Dr. Crofford has received research funding for a clinical trial from RiboCor, Inc.
Association of fibromyalgia with altered skeletal muscle characteristics which may contribute to postexertional fatigue in postmenopausal women†
Article first published online: 28 JAN 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 65, Issue 2, pages 519–528, February 2013
How to Cite
Srikuea, R., Symons, T. B., Long, D. E., Lee, J. D., Shang, Y., Chomentowski, P. J., Yu, G., Crofford, L. J. and Peterson, C. A. (2013), Association of fibromyalgia with altered skeletal muscle characteristics which may contribute to postexertional fatigue in postmenopausal women. Arthritis & Rheumatism, 65: 519–528. doi: 10.1002/art.37763
The content of this article is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
- Issue published online: 28 JAN 2013
- Article first published online: 28 JAN 2013
- Accepted manuscript online: 1 NOV 2012 12:39PM EST
- Manuscript Accepted: 16 OCT 2012
- Manuscript Received: 18 APR 2012
- NIH (National Institute of Arthritis and Musculoskeletal and Skin Diseases). Grant Number: R21-AG-34279
- National Center for Research Resources/National Center for Advancing Translational Sciences. Grant Number: UL1-TR-000117
To identify muscle physiologic properties that may contribute to postexertional fatigue and malaise in women with fibromyalgia (FM).
Healthy postmenopausal women with (n = 11) and without (n = 11) FM, ages 51–70 years, participated in this study. Physical characteristics and responses to self-reported questionnaires were evaluated. Strength loss and tissue oxygenation in response to a fatiguing exercise protocol were used to quantify fatigability and the local muscle hemodynamic profile. Muscle biopsies were performed to assess between-group differences in baseline muscle properties using histochemical, immunohistochemical, and electron microscopic analyses.
There was no significant difference between healthy controls and FM patients in muscle fatigue in response to exercise. However, self-reported fatigue and pain were correlated with prolonged loss of strength following 12 minutes of recovery in patients with FM. Although there was no difference in percent succinate dehydrogenase (SDH)–positive (type I) and SDH-negative (type II) fibers or in mean fiber cross-sectional area between groups, FM patients exhibited greater variability in fiber size and altered fiber size distribution. In healthy controls only, fatigue resistance was strongly correlated with the size of SDH-positive fibers and hemoglobin oxygenation. In contrast, FM patients with the highest percentage of SDH-positive fibers recovered strength most effectively, and this was correlated with capillary density. However, overall, capillary density was lower in the FM group.
Peripheral mechanisms, i.e., altered muscle fiber size distribution and decreased capillary density, may contribute to postexertional fatigue in FM. Understanding of these defects in fibromyalgic muscle may provide valuable insight with regard to treatment.