Vascular responses to manual PC6 acupuncture in nonsmokers and smokers assessed by the second derivative of the finger photoplethysmogram waveform.

BACKGROUND: Smoking is reported to increase arterial stiffness. Indices obtained from the second derivative of digital volume pulse (SDDVP) waveform have been proposed to characterize vascular aging and arterial rigidity. PC6 (Neiguan) is a traditional acupoint in each forearm that has been shown to modify cardiovascular functioning. OBJECTIVE: To investigate the acute effects of manual needling with PC6 on SDDVP indices in healthy chronic smoker and nonsmoker subjects. SUBJECTS AND METHODS: Aging index (AI) was defined as (b - c - d - e)/a, B:A was calculated as the ratio of the absolute value for the height of the b wave (B) to that of the a wave (A), and D:A was calculated as the ratio of the absolute value for the height of the d wave (D) to that of the a wave (A). These indices derived of the wave components of SDDVP of healthy nonsmokers (n=40; 28.3+/-3.0 years old) vs. chronic smokers (n=30; 29.9+/-2.9 years old) were compared. The digital volume pulse (DVP) was obtained by measuring infrared light transmission through the finger. Of each subject, a DVP registration 20 minutes long was obtained. PC6 was stimulated unilaterally by manual needling for 5 minutes (1-6 minutes). SDDVP indices were compared in each subject in pre- vs. post-acupuncture periods (30 seconds vs. 18 minutes, respectively). RESULTS: At baseline, we found significant difference in B:A between nonsmokers and smokers. Comparing pre- vs. post-acupuncture periods, B:A and D:A did not show significant differences among nonsmokers, but B:A improved significantly in smokers and AI improved significantly in both nonsmokers and smokers. CONCLUSION: These findings suggest that manual needling with PC6 could revert some of the deleterious effects on vascular functioning produced by chronic cigarette smoking.

Assessment of the vascular effects of PC6 (Neiguan) using the second derivative of the finger photoplethysmogram in healthy and hypertensive subjects.

Indices obtained from the second derivative of the digital volume pulse waveform have been proposed to characterize vascular aging, arterial rigidity, and the effects of vasoactive drugs. The purpose of this study was to assess the effects of manual needling of PC6 on SD(DVP) indices in healthy and untreated hypertensive subjects. AI, B:A, and D:A indices, based on the height of the wave components of SD(DVP), in 40 healthy subjects and 25 untreated hypertensive subjects were compared. DVP was obtained by measuring infrared light transmission through the finger. For each subject, 20-min-long DVP registration was obtained. PC6 was stimulated unilaterally by manual needling for 5 min (1-6 min). In each subject, pre-acupuncture DVP indices were compared to those of during acupuncture (1 vs. 4 min) and post-acupuncture (1 vs. 18 min). In healthy subjects, AI was significantly improved when comparing the pre- to the post-acupuncture values. In hypertensive subjects, the SD(DVP) indices improved significantly as follows: the AI index when the value of pre-acupuncture comparing to that of during acupuncture and post-acupuncture values; B:A and D:A indices when the pre-comparing to post-acupuncture values. There were significant differences between healthy and hypertensive subjects in AI, B:A, and D:A at baseline and in B:A in the during acupuncture period; there were no significant differences at post-acupuncture. These results indicate that manual needling of PC6 produced acute effects on vascular pathophysiology. Moreover, PC6 needling produced changes in SD(DVP) indices related to both large artery stiffness and the reflected wave originating in small arteries.