Dynamic training and circulating neuropeptides in rheumatoid arthritis: a two-year follow-up study

Previous research has suggested that a short-term (6 week) high-intensity and a subsequent long-term (1 year) low-intensity dynamic training programme in 8 patients with rheumatoid arthritis (RA) increased circulating levels of beta-endorphin (beta-EP) during the high-intensity training and of corticotropin-releasing factor (CRF) and beta-lipotropin (beta-LPH) levels during the low-intensity training, without an increase of pain experience. The present follow-up study of the patients, using the data obtained after an additional 1-year period of no standardized training as reference values, indicated that CRF levels decreased significantly (P less than 0.01) in relation to those obtained 1 year earlier. For beta-LPH and beta-EP, no corresponding decreases were noted. No significant difference concerning experience of pain over time was found. High-performance liquid chromatography demonstrated a complex elution pattern with low basal concentration of beta-LPH, which increased after 60 min of training.