From the Journal of Workplace Health and Safety, 24 June 2013 [Epub ahead of print].
Examining the Impact of Obesity on Individuals With Chronic Fatigue Syndrome.
Flores S, Brown A, Adeoye S, Jason LA, Evans M.
Chronic fatigue syndrome (CFS) is a complex disorder affecting multiple body systems. The most commonly used definition of CFS is 6 or more months of fatigue and the presence of at least four of eight minor symptoms. In addition, many health and psychological conditions, including severe obesity-body mass index (BMI) of 40 kg/m2 or greater-exclude individuals from a diagnosis of CFS. Obesity has been correlated with fatigue, sleep problems, and less satisfaction with general health, functioning, and vitality.
The current study investigated weight trends over time in a community-based sample of individuals with CFS and healthy controls. The study further investigated the impact of comorbid weight issues on several health and disability outcomes in a subset of overweight individuals.
Overweight and obese individuals with CFS demonstrated poorer functioning than controls who were similarly weighted. One participant was excluded because she had gained weight at a monitoring visit and her BMI was greater
than 40 kg/m2.
The implications of these findings for health care workers are discussed.
[Workplace Health Saf 2013;61.].
From PLoS One, 14 June 2013. Links to full text.
Exercise Challenge in Gulf War Illness Reveals Two Subgroups with Altered Brain Structure and Function.
Rayhan RU, Stevens BW, Raksit MP, Ripple JA, Timbol CR, Adewuyi O, Vanmeter JW, Baraniuk JN.
Division of Rheumatology, Immunology and Allergy, Department of Medicine, Georgetown University Medical Center, Washington, District of Columbia, United States of America.
Nearly 30% of the approximately 700,000 military personnel who served in Operation Desert Storm (1990-1991) have developed Gulf War Illness, a condition that presents with symptoms such as cognitive impairment, autonomic dysfunction, debilitating fatigue and chronic widespread pain that implicate the central nervous system.
A hallmark complaint of subjects with Gulf War Illness is post-exertional malaise; defined as an exacerbation of symptoms following physical and/or mental effort. To study the causal relationship between exercise, the brain, and changes in symptoms, 28 Gulf War veterans and 10 controls completed an fMRI scan before and after two exercise stress tests to investigate serial changes in pain, autonomic function, and working memory.
Exercise induced two clinical Gulf War Illness subgroups. One subgroup presented with orthostatic tachycardia (n = 10). This phenotype correlated with brainstem atrophy, baseline working memory compensation in the cerebellar vermis, and subsequent loss of compensation after exercise.
The other subgroup developed exercise induced hyperalgesia (n = 18) that was associated with cortical atrophy and baseline working memory
compensation in the basal ganglia. Alterations in cognition, brain structure, and symptoms were absent in controls.
Our novel findings may provide an understanding of the relationship between the brain and post-exertional malaise in Gulf War Illness.
From the Journal of Physical Therapy, 27 June 2013 (E-published before print).
Discriminative Validity of Metabolic and Workload Measurements to Identify Individuals With Chronic Fatigue Syndrome
Christopher R. Snell, Staci R. Stevens, Todd E. Davenport and J. Mark Van Ness
C.R. Snell, Department of Sport Sciences, University of the Pacific, Stockton, California.
S.R. Stevens, Workwell Foundation, Ripon, California.
T.E. Davenport, Department of Physical Therapy, University of the Pacific, 3601 Pacific Ave, Stockton, CA 95211 (USA).
J.M. Van Ness, Department of Sport Sciences, University of the Pacific.
Reduced functional capacity and post-exertional fatigue following physical activity are hallmark symptoms of chronic fatigue syndrome (CFS) and may even qualify for biomarker status. That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing among individuals with CFS.
Test reproducibility in healthy subjects is well documented. This may not be the case with CFS due to delayed recovery symptoms. The
objectives for this study was to determine the discriminative validity of objective measurements obtained during CPET to distinguish individuals with CFS from non-disabled sedentary individuals.
Gas exchange data, workloads and related physiological parameters were compared between 51 individuals with CFS and 10 control subjects, all females, for two maximal exercise tests separated by 24 hours.
Multivariate analysis showed no significant differences between controls and CFS for Test 1. However, for Test 2 the individuals with CFS achieved significantly lower values for oxygen consumption and workload at peak exercise and at the ventilatory/anaerobic threshold. Follow-up classification analysis differentiated between groups with an overall accuracy of 95.1%.
The lack of any significant differences between groups for the first exercise test would appear to support a deconditioning hypothesis for CFS symptoms. However, results from the second test indicate the presence of a CFS related post-exertional fatigue.
It might be concluded that a single exercise test is insufficient to reliably demonstrate functional impairment in individuals with CFS. A
second test may be necessary to document the atypical recovery response and protracted fatigue possibly unique to CFS, which can severely limit productivity in the home and workplace.