Warm acupuncture for fibromyalgia with increased cold sensitivity: a cross-over randomised controlled trial.

Objectives: Although approximately 85% of fibromyalgia patients exhibit increased sensitivity to cold, no therapy is available for this particular subgroup. This exploratory clinical trial to evaluate the effect of warm acupuncture, a traditional and common used acupuncture therapy, in treating fibromyalgia patients with high cold sensitivity.

Methods: This randomised, single-blinded, cross-over preliminary study involved an 8-weeks observation and 8-weeks intervention. Thirty-eight patients were assigned to either warm acupuncture group or observation group for 8 weeks randomly, then the assignment switched. The primary outcome was the change in Visual Analogue Scale (VAS) score for cold sensitivity. Secondary outcomes included changes in sensitivity to pain, wind, noise, bright light, and odour assessed by VAS, and series of specialised scales regarding other common fibromyalgia symptoms. A modified intention-to-treat analysis was used to compare differences.

Results: The VAS for cold sensitivity decreased by 2.31-cm in the treatment period and by 0.83-cm in the observation period at week 8 (MD, 1.48; 95% CI, 0.28 to 2.67; p=0.019), and the between-group difference became apparent starting at week 4 (MD, 1.16; 95% CI, -0.03 to 2.36; p=0.015). The secondary efficacy measures, including the VAS for pain, wind, and the Polysymptomatic Distress Scale scores, showed greater improvement during the treatment period compared with that in the observation period at week 8. Adverse events were infrequent and minor.

Conclusions: Warm acupuncture may reduce the heightened sensitivity to cold, pain and wind, as well as the severity of the fibromyalgia in those patients with cold intolerance.