TGI Friday! Our weekly round-up of recently published research abstracts | 22 August 2014

From Clinical Infectious Diseases, 12 August 2014 (E-published before print).

Irritable bowel syndrome and chronic fatigue six years after Giardia infection: a controlled prospective cohort study.

Hanevik K(1), Wensaas KA(2), Rortveit G(3), Eide GE(4), Mørch K(5), Langeland N(6).
1) University of Bergen, Department of Clinical Science, 8 floor, Lab-building, N-5021 Bergen, Norway.
2) Research Unit for General Practice, Uni Research Health, N-5018 Bergen, Norway.
3) Research Unit for General Practice, Uni Research Health, N-5018 Bergen, Norway and University of Bergen, Department of Global Public Health and Primary Care, N-5021 Bergen, Norway.
4) Centre for Clinical Research, Haukeland University Hospital, Armauer Hansen's House, N-5021 Bergen, Norway & Department of Global Public Health and Primary Care, University of Bergen, Kalfarveien 31, N-5020 Bergen, Norway.
5) National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, N-5021 Bergen, Norway.
6 University of Bergen, Department of Clinical Science, Armauer Hansen's House, N-5021 Bergen, Norway.

Abstract

BACKGROUND  

Functional gastrointestinal disorders and fatigue may follow acute infections. This study aimed to estimate the persistence, prevalence and risk of irritable bowel syndrome and chronic fatigue six years after Giardia infection.

METHODS  

Controlled prospective study of a cohort of 1252 individuals who had laboratory confirmed Giardia infection during a waterborne outbreak in 2004. In total, 748 cohort cases (exposed) and 878 matched controls responded to a postal questionnaire six years later (in 2010). Responses were compared to data from the same cohort three years before (in 2007).

RESULTS  

The prevalences of irritable bowel syndrome (39.4%) by Rome III criteria and chronic fatigue (30.8%) in the exposed group six years after giardiasis were significantly elevated compared to controls with adjusted RRs of 3.4 (95% CI: 2.9 to 3.9) and 2.9 (95% CI: 2.3 to 3.4) respectively. In the exposed group the prevalence of irritable bowel syndrome decreased by 6.7% (RR: 0.85; 95% CI: 0.77 to 0.93), while the prevalence of chronic fatigue decreased by 15.3% from three to six years after Giardia infection (RR: 0.69; 95% CI: 0.62 to 0.77). Giardia exposure was a significant risk factor for persistence of both conditions and increasing age was a risk factor for persisting chronic fatigue.

CONCLUSIONS  

Giardia infection in a non-endemic setting is associated with an increased risk for irritable bowel syndrome and chronic fatigue six years later. The prevalences of both conditions decrease over time indicating that this intestinal protozoan parasite may elicit very long term, but slowly self-limiting, complications.

From Fatigue: Biomedicine, Health & Behavior, 23 July 2014.

Validating a measure of myalgic encephalomyelitis/chronic fatigue syndrome symptomatology

Abigail A. Brown(*) and Leonard A. Jason
Center for Community Research, DePaul University, Chicago, USA
* Corresponding author

Abstract

BACKGROUND

The diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is complex and largely based on self-reported symptom profiles. The field lacks consensus for a singular case definition and heterogeneous samples make comparability across studies difficult.

PURPOSE

The present study sought to validate a comprehensive self-report measure of ME/CFS symptomatology to aid in clinical and research assessment.

METHODS

Exploratory factor analysis (EFA) was used to establish the underlying factor structure of the DePaul Symptom Questionnaire (DSQ) using a well-characterized sample of individuals (92.6% met the Fukuda et al. criteria and/or the Clinical Canadian Criteria) and this structure was then tested on a less stringently recruited sample of individuals utilizing a confirmatory factor analysis (CFA). Convergent and discriminant validity of the DSQ were also examined utilizing alternative measures of symptomatology and functioning.

RESULTS

A three-factor solution was found using EFA (Neuroendocrine, Autonomic, and Immune Symptoms; Neurological/Cognitive Dysfunction; Post-Exertional Malaise) and the fit of this factor structure was adequate for the second sample. The DSQ was found to have good convergent and discriminant validity.

CONCUSIONS
The DSQ is a valid tool for assessing ME/CFS symptoms. There may be two core ME/CFS symptom clusters: post-exertional malaise and cognitive dysfunction.

From Southern African Journal of Anaesthesia and Analgesia, 25 July 2014.

Paravertebral block as a sole technique for the anaesthetic management of a patient with myalgic encephalomyelitis undergoing breast cancer surgery

Kinsley Enohumah, S. Raza Mehdi, Alan J. McShane(a) and Crina L. Burlacu(*)
Department of Anaesthesia, Intensive Care and Pain Medicine, St Vincent's University Hospital, Dublin, Ireland
* Corresponding author, e-mail: c.burlacu@st-vincents.ie

Abstract

Myalgic encephalomyelitis (ME) is a multifaceted organic disease which, owing to its non-specific multiple symptoms that include incapacitating fatigue, deeply affects the quality of life of diseased patients. It carries a perceived risk of an adverse reaction to drugs, including anaesthetics. However, there is very little information in the medical literature on the anaesthetic management and outcomes of patients with this condition. According to current scientific literature, there is no causal relationship between ME relapse and anaesthesia, surgery or both. We present the anaesthetic management of a ME patient who underwent breast cancer surgery.

BMC Research Notes, 4 August 2014. Full text available.

No association found between the detection of either xenotropic murine leukemia virus-related virus or polytropic murine leukaemia virus and chronic fatigue syndrome in a blinded, multi-site, prospective study by the establishment and use of the SolveCFS BioBank.

David M Irlbeck(1), Suzanne D Vernon(2), K Kimberly McCleary(2), Lucinda Bateman(3), Nancy G Klimas(4), Charles W Lapp(5), Daniel L Peterson(6), James R Brown(7), Katja S Remlinger(8), David A Wilfret(1) and Peter Gerondelis(1,*)
1) Division of Infectious Diseases, GlaxoSmithKline, Research Triangle Park, NC, USA
2) The CFIDS Association of America, Charlotte, NC, USA
3) Fatigue Consultation Clinic, Salt Lake City, UT, USA
4) Chronic Fatigue & Immune Disorders Research and Treatment Center, Miami, FL, USA
5) Hunter-Hopkins Center, Charlotte, NC, USA
6) Sierra Internal Medicine Associates, Incline Village, NV, USA
7) Department of Computational Biology, GlaxoSmithKline, Collegeville, PA, USA
8) Statistical Consulting Group, GlaxoSmithKline, Research Triangle Park, NC, USA
* Corresponding author. Email: peter.z.gerondelis@gsk.com

Abstract

BACKGROUND

In 2009, a retrospective study reported the detection of xenotropic murine leukemia virus-related virus (XMRV) in clinical isolates derived from individuals with chronic fatigue syndrome or myalgic encephalomyelitis (CFS). While many efforts to confirm this observation failed, one report detected polytropic murine leukemia virus (pMLV), instead of XMRV. In both studies, Polymerase Chain Reaction (PCR)-based methods were employed which could provide the basis for the development of a practical diagnostic tool. To confirm these studies, we hypothesized that the ability to detect these viruses will not only depend upon the technical details of the methods employed but also on the criteria used to diagnose CFS and the availability of well characterized clinical isolates.

METHODS

A repository of clinical isolates from geographically distinct sites was generated by the collection of fresh blood samples from well characterized CFS subjects and healthy subjects. Molecular techniques were used to generate assay positive controls and to determine the lower limit of detection (LLOD) for murine retroviral and Intracisternal A particle (Cell 12(4):963-72, 1977) detection methods.

RESULTS

We report the establishment of a repository of well-defined, clinical isolates from five, geographically distinct regions of the US, the comparative determination of the LLODs and validation efforts for the previously reported detection methods and the results of an effort to confirm the association of these retroviral signatures in isolates from individuals with CFS in a blinded, multi-site, prospective study. We detected various, murine retroviral DNA signatures but were unable to resolve a difference in the incidence of their detection between isolates from CFS (5/72; 6.7%) and healthy (2/37; 5.4%) subjects (Fisher's Exact Test, p-value=1). The observed sequences appeared to reflect the detection of endogenous murine retroviral DNA, which was not identical to either XMRV or pMLV.

CONCLUSIONS

We were unable to confirm a previously reported association between the detection of XMRV or pMLV sequences and CFS in a prospective, multi-site study. Murine retroviral sequences were detected at a low frequency that did not differ between CFS and control subjects. The nature of these sequences appeared to reflect the detection of pre-existing, endogenous, murine retroviral DNA in the PCR reagents employed.

From International Journal of MS Care, Summer 2014.

Short-term effect of aerobic exercise on symptoms in multiple sclerosis and chronic fatigue syndrome: a pilot study

Yvonne C. Learmonth(*), PhD; Lorna Paul, PhD; Angus K. McFadyen, PhD; Rebecca Marshall-McKenna, PhD; Paul Mattison, MD; Linda Miller, MPhil; Niall G. McFarlane, PhD
– From the College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, UK (YCL, LP, RMM, NGM);
Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA (YCL);
AKM-STATS, Statistical Consultants, Glasgow, Scotland, UK (AKM);
Multiple Sclerosis Service, NHS Ayrshire and Arran, Scotland, UK (PM, LM);
chool of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK (LM).
* Correspondence: Yvonne C. Learmonth, PhD, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, 906 S. Goodwin Ave., Urbana, IL 61801;
e-mail: ycl@illinois.edu.

Abstract

BACKGROUND

This pilot study was conducted to determine whether a 15-minute bout of moderate-intensity aerobic cycling exercise would affect symptoms (pain and fatigue) and function (Timed 25-Foot Walk test [T25FW] and Timed Up and Go test [TUG]) in people with multiple sclerosis (MS) or chronic fatigue syndrome (CFS), and to compare these results with those of a healthy control group.

METHODS

Eight people with MS (Expanded Disability Status Scale score 5-6; Karnofsky score 50-80), eight people with CFS (Karnofsky score 50-80), and eight healthy volunteers participated in the study. Pain and fatigue levels and results of the T25FW and TUG were established at baseline as well as at 30 minutes, 2 hours, and 24 hours following a 15-minute stationary cycling aerobic exercise test. Repeated-measures analysis of variance (ANOVA) and covariance (ANCOVA) were used to analyze the findings over time.

RESULTS

At baseline there were statistically significant differences between groups in fatigue (P=.039), T25FW (P=.034), and TUG (P=.010). A significant group/time interaction emerged for fatigue levels (P=.005). We found no significant group/time interaction for pain levels or function.

CONCLUSIONS

Undertaking 15 minutes of moderate-intensity aerobic cycling exercise had no significant adverse effects on pain or function in people with MS and CFS (with a Karnofsky score of 50-80) within a 24-hour time period. These initial results suggest that people with MS or CFS may undertake 15 minutes of cycling as moderate aerobic exercise with no expected negative impact on pain or function.

From Fatigue: Biomedicine, Health & Behavior, 23 July 2014.

The role of sleep in chronic fatigue syndrome: a narrative review

Zoe M. Gotts(a,*), Jason G. Ellis(a), Julia L. Newton(b) and Vincent Deary(a)
a) Faculty of Health and Life Sciences, Northumbria Centre for Sleep Research, Northumbria University, Newcastle-upon-Tyne, UK
b) Medical School, Institute of Ageing and Health, Newcastle University & Newcastle Hospitals NHS Foundation Trust and UK NIHR Biomedical Research Centre in Ageing, Newcastle-upon-Tyne, UK
* Corresponding author

Abstract

BACKGROUND

Chronic Fatigue Syndrome (CFS) affects 0.23-2.6% of the adult population. Sleep-related complaints are amongst the most frequently reported symptoms in these patients. Although a biopsychosocial model of CFS offers a plausible framework for understanding the condition, the role of sleep and how it functions within this model remains unclear.

PURPOSE

This narrative review describes the findings of studies of sleep in CFS and considers the reasons behind the diversity of results. The review also discusses the difficulties that exist in establishing relationships between sleep, behaviour, cognition, physiology, and the physical symptoms of CFS.

METHODS

A search of Medline for the terms ‘CFS,' ‘chronic fatigue syndrome,' AND ‘sleep' was performed to identify articles concerning sleep and CFS from 1988 to the present.

RESULTS

Subjective sleep dysfunction was frequently reported in the CFS sleep studies. However, objective sleep research in CFS has shown no consistent picture of sleep disturbance, particularly with regard to polysomnography. This may be attributable to the heterogeneity of sleep phenotypes in the CFS population as well as the variability in sleep assessment protocols, case definitions, and exclusion criteria used across studies.

CONCLUSIONS

Given the high prevalence of disturbed sleep in this population in combination with inconsistent findings, exploration of new protocols for the objective assessment of sleep in CFS (e.g., three-night PSG protocol) is recommended. Understanding the distinct sleep characteristics in this population could serve to improve insight into perpetuating factors of CFS symptoms which is relevant for diagnosis and therapy.