Trial registration: ClinicalTrials.gov http://clinicaltrials.gov/: NCT01154647.
Endogenous Pain Modulation in Response to Exercise in Patients with Rheumatoid Arthritis, Patients with Chronic Fatigue Syndrome and Comorbid Fibromyalgia, and Healthy Controls: A Double-Blind Randomized Controlled Trial
Article first published online: 17 FEB 2014
© 2014 World Institute of Pain
Volume 15, Issue 2, pages 98–106, February 2015
How to Cite
Meeus, M., Hermans, L., Ickmans, K., Struyf, F., Van Cauwenbergh, D., Bronckaerts, L., De Clerck, L. S., Moorken, G., Hans, G., Grosemans, S. and Nijs, J. (2015), Endogenous Pain Modulation in Response to Exercise in Patients with Rheumatoid Arthritis, Patients with Chronic Fatigue Syndrome and Comorbid Fibromyalgia, and Healthy Controls: A Double-Blind Randomized Controlled Trial. Pain Practice, 15: 98–106. doi: 10.1111/papr.12181
- Issue published online: 2 FEB 2015
- Article first published online: 17 FEB 2014
- Manuscript Accepted: 3 DEC 2013
- Manuscript Received: 2 AUG 2013
- ME Research UK
- pain inhibition;
- chronic fatigue syndrome;
- rheumatoid arthritis;
- exercise-induced analgesia;
- conditioned pain modulation;
- temporal summation;
- randomized controlled trial
Temporal summation (TS) of pain, conditioned pain modulation (CPM), and exercise-induced analgesia (EIA) are often investigated in chronic pain populations as an indicator for enhanced pain facilitation and impaired endogenous pain inhibition, respectively, but interactions are not yet clear both in healthy controls and in chronic pain patients. Therefore, the present double-blind randomized placebo-controlled study evaluates pains cores, TS, and CPM in response to exercise in healthy controls, patients with chronic fatigue syndrome and comorbid fibromyalgia (CFS/FM), and patients with rheumatoid arthritis (RA), both under placebo and paracetamol condition.
Fifty-three female volunteers – of which 19 patients with CFS/FM, 16 patients with RA, and 18 healthy controls – underwent a submaximal exercise test on a bicycle ergometer on 2 different occasions (paracetamol vs. placebo), with an interval of 7 days. Before and after exercise, participants rated pain intensity during TS and CPM.
Patients with rheumatoid arthritis showed decreased TS after exercise, both after paracetamol and placebo (P < 0.05). In patients with CFS/FM, results were less univocal. A nonsignificant decrease in TS was only observed after taking paracetamol. CPM responses to exercise are inconclusive, but seem to worsen after exercise. No adverse effects were seen.
This study evaluates pain scores, TS, and CPM in response to submaximal exercise in 2 different chronic pain populations and healthy controls. In patients with RA, exercise had positive effects on TS, suggesting normal EIA. In patients with CFS/FM, these positive effects were only observed after paracetamol and results were inconsistent.