Sleep assessment in a population-based study of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a disabling condition that affects approximately 800,000 adult Americans. The pathophysiology remains unknown and there are no diagnostic markers or characteristic physical signs or laboratory abnormalities. Most CFS patients complain of unrefreshing sleep and many of the postulated etiologies of CFS affect sleep. Conversely, many sleep disorders present similarly to CFS. Few studies characterizing sleep in unselected CFS subjects have been published and none have been performed in cases identified from population-based studies.

METHODS: The study included 339 subjects (mean age 45.8 years, 77% female, 94.1% white) identified through telephone screen in a previously described population-based study of CFS in Wichita, Kansas. They completed questionnaires to assess fatigue and wellness and 2 self-administered sleep questionnaires. Scores for five of the six sleep factors (insomnia/hypersomnia, non-restorative sleep, excessive daytime somnolence, sleep apnea, and restlessness) in the Centre for Sleep and Chronobiology’s Sleep Assessment Questionnaire (SAQ) were dichotomized based on threshold. The Epworth Sleepiness Scale score was used as a continuous variable.

RESULTS: 81.4% of subjects had an abnormality in at least one SAQ sleep factor. Subjects with sleep factor abnormalities had significantly lower wellness scores but statistically unchanged fatigue severity scores compared to those without SAQ abnormality. CFS subjects had significantly increased risk of abnormal scores in the non-restorative (adjusted odds ratio [OR] = 28.1; 95% confidence interval [CI]= 7.4-107.0) and restlessness (OR = 16.0; 95% CI = 4.2-61.6) SAQ factors compared to non-fatigued, but not for factors of sleep apnea or excessive daytime somnolence. This is consistent with studies finding that, while fatigued, CFS subjects are not sleepy. A strong correlation (0.78) of Epworth score was found only for the excessive daytime somnolence factor.

CONCLUSIONS: SAQ factors describe sleep abnormalities associated with CFS and provide more information than the Epworth score. Validation of these promising results will require formal polysomnographic sleep studies.

 

Source: Unger ER, Nisenbaum R, Moldofsky H, Cesta A, Sammut C, Reyes M, Reeves WC. Sleep assessment in a population-based study of chronic fatigue syndrome. BMC Neurol. 2004 Apr 19;4:6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC419502/  (Full article)

 

Prevalence of chronic fatigue syndrome-like caseness in the working population: results from the Maastricht cohort study

Abstract:

AIM: To determine the prevalence of chronic fatigue syndrome (CFS)-like caseness in the working population.

METHODS: Using data from the prospective Maastricht Cohort Study on Fatigue at Work, the prevalence and incidence of CFS-like cases (employees meeting research criteria for CFS) were determined among 5499 employees who responded to the follow up assessment 3 years and 8 months after baseline.

RESULTS: Of the 5499 employees, 199 (3.6%) were identified as CFS-like cases. By deleting possible CFS-like cases at baseline, the annual incidence of CFS-like caseness was estimated to be 85 per 10 000. Twenty employees (0.36%) reported having been diagnosed with CFS by a physician.

CONCLUSIONS: The prevalence of CFS-like cases (3.6%) was considerably higher than the prevalence of CFS reported in previous studies (0.006-3%). These findings suggest that the CFS-like caseness may be underdetected in the working population and perhaps in other populations as well.

 

Source: Huibers MJ, Kant IJ, Swaen GM, Kasl SV. Prevalence of chronic fatigue syndrome-like caseness in the working population: results from the Maastricht cohort study. Occup Environ Med. 2004 May;61(5):464-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1740780/ (Full article)

 

Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients

Abstract:

The major goal of this study was to determine indictors of long-term disability for psychosomatic inpatients with chronic fatigue syndrome. To this end, a cross-sectional study was performed with a random sample of patients (n=1000, response rate: 83.9%) at a psychosomatic inpatient clinic. 51.1% of the patients (n=429) reported intensely persistent exhaustion that had no logical relation to actual exertion. 159 (37.1%) patients in this group were disabled from working and these comprised the main target group of this study.

Significantly more patients in the target group worked part time, were disabled for a disproportionately long period of time (50.9% of all were disabled for more than 6 months in the previous year), and felt stressed because of conflicts with their superiors and/or colleagues (in each case, P<0.01). While more frequent psychological comorbidity was not found, they reported physical complaints more often. It was not the patients fit for work who felt more burdened with chronic fatigue, but rather the employment-disabled, who were actually exposed to fewer demands.

These patients had, in comparison with those fit to work, a stronger fixation on somatic complaints, inadequate perception of physical and psychic sensations, difficulties getting along with other people and in coping with a regular job (in each case, P<0.01). Prospective examination of these indicators could help detect predictor variables for long-term disability in chronic fatigue. Such predictors could contribute to timely social-medical assessment and treatment.

 

Source: Tritt K, Nickel M, Mitterlehner F, Nickel C, Forthuber P, Leiberich P, Rother W, Loew T. Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients. Wien Klin Wochenschr. 2004 Mar 31;116(5-6):182-9. http://www.ncbi.nlm.nih.gov/pubmed/15088993

 

Alcohol use in chronic fatigue syndrome

Abstract:

OBJECTIVE: To examine the anecdotal observation that patients with chronic fatigue syndrome develop alcohol intolerance.

METHODS: A consecutive case series of 114 patients fulfilling UK criteria for chronic fatigue syndrome referred to a specialist clinic. Self-reported alcohol use pre- and postdiagnosis, fatigue symptoms and comorbidity measures were collected.

RESULTS: Two-thirds reduced alcohol intake. The most common reasons were increased tiredness after drinking (67%), increased nausea (33%), exacerbated hangovers (23%) and sleep disturbance (24%). One-third of the subjects also stopped drinking because “it seemed sensible.” Some had been advised to avoid alcohol, but the majority (66%) did so on the basis of personal experience.

CONCLUSION: Our data supports the anecdotal belief that chronic fatigue syndrome patients reduce or cease alcohol intake. This is associated with greater impairment in employment, leisure and social domains of function, and may hint at psycho-pathophysiological processes in common with other conditions that result in alcohol intolerance.

 

Source: Woolley J, Allen R, Wessely S. Alcohol use in chronic fatigue syndrome. J Psychosom Res. 2004 Feb;56(2):203-6. http://www.ncbi.nlm.nih.gov/pubmed/15016579

 

Regional distribution of fatiguing illnesses in the United States: a pilot study

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a debilitating illness with no known cause or effective therapy. Population-based epidemiologic data on CFS prevalence are critical to put CFS in a realistic context for public health officials and others responsible for allocating resources.

METHODS: We conducted a pilot random-digit-dialing survey to estimate the prevalence of fatiguing illnesses in different geographic regions and in urban and rural populations of the United States. This report focuses on 884 of 7,317 respondents 18 to 69 years old. Fatigued (440) and randomly selected non-fatigued (444) respondents completed telephone questionnaires concerning fatigue, other symptoms, and medical history.

RESULTS: We estimated 12,186 per 100,000 persons 18 to 69 years of age suffered from fatigue lasting for at least 6 months (chronic fatigue), and 1,197 per 100,000 described an illness that, though lacking clinical evaluation, met criteria for CFS (CFS-like). Chronic fatigue and CFS-like illness were more common in rural than in urban populations, although the differences were not significant. The prevalence of these fatiguing illnesses did not differ meaningfully among the four regions surveyed, and no significant geographic trends were observed.

CONCLUSIONS: This investigation estimated that nearly 2.2 million American adults suffer from CFS-like illness. The study also suggested the need to focus future investigations of fatigue on populations with lower incomes and less education. There was no evidence for regional differences in the occurrence of fatiguing illnesses.

 

Source: Bierl C, Nisenbaum R, Hoaglin DC, Randall B, Jones AB, Unger ER, Reeves WC. Regional distribution of fatiguing illnesses in the United States: a pilot study. Popul Health Metr. 2004 Feb 4;2(1):1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC356930/ (Full article)

 

Medication use by persons with chronic fatigue syndrome: results of a randomized telephone survey in Wichita, Kansas

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is characterized by profound fatigue, which substantially interferes with daily activities, and a characteristic symptom complex. Patients use a variety of prescribed and self-administered medications, vitamins, and supplements for relief of their symptoms. The objective of this study was to describe utilization of medications and supplements by persons with CFS and non-fatigued individuals representative of the general population of Wichita, Kansas.

METHODS: We used a random-digit dialing telephone survey to identify persons with CFS in the general population of Wichita, Kansas. Subjects who on the basis of telephone interview met the CFS case definition, and randomly selected non-fatigued controls, were invited for a clinic evaluation that included self-reported use of medications and supplements. Sex-adjusted odds ratios and 95% confidence interval were estimated to measure the association between CFS and use of various drug categories.

RESULTS: We clinically evaluated and classified 90 subjects as CFS during the study and also collected clinical data on 63 who never described fatigue. Subjects with CFS reported using 316 different drugs compared to 157 reported by non-fatigued controls. CFS subjects were more likely to use any drug category than controls (p = 0.0009). Pain relievers and vitamins/supplements were the two most common agents listed by both groups. In addition CFS persons were more likely to use pain relievers, hormones, antidepressants, benzodiazepines, gastro-intestinal, and central nervous system medications (Sex-adjusted odds ratios range = 2.97 – 12.78).

CONCLUSION: Although the reasons for increased use of these agents were not elucidated, the data indicated the CFS patients’ need for symptom relief.

 

Source: Jones JF, Nisenbaum R, Reeves WC. Medication use by persons with chronic fatigue syndrome: results of a randomized telephone survey in Wichita, Kansas. Health Qual Life Outcomes. 2003 Dec 2;1:74. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC293479/ (Full article)

 

Rupture of silicone gel breast implants and symptoms of pain and fatigue

Abstract:

OBJECTIVE: To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant.

METHODS: Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls.

RESULTS: The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% vs 51%), postexertional malaise > 24 h (77% vs 51%), impaired short term memory (58% vs 38%), and multi-joint pain (77% vs 60%).

CONCLUSION: Women with silicone breast implants often report severe pain and chronic fatigue. Rupture of the implant is associated with an increase in symptoms of pain and chronic fatigue.

Comment in:

Where there’s smoke there’s fire: the silicone breast implant controversy continues to flicker: a new disease that needs to be defined. [J Rheumatol. 2003]

Breast implant related disease. [J Rheumatol. 2004]

 

Source: Vermeulen RC, Scholte HR. Rupture of silicone gel breast implants and symptoms of pain and fatigue. J Rheumatol. 2003 Oct;30(10):2263-7. http://www.ncbi.nlm.nih.gov/pubmed/14528527

 

Pathology of the organ of vision in chronic fatigue syndrome

Abstract:

218 patients were examined and the chronic fatigue syndrome (CFS) was diagnosed in them on the basis of clinical-and-immunologic data. 126 somatically healthy persons of the same age and sex were in the control group. Vascular pathology of the vision organ was found in 153 (70.2%) persons, and dystrophic pathology was found in 115 (52.8%) persons. A combination of vascular and dystrophic pathologies of the vision organ was diagnosed in 46 (21.1%) patients. The detection of vision pathology in the CFS patients essentially exceeded the morbidity of similar pathology in the controls. No reliable differences of refraction anomalies were found between the CFS patients and the controls.

 

Source: Frolov VM, Petrunia AM. Pathology of the organ of vision in chronic fatigue syndrome. Vestn Oftalmol. 2003 Mar-Apr;119(2):45-7. [Article in Russian] http://www.ncbi.nlm.nih.gov/pubmed/13678013

 

 

 

Distinguishing patients with chronic fatigue from those with chronic fatigue syndrome: a diagnostic study in UK primary care

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has been defined, but many more patients consult in primary care with chronic fatigue that does not meet the criteria for CFS. General practitioners (GPs) do not generally use the CFS diagnosis, and have some doubt about the validity of CFS as an illness.

AIM: To describe the proportion of patients consulting their GP for fatigue that met the criteria for CFS, and to describe the social, psychological, and physical differences between patients with CFS and those with non-CFS chronic fatigue in primary care.

DESIGN OF STUDY: Baseline data from a trial of complex interventions for fatigue in primary care.

SETTING: Twenty-two general practices located in London and the South Thames region of the United Kingdom recruited patients to the study between 1999 and 2001.

METHOD: One hundred and forty-one patients who presented to their GP with unexplained fatigue lasting six months or more as a main symptom were recruited, and the Centers for Disease Control (CDC) case definition was applied to classify CFS.

RESULTS: Approximately two-thirds (69%) of patients had chronic fatigue and not CFS. The duration of fatigue (32 months) and perceived control over fatigue were similar between groups; however, fatigue, functioning, associated symptoms, and psychological distress were more severe in the patients in the CFS group, who also consulted their GP significantly more frequently, were twice as likely to be depressed, and more than twice as likely to be unemployed. About half (CFS = 50%; chronic fatigue = 55%) in each group attributed their fatigue to mainly psychological causes.

CONCLUSIONS: In primary care, CFS is a more severe illness than chronic fatigue, but non-CFS chronic fatigue is associated with significant fatigue and is reported at least twice as often. That half of patients, irrespective of CFS status, attribute their fatigue to psychological causes, more than is observed in secondary care, indicates an openness to the psychological therapies provided in that setting. More evidence on the natural history of chronic fatigue and CFS in primary care is required, as are trials of complex interventions. The results may help determine the usefulness of differentiating between chronic fatigue and CFS.

 

Source: Darbishire L, Ridsdale L, Seed PT. Distinguishing patients with chronic fatigue from those with chronic fatigue syndrome: a diagnostic study in UK primary care. Br J Gen Pract. 2003 Jun;53(491):441-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1314617/ (Full article)

 

One-year outcome of unexplained fatigue syndromes in primary care: results from an international study

Abstract:

BACKGROUND: Outcome studies of chronic fatigue, neurasthenia and other unexplained fatigue syndromes are few and have been carried out in developed Western countries. This paper aimed to study the outcome of unexplained fatigue syndromes in an international primary care sample and to identify risk factors for persistence.

METHOD: We used data from the WHO collaborative study of psychological problems in general health care, in which 3201 primary care attenders from 14 countries were followed-up for 12 months. The assessment included a modified version of the Composite International Diagnostic Interview.

RESULTS: Unexplained fatigue persisted in one-fifth to one-third of the subjects depending on the definition of fatigue. From the factors studied only severity of fatigue and psychiatric morbidity at baseline were associated with persistence 12 months later. Outcome did not differ between countries of different stages of economic development.

CONCLUSIONS: The prognosis of fatigue syndromes in international primary care is relatively good. The study underlines the importance of psychological factors in influencing short-term prognosis.

 

Source: Skapinakis P, Lewis G, Mavreas V. One-year outcome of unexplained fatigue syndromes in primary care: results from an international study. Psychol Med. 2003 Jul;33(5):857-66. http://www.ncbi.nlm.nih.gov/pubmed/12877400