PM&R
Volume 1, Issue 7 , Pages 620-628, July 2009

Exploratory Analysis of the Relationships between Aerobic Capacity and Self-Reported Fatigue in Patients with Rheumatoid Arthritis, Polymyositis, and Chronic Fatigue Syndrome

  • Ali A. Weinstein, PhD

      Affiliations

    • Center for the Study of Chronic Illness and Disability, 4400 University Drive, MSN 5B7, George Mason University, Fairfax, VA 22030†
    • Corresponding Author InformationAddress correspondence to: A.A.W.
    • ,
  • Bart M. Drinkard, PT, MS

      Affiliations

    • Rehabilitation Medicine Department, Clinical Research Center, National Institutes of Health, Bethesda, MD‡
    • ,
  • Guoqing Diao, PhD

      Affiliations

    • Department of Statistics, George Mason University, Fairfax, VA§
    • ,
  • Gloria Furst, OT, MPH

      Affiliations

    • Rehabilitation Medicine Department, Clinical Research Center, National Institutes of Health, Bethesda, MD
    • ,
  • Janet K. Dale, RN, MPH

      Affiliations

    • Clinical Research Program, Division of Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD∥
    • ,
  • Stephen E. Straus, MD

      Affiliations

    • Laboratory of Clinical Infectious Disease, NIAID, NIH, Bethesda, MD#
    • Deceased.
    • ,
  • Lynn H. Gerber, MD

      Affiliations

    • Center for the Study of Chronic Illness and Disability, George Mason University, Fairfax, VA⁎⁎

Received 29 July 2008; accepted 22 April 2009.

Objective

To determine if self-reported levels of physical activity and fatigue are related to peak oxygen uptake (VO2peak) and whether these relationships differ among the patient groups (rheumatoid arthritis [RA], polymyositis [PM], and chronic fatigue syndrome [CFS]).

Design

Correlational investigation.

Setting

Two ambulatory research clinics at the National Institutes of Health, Clinical Center, Bethesda, MD.

Participants

There were 9 patients with PM, 10 with RA, and 10 with CFS. All patients met case criteria for their respective diagnoses.

Methods/Main Outcome Measurements

VO2peak during bicycle ergometry and self-reported fatigability, fatigue, and physical activity. VO2peak was used as the criterion measurement of physiological fatigue with which the self-reported variables were compared.

Results

The Pearson r revealed that self-reported physical activity correlated with VO2peak (r = 61, P = .01). However, fatigability and fatigue did not correlate with VO2peak. Linear regression analysis was performed to assess the effects of diagnosis group, self-reported activity level or fatigue, and their interaction. A trend in the data showed a distinctive relationship between fatigue/fatigability within the 3 groups. In addition, when controlling for group status, self-reported activity predicted aerobic capacity as measured by VO2peak.

Conclusions

This study confirms that patients with chronic, but stable RA, PM, or CFS are fatigued and have significantly decreased aerobic capacity. Self-reports of physical activity predicted VO2peak, and may be used as an indicator of activity-based aerobic capacity. Self-reports of fatigue, however, did not correlate with VO2peak and hence are assessing something other than an index of aerobic capacity, and provide additional information about patients' perceptions, which will require further investigation.

To access this article, please choose from the options below

Login to an existing account or Register a new account.

  • Purchase this article for 31.50 USD (You must login/register to purchase this article)

    Online access for 24 hours. The PDF version can be downloaded as your permanent record.

  • Subscribe to this title

    Get unlimited online access to this article and all other articles in this title 24/7 for one year.

  • Claim access now

    For current subscribers with Society Membership or Account Number.

  • Visit SciVerse ScienceDirect to see if you have access via your institution.
 
  • † Disclosure: nothing to disclose
  • ‡ Disclosure: nothing to disclose
  • § Disclosure: nothing to disclose
  •  Disclosure: nothing to disclose
  • ∥ Disclosure: nothing to disclose
  • # Disclosure: 8; NSF, NIDRR, NIH
  • ⁎⁎ Disclosure: 8; NSF, NIDRR, NIH

 Research supported by the Divisions for Intramural Research, Rehabilitation Medicine Department of the Clinical Center, and NIAID, National Institute of Health.

 The present investigation did not use any medical devices.

 This material was not presented at an AAPM&R Annual Assembly.

 Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org

PII: S1934-1482(09)00436-5

doi:10.1016/j.pmrj.2009.04.007

PM&R
Volume 1, Issue 7 , Pages 620-628, July 2009

Article Tools

* Image Usage & Resolution