Acupuncture increases parasympathetic tone, modulating HRV - Systematic review and meta-analysis

Acupuncture modulates emotional network resting-state functional connectivity in patients with insomnia disorder: a randomized controlled trial and fMRI study

BACKGROUND

Insomnia disorder (ID) is one of the most common sleep problems, usually accompanied by anxiety and depression symptoms. Functional magnetic resonance imaging (fMRI) study suggests that both poor sleep quality and negative emotion are linked to the dysregulation of brain network related to emotion processing in ID patients. Acupuncture therapy has been proven effective in improving sleep quality and mood of ID patients, but the involved neurobiological mechanism remains unclear. We aimed to investigate the modulation effect of acupuncture on resting-state functional connectivity (rsFC) of the emotional network (EN) in patients experiencing insomnia.

METHODS

A total of 30 healthy controls (HCs) and 60 ID patients were enrolled in this study. Sixty ID patients were randomly assigned to real and sham acupuncture groups and attended resting-state fMRI scans before and after 4 weeks of acupuncture treatment. HCs completed an MRI/fMRI scan at baseline. The rsFC values within EN were calculated, and Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Pittsburgh Sleep Quality Index (PSQI), Hyperarousal Scale (HAS), and actigraphy data were collected for clinical efficacy evaluation.

RESULTS

Resting-state FC analysis showed abnormalities in rsFC centered on the thalamus and dorsolateral prefrontal cortex within EN of ID patients compared to HCs. After real acupuncture treatment, rsFC of the anterior cingulate cortex, hippocampus, and amygdala were increased compared with the sham acupuncture group (p < 0.05, FDR corrected). In real acupuncture group, the rsFC value was decreased between left amygdala and left thalamus after 4 weeks of treatment compared with baseline. A trend of correlation was found that the increased rsFC value between the right amygdala and left hippocampus was positively correlated with the decreased HAMA scores across all ID patients, and the decreased left amygdala rsFC value with the left thalamus was negatively correlated with the increased sleep efficiency in the real acupuncture group.

CONCLUSION

Our findings showed that real acupuncture could produce a positive effect on modulating rsFC within network related to emotion processing in ID patients, which may illustrate the central mechanism underlying acupuncture for insomnia in improving sleep quality and emotion regulation.

TRIAL REGISTRATION

http://www.chictr.org.cn ., ChiCTR1800015282, 20/03/2018.

Enhancing Vagal Tone, Modulating Heart Rate Variability with Auricular Acupressure at Point Zero: A Randomized Controlled Trial

Introduction

Point Zero located within the vagus nerve's auricular branch shows promise in addressing imbalances. This study aims to explore its effects on vagal activity using auricular acupressure (AA), measured through heart rate variability (HRV).

Methods

This single-blinded randomized controlled trial involved 114 healthy volunteers randomly assigned to receive AA (AA group, n = 57) or sham-AA (SA group, n = 57) at Point Zero. The 30-minute procedure comprised six stages: T1 and T2 (pre-intervention), T3 to T5 (intervention), and T6 (post-intervention). Interventions involving 30-s acupoint pressure stimulations at T3 and T5. The HRV-measured outcomes included heart rate (HR), standard deviation of R-R intervals (SDNN), root mean square of successive RR interval differences (RMSSD), natural logarithm of low-frequency power (LnLF), and natural logarithm of high-frequency power (LnHF). In addition, respiratory rate (RR) was monitored for its stability.

Results

The AA group demonstrated a significant decrease in HR and increases in SDNN, RMSSD, and LnHF from stages T3 to T6 compared with T1 (baseline), notably prominent at T3 (median changes [25th; 75th percentiles]: -2 [-5; -1], 17.85 [9.65; 31.72], 4.9 [1.08; 10.65], 0.26 [0.00; 0.62], respectively) and T5 (-3 [-6; -1], 19.45 [10.6; 32.89], 6.17 [-0.17; 16.34], 0.40 [-0.14; 0.83], respectively), while the SA group did not. LnLF showed nonsignificant alterations, and RR remained stable in both groups. Despite minor HRV fluctuations, the AA group consistently displayed significantly higher changes in SDNN and RMSSD compared with the SA group from T3 onwards. HR remained unchanged at T6, and LnHF significantly differed only at T5.

Conclusion

AA at Point Zero may promptly enhance vagal activity, evident in the modulation of HRV, notably pronounced with pressure stimulation, and can be sustained for at least 5 min. Further studies are needed to assess its long-term effectiveness and efficacy in preventing or treating patients.(Clinical Trial Registration: NCT05586698).

Head-to-Head Comparison of Electroacupuncture and Laser Acupuncture Effects on Autonomic Regulation and Clinical Effects in Dysmenorrhea: A Randomized Crossover Clinical Trial

Introduction: Electroacupuncture (EA) has been applied in dysmenorrhea and has shown good efficacy. The mechanisms of EA are associated with autonomic nervous system adjustments and neuroendocrine regulation. Laser acupuncture (LA), however, has been widely investigated for its noninvasiveness. However, it remains uncertain whether LA is as effective as EA. This study aimed to compare EA and LA head to head in dysmenorrhea. Methods: A crossover, randomized clinical trial was conducted. EA or LA was applied to selected acupuncture points. Participants were randomized into two sequence treatment groups who received either EA or LA twice per week in luteal phase for 3 months followed by 2-month washout, then shifted to other groups (sequence 1: EA > LA; sequence 2: LA > EA). Outcome measures were heart rate variability (HRV), prostaglandins (PGs), pain, and quality-of-life (QoL) assessment (QoL-SF12). We also compared the effect of EA and LA in low and high LF/HF (low frequency/high frequency) status. Results: Totally, 43 participants completed all treatments. Both EA and LA significantly improved HRV activity and were effective in reducing pain (Visual Analog Scale [VAS]; EA: p < 0.001 and LA: p = 0.010) and improving QoL (SF12: EA: p < 0.001, LA, p = 0.017); although without intergroup difference. EA reduced PGs significantly (p < 0.001; δ p = 0.068). In low LF/HF, EA had stronger effects than LA in increasing parasympathetic tone in respect of percentage of successive RR intervals that differ by more than 50 ms (pNN50; p = 0.053) and very low-frequency band (VLF; p = 0.035). Conclusion: There is no significant difference between EA and LA in improving autonomic nervous system dysfunction, pain, and QoL in dysmenorrhea. EA is prominent in PGs changing and preserving vagus tone in low LF/HF; yet LA is noninvasive for those who have needle phobia. Whether LA is equivalent with EA and the mechanism warrants further study. Clinical trial identification number: NCT04178226.

Effect of "needle sensation" and the real-time changes in autonomic nervous system activity during acupuncture analgesia

Introduction

Acupuncture analgesia (AA) is widely used in clinical practice. The autonomic nervous system (ANS) may be an important pathway for acupuncture signal transduction. However, real-time changes in autonomic function during AA and the effect of "needle sensation" remain unclear.

Methods

We established a human pain model in healthy adults and randomly assigned 128 participants to the model, sham acupuncture, and acupuncture groups in a 1:1:2 ratio. Heart rate variability (HRV), including total power (TP), low-frequency power (LF), high-frequency power (HF), ratio of LF to HF (LF/HF), standard deviation of the normal-normal intervals (SDNN), and root mean square of successive interval differences (RMSSD), were used to assess autonomic function. The visual analog scale (VAS) and efficiency were used to assess the analgesic effect of acupuncture. The Massachusetts General Hospital acupuncture sensation scale (MASS) was used to indicate the intensity of the needle sensation. Anxiety levels were also measured. Finally, the correlation of MASS with HRV, VAS, and anxiety levels was analyzed.

Results

VAS decreased after 10 min of needling and 5 min after needle withdrawal in the acupuncture group compared with those in the model group (p = 0.038, p = 0.020). The efficacy rates were 82.0, 50.0, and 61.3% in the acupuncture, model, and sham groups, respectively. These represent significant differences between the acupuncture group and the model and sham acupuncture groups (p < 0.001 in each case). No differences were observed between the model and sham acupuncture groups. HF, TP, SDNN, and RMSSD were all increased in the acupuncture group compared with those in the model group (p = 0.045, p = 0.041, p = 0.002, p = 0.006, respectively). No differences were observed in the sham acupuncture group compared to the model group (p = 0.632, p = 0.542, p = 0.093, p = 0.222, respectively). The LF and LF/HF did not differ among all three groups. A positive correlation was observed between MASS and RMSSD2, LF2, RMSSD4, TP4, VAS5, and anxiety levels.

Conclusion

AA was associated with enhanced vagal activity. The intensity of needle sensation was positively correlated with vagal and sympathetic nerve activities. Acupuncture is an effective means of regulating autonomic function, and needle sensation may be an important modulator.

Acupuncture Treatment for Generalized Anxiety Disorder by Activating the Vagus Nerve and Improving Heart-Rate Variability and Heart-Rhythm Coherence, A Case-Series Study

Objective

The goal of this case series was to observe the effectiveness of acupuncture for reducing sympathetic stress and anxiety-related symptoms in generalized anxiety disorder. The effect of acupuncture on the balance of the autonomic nervous system was also examined.

Materials and Methods

This was a case-series study with 10 participants enrolled. Each participant received acupuncture treatment 2 times per week for 4 weeks. Participants were evaluated with the Generalized Anxiety Disorder-7 (GAD-7) scale and the Body Perception Questionnaire-Short Form (BPQ-SF) before and after the treatment program. Heart-rate variability heart-rhythm coherence (HRC) was also assessed during each acupuncture session.

Results

Five participants completed the program. Both GAD-7 and BPQ mean scores showed significant reductions. The mean HRC high-coherence ratio also increased significantly after acupuncture treatment. No adverse effects occurred.

Conclusions

Acupuncture may be an effective therapy for sympathetic stress and anxiety-related symptoms. The mechanism of action may be through activating the vagus nerve and improving the HRC high coherence ratio. It is feasible to conduct larger clinical trials with random controls, longer treatment durations, and long-term follow-ups to support the results of this study.

Effect on Satisfactory Seizure Control and Heart Rate Variability of Thread-Embedding Acupuncture for Drug-Resistant Epilepsy: A Patient-Assessor Blinded, Randomized Controlled Trial

This randomized controlled trial investigates the efficacy of thread-embedding acupuncture (TEA) compared to sham TEA in treating drug-resistant epilepsy (DRE). Fifty-four DRE outpatients were randomly divided into two groups: TEA (27 patients) and sham TEA (27 patients). Both groups received four sessions of TEA or sham TEA, spaced four weeks apart, targeting GV20, GV14, BL15, BL18, ST40, and GB34 acupoints. Antiseizure medications were maintained at consistent doses throughout the study. Outcome measures included satisfactory seizure control, seizure freedom, and heart rate (HR) and heart rate variability (HRV) measurements. TEA demonstrated a significantly higher rate of satisfactory seizure control at follow-up compared to the sham TEA group (37% vs. 3.7%, p = 0.003). While no significant intergroup differences were observed in HR, HRV, and HRV components at each stage, the TEA group experienced a significant decrease in HR and a significant increase in HRV posttreatment. This study demonstrates TEA's effectiveness in managing DRE and suggests its impact may relate to heightened parasympathetic nerve activity. Further research with extended follow-up periods is necessary to validate these findings.

A randomized-controlled trial assessing the effect of intraoperative acupuncture on anesthesia-related parameters during gynecological oncology surgery

CONTEXT AND OBJECTIVES

The present study examined the impact of intraoperative acupuncture on anesthesia-related parameters in patients undergoing gynecological oncology surgery.

METHODS

Participants underwent preoperative integrative oncology (IO) touch/relaxation treatments, followed by intraoperative acupuncture (Group A); preoperative IO treatments without acupuncture (Group B); or standard care only (Group C). Mean arterial pressure (MAP), heart rate (HR), MAP variability (mean of MAP standard deviation), bispectral index (BIS), and calculated blood pressure Average Real Variability (ARV) were measured intraoperatively.

RESULTS

A total of 91 patients participated: Group A, 41; Group B, 24; Group C, 26. Among patients undergoing open laparotomy, Group A showed lower and more stable MAP and HR compared to Group B, (MAP, p = 0.026; HR, p = 0.029) and Group C (MAP, p = 0.025). Mean BIS, from incision to suture closing, was lower in Group A (vs. controls, p = 0.024). In patients undergoing laparoscopic surgery, MAP was elevated within Group A (p = 0.026) throughout surgery, with MAP variability significantly higher in Group A (P = 0.023) and Group B (P = 0.013) 10 min post-incision (vs. pre-incision). All groups showed similar intraoperative and post-anesthesia use of analgesic medication.

CONCLUSION

Intraoperative acupuncture was shown to reduce and stabilize MAP and HR, and reduce BIS in gynecology oncology patients undergoing laparotomy, with no impact on perioperative analgesic medication use. In the laparoscopic setting, intraoperative acupuncture was associated with elevated MAP. Further research is needed to explore the hemodynamic and BIS-associated benefits and risks of intraoperative acupuncture, and the impact on the use of analgesic drugs in response to these changes.