The acute effect of maximal exercise on plasma beta-endorphin levels in fibromyalgia patients

• Published in: The Korean journal of pain 2016-10, Vol.29 (4), p.249-254
• Main Authors: Bidari, Ali, Ghavidel-Parsa, Banafsheh, Rajabi, Sahar, Sanaei, Omid, Toutounchi, Mehrangiz
• Format: Article
• Language: Korean
• Subjects: Beta-endorphin; Exercise; Fibromyalgia; Healthy subjects; Pain; Serum
• ISSN: 2005-9159; 2093-0569

Background: This study aimed to investigate the effect of strenuous exercise on β-endorphine (β-END) level in fibromyalgia (FM) patients compared to healthy subjects. Methods: We enrolled 30 FM patients and 15 healthy individuals. All study participants underwent a treadmill exercise test using modified Bruce protocol (M.Bruce). The goal of the test was achieving at least 70% of the predicted maximal heart rate (HRMax). The serum levels of β-END were measured before and after the exercise program. Measurements were done while heart rate was at least 70% of its predicted maximum. Results: The mean ± the standard deviation (SD) of exercise duration in the FM and control groups were 24.26 ± 5.29 and 29.06 ± 3.26 minutes, respectively, indicating a shorter time to achieve the goal heart rate in FM patients (P < 0.003). Most FM patients attained 70% HRMax at lower stages (stage 2 and 3) of M.Bruce compared to the control group (70% versus 6.6%, respectively; P ＜ 0.0001). Compared to healthy subjects, FM patients had lower serum β-END levels both in baseline and post-exercise status (Mean ± SD: 122.07 ± 28.56 ug/ml and 246.55 ± 29.57 ug/ml in the control group versus 90.12 ± 20.91 ug/ml and 179.80 ± 28.57 ug/ml in FM patients, respectively; P ＜ 0.001). Conclusions: We found that FM patients had lower levels of β-END in both basal and post-exercise status. Exercise increased serum the β-END level in both groups but the average increase in β -END in FM patients was significantly lower than in the control group. (Korean J Pain 2016; 29: 249-54)