Increased Anandamide and Decreased Pain and Depression after Exercise in Fibromyalgia.

PURPOSE:

Physical exercise is increasingly being promoted by healthcare for chronic pain conditions with beneficial outcomes such as: pain and fatigue reduction, and increased quality of life. Nevertheless, knowledge about biochemical consequences of physical exercise in chronic pain is still relatively poor. The endocannabinoid system has been suggested to play a role for acute exercise-induced reward and pain inhibition. The aim of this study is to investigate the chronic outcomes of resistance exercise on levels of endocannabinoids and related lipids in fibromyalgia (FM).

METHODS:

This study examine the outcomes of a 15-week person-centered resistance exercise program on plasma levels of the lipid mediators; anandamide, 2-arachidonoylglycerol (2-AG), oleoylethanolamide (OEA), palmitoylethanolamide (PEA), and stearoylethanolamide (SEA) sampled from 37 women with FM and 33 healthy controls. The associations between clinical scorings of pain, depression, anxiety, fatigue, and muscle strength with levels of these lipid mediators before and after the exercise program are also analysed.

RESULTS:

After the 15 weeks exercise program anandamide levels were significantly increased and SEA levels significantly decreased in FM. Pain intensity and depression scorings decreased and muscle strength increased, and in a multivariate context muscle strength was positively associated with 2-AG levels after the resistance exercise program in FM.

CONCLUSIONS:

The increased anandamide and decreased SEA in women with fibromyalgia after the 15 weeks program might point to a chronic effect of resistance exercise. Pain and depression scorings decreased in the fibromyalgia group after the program but no associations between pain, depression and lipid level changes were assured.