was used to identify children who had ever experienced a period of disabling fatigue. Standardised telephone interviews were then conducted with the parents of these affected children. Data on clinical and demographic characteristics, including age of onset, gender, days per week affected, hours per day spent resting, absence from school, comorbidity with depression and a global measure of impairment due to the fatigue, were examined. A narrow definition was defined as a minimum of 6 months disabling fatigue plus at least 4 associated symptoms, which is comparable to the operational criteria for CFS in adults. Broader definitions included those with at least 3 months of disabling fatigue and 4 or more of the associated symptoms and those with simply a minimum of 3 months of disabling fatigue. Groups were mutually exclusive.

RESULTS: Questionnaires were returned by 1468 families (65% response rate) and telephone interviews were completed on 99 of the 129 participants (77%) who had experienced fatigue. There were no significant differences in demographic and clinical characteristics or levels of impairment between those who fulfilled the narrower definition and those who fulfilled the broader definitions. The only exception was the reported number of days per week that the child was affected by the fatigue. All groups demonstrated evidence of substantial impairment associated with the fatigue.

CONCLUSION: Children and adolescents who do not fulfil the current narrow definition of CFS but do suffer from disabling fatigue show comparable and substantial impairment. In primary care settings, a broader definition of disabling fatigue would improve the identification of impaired children and adolescents who require support.

 

Source: Fowler T, Duthie P, Thapar A, Farmer A. The definition of disabling fatigue in children and adolescents. BMC Fam Pract. 2005 Aug 9;6:33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1192794/ (Full article)