Jessica R. Shaw

Electrical Impedance of Acupuncture Meridians: The Relevance of Subcutaneous Collagenous Bands

Background The scientific basis for acupuncture meridians is unknown. Past studies have suggested that acupuncture meridians are physiologically characterized by low electrical impedance and anatomically associated with connective tissue planes. We are interested in seeing whether acupuncture meridians are associated with lower electrical impedance and whether ultrasound-derived measures – specifically echogenic collagenous bands - can account for these impedance differences. Methods/Results In 28 healthy subjects, we assessed electrical impedance of skin and underlying subcutaneous connective tissue using a four needle-electrode approach. The impedances were obtained at 10 kHz and 100 kHz frequencies and at three body sites - upper arm (Large Intestine meridian), thigh (Liver), and lower leg (Bladder). Meridian locations were determined by acupuncturists. Ultrasound images were obtained to characterize the anatomical features at each measured site. We found significantly reduced electrical impedance at the Large Intestine meridian compared to adjacent control for both frequencies. No significant decrease in impedance was found at the Liver or Bladder meridian. Greater subcutaneous echogenic densities were significantly associated with reduced impedances in both within-site (meridian vs. adjacent control) and between-site (arm vs. thigh vs. lower leg) analyses. This relationship remained significant in multivariable analyses which also accounted for gender, needle penetration depth, subcutaneous layer thickness, and other ultrasound-derived measures. Conclusion/Significance Collagenous bands, represented by increased ultrasound echogenicity, are significantly associated with lower electrical impedance and may account for reduced impedances previously reported at acupuncture meridians. This finding may provide important insights into the nature of acupuncture meridians and the relevance of collagen in bioelectrical measurements.

Participants’ Experiences of Being Debriefed to Placebo Allocation in a Clinical Trial

Participants in placebo-controlled clinical trials give informed consent to be randomized to verum or placebo. However, researchers rarely tell participants which treatment they actually received. We interviewed 4 participants in a trial of acupuncture for irritable bowel syndrome before, during, and after they received a course of placebo treatments over 6 weeks. During the final interview, we informed participants that they had received a course of placebo treatments. We used an idiographic phenomenological approach based on the Sheffield School to describe each participant’s experiences of being blinded to and then debriefed to placebo allocation. The participants’ experiences of blinding and debriefing were embodied, related to their goals in undertaking the study, and social (e.g., embedded in trusting and valued relationships with acupuncturists). We suggest ways in which debriefing to placebo allocation can be managed sensitively to facilitate positive outcomes for participants.