Comprehensive electroacupuncture treatments reduce serum inflammatory factors and relieve pain symptoms in patients with lumbar disc herniation: a systematic review and network meta-analysis

Introduction

Highlights

• This work discusses the effects of comprehensive electroacupuncture therapies on relieving inflammation and pain in patients with LDH, aiming to explore better treatment methods for alleviating clinical symptoms in patients.

• Routine electroacupuncture + Tuina + rehabilitation therapy significantly reduced IL-6 and TNF-α levels.

• Routine electroacupuncture + Chinese medicine + Western medicine shows notable effectiveness in relieving pain.

• The findings of this work can provide valuable guidance for the clinical treatment of discogenic pain.

Discogenic pain is usually caused by a herniated disc compressing or irritating surrounding tissue or nerves¹. However, current treatments mostly have side effects and do not provide long-lasting efficacy. The mRNA and protein levels of IL-6 and TNF-α in intervertebral discs are significantly increased and are positively correlated with visual analogue scale (VAS) scores in LDH patients^2,3. Previous research has shown that electroacupuncture (EA) decreases the release of IL-6 and TNF-α and alleviates pain hyperalgesia⁴. Therefore, this study conducted a network meta-analysis of various EA combination treatments to explore the optimal strategy for reducing serum IL-6 and TNF-α levels and relieving pain in LDH patients.

Methods

The study has been registered with PROSPERO. The work has been reported in line with PRISMA (Supplemental Digital Content 1, http://links.lww.com/JS9/D167, Supplemental Digital Content 2, http://links.lww.com/JS9/D168) and AMSTAR (Supplemental Digital Content 3, http://links.lww.com/JS9/D169) guidelines^5,6. Two researchers independently searched ‘electroacupuncture’, ‘inflammatory factors’, ‘lumbar disc herniation’, and related terms in public databases for randomized controlled trials (RCTs). Stata 17 and RoB2 were used for data analysis and bias risk assessment. The details of the methods are all presented in the Supplementary Methods (Supplemental Digital Content 4, http://links.lww.com/JS9/D170) and Tables (Supplemental Digital Content 5, http://links.lww.com/JS9/D171, Supplemental Digital Content 6, http://links.lww.com/JS9/D172).

Results and discussion

A total of 38 articles involving 3246 patients were included in the quantitative meta-analysis (Tables S1-S2, Supplemental Digital Content 5, http://links.lww.com/JS9/D171, Supplemental Digital Content 6, http://links.lww.com/JS9/D172). The flow diagram is shown in Figure 1A. RoB2 was used to analyse bias, with 15.8% of the studies identified as low risk, 73.7% having some concerns, and 10.5% considered high risk (Fig. 1B-C).

Figure 1.

Flowchart of the study selection process (A), bias risk assessment graph (B), and bias risk summary graph (C) for the included literature.

In terms of reducing IL-6, 29 studies reported serum IL-6 levels after comprehensive electroacupuncture treatment, and 18 studies reported the formation of three closed loops (Fig. 2A). The global inconsistency result was acceptable (Prob > χ ²) (Fig. 2B). The loop inconsistency tests revealed inconsistencies in C-J-R and B-F-K (Fig. 2C). Subsequently, the node-splitting method was used to determine that C-J and F-K may be the main sources of inconsistency (Figure S1A, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). The local inconsistency was acceptable after excluding the two pairs of interventions (Fig. 2D). Combining the data of direct and indirect comparisons, 16 groups were found to be significantly different (Figure S1B, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). According to the SUCRA values, the top three treatments were routine electroacupuncture + Tuina + rehabilitation therapy (95.0%), special acupoint electroacupuncture + Chinese medicine (69.5%), and routine electroacupuncture + semiconductor laser (68.7%) (Figure S1C, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). Routine electroacupuncture + Tuina + rehabilitation therapy was superior to most other interventions. However, special acupoint electroacupuncture + Chinese medicine and routine electroacupuncture + semiconductor laser did not significantly differ from the other treatment regimens. Egger’s test revealed publication bias for the 26 included studies (P=0.134), suggesting that there was no significant publication bias (Fig. 2E). The funnel plot is shown in Figure 2F. For TNF-α, 25 studies reported serum TNF-α levels, and no closed loop was formed between the 18 interventions (Fig. 2G). A total of 153 pairwise comparisons were performed, and 57 pairs were statistically significant (Figure S2A, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). The top three treatments were routine electroacupuncture + Tuina + rehabilitation therapy (97.6%), routine electroacupuncture + a semiconductor laser (93.5%), and routine electroacupuncture + Chinese medicine + Western medicine (81.1%) (Figure S2B, Supplemental Digital Content 7, http://links.lww.com/JS9/D173).

Figure 2.

Evidence network diagram of interventions for IL-6 levels (A), Global inconsistency test chart (B), Loop inconsistency test before (C) and after (D) removing interferential interventions for IL-6 levels. Bias analysis of the included studies of IL-6 levels by Egger’s test (E) and Egger’s test funnel plot (F). Evidence network diagram of interventions for TNF-α levels (G).

Fig. 3A-B shows that routine electroacupuncture + Tuina + rehabilitation therapy and routine electroacupuncture + semiconductor laser outperformed most other therapies. Routine electroacupuncture + Chinese medicine + Western medicine was better than any of the other five interventions. There was no significant publication bias for the 25 studies. In terms of pain relief, we used the VAS score as the evaluation index. Thirty-one studies reported VAS scores, and 19 interventions formed two closed loops (Fig. 3C). The global inconsistency was acceptable (Prob > χ ²) (Fig. 3D). The local inconsistency for the two closed loops was also acceptable (Fig. 3E). A total of 171 pairwise comparisons were performed, of which 36 groups were statistically significant (Figure S3A, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). The top three treatments were routine electroacupuncture + Chinese medicine + Western medicine (100%), routine electroacupuncture + Tuina + rehabilitation therapy (79%), and routine electroacupuncture + Chinese medicine (77.2%) (Figure S3B, Supplemental Digital Content 7, http://links.lww.com/JS9/D173). Routine electroacupuncture + Chinese medicine + Western medicine is better than all other interventions, suggesting that this intervention has outstanding advantages in relieving pain. Routine electroacupuncture + Tuina + rehabilitation therapy and routine electroacupuncture + Chinese medicine are superior to only a few other therapies. Publication bias (P = 0.045) was found in 31 articles (Fig. 3F). However, there was no change in the effect size after trimming and patching, indicating that publication bias had no impact on the results and that the findings were relatively robust (Fig. 3G). Then, the funnel plot was drawn, as shown in Fig. 3H.

Figure 3.

Bias analysis of TNF-α levels in the included studies according to Egger’s test (A) and Egger’s test funnel plot (B). Evidence network diagram of interventions for the VAS score (C), Global (D) and Loop (E) inconsistency test chart of interventions for VAS score. Bias analysis of the VAS-Egger’s test results before (F) and after (G) trimming and patching for the included studies; Egger’s test funnel plot (H).

Based on the above results, we found that routine electroacupuncture + Chinese medicine + Western medicine had the most significant effect on relieving pain, while routine electroacupuncture + Tuina + rehabilitation therapy was more effective at reducing the levels of inflammatory factors. However, the patients in the studies were mainly from China, and some studies had irregular randomisation processes and inadequate implementation of blinding, which may have affected the reliability of the results. In alleviating discogenic pain, comprehensive electroacupuncture therapy can achieve better analgesic and anti-inflammatory effects than single therapy. It is highly suitable for the integrated management of chronic pain, providing a safer and more effective treatment option for clinical practice.

Ethical approval and consent to participate

This study is not a clinical trial and does not require ethical approval.

Consent for publication

This study is not a clinical trial, therefore written informed consent from patients is not required.

Source of funding

This work was supported by grants from the National Natural Science Foundation of China (81901125 and 82271260), the Fundamental Research Funds for the Central Universities (Grant No. 2024-JYBJBZD-024), the Capital Medical University Research Foundation (PYZ22065) and the Beijing Natural Science Foundation (7232103).

Author contribution

F.L., L.Z., and G.L.: designed this study; R.H., X.S., and J.S.: searched for literature and analysed the data; Z.X. and M.D.: analysed the data; R.H., F.L., and L.Z.: wrote the manuscript.

Conflicts of interest disclosure

The authors declare no conflicts of interest.

Research registration unique identifying number (UIN)

This study has been registered on the Prospero website, with registration number is CRD42023485944.

Guarantor

Guokai Liu, E-mail: guokai_liu@126.com; Fan Liu, E-mail: liufan132@126.com and liufan@ibms.pumc.edu.cn; Li Zhang, E-mail: zhangli8828@163.com; Ran Hu, E-mail: 17856514426@163.com.

Data availability statement

All studies and data are available in the public databases mentioned in the review, and analytic code can be obtained by contacting the author.

Provenance and peer review

Not commissioned, externally peer-reviewed.

Supplementary Material

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