Systematic review and meta-analysis of the therapeutic effect on functional dyspepsia treated with acupuncture and electroacupuncture

Transcutaneous auricular vagus nerve stimulation as a novel therapy connecting the central and peripheral systems: a review

Currently, clinical practice and scientific research mostly revolve around a single disease or system, but the single disease-oriented diagnostic and therapeutic paradigm needs to be revised. This review describes how transcutaneous auricular vagus nerve stimulation (taVNS), a novel non-invasive neuromodulation approach, connects the central and peripheral systems of the body. Through stimulation of the widely distributed vagus nerve from the head to the abdominal cavity, this therapy can improve and treat central system disorders, peripheral system disorders, and central-peripheral comorbidities caused by autonomic dysfunction. In the past, research on taVNS has focused on the treatment of central system disorders by modulating this brain nerve. As the vagus nerve innervates the heart, lungs, liver, pancreas, gastrointestinal tract, spleen and other peripheral organs, taVNS could have an overall modulatory effect on the region of the body where the vagus nerve is widespread. Based on this physiological basis, the authors summarize the existing evidence of the taVNS ability to regulate cardiac function, adiposity, glucose levels, gastrointestinal function, and immune function, among others, to treat peripheral system diseases, and complex diseases with central and peripheral comorbidities. This review shows the successful examples and research progress of taVNS using peripheral neuromodulation mechanisms from more perspectives, demonstrating the expanded scope and value of taVNS to provide new ideas and approaches for holistic therapy from both central and peripheral perspectives.

Reliability of the Evidence to Guide Decision-Making in Acupuncture for Functional Dyspepsia

Background and Aims

There has been a significant increase in the number of systematic reviews (SRs)/meta-analyses (MAs) investigating the effects of acupuncture for functional dyspepsia (FD). To systematically collate, appraise, and synthesize the current evidence, we carried out an umbrella review of SRs/MAs.

Methods

Systemic reviews/meta-analyses on acupuncture for FD were collected by searching major medical databases. The included studies were evaluated in terms of methodological quality, reporting quality, and evidence quality using the criteria from the Assessment of Multiple Systematic Reviews 2 (AMSTAR-2) tool, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, and the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system, respectively.

Results

Ten SRs/MAs were analyzed for this study. The methodological quality, reporting quality, and evidence quality of the included SRs/MAs were generally unsatisfactory. Lack of protocol registration, no list of excluded trials, or lack of a comprehensive search strategy were the main limitations. No high-quality evidence was found to support the effects of acupuncture for FD; the qualitative data synthesis relied on low quality trials with small sample sizes and was the main factor for evidence degradation.

Conclusions

Acupuncture seems to have a promising efficacy in the treatment of FD. It provides a new and prospective therapeutic method for FD. Although the quality of the included SRs/MAs was generally low and defects were frequent, this umbrella review highlights areas where improvement in methodology is required.

Placebo Response Rates in Acupuncture Therapy Trials for Functional Dyspepsia: A Systematic Review and Meta-Analysis

BACKGROUND

Functional dyspepsia (FD) is a functional digestive disease with limited management selection. Previous studies revealed that acupuncture therapy is effective for FD. However, because sham controls were not implemented in most clinical trials following acupuncture therapy, it is difficult to differentiate overall treatment responses from placebo. This study aims to quantify placebo responses in clinical trials in which FD patients received sham manual acupuncture (MA) and sham electroacupuncture (EA).

MATERIALS AND METHODS

Randomized controlled trials of MA and EA for FD patients were searched in PubMed, Web of Science, Cochrane Library, and Embase databases, as well as 4 Chinese language databases from inception to January 2021. RevMan 5.20 software was used for pooled analysis of symptom scores and quality of life. The symptom scores were combined using standard mean difference (SMD) or weighted mean difference (WMD) with a 95% confidence interval (CI). The quality of included studies was tested using modified Jadad scale and Standards for Reporting Interventions in Controlled Trials of Acupuncture (STRICTA) checklist. Egger's test, Begg's test, and sensitivity analyses were conducted using Stata 11.0 statistical software. The protocol of this study is registered in PROSPERO as CRD42021233858.

RESULTS

After screening, the current systematic review included 13 randomized controlled trials, of which 8 studies were used in the meta-analysis. Regarding subjective outcomes, the combined effect of sham MA on FD symptoms was [SMD=-0.42, 95% CI (-0.72, -0.12); P=0.005], whereas sham EA treatment was [SMD=-0.54, 95% CI (-0.81, -0.27); P<0.001]. The combined effect on FD quality of life of post-sham MA group was [SMD=-0.32, 95% CI (-0.52, -0.12); P=0.002]. With regard to objective outcomes, the combined effect of sham EA on dominant frequency was [WMD=-0.11, 95% CI (-0.30, -0.08); P=0.24], while the combined effect of sham EA on dominant power was [WMD=-3.35, 95% CI (-8.04, 1.35); P=0.16].

CONCLUSIONS

Sham MA and sham EA remarkably improve symptoms and quality of life scores of FD without influencing objective outcomes, highlighting the significance of sham controls in acupuncture therapy clinical trials.