Mild water-filtered near-infrared whole-body hyperthermia as an adjunct to a standard multimodal rehabilitation in the treatment of fibromyalgia: Results from a randomized controlled trial

Abstract

The value of systemic thermotherapy for treating fibromyalgia is unclear. Both extreme systemic cold and mild systemic heat are applied in clinical practice. However, no data exist from randomized controlled trials. The study aimed to evaluate whether mild water-filtered near-infrared whole-body hyperthermia (NI-WBH) has an additional benefit when applied as an adjunct to a standard multimodal rehabilitation (MR) compared to MR only in patients with fibromyalgia. One hundred and thirty-nine patients of a German inpatient rehabilitation hospital meeting the ACR 1990 criteria for fibromyalgia were randomly allocated to NI-WBH (heating-up to 38.1 °C body core temperature followed by a 15-min heat retention period) and MR or MR only, twice a week over 3 weeks. MR was given on a group basis and consisted of water- and land-based exercise, cognitive behavioral therapy, occupational therapy and health education. MR was administered in the same frequency as NI-WBH. The main outcome measures were affective and sensory pain assessed by a German version of the McGill pain questionnaire, measured at baseline, postintervention, 3 and 6 months postintervention and analyzed by intention to treat. Repeated-measures ANCOVA showed significant differences between groups for both primary outcome measures in favor of NI-WBH and MR compared to MR only (P<.001 for affective pain, P=.001 for sensory pain). Secondary analyses on pain intensity, fibromyalgia-related quality of life and tender point assessment yielded similar results. Moderate effect sizes were observed for all outcome measures considered (range .41–.75). NI-WBH related side effects were observed in 14 of 69 participants (20%) but all disappeared in less than 30 min. The study indicates that NI-WBH is a worthwhile adjunct to MR in the treatment of fibromyalgia. Future trials on NI-WBH should attempt to control for non-specific effects.