Tag: 2007

Diminished Cardiopulmonary Capacity During Post-Exertional Malaise

Abstract:

Reduced functional capacity and post-exertional malaise following physical activity are hallmark symptoms of Chronic Fatigue Syndrome (CFS). That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing with CFS patients. The reproducibility of VO2 max in healthy subjects is well documented. This may not be the case with CFS due to delayed recovery symptoms.

Purpose: To compare results from repeated exercise tests as indicators of post-exertional malaise in CFS.

Methods: Peak oxygen consumption (VO2 peak), percentage of predicted peak heart rate (HR%), and VO2 at anaerobic threshold (AT), were compared between six CFS patients and six control subjects for two maximal exercise tests separated by 24 hours.

Results: Multivariate analysis showed no significant differences between control and CFS, respectively, for test 1: VO2 peak (28.4 ± 7.2 ml/ kg/min; 26.2 ± 4.9 ml/kg/min), AT (17.5 ± 4.8 ml/kg/min; 15.0 ± 4.9 ml/ kg/min) or HR% (87.0 ± 25.4%; 94.8 ± 8.8%). However, for test 2 the CFS patients achieved significantly lower values for both VO2 peak (28.9 ± 8.0 ml/kg/min; 20.5 ± 1.8 ml/kg/min, p = 0.031) and AT (18.0 ± 5.2 ml/kg/min; 11.0 ± 3.4 ml/kg/min, p = 0.021). HR% was not significantly different (97.6 ± 27.2%; 87.8 ± 9.3%, p = 0.07). A follow-up classification analysis differentiated between CFS patients and controls with an overall accuracy of 92%.

Conclusion: In the absence of a second exercise test, the lack of any significant differences for the first test would appear to suggest no functional impairment in CFS patients. However, the results from the second test indicate the presence of a CFS related post-exertional malaise. It might be concluded then that a single exercise test is insufficient to demonstrate functional impairment in CFS patients. A second test may be necessary to document the atypical recovery response and protracted malaise unique to CFS.

Source: J. Mark Vanness, Christopher R. Snell & Staci R. Stevens (2007) Diminished Cardiopulmonary Capacity During Post-Exertional Malaise, Journal of Chronic Fatigue Syndrome, 14:2, 77-85, DOI: 10.1300/J092v14n02_07

Chronic Fatigue Syndrome Linked To Stomach Virus

Chronic fatigue syndrome, also known as ME (myalgic encephalitis), is linked to a stomach virus, suggests research published ahead of print in Journal of Clinical Pathology.

The researchers base their findings on 165 patients with ME, all of whom were subjected to endoscopy because of longstanding gut complaints.

Endoscopy involves the threading of a long tube with a camera on the tip through the gullet into the stomach.

Specimens of stomach tissue were also taken to search for viral proteins and compared with specimens taken from healthy people and patients with other gut diseases none of whom had been diagnosed with ME.

Patients with ME often have intermittent or persistent gut problems, including indigestion and irritable bowel syndrome.

And viral infections, such as Epstein Barr virus (glandular fever), cytomegalovirus, and parvovirus, among others, produce many of the symptoms associated with chronic fatigue syndrome.

Enteroviruses, which infect the bowel, cause severe but short lasting respiratory and gut infections.

There are more than 70 different types, and they head for the central nervous system, heart and muscles.

Most of the biopsy specimens from patients with gut problems showed evidence of mild long term inflammation, although few were infected with Helicobacter pylori, a common bacterial infection associated with inflammation.

But more than 80% of the specimens from the ME patients tested positive for enteroviral particles compared with only seven of the 34 specimens from healthy people.

In a significant proportion of patients, the initial infection had occurred many years earlier.

 

Source: BMJ Specialty Journals. (2007, September 17). Chronic Fatigue Syndrome Linked To Stomach Virus. ScienceDaily. Retrieved March 4, 2017 from  https://www.sciencedaily.com/releases/2007/09/070913132933.htm

 

New Therapy For Chronic Fatigue Syndrome To Be Tested

Press Release: A preliminary study suggests there may be hope in the offing for some sufferers of chronic fatigue syndrome with a new therapy being tested by researchers at the Stanford University School of Medicine.

José Montoya, MD, associate professor of medicine (infectious diseases), and postdoctoral scholar Andreas Kogelnik, MD, PhD, have used the drug valganciclovir – an antiviral often used in treating diseases caused by human herpes viruses – to treat a small number of CFS patients.

The researchers said they treated 25 patients during the last three years, 21 of whom responded with significant improvement that was sustained even after going off the medication at the end of the treatment regimen, which usually lasts six months. The first patient has now been off the drug for almost three years and has had no relapses. A paper describing the first dozen patients Montoya and Kogelnik treated with the drug was published in the December issue of Journal of Clinical Virology.

“This study is small and preliminary, but potentially very important,” said Anthony Komaroff, MD, professor of medicine at Harvard Medical School, who was not involved in the study. “If a randomized trial confirmed the value of this therapy for patients like the ones studied here, it would be an important landmark in the treatment of this illness.”

Montoya has received a $1.3 million grant from Roche Pharmaceutical, which manufactures the drug under the brand name Valcyte, to conduct a randomized, placebo-controlled, double-blind study set to begin this quarter at Stanford. The study will assess the effectiveness of the drug in treating a subset of CFS patients.

Montoya is speaking about his efforts at the biannual meeting of the International Association for Chronic Fatigue Syndrome in Fort Lauderdale on Jan. 11 and 12.

Chronic fatigue syndrome has baffled doctors and researchers for decades, because aside from debilitating fatigue, it lacks consistent symptoms. Although many genetic, infectious, psychiatric and environmental factors have been proposed as possible causes, none has been nailed down. It was often derided as “yuppie flu,” since it seemed to occur frequently in young professionals, though the Centers for Disease Control and Prevention says it’s most common in the middle-aged. But to those suffering from it, CFS is all too real and its effects are devastating, reducing once-vigorous individuals to the ranks of the bedridden, with an all-encompassing, painful and sleep-depriving fatigue.

More than 1 million Americans suffer from the disorder, according to the CDC. The disease often begins with what appears to be routine flulike symptoms, but then fails to subside completely – resulting in chronic, waxing and waning debilitation for years.

Valganciclovir is normally used against diseases caused by viruses in the herpes family, including cytomegalovirus, Epstein-Barr virus and human herpes virus-6. These diseases usually affect patients whose immune systems are severely weakened, such as transplant and cancer patients. Montoya, who had used the drug in treating such patients for years, decided to try using it on a CFS patient who came to him in early 2004 with extremely high levels of antibodies for three of the herpes family viruses in her blood. At the time, she had been suffering from CFS for five years.

When a virus infects someone, the levels of antibodies cranked out by the immune system in response typically increase until the virus is overcome, then slowly diminish over time. But Montoya’s patient had persistently high antibodies for the three viruses. In addition, the lymph nodes in her neck were significantly enlarged, some up to eight times their normal size, suggesting her immune system was fighting some kind of infection, even though a comprehensive evaluation had failed to point to any infectious cause.

Concerned about the unusual elevations in antibody levels as well as the swelling of her lymph nodes, Montoya decided to prescribe valganciclovir. “I thought by giving an antiviral that was effective against herpes viruses for a relatively long period of time, perhaps we could impact somehow the inflammation that she had in her lymph nodes,” said Montoya.

Within four weeks, the patient’s lymph nodes began shrinking. Six weeks later she phoned Montoya from her home in South America, describing how she was now exercising, bicycling and going back to work at the company she ran before her illness. “We were really shocked by this,” recalled Montoya.

Of the two dozen patients Montoya and Kogelnik have since treated, the 20 that responded all had developed CFS after an initial flulike illness, while the non-responders had suffered no initial flu.

Some of the patients take the drug for more than six months, such as Michael Manson, whose battle with CFS has lasted more than 18 years. The former triathlete was stricken with a viral infection a year after his marriage. After trying unsuccessfully to overcome what he thought were lingering effects of the flu, he had no choice but to drastically curtail all his activities and eventually stop working.

During his longest period of extreme fatigue, 13 1/2 weeks, Manson said, “My wife literally thought I was passing away. I could hear the emotion in her voice as she tried to wake me, but I couldn’t wake up to console her. That was just maddening.”

Now in his seventh month of treatment, Manson is able to go backpacking with his children with no ill after-effects. Prior to starting the treatment, Manson’s three children, ages 9 to 14, had never seen him healthy.

Montoya and Kogelnik emphasized that even if their new clinical trial validates the use of valganciclovir in treating some CFS patients, the drug may not be effective in all cases. In fact, the trial will assess the effectiveness of the medication among a specific subset of CFS patients; namely, those who have viral-induced dysfunction of the central nervous system.

“This could be a solution for a subset of patients, but that subset could be quite large,” said Kristin Loomis, executive director of the HHV-6 Foundation, which has helped fund a significant portion of the preparatory work for the clinical trial. “These viruses have been suspected in CFS for decades, but researchers couldn’t prove it because they are so difficult to detect in the blood. If Montoya’s results are confirmed, he will have made a real breakthrough.”

“What is desperately needed is the completion of the randomized, double-blind, placebo-controlled clinical trial that we are about to embark on,” Montoya said.

 

Source: Stanford University Medical Center. “New Therapy For Chronic Fatigue Syndrome To Be Tested.” ScienceDaily. ScienceDaily, 9 January 2007. https://www.sciencedaily.com/releases/2007/01/070108191506.htm

 

Chronic Fatigue Syndrome Impairs A Person’s Slow Wave Activity During Sleep

Press Release: Chronic fatigue syndrome (CFS) has been associated with altered amounts of slow wave sleep, which could reflect reduced electroencephalograph (EEG) activity and impaired sleep regulation. A study published in the journal SLEEP finds that CFS is also associated with a blunted slow wave activity (SWA) response to sleep challenge, suggesting an impairment of the basic sleep drive and homeostatic response.

The study, authored by Roseanna Armitage, PhD, and colleagues at the University of Michigan, focused on 13 pairs of identical twins discordant for CFS. Analyses, which were restricted to the first four non-REM periods each night in order to show comparability, revealed that SWA, or other sleep EEG measures, did not differ between the CFS and healthy twins during a regular night’s sleep. According to Armitage, it was only after a “challenge” to sleep regulation was introduced (keeping them awake an extra four hours) that the CFS twins exhibited significantly less SWA power in the first non-REM period of recovery sleep and accumulated a smaller percentage of SWA in the first non-REM period than their twin counterparts.

“CFS shares symptoms with depression, and some experts have suggested that it is not a distinctly different disorder,” said Armitage. “We have also conducted studies of SWA response to sleep challenge in depression, and the results are very different. Depressed women did not show a blunted SWA response to sleep challenge. The present CFS study included only women, and none had current depression. Therefore, our results cannot be explained on the basis of depression.”

Experts recommend that adults get between seven and eight hours of sleep each night to maintain good health and optimum performance. Persons who think they might have a sleep disorder are urged to consult with their primary care physician, who will refer them to a sleep specialist.

Article: “The Impact of a Four-Hour Sleep Delay on Slow Wave Activity in Twins Discordant for Chronic Fatigue Syndrome”, Sleep, May 1, 2007.

 

Source: American Academy of Sleep Medicine. “Chronic Fatigue Syndrome Impairs A Person’s Slow Wave Activity During Sleep.” ScienceDaily. ScienceDaily, 7 May 2007. www.sciencedaily.com/releases/2007/05/070501075253.htm

Chronic Fatigue: Clues In The Blood

Press Release: University of New South Wales, July 8, 2007. Researchers at UNSW believe that blood may hold vital insights into what is happening in the brain of patients with chronic fatigue syndrome (CFS).

In a study unparalleled in its scope, a team led by UNSW Professor Andrew Lloyd of the Centre for Infection and Inflammation Research, has studied the differences in gene expression patterns in the blood of people who either recover promptly after acute glandular fever or develop the prolonged illness called post-infective syndrome.

The researchers examined six million pieces of gene expression information for analysis in the project, known as the Dubbo Infection Outcomes Study. The study is named after the NSW town in which the work was conducted. The team studied the expression of 30,000 genes in the blood, testing each of the 15 individuals between four and five times over a 12-month period.

The team was able to narrow its findings to the expression of just 35 genes whose pattern of expression correlated closely with the key symptoms of the illness when examined from onset through to recovery. Gene expression is significant because it is the process by which a gene’s DNA sequence is converted into the proteins which ultimately determine the manifestations of disease.

Since 1999, the team has been tracking the long-term health of individuals infected with Ross River virus (RRV), Q fever infection and Epstein-Barr virus, which causes glandular fever.

“These [35] genes might point to the nature of the disease process that underlies CFS, which is currently unknown,” said Professor Lloyd, who is based in the School of Medical Sciences at UNSW. “None of them are ones that I would have predicted, except for those relating to neurotransmitters,” he concedes. “Some of them relate to transport of zinc and other metal ions within the cell, which may suggest a fundamental disturbance in cellular function.”

The researchers now hope to narrow the focus of research onto the expression of these 35 genes in the blood of a much larger group of subjects from the Dubbo Infection Outcomes Study, with varied patterns of illness and recovery.

“There are very few complex diseases which have been comprehensively analysed, with large scale and longitudinal studies, like this,” said Professor Lloyd. “It sets a standard for highly sophisticated, comprehensive gene expression studies in the blood of all sorts of human diseases from rheumatoid arthritis and multiple sclerosis through to schizophrenia.”

The research paper has been published in the Journal of Infectious Diseases.

 

Source: University of New South Wales. “Chronic Fatigue: Clues In The Blood.” ScienceDaily. ScienceDaily, 8 July 2007. https://www.sciencedaily.com/releases/2007/07/070706090020.htm

Exercise performance and chronic pain in chronic fatigue syndrome: the role of pain catastrophizing

Abstract:

OBJECTIVES: This study aimed to examine the associations between bodily pain, pain catastrophizing, depression, activity limitations/participation restrictions, employment status, and exercise performance in female patients with chronic fatigue syndrome (CFS) who experience widespread pain.

DESIGN: Cross-sectional observational study.

SETTING: A university-based clinic.

PATIENTS: Thirty-six female CFS patients who experienced widespread pain.

OUTCOME MEASURES: Patients filled in the Medical Outcomes Short-Form 36 Health Status Survey, the Chronic Fatigue Syndrome Activities and Participation Questionnaire, the Beck Depression Inventory, and the Pain Catastrophizing Scale, and underwent a maximal exercise stress test with continuous monitoring of electrocardiographic and ventilatory parameters.

RESULTS: Pain catastrophizing was related to bodily pain (r = -0.70), depression (r = 0.55), activity limitations/participation restrictions (r = 0.68), various aspects of quality of life ( r varied between -0.51 and -0.64), and exercise capacity (r varied between -0.41 and -0.61). Based on hierarchical multiple regression analysis, pain catastrophizing accounted for 41% of the variance in bodily pain in female CFS patients who experience chronic widespread musculoskeletal pain. Among the three subscale scores of the Pain Catastrophizing Scale, helplessness and rumination rather than magnification were strongly related to bodily pain. Neither pain catastrophizing nor depression was related to employment status.

CONCLUSIONS: These data provide evidence favoring a significant association between pain catastrophizing, bodily pain, exercise performance, and self-reported disability in female patients with CFS who experience widespread pain. Further prospective longitudinal studying of these variables is required.

Comment in: Response to: exercise performance and chronic pain in chronic fatigue syndrome: the role of pain catastrophizing. [Pain Med. 2009]

 

Source: Nijs J, Van de Putte K, Louckx F, Truijen S, De Meirleir K. Exercise performance and chronic pain in chronic fatigue syndrome: the role of pain catastrophizing. Pain Med. 2008 Nov;9(8):1164-72. Epub 2007 Oct 3. http://painmedicine.oxfordjournals.org/content/9/8/1164.long (Full article)

 

Electrocardiographic QT interval and cardiovascular reactivity in fibromyalgia differ from chronic fatigue syndrome

Abstract:

BACKGROUND: Fibromyalgia (FM) and chronic fatigue syndrome (CFS) frequently overlap clinically and have been considered variants of one common disorder. We have recently shown that CFS is associated with a short corrected electrocardiographic QT interval (QTc). In the present study, we evaluated whether FM and CFS can be distinguished by QTc.

METHODS: The study groups were comprised of women with FM (n=30) and with CFS (n=28). The patients were evaluated with a 10 min supine-30 min head-up tilt test. The electrocardiographic QT interval was corrected for heart rate (HR) according to Fridericia’s equation (QTc). In addition, cardiovascular reactivity was assessed based on blood pressure and HR changes and was expressed as the ‘hemodynamic instability score’ (HIS).

RESULTS: The average supine QTc in FM was 417 ms (SD 25) versus 372 ms (SD 22) in CFS (p<0.0001); the supine QTc cut-off <385.7 ms was 79% sensitive and 87% specific for CFS vs. FM. The average QTc at the 10th minute of tilt was 409 ms (SD 18) in FM versus 367 ms (SD 21) in CFS (p<0.0001); the tilt QTc cut-off <383.3 ms was 71% sensitive and 91% specific for CFS vs. FM. The average HIS in FM patients was -3.52 (SD 1.96) versus +3.21 (SD 2.43) in CFS (p<0.0001).

CONCLUSION: A relatively short QTc and positive HIS characterize CFS patients and distinguish them from FM patients. These data may support the contention that FM and CFS are separate disorders.

 

Source: Naschitz JE, Slobodin G, Sharif D, Fields M, Isseroff H, Sabo E, Rosner I. Electrocardiographic QT interval and cardiovascular reactivity in fibromyalgia differ from chronic fatigue syndrome. Eur J Intern Med. 2008 May;19(3):187-91. doi: 10.1016/j.ejim.2007.08.003. Epub 2007 Nov 19. https://www.ncbi.nlm.nih.gov/pubmed/18395162

 

Specific correlations between muscle oxidative stress and chronic fatigue syndrome: a working hypothesis

Abstract:

Chronic fatigue syndrome (CFS) is a relatively common disorder defined as a status of severe persistent disabling fatigue and subjective unwellness. While the biological basis of the pathology of this disease has recently been confirmed, its pathophysiology remains to be elucidated. Moreover, since the causes of CFS have not been identified, treatment programs are directed at symptom relief, with the ultimate goal of the patient regaining some level of pre-existing function and well-being.

Several studies have examined whether CFS is associated with: (i) a range of infectious agents and or immune disturbance; (ii) specific changes of activity in the central or peripheral nervous systems; and (iii) elevated stress periods, which may be associated with the pathology via genetic mechanisms.

The role of oxidative stress in CFS is an emerging focus of research due to evidence of its association with some pathological features of this syndrome. New data collectively support the presence of specific critical points in the muscle that are affected by free radicals and in view of these considerations, the possible role of skeletal muscle oxidative imbalance in the genesis of CFS is discussed.

 

Source: Fulle S, Pietrangelo T, Mancinelli R, Saggini R, Fanò G. Specific correlations between muscle oxidative stress and chronic fatigue syndrome: a working hypothesis. J Muscle Res Cell Motil. 2007;28(6):355-62. doi: 10.1007/s10974-008-9128-y. Epub 2008 Feb 15. https://www.ncbi.nlm.nih.gov/pubmed/18274865

 

Comparison of two exercise testing protocols in patients with chronic fatigue syndrome

Abstract:

This study examined whether a linear exercise stress-testing protocol generated different peak exercise performance variables than a stepwise exercise testing protocol in patients with chronic fatigue syndrome (CFS). We conducted a comparative study with patients randomly allocated to one of two exercise testing protocols.

Twenty-eight women with CFS completed two self-reported measures (the CFS Symptom List and the CFS Activities and Participation Questionnaire) and then performed until exhaustion either the linear or the stepwise exercise testing protocol with continuous monitoring of physiological variables (heart rate and oxygen uptake).

At baseline, we found no significant differences in demographic features and health status between groups (p > 0.05). Based on ratio peak workload/peak oxygen uptake, mechanical efficiency was lower among the subjects performing the stepwise protocol (p = 0.002). When we analyzed the mean linear regression slope values between oxygen uptake and workload from each subject’s minute-by-minute exercise data points, we found that mechanical efficiency was lower among the subjects performing the stepwise protocol (p = 0.039). Apart from mechanical efficiency, we found no differences in exercise performance data between groups (p > 0.05).

Our results suggest that the difference between linear and stepwise exercise protocols cannot account for all discrepancies of previous studies on exercise performance data in women with CFS, but they do suggest that the nature of the exercise testing protocol influences mechanical efficiency in these patients. Further study is warranted.

 

Source: Nijs J, Zwinnen K, Meeusen R, de Geus B, De Meirleir K. Comparison of two exercise testing protocols in patients with chronic fatigue syndrome. J Rehabil Res Dev. 2007;44(4):553-9. http://www.rehab.research.va.gov/jour/07/44/4/Nijs.html (Full article)

 

Chronic fatigue syndrome: inflammation, immune function, and neuroendocrine interactions

Abstract:

Investigations into the underlying cause of chronic fatigue syndrome have advanced the field considerably in the past year. Gene microarray data have led to a better understanding of pathogenesis. Recent research has evaluated genetic signatures, described biologic subgroups, and suggested potential targeted treatments. Acute viral infection studies found that initial infection severity was the single best predictor of persistent fatigue. Genomic studies showed that persistent cases express Epstein Barr virus-specific genes and demonstrate abnormalities of mitochondrial function. Studies of immune dysfunction extended observations of natural killer cytotoxic cell dysfunction of the cytotoxic T cell through quantitative evaluation of intracellular perforins and granzymes. Other research has focused on a subgroup of patients with reactivated viral infection. These advances should result in targeted therapies that impact immune function, hypothalamic-pituitary-adrenal axis regulation, and persistent viral reactivation.

 

Source: Klimas NG, Koneru AO. Chronic fatigue syndrome: inflammation, immune function, and neuroendocrine interactions. Curr Rheumatol Rep. 2007 Dec;9(6):482-7. https://www.ncbi.nlm.nih.gov/pubmed/18177602