Whole-body cryotherapy (WBC) significantly reduced pain and disease activity in people with fibromyalgia; and that result likely was due to alterations to levels of immune signaling proteins called cytokines, a study has found.
However, the benefits disappeared three months after the last WBC session.
While more research is required to validate the clinical significance of the treatment, the results suggest that WBC is a clinically valid and fast-acting treatment for people with fibromyalgia, investigators said.
The trial, “Serial whole-body cryotherapy in fibromyalgia is effective and alters cytokine profiles,” appeared in the journal Advances in Rheumatology.
Dysregulation of cytokines, along with other immune factors, are thought to play an important role in the development and disease course of fibromyalgia and other chronic pain disorders. In patients experiencing neuropathic pain (damage or injury to nerves), levels of pro-inflammatory and anti-inflammatory cytokines are unbalanced leading to impairments in pain processing.
WBC involves briefly exposing patients to extremely cold dry air in a controlled environment that reduces pain by stimulating constriction of blood vessels and temperature receptors in the skin. Used to treat athletic injuries, rheumatoid arthritis and other inflammatory diseases, WBC modulates cytokine levels and immune function in healthy individuals, making it a potential therapy for fibromyalgia-related pain. A previous study showed positive short-term effects in fibromyalgia patients, as the treatment reduced pain and fatigue, and improved health-related quality of life.
Researchers in Germany sought to assess the long-term effectiveness of WBC on fibromyalgia-related pain, disease activity, and cytokine levels. Study participants received WBC at minus 130 C (minus 202 F) in six serial sessions, from 90 seconds to three minutes, over three weeks.
Changes in pain level were measured using a visual analog scale form, while disease activity was assessed using the revised Fibromyalgia Impact Questionnaire that has a zero (best) to 100 (worst) scale.
From 2014 to 2015, a total of 57 participants were recruited, including 26 fibromyalgia patients and 31 healthy controls. Three patients and one control dropped out during treatment, leaving 23 patients and 30 controls to be included in the analysis. The study participants were 66% (15 of 23) female, mean age was 46 years, and mean disease duration (time since disease onset) was 13.9 years.
After three WBC sessions, the mean pain score decreased from 5.91 mm to 4.00 mm, a reduction that failed to meet the 2.1 point threshold for a clinically important difference. However, after six sessions, the mean patient pain score had decreased to 3.43 mm, a clinically meaningful reduction. At the three-month follow-up, the mean pain score had increased to 7.17, which was above baseline (study start).
Mean disease activity decreased from 60.7 to 48.5 following six sessions. The 12.2% decrease did not achieve the clinically important threshold of 14%. Three months after treatment, disease activity had returned to the baseline level of 64.1.
Blood levels of cytokines were higher in patients than in controls at every timepoint. Levels of interleukin (IL)-1, an inflammatory molecule, decreased significantly in fibromyalgia patients after both three and six sessions, and at the three months follow up. Interestingly, IL-1 levels in fibromyalgia patients were higher after treatment than in healthy controls at baseline.
Likewise, IL-6 levels decreased significantly in both patients and controls following treatment. At the three month follow-up, IL-6 levels were still reduced in patients but had returned to baseline in controls. In turn. levels of the anti-inflammatory molecule IL-10 were higher in patients than in controls at baseline, after six sessions and three months after the last WBC application.
“Until now, it was not known how long the beneficial effects of WBC on [fibromyalgia] would last after treatment,” the investigators wrote. “Serial WBC … had effects for more than 1 month after termination of WBC treatment, which then decreased over time and were not effective after 3 months.”
After completing the treatment, most patients reported high satisfaction with WBC as a treatment option.
According to the scientists, the study was limited by the lack of a control group of fibromyalgia patients not receiving whole-body cryotherapy.