Effects of Cathode Direct-Current Electroacupuncture Stimulus of the Promixal Anterior Lower Limbs on Heart Rate and Lumbar Blood Flow.

Objective: There has been little research on direct-current acupuncture. This study was conducted to verify the effect of acupuncture current intensity and polarity on heart rate (HR) when applying direct-current electroacupuncture (DCEA) to the proximal anterior part of the lower limbs and to clarify the effect of cathodes (-) on lumbar blood flow. Materials and Methods: This study was conducted at Teikyo Heisei University, Chiba, Japan. The subjects were 144 healthy male volunteers (21.7 ± 0.6 years' old). These participants were divided into 1 control, 1 manual acupuncture (MA), and 3 DECEA groups (-25 µA, +75 µA, and -75 µA). Acupuncture was performed on the lower limbs (at ST 36), and HR and intertissue blood flow (ITBF) were observed as the main outcome measures. Results: For intensity, HR was significantly lower in the -75 µA group than in the control (P < 0.001), MA (P < 0.001), and -25 µA (P < 0.01) groups. For polarity, HR was significantly lower in the -75 µA group than in the +75 µA group (P = 0.0028). For blood flow, the volume of HbO2 in the L-4-L-5 region at 1 minute after stimulation was significantly higher in the -75 µA stimulus group than in the MA group (P < 0.05). There was no change in the T-7-T-8 region. Conclusions: A -75 µA stimulus to ST 36 reduced HR and increased ITBF.