Elsevier

The American Journal of Medicine

Volume 118, Issue 12, December 2005, Pages 1415.e19-1415.e28
The American Journal of Medicine

Clinical research study
Orthostatic instability in a population-based study of chronic fatigue syndrome

https://doi.org/10.1016/j.amjmed.2005.06.013Get rights and content

Abstract

Purpose

Autonomic nervous system dysfunction has been suggested as involved in the pathophysiology of chronic fatigue syndrome. This population-based case control study addressed the potential association between orthostatic instability (one sign of dysautonomia) and chronic fatigue syndrome.

Subjects and methods

Fifty-eight subjects who fulfilled criteria of the 1994 chronic fatigue syndrome research case definition and 55 healthy controls participated in a 2-day inpatient evaluation. Subjects had been identified during a 4-year population-based chronic fatigue syndrome surveillance study in Wichita, Kan. The present study evaluated subjects’ current medical and psychiatric status, reviewed past medical/psychiatric history and medication use, used a stand-up test to screen for orthostatic instability, and conducted a head-up tilt table test to diagnose orthostatic instability.

Results

No one manifested orthostatic instability in the stand-up test. The head-up tilt test elicited orthostatic instability in 30% of eligible chronic fatigue syndrome subjects (all with postural orthostatic tachycardia) and 48% of controls (50% with neurally mediated hypotension); intolerance was present in only nonfatigued (n = 7) subjects. Neither fatigue nor illness severity were associated with outcome.

Conclusions

Orthostatic instability was similar in persons with chronic fatigue syndrome and nonfatigued controls subjects recruited from the general Wichita population. Delayed responses to head-up tilt tests were common and may reflect hydration status. These findings suggest reappraisal of primary dysautonomia as a factor in the pathogenesis of chronic fatigue syndrome.

Section snippets

Materials and methods

This study adhered to human experimentation guidelines of the US Department of Health and Human Services and complied with the Helsinki Declaration. All participants were volunteers who gave informed consent.

Stand-up screening test

To screen for autonomic nervous system dysfunction, all 113 study subjects underwent a stand-up test during the arrival medical evaluation.29 The stand-up test recorded systolic and diastolic blood pressure and heart rate after 30 minutes in a recumbent position, immediately upon standing, and after standing for 5 minutes. Standing was performed without support or swaying. Orthostatic instability is suggested by a heart rate increase >30 beats per minute above supine baseline (either

Results

There were no significant differences in age, sex, or race/ethnicity between subjects who agreed to participate in the study (Table 2) and those who did not.

Participation

Significantly more subjects with chronic fatigue syndrome were ineligible for head-up tilt table testing than were nonfatigued controls (P = .05). Performance of the tilt test was limited by refusal (7 chronic fatigue syndrome and 1 control), use of antidepressants (15 chronic fatigue syndrome and 4 controls), use of anti-hypertensives (10 chronic fatigue syndrome and 9 controls), exclusionary medical conditions (3 chronic fatigue syndrome, 2 controls), melancholic depression (1 chronic fatigue

Discussion

In this study we found no association between chronic fatigue syndrome and orthostatic instability/intolerance as measured by stand-up or head-up tilt table testing. Participants were screened to insure exclusion of those with possible confounding factors such as underlying medical/psychiatric diseases, older age, and medication use. The study design was particularly powerful because subjects with chronic fatigue syndrome represented those with the illness in the general population rather than

References (41)

  • K. Fukuda et al.

    The chronic fatigue syndromea comprehensive approach to its definition and study

    Ann Intern Med

    (1994)
  • R. Glaser et al.

    Stress-associated immune modulationrelevance to viral infection and chronic fatigue syndrome

    Am J Med

    (1998)
  • P.A. Low et al.

    Postural tachycardia syndrome (POTS)

    Neurology

    (1995)
  • A.M.O. Bakheit et al.

    Abnormal arginine—vasopressin secretion and water metabolism in patients with postviral fatigue syndrome

    Acta Neurol Scand

    (1993)
  • D.J. Kosinski et al.

    Neurally mediated syncope with an update on indications and usefulness of head-upright tilt table testing and pharmacologic therapy

    Curr Opin Cardiol

    (1994)
  • I. Bou-Holaigah et al.

    The relationship between neurally mediated hypotension and the chronic fatigue syndrome

    JAMA

    (1995)
  • J. Poole et al.

    Results of isoproterenol tilt table testing in monozygotic twins discordant for chronic fatigue syndrome

    Arch Intern Med

    (2000)
  • F. De Lorenzo et al.

    Possible relationship between chronic fatigue and postural tachycardia syndromes

    Clin Auton Res

    (1996)
  • M. Pagani et al.

    Chronic fatigue syndromea hypothesis focusing on the autonomic nervous system

    Clin Sci

    (1999)
  • P.C. Rowe et al.

    Fludrocortisone acetate to treat neurally mediated hypotension in chronic fatigue syndromea randomized controlled trial

    JAMA

    (2001)
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