The influence of aerobic fitness and fibromyalgia on cardiorespiratory and perceptual responses to exercise in patients with chronic fatigue syndrome

Abstract:

OBJECTIVE: To investigate cardiorespiratory and perceptual responses to exercise in patients with chronic fatigue syndrome (CFS), accounting for comorbid fibromyalgia (FM) and controlling for aerobic fitness.

METHODS: Twenty-nine patients with CFS only, 23 patients with CFS plus FM, and 32 controls completed an incremental bicycle test to exhaustion. Cardiorespiratory and perceptual responses were measured. Results were determined for the entire sample and for 18 subjects from each group matched for peak oxygen consumption.

RESULTS: In the overall sample, there were no significant differences in cardiorespiratory parameters between the CFS only group and the controls. However, the CFS plus FM group exhibited lower ventilation, lower end-tidal CO2, and higher ventilatory equivalent of carbon dioxide compared with controls, and slower increases in heart rate compared with both patients with CFS only and controls. Peak oxygen consumption, ventilation, and workload were lower in the CFS plus FM group. Subjects in both the CFS only group and the CFS plus FM group rated exercise as more effortful than did controls. Patients with CFS plus FM rated exercise as significantly more painful than did patients with CFS only or controls. In the subgroups matched for aerobic fitness, there were no significant differences among the groups for any measured cardiorespiratory response, but perceptual differences in the CFS plus FM group remained.

CONCLUSION: With matching for aerobic fitness, cardiorespiratory responses to exercise in patients with CFS only and CFS plus FM are not different from those in sedentary healthy subjects. While CFS patients with comorbid FM perceive exercise as more effortful and painful than do controls, those with CFS alone do not. These results suggest that aerobic fitness and a concurrent diagnosis of FM are likely explanations for currently conflicting data and challenge ideas implicating metabolic disease in the pathogenesis of CFS.

 

Source: Cook DB, Nagelkirk PR, Poluri A, Mores J, Natelson BH. The influence of aerobic fitness and fibromyalgia on cardiorespiratory and perceptual responses to exercise in patients with chronic fatigue syndrome. Arthritis Rheum. 2006 Oct;54(10):3351-62. https://www.ncbi.nlm.nih.gov/pubmed/17009309

 

A Chronic Fatigue Syndrome – related proteome in human cerebrospinal fluid

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS), Persian Gulf War Illness (PGI), and fibromyalgia are overlapping symptom complexes without objective markers or known pathophysiology. Neurological dysfunction is common. We assessed cerebrospinal fluid to find proteins that were differentially expressed in this CFS-spectrum of illnesses compared to control subjects.

METHODS: Cerebrospinal fluid specimens from 10 CFS, 10 PGI, and 10 control subjects (50 mul/subject) were pooled into one sample per group (cohort 1). Cohort 2 of 12 control and 9 CFS subjects had their fluids (200 mul/subject) assessed individually. After trypsin digestion, peptides were analyzed by capillary chromatography, quadrupole-time-of-flight mass spectrometry, peptide sequencing, bioinformatic protein identification, and statistical analysis.

RESULTS: Pooled CFS and PGI samples shared 20 proteins that were not detectable in the pooled control sample (cohort 1 CFS-related proteome). Multilogistic regression analysis (GLM) of cohort 2 detected 10 proteins that were shared by CFS individuals and the cohort 1 CFS-related proteome, but were not detected in control samples. Detection of >or=1 of a select set of 5 CFS-related proteins predicted CFS status with 80% concordance (logistic model). The proteins were alpha-1-macroglobulin, amyloid precursor-like protein 1, keratin 16, orosomucoid 2 and pigment epithelium-derived factor. Overall, 62 of 115 proteins were newly described.

CONCLUSION: This pilot study detected an identical set of central nervous system, innate immune and amyloidogenic proteins in cerebrospinal fluids from two independent cohorts of subjects with overlapping CFS, PGI and fibromyalgia. Although syndrome names and definitions were different, the proteome and presumed pathological mechanism(s) may be shared.

 

Source: Baraniuk JN, Casado B, Maibach H, Clauw DJ, Pannell LK, Hess S S. A Chronic Fatigue Syndrome – related proteome in human cerebrospinal fluid. BMC Neurol. 2005 Dec 1;5:22. http://www.ncbi.nlm.nih.gov/pubmed/16321154

 

Gulf War veterans’ health: medical evaluation of a U.S. cohort

Abstract:

BACKGROUND: United States military personnel reported various symptoms after deployment to the Persian Gulf during the 1991 Gulf War. However, the symptoms’ long-term prevalence and association with deployment remain controversial.

OBJECTIVE: To assess and compare the prevalence of selected medical conditions in a national cohort of deployed and nondeployed Gulf War veterans who were evaluated by direct medical and teledermatologic examinations.

DESIGN: A cross-sectional prevalence study performed 10 years after the 1991 Gulf War.

SETTING: Veterans were examined at 1 of 16 Veterans Affairs medical centers.

PARTICIPANTS: Deployed (n = 1061) and nondeployed (n = 1128) veterans of the 1991 Gulf War.

MEASUREMENTS: Primary outcome measures included fibromyalgia, the chronic fatigue syndrome, dermatologic conditions, dyspepsia, physical health-related quality of life (Short Form-36 [SF-36]), hypertension, obstructive lung disease, arthralgias, and peripheral neuropathy.

RESULTS: Of 12 conditions, only 4 conditions were more prevalent among deployed than nondeployed veterans: fibromyalgia (deployed, 2.0%; nondeployed, 1.2%; odds ratio, 2.32 [95% CI, 1.02 to 5.27]); the chronic fatigue syndrome (deployed, 1.6%; nondeployed 0.1%; odds ratio, 40.6 [CI, 10.2 to 161]); dermatologic conditions (deployed, 34.6%; nondeployed, 26.8%; odds ratio, 1.38 [CI, 1.06 to 1.80]), and dyspepsia (deployed, 9.1%; nondeployed, 6.0%; odds ratio, 1.87 [CI, 1.16 to 2.99]). The mean physical component summary score of the SF-36 for deployed and nondeployed veterans was 49.3 and 50.8, respectively.

LIMITATIONS: Relatively low participation rates introduce potential participation bias, and deployment-related illnesses that resolved before the research examination could not, by design, be detected.

CONCLUSIONS: Ten years after the Gulf War, the physical health of deployed and nondeployed veterans is similar. However, Gulf War deployment is associated with an increased risk for fibromyalgia, the chronic fatigue syndrome, skin conditions, dyspepsia, and a clinically insignificant decrease in the SF-36 physical component score.

Comment in: Unexplained suffering in the aftermath of war. [Ann Intern Med. 2005]

 

Source: Eisen SA, Kang HK, Murphy FM, Blanchard MS, Reda DJ, Henderson WG, Toomey R, Jackson LW, Alpern R, Parks BJ, Klimas N, Hall C, Pak HS, Hunter J,Karlinsky J, Battistone MJ, Lyons MJ; Gulf War Study Participating Investigators. Gulf War veterans’ health: medical evaluation of a U.S. cohort. Ann Intern Med. 2005 Jun 7;142(11):881-90. http://www.ncbi.nlm.nih.gov/pubmed/15941694

 

Urinary electrophoretic profiles from chronic fatigue syndrome and chronic fatigue syndrome/fibromyalgia patients: a pilot study for achieving their normalization

Abstract:

Aim of our study was to determine if there were distinct, disease-related patterns of urinary analytes in chronic fatigue syndrome (CFS) and chronic fatigue syndrome/fibromyalgia (CFS/FM) compared to normal controls (NC).

Urine was collected from these subjects for two consecutive 24 h periods and aliquots were submitted to micellar electrokinetic chromatography (MEKC). To compensate for the differences in peak migration times, these were normalized from the 35 min duration of run to a 100-point scale, and each peak was assigned its normalized time measure. Peak heights were also normalized by dividing the mAU by that of the internal standard (creatinine) and multiplying by 100. MEKC with normalization for peak height and migration time generated comparable results within each of the patient groups.

CFS/FM and CFS had significant differences in peaks compared to NC that may be of significance as biomarkers of illnesses.

 

Source: Casado B, Zanone C, Annovazzi L, Iadarola P, Whalen G, Baraniuk JN. Urinary electrophoretic profiles from chronic fatigue syndrome and chronic fatigue syndrome/fibromyalgia patients: a pilot study for achieving their normalization. J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Jan 5;814(1):43-51. http://www.ncbi.nlm.nih.gov/pubmed/15607706

 

Incidence of fatigue symptoms and diagnoses presenting in UK primary care from 1990 to 2001

Erratum in: J R Soc Med. 2005 Feb;98(2):88.

 

Abstract:

Little is known about whether the incidence of symptoms of fatigue presented in primary care, and the consequent diagnoses made, change over time. The UK General Practice Research Database was used to investigate the annual incidence of both fatigue symptoms and diagnoses recorded in UK primary care from 1990 to 2001. The overall incidence of all fatigue diagnoses decreased from 87 per 100 000 patients in 1990 to 49 in 2001, a reduction of 44%, while postviral fatigue syndromes decreased from 81% of all fatigue diagnoses in 1990 to 60% in 2001. Chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) together increased from 9% to 26% of all fatigue diagnoses. The incidence of fibromyalgia increased from less than 1 per 100 000 to 35 per 100 000. In contrast, there was no consistent change in the incidence of all recorded symptoms of fatigue, with an average of 1503 per 100 000, equivalent to 1.5% per year. CFS/ME and fibromyalgia were rarely diagnosed in children and were uncommon in the elderly. All symptoms and diagnoses were more common in females than in males. The overall incidence of fatigue diagnoses in general has fallen, but the incidence rates of the specific diagnoses of CFS/ME and fibromyalgia have risen, against a background of little change in symptom reporting. This is likely to reflect fashions in diagnostic labelling rather than true changes in incidence.

Comment in: Brain imaging in fatigue syndromes. [J R Soc Med. 2005]

 

Source: Gallagher AM, Thomas JM, Hamilton WT, White PD. Incidence of fatigue symptoms and diagnoses presenting in UK primary care from 1990 to 2001. J R Soc Med. 2004 Dec;97(12):571-5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1079668/ (Full article)

 

Patient power and control: a study of women with uncertain illness trajectories

Abstract:

The authors interviewed 12 women diagnosed with chronic fatigue syndrome and 13 with fibromyalgia with the aim of determining the strategies they perceive themselves as using to gain control over their situation during the health care process. The results highlight various strategies that the women report applying to find a way of managing the illness and to influence caregivers. They describe, for example, how they try to gain control over their situation by acquiring knowledge about the illness. The women also describe various power strategies they use in their interaction with the caregivers to take command of their situation, namely exiting, noncompliance, confrontation, persuasion/insistence, making demands, and demonstrative distancing.

 

Source: Asbring P, Närvänen AL. Patient power and control: a study of women with uncertain illness trajectories. Qual Health Res. 2004 Feb;14(2):226-40. http://www.ncbi.nlm.nih.gov/pubmed/14768459

 

Medically unexplained physical symptoms, anxiety, and depression: a meta-analytic review

Abstract:

OBJECTIVE: Our objective was to review and compare, with meta-analytic methods, observational studies on the association of medically unexplained physical symptoms, anxiety, and depression with special emphasis on healthy and organically ill control groups and on different types of symptoms, measures, and illness behavior.

METHODS: A search of MEDLINE and PsycLIT/PsycINFO for abstracts from 1980 to April 2001 was performed; principal investigators in the field were contacted and article reference lists were used to retrieve additional relevant articles. Two hundred forty-four studies were included on the basis of consensus ratings if they fulfilled seven of eight inclusion criteria pertaining to diagnostic accuracy and statistical appropriateness. Five hundred twenty-two studies were deferred or excluded. We focused specifically on the four functional somatic syndromes for which there were sufficient numbers for meta-analytic integration: irritable bowel syndrome (IBS), nonulcer dyspepsia (NUD), fibromyalgia (FM), and chronic fatigue syndrome (CFS). Data were extracted independently by two authors according to a prespecified coding manual with up to 70 parameters per study.

RESULTS: Effect sizes for the association of the four functional somatic syndromes with depression and anxiety were of moderate magnitude but were highly significant statistically when compared with healthy persons and controls with medical disorders of known organic pathology. Moreover, this association was significant whether depression was measured with or without somatic items. Chronic fatigue syndrome is characterized by higher scores of depression, fibromyalgia by lower scores of anxiety than irritable bowel syndrome. Consulting behavior and severity of somatization is related to higher levels of anxiety and depression.

CONCLUSIONS: Meta-analytic integration confirms that the four functional somatic syndromes (IBS, NUD, FM, CFS) are related to (but not fully dependent on) depression and anxiety. At present, there is only limited meta-analytic evidence for the same sort of association for medically unexplained physical symptoms in general. In view of the relative independence from depression and anxiety, classification and treatment of these symptoms and syndromes as “common mental disorders” does not seem fully appropriate.

 

Source: Henningsen P, Zimmermann T, Sattel H. Medically unexplained physical symptoms, anxiety, and depression: a meta-analytic review. Psychosom Med. 2003 Jul-Aug;65(4):528-33. http://www.ncbi.nlm.nih.gov/pubmed/12883101

 

Mycoplasma blood infection in chronic fatigue and fibromyalgia syndromes

Abstract:

Chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) are characterised by a lack of consistent laboratory and clinical abnormalities. Although they are distinguishable as separate syndromes based on established criteria, a great number of patients are diagnosed with both.

In studies using polymerase chain reaction methods, mycoplasma blood infection has been detected in about 50% of patients with CFS and/or FMS, including patients with Gulf War illnesses and symptoms that overlap with one or both syndromes. Such infection is detected in only about 10% of healthy individuals, significantly less than in patients.

Most patients with CFS/FMS who have mycoplasma infection appear to recover and reach their pre-illness state after long-term antibiotic therapy with doxycycline, and the infection can not be detected after recovery. By means of causation and therapy, mycoplasma blood infection may permit a further subclassification of CFS and FMS.

It is not clear whether mycoplasmas are associated with CFS/FMS as causal agents, cofactors, or opportunistic infections in patients with immune disturbances. Whether mycoplasma infection can be detected in about 50% of all patient populations with CFS and/or FMS is yet to be determined.

 

Source: Endresen GK. Mycoplasma blood infection in chronic fatigue and fibromyalgia syndromes. Rheumatol Int. 2003 Sep;23(5):211-5. Epub 2003 Jul 16. http://www.ncbi.nlm.nih.gov/pubmed/12879275

 

Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis

Abstract:

OBJECTIVE: Evidence of comorbidity among unexplained illness syndromes raises the possibility that all are variants of a single functional disorder, leading some to suggest that separate case definitions for chronic fatigue syndrome (CFS), fibromyalgia (FM), and multiple chemical sensitivity (MCS) may be unnecessary. Our objective was to determine whether discrete diagnostic labels provide useful information about physical functioning, symptom severity, and risk of psychiatric illness.

METHODS: The sample consisted of 163 consecutive female referrals with CFS enrolled at a tertiary clinic. Each participant was retrospectively assigned to one of four groups: CFS only, CFS/FM, CFS/MCS, and CFS/FM/MCS. At enrollment, participants gave their history, underwent a physical examination and a standardized psychiatric interview (Diagnostic Interview Schedule), and answered self-report questionnaires.

RESULTS: Additional unexplained syndromes were prevalent: 37% met criteria for FM, and 33% met criteria for MCS. With the exception of FM-related pain and disability, there were few differences between the CFS only and CFS with comorbid illness groups. Patients with additional illness were more likely to have major depression and a higher risk of psychiatric morbidity compared with patients in the CFS only group (p <.01). Rates of lifetime depression increased from 27.4% in the CFS only group to 52.3% in the CFS/FM group, 45.2% in the CFS/MCS group, and 69.2% in the CFS/FM/MCS group.

CONCLUSIONS: The prevalence of comorbid illness in the present CFS sample and the failure to find widespread differences in symptom severity can be seen as support for the single syndrome hypothesis. On the other hand, the existence of discrete syndromes could not be ruled out because of reliable differences between CFS and CFS/FM. Increasing comorbidity was associated with a corresponding increase in risk of major depression.

 

Source: Ciccone DS, Natelson BH. Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis. Psychosom Med. 2003 Mar-Apr;65(2):268-75. http://www.ncbi.nlm.nih.gov/pubmed/12651994

 

 

Women experienced chronic fatigue syndrome and fibromyalgia as stigmatising

Comment on: Women’s experiences of stigma in relation to chronic fatigue syndrome and fibromyalgia. [Qual Health Res. 2002]

 

Any clinician who has taken the trouble to get to know a patient with fibromyalgia or CFS will recognise the basic finding of the study by Åsbring and Närvänen — patients attending specialist clinics with either condition (the similarities between the 2 outweigh the differences) feel acutely a sense of discrimination and stigmatisation. Many describe negative interactions with the medical profession.1 This is most acute when doctors are perceived to be “psychologising” the condition. Indeed, patients in this study found the act of prescribing antidepressants to be “violating”. This is regrettable because evidence exists that antidepressants can reduce pain, fatigue, and sleep disturbances in patients with fibromyalgia,2 although similar evidence does not exist for patients with CFS.

You can read the rest of this comment here: http://ebmh.bmj.com/content/5/4/127.long

 

Source: Wessely S. Women experienced chronic fatigue syndrome and fibromyalgia as stigmatising. Evid Based Ment Health. 2002 Nov;5(4):127. http://ebmh.bmj.com/content/5/4/127.long (Full comment)