Effects of noninvasive electroacupuncture at Hegu (LI4) and Sanyinjiao (SP6) acupoints on dysmenorrhea: a randomized controlled trial

Transcutaneous electrical nerve stimulation (TENS) for pain control in women with primary dysmenorrhoea

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological treatment that works by delivering electrical currents via electrodes attached to the skin at the site of pain. It can be an alternative to pharmacological treatments. The mechanism of action of TENS for pain relief is related to the inhibition of the transmission of painful stimuli, release of endogenous opioids, and reduced muscle ischaemia of the uterus. Although it has been used for primary dysmenorrhoea ((PD); period pain or menstrual cramps), evidence of the efficacy and safety of high-frequency TENS, low-frequency TENS, or other treatments for PD is limited.

OBJECTIVES

To evaluate the effectiveness and safety of transcutaneous electrical nerve stimulation (TENS) in comparison with placebo, no treatment, and other treatments for primary dysmenorrhoea (PD).

SEARCH METHODS

We searched the Gynaecology and Fertility Group's Specialized Register of controlled trials, CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, and the Korean and Chinese language databases up to 9 April 2024. We also searched for ongoing trials in trials registries and the reference lists of relevant studies for additional trials. Language restrictions were not applied.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that included women (aged 12 to 49 years) with PD. Included trials compared low-frequency TENS or high-frequency TENS with other TENS, placebo, or other treatment.

DATA COLLECTION AND ANALYSIS

Four review authors screened the trials, extracted the data according to the protocol, assessed the risk of bias using RoB 2, and assessed the certainty of evidence for all review comparisons and primary outcomes (i.e. pain relief and adverse effects) using the GRADE approach.

MAIN RESULTS

This review replaces the current review, published in 2009. We included 20 RCTs involving 585 randomized women with high-frequency TENS, low-frequency TENS, placebo or no treatment, or other treatment. We included five comparisons: high-frequency TENS versus placebo or no treatment, low-frequency TENS versus placebo or no treatment, high-frequency TENS versus low-frequency TENS, high-frequency TENS versus other treatments, and low-frequency TENS versus other treatments. High-frequency TENS versus placebo or no treatment High-frequency TENS may reduce pain compared with placebo or no treatment (mean difference (MD) -1.39, 95% confidence interval (CI) -2.51 to -0.28; 10 RCTs, 345 women; low-certainty evidence; I2 = 88%). Two out of three RCTs reported no adverse effects and hence we were unable to estimate the effect of high-frequency TENS on adverse effects. Low-frequency TENS versus placebo or no treatment Low-frequency TENS may reduce pain compared with placebo or no treatment (MD -2.04, 95% CI -2.95 to -1.14; 3 RCTs, 645 women; low-certainty evidence; I2 = 0%). No trials reported adverse effects for this comparison. High-frequency TENS versus low-frequency TENS It is uncertain whether high-frequency TENS had an effect on pain relief compared with low-frequency TENS (MD 0.89, 95% CI -0.19 to 1.96; 3 RCTs, 54 women; low-certainty evidence; I2 = 0%). One trial contributed data on adverse effects but no adverse events occurred. High-frequency TENS versus other treatments It is uncertain whether high-frequency TENS had an effect on pain relief compared to acupressure (MD -0.66, 95% CI -1.72 to 0.40; 1 RCT, 18 women; very low-certainty evidence), acetaminophen (paracetamol) (MD -0.98, 95% CI -3.30 to 1.34; 1 RCT, 20 women; very low-certainty evidence), and interferential current therapy (MD -0.03, 95% CI -1.04 to 0.98; 2 RCTs, 62 women; low-certainty evidence; I2 = 0%). The occurrence of adverse effects may not differ significantly between high-frequency TENS and NSAIDs (OR 12.06, 95% CI 0.26 to 570.62; 2 RCTs, 88 women; low-certainty evidence; I2 = 78%). Low-frequency TENS versus other treatments It is uncertain whether low-frequency TENS had an effect on pain relief compared with acetaminophen (MD -1.48, 95% CI -3.61 to 0.65; 1 RCT, 20 women; very low-certainty evidence). No trials reported adverse effects for this comparison.

AUTHORS' CONCLUSIONS

High-frequency TENS and low-frequency TENS may reduce pain compared with placebo or no treatment. We downgraded the certainty of the evidence because of the risk of bias. Future RCTs should focus more on secondary outcomes of this review (e.g. requirement for additional analgesics, limitation of daily activities, or health-related quality of life) and should be designed to ensure a low risk of bias.

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.

Placebo response of sham acupuncture in patients with primary dysmenorrhea: A meta-analysis

BACKGROUND

The placebo response of sham acupuncture in patients with primary dysmenorrhea is a substantial factor associated with analgesia. However, the magnitude of the placebo response is unclear.

OBJECTIVE

This meta-analysis assessed the effects of sham acupuncture in patients with primary dysmenorrhea and the factors contributing to these effects.

SEARCH STRATEGY

PubMed, Embase, Web of Science, and Cochrane CENTRAL databases were searched from inception up to August 20, 2022.

INCLUSION CRITERIA

Randomized controlled trials (RCTs) using sham acupuncture as a control for female patients of reproductive age with primary dysmenorrhea were included.

DATA EXTRACTION AND ANALYSIS

Pain intensity, retrospective symptom scale, and health-related quality of life were outcome measures used in these trials. Placebo response was defined as the change in the outcome of interest from baseline to endpoint. We used standardized mean difference (SMD) to estimate the effect size of the placebo response.

RESULTS

Thirteen RCTs were included. The pooled placebo response size for pain intensity was the largest (SMD = -0.99; 95% confidence interval [CI], -1.31 to -0.68), followed by the retrospective symptom scale (Total frequency rating score: SMD = -0.20; 95% CI, -0.80 to -0.39. Average severity score: SMD = -0.35; 95% CI, -0.90 to -0.20) and physical component of SF-36 (SMD = 0.27; 95% CI, -0.17 to 0.72). Studies using blunt-tip needles, single-center trials, studies with a low risk of bias, studies in which patients had a longer disease course, studies in which clinicians had < 5 years of experience, and trials conducted outside Asia were more likely to have a lower placebo response.

CONCLUSION

Strong placebo response and some relative factors were found in patients with primary dysmenorrhea. PROSPERO registration number: CRD42022304215. Please cite this article as: Sun CY, Xiong ZY, Sun CY, Ma PH, Liu XY, Sun CY, Xin ZY, Liu BY, Liu CZ, Yan SY. Placebo response of sham acupuncture in patients with primary dysmenorrhea: A meta-analysis. J Integr Med. 2023; 21(5): 455-463.

Effect of transcutaneous electrical acupoint stimulation on pregnancy outcomes in women with in vitro fertilization-embryo transfer: A systematic review and meta-analysis

Objective: The purpose of this systematic review and meta-analysis was to evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) on pregnancy outcomes in women undergoing in vitro fertilization-embryo transfer (IVF-ET), in order to provide evidence-based medical support. Methods: We searched the Cochrane Library, Embase, PubMed, Web of Science, SinoMed, and CNKI for relevant randomized controlled trials (RCTs) from inception to 31 May 2022, using the search terms "transcutaneous electrical acupoint stimulation," "TEAS," "in vitro fertilization-embryo transfer," "IVF-ET," "randomized controlled trial," and "clinical trials." The experimental group was treated with TEAS or combined with ovulation-inducing medication, and the control group was treated with mock TEAS (mTEAS), ovulation-inducing medication, or no intervention. The main outcome was the clinical pregnancy rate. Secondary outcomes were the embryo implantation rate, live birth rate, biochemical pregnancy rate, and number of oocytes retrieved. Stata15.1 software was used for data summary and analysis. Results: This review involved 15 RCTs and 4,281 participants. TEAS were superior to the control group for improving the clinical pregnancy rate [RR: 1.29, 95% CI: 1.19 to 1.40; p < 0.001; I² = 23.0%], embryo implantation rate [RR: 1.43, 95% CI: 1.22 to 1.69; p < 0.001; I² = 35.9%], live birth rate [RR: 1.33, 95% CI: 1.14 to 1.54; p < 0.001; I² = 47.3%], and biochemical pregnancy rate [RR: 1.15, 95% CI: 1.05 to 1.26; p = 0.003; I² = 49.1%], without significant heterogeneity. TEAS had no statistically significant effect on the number of oocytes retrieved as compared with the control group, and the heterogeneity was high [SMD: 0.34, 95% CI: -0.04 to 0.72; p = 0.081; I² = 77.6%]. We performed subgroup analysis based on the sample size, interventions and intervention time-point. The results showed that the sample size had no effect on the results. There was no significant difference between TEAS and ovulation-inducing medication in the clinical pregnancy rate or the embryo implantation rate. In addition, TEAS did not significantly increase the embryo implantation rate or the live birth rate, compared with no intervention. In terms of safety, mild allergic symptoms were found in both the experimental group and the control group. Conclusion: In general, existing evidence supports the potential value of TEAS as an adjunctive treatment for improving pregnancy outcomes. High-quality, large-sample RCTs are needed to further support this conclusion. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=334892, identifier PROSPERO CRD42022334892.

Neuromodulation in Chronic Pelvic Pain: A Narrative Review

Chronic primary pelvic pain syndrome (CPPPS) is a heterogeneous disease with unknown pathogenesis and a lack of distinct pathological features, which complicates diagnosis and therapy and has a significant impact on patients' daily life. Because pharmacological management is ineffective and long-term use may result in additional system damage, developing a more effective treatment is critical. Neuromodulation has advanced rapidly over the last few decades, and various types of neuromodulations have demonstrated efficacy in the treatment of CPPPS. In this article we discuss the evolution of neuromodulation technology in the treatment of chronic pelvic pain, its application to various subtypes of chronic pelvic pain, and the comparison of relevant efficacy and parameter differences, as well as assess the relative advantages and disadvantages of sacral neuromodulation, percutaneous tibial nerve stimulation , transcutaneous electrical nerve stimulation, electroacupuncture, and pudendal neuromodulation. Furthermore, it was noted that chronic pelvic pain should be evaluated in terms of pain, associated symptoms, psychological problems, and quality of life. Although neuromodulation approaches have been shown to be effective in treating chronic pelvic pain, more extensive multicenter trials are required to confirm this.

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

The Combination of Electroacupuncture and Massage Therapy Alleviates Myofibroblast Transdifferentiation and Extracellular Matrix Production in Blunt Trauma-Induced Skeletal Muscle Fibrosis

Complementary therapies, such as acupuncture and massage, had been previously reported to have therapeutic effects on skeletal muscle contusions. However, the recovery mechanisms on skeletal muscles after blunt trauma via the combination of electroacupuncture (EA) and massage therapy remain unclear. In the present study, a rat model of the skeletal muscle fibrosis following blunt trauma to rat skeletal muscle was established, and the potential molecular mechanisms of EA + massage therapy on the skeletal muscle fibrosis were investigated. The results suggested that EA + massage therapy could significantly decrease inflammatory cells infiltration and collagenous fiber content and ameliorate the disarrangement of sarcomeres within myofibrils compared to the model group. Further analysis revealed that EA + massage therapy could reduce the degree of fibrosis and increase the degree of myofibroblast apoptosis by downregulating the mRNA and protein expression of transforming growth factor- (TGF-) β1 and connective tissue growth factor (CTGF). Furthermore, the fibrosis of injured skeletal muscle was inhibited after treatment through the normalization of balance between matrix metalloproteinase- (MMP-) 1 and tissue inhibitor of matrix metalloproteinase (TIMP). These findings suggested that the combination of electroacupuncture and massage therapy could alleviate the fibrotic process by regulating TGF β1-CTGF-induced myofibroblast transdifferentiation and MMP-1/TIMP-1 balance for extracellular matrix production.

The Mechanism of Electroacupuncture at Zusanli Promotes Macrophage Polarization during the Fibrotic Process in Contused Skeletal Muscle

INTRODUCTION

Currently, many clinical experiments are being conducted to study the effect of acupuncture on skeletal muscle contusions, and its therapeutic effect has been confirmed to some extent. However, the mechanism of recovery by electroacupuncture (EA) in skeletal muscles after blunt trauma remains unknown.

OBJECTIVE

To determine whether EA at Zusanli can contribute to the regeneration of contused skeletal muscle and the molecular mechanism involved.

METHODS

Masson's trichrome staining and hematoxylin and eosin staining were used to measure the area of fibrotic tissue and determine the number of centrally nucleated muscle fibers respectively. The different immune phenotypes of macrophages were determined by flow cytometry. Then, ELISA was used to analyze the levels of interleukin-4 (IL-4), IL-6, interferon-α (IFN-α) and interferon-γ (IFN-γ) in the injured tissue. Finally, the expression of MyoD in the tissue was detected by quantitative real-time polymerase chain reaction.

RESULTS

EA at Zusanli helped regenerate contused skeletal muscle by alleviating fibrosis and increasing the size of the regenerating myofibres in the injured skeletal muscle. EA at Zusanli increased the number of M2 macrophages and decreased the number of M1 macrophages in contused skeletal muscle. EA at Zusanli decreased the level of cytokine IFN-γ and increased the levels of IL-4, interleukin-13 (IL-13), and IFN-α, which promoted macrophage polarization during the fibrosis recovery process in the contused skeletal muscle. EA at Zusanli could increase the expression of MyoD in tissues.

CONCLUSIONS

EA at Zusanli promoted macrophage polarization during the fibrotic process in contused skeletal muscle by decreasing cytokine IFN-γ and increasing IL-4, IL-13, and IFN-α, which contributed to the regeneration of the contused skeletal muscle.

No. 345-Primary Dysmenorrhea Consensus Guideline

OBJECTIVE

This guideline reviews the investigation and treatment of primary dysmenorrhea.

INTENDED USERS

Health care providers.

TARGET POPULATION

Women and adolescents experiencing menstrual pain for which no underlying cause has been identified.

EVIDENCE

Published clinical trials, population studies, and review articles cited in PubMed or the Cochrane database from January 2005 to March 2016.

VALIDATION METHODS

Seven clinical questions were generated by the authors and reviewed by the SOGC Clinical Practice-Gynaecology Committee. The available literature was searched. Guideline No. 169 was reviewed and rewritten in order to incorporate current evidence. Recommendations addressing the identified clinical questions were formulated and evaluated using the ranking of the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Primary dysmenorrhea is common and frequently undertreated. Effective therapy is widely available at minimal cost. Treatment has the potential to improve quality of life and to decrease time lost from school or work.

GUIDELINE UPDATE

This guideline is a revision and update of No. 169, December 2005.

SPONSORS

SOGC.

SUMMARY STATEMENTS

RECOMMENDATIONS.

TENS and heat therapy for pain relief and quality of life improvement in individuals with primary dysmenorrhea: A systematic review

The present systematic review aimed to synthesize evidence for the effectiveness of TENS and heat therapy interventions from randomized trials. Six relevant databases were searched for studies on TENS and heat therapy for primary dysmenorrhea. Menstrual pain intensity and quality of life were the primary and secondary outcomes respectively. The search yielded 46 citations from which six studies on TENS and three studies on heat therapy were systematically reviewed. On the PEDRO quality scale, the trials methodological quality was 4.8 out of 10 for TENS and 6.3 out of 10 for heat therapy. TENS and heat therapy both showed evidence of pain reduction, but no study included quality of life as an outcome. Meta-analysis was not possible due to substantial heterogeneity in included studies. TENS and heat therapy show potential as adjunct remedies in the management of primary dysmenorrhea, but rigorous high quality trials are still needed to made conclusive recommendation.

Modern acupuncture-like stimulation methods: a literature review

Acupuncture therapy has been proved to be effective for diverse diseases, symptoms, and conditions in numerous clinical trials. The growing popularity of acupuncture therapy has triggered the development of modern acupuncture-like stimulation devices (ASDs), which are equivalent or superior to manual acupuncture with respect to safety, decreased risk of infection, and facilitation of clinical trials. Here, we aim to summarize the research on modern ASDs, with a focus on featured devices undergoing active research and their effectiveness and target symptoms, along with annual publication rates. We searched the popular electronic databases Medline, PubMed, the Cochrane Library, and Web of Science, and analyzed English-language studies on humans. Thereby, a total of 728 studies were identified, of which 195 studies met our inclusion criteria. Electrical stimulators were found to be the earliest and most widely studied devices (133 articles), followed by laser (44 articles), magnetic (16 articles), and ultrasound (2 articles) stimulators. A total of 114 studies used randomized controlled trials, and 109 studies reported therapeutic benefits. The majority of the studies (32%) focused on analgesia and pain-relief effects, followed by effects on brain activity (16%). All types of the reviewed ASDs were associated with increasing annual publication trends; specifically, the annual growth in publications regarding noninvasive stimulation methods was more rapid than that regarding invasive methods. Based on this observation, we anticipate that the noninvasive or minimally invasive ASDs will become more popular in acupuncture therapy.

As Acupressure Decreases Pain, Acupuncture May Improve Some Aspects of Quality of Life for Women with Primary Dysmenorrhea: A Systematic Review with Meta-Analysis

Primary dysmenorrhea is the most common gynecological symptom reported by women and constitutes a high health, social, and economic burden. Chemotherapies, along with their side effects, have not yielded satisfactory outcomes. Alternative nonpharmacological interventions, including acupuncture and acupressure, have been advocated, but evidence regarding their beneficial effect is inconclusive. This study sought to obtain evidence on the effectiveness of acupuncture and acupressure interventions. Twelve electronic databases were searched by using menstrual pain intensity and quality of life as primary and secondary outcomes, respectively, with the PEDro guideline for quality appraisal. Data unsuitable for a meta-analysis were reported as descriptive data. The search yielded 38 citations, from which eight studies were systematically reviewed, four of the eight being eligible for meta-analysis. The systematic review showed moderate methodological quality with a mean of 6.1 out of 10 on the PEDro quality scale. Acupressure showed evidence of pain relief while acupuncture improved both the mental and the physical components of quality of life. In conclusion, physiotherapists should consider using acupuncture and acupressure to treat primary dysmenorrhea, but a need exists for higher quality, randomized, blinded, sham-controlled trials with adequate sample sizes to establish clearly the effects of these modalities.

The time course effects of electroacupuncture on promoting skeletal muscle regeneration and inhibiting excessive fibrosis after contusion in rabbits

The aim of this study was to investigate the longitudinal effects of electroacupuncture (EA) on Zusanli (ST36) and Ashi acupoints in promoting skeletal muscle regeneration and inhibiting excessive fibrosis after contusion in rabbits. Sixty rabbits were randomly divided into four groups: normal, contusion, EA, and recombinant human insulin-like growth factor-I (rhIGF-I). An acute skeletal muscle contusion was produced on the right gastrocnemius (GM) by an instrument-based drop-mass technique. EA was performed for 15 minutes every two days with 0.4 mA (2 Hz), and GM injections were executed with rhIGF-I (0.25 mL once a week). Rabbits treated with EA had a higher T-SOD and T-AOC serum activities and lower MDA serum level, the blood perfusion of which was also significantly higher. In the EA group, the diameter of the myofibril was uniform and the arrangement was regular, contrary to the contusion group. The number and diameter of regenerative myofibers and MHC expression were increased in the EA group. EA treatment significantly decreased fibrosis formation and reduced both GDF-8 and p-Smad2/3 expressions in injured muscle. Our data indicate that EA may promote myofiber regeneration and reduce excessive fibrosis by improving blood flow and antioxidant capacities. Additionally, EA may regulate signaling factor expression after contusion.

Acupuncture Alleviates Colorectal Hypersensitivity and Correlates with the Regulatory Mechanism of TrpV1 and p-ERK

Here we used a mouse model of zymosan-induced colorectal hypersensitivity, a similar model of IBS in our previous work, to evaluate the effectiveness of the different number of times of acupuncture and elucidate its potential mechanism of EA treatment. Colorectal distension (CRD) tests show that intracolonic zymosan injection does, while saline injection does not, induce a typical colorectal hypersensitivity. EA treatment at classical acupoints Zusanli (ST36) and Shangjuxu (ST37) in both hind limbs for 15 min slightly attenuated and significantly blunted the hypersensitive responses after first and fifth acupunctures, respectively, to colorectal distention in zymosan treatment mice, but not in saline treatment mice. Western blot results indicated that ion channel and TrpV1 expression in colorectum as well as ERK1/2 MAPK pathway activation in peripheral and central nerve system might be involved in this process. Hence, we conclude that EA is a potential therapeutic tool in the treatment and alleviation of chronic abdominal pain, and the effectiveness of acupuncture analgesia is accumulative with increased number of times of acupuncture when compared to that of a single time of acupuncture.