Systematic review and Meta-analysis of acupuncture and acupoint catgut embedding for the treatment of abdominal obesity

Abstract

OBJECTIVE:

To systematically review and analyze the effect of acupuncture and acupoint catgut embedding in treatment of abdominal obesity to provide a more reasonable clinical treatment regimen.

METHODS:

Ten databases were searched as of August 2022: the English databases PubMed, Embase, Cochrane Library, Web of Science, Wiley, and Scopus and the Chinese databases China National Knowledge Infrastructure Database, China Science and Technology Journal Database, Wanfang, and SinoMed/Chinese Biomedical Literature Database. Randomized controlled trials (RCTs) of acupuncture and acupoint catgut embedding as the main interventions to treat abdominal obesity were extracted. The investigators imported the citations into EndNote version X9.1 for deduplication, screening, extraction, and integration. The risk of bias in the included RCTs was assessed according to the Cochrane Handbook. RevMan 5.4 software was used to conduct a Meta-analysis of RCTs that met the inclusion criteria.

RESULTS:

Thirteen RCTs (1069 patients) were included in this study, and the data of eleven RCTs (966 patients) were include in the Meta-analysis. The results showed that acupoint catgut embedding can significantly change the weight and waist circumference of patients with abdominal obesity when compared to sham acupuncture or no treatment [mean difference (MD) = 2.32, 95% confidence interval (CI) (1.88, 2.76), P < 0.000 01], [MD = 3.47, 95% CI (1.99, 4.94), P < 0.000 01]. The change in hip circumference after acupuncture was also significant [MD = 0.89, 95% CI (0.12, 1.66), P = 0.02].

CONCLUSION:

This study found that acupuncture and acupoint catgut embedding can effectively treat abdominal obesity, therefore, these interventions can be used as clinical supplements and alternative therapies. The diagnostic criteria of the existing studies and the intervention measures of the control group are not unified. It will be necessary to improve the clinical study protocols and expand the sample size to further validate the reliability of the results obtained of this study.

1. INTRODUCTION

Obesity is divided into abdominal obesity (central obesity and visceral obesity) and peripheral obesity (homogeneous obesity and systemic obesity) according to the body fat distribution. Abdominal obesity arises from the accumulation of fat in the intra-abdominal mesentery, visceral organs, and around the aorta.^1,2 Abdominal obesity is mainly caused by external environmental, genetic, and epigenetic factors. High accumulation of visceral and peripheral fat increases the risk of metabolic syndrome, diabetes mellitus, cardiovascular disease, fatty liver disease, and other diseases.^3,⇓-5 It also reduces quality of life to a certain extent and increases the economic burden on the family and society.^6,7 According to a survey in 2015, the prevalence of obesity in more than 70 countries doubled in 30 years, and more than 100 million children and 600 million adults have become obese worldwide.^{8,⇓,⇓,⇓-12} By 2016, the number of obese people in China was nearly 90 million, causing China to surpass the United States and become the country with the most obese people in the world.¹³ Therefore, effective measures are urgently needed to treat abdominal obesity.

In clinical practice, abdominal obesity is mainly treated by drugs, surgery, lifestyle intervention, oral administration of traditional Chinese medicines, and acupuncture treatment.^14,⇓-16 Lifestyle or behavioral intervention is effective for weight loss, but patients easily rebound because they cannot maintain the habits needed.^17,⇓-19 Western medicine treatments, which include lipase inhibitors and appetite-suppressive weight loss drugs, often cause adverse reactions, such as hypoglycemia, dizziness, headache, constipation, nausea and vomiting, or insomnia, so they are generally not recommended as good choices.^16,20,21 The high medical costs, high recurrence rates, and series of inevitable complications associated with surgery are limitations of bariatric surgery.^22,⇓-24

As a safe and effective therapy, acupuncture has the advantages of significant efficacy, simple operation, and relatively few adverse reactions. It is widely accepted by patients with abdominal obesity as well as medical workers in the clinic. Acupuncture therapy has diverse application modes, including acupuncture and acupoint catgut embedding for the treatment of abdominal obesity.^25,⇓-27 Acupoint catgut embedding is a kind of acupoint stimulation method based on traditional acupuncture. The catgut, collagen thread, or polymer line is buried in the target acupoints, and the continuous stimulation of the catgut itself and the acupoint is used to prevent and treat diseases. Acupoint catgut embedding and acupuncture have their own particular characteristics.^28,⇓-30

Experiments have confirmed the effectiveness of acupuncture therapy for the treatment of abdominal obesity,^31,32 but we have conducted an updated Meta-analysis research on the effects of acupuncture and acupoint catgut embedding for abdominal obesity due to more high-quality clinical studies in recent years. Therefore, in this study, we analyzed randomized controlled trials (RCTs) on this topic in detail, systematically reviewed and Meta-analyzed clinical trials of acupuncture and acupoint catgut embedding in the treatment of abdominal obesity, and provided empirical evidence for clinical treatment and further research.

2. METHODS AND MATERIALS

This systematic review and Meta-analysis has been registered with PROSPERO (International prospective register of systematic reviews, CRD42021283496), and was conducted according to PRISMA checklist.

2.1. Search strategy

Chinese and English databases were searched for Chinese and English literature in detail up to August 2022. These databases included PubMed, Embase, Cochrane Library, Web of Science, Wiley, Scopus, China National Knowledge Infrastructure Database, China Science and Technology Journal Database, Wanfang, and SinoMed/Chinese Biomedical Literature Database. The search algorithm contained MeSH free words. The following search terms and their synonyms were used in the retrieval strategy: “abdominal obesity”, “acupuncture”, “catgut embedding”, and “RCT”, “ran-domized controlled trials. The review publications were identified to find more RCTs from their reference lists. The wildcard character “*” was also used to increase the sensitivity of the search strategy.

2.2. Inclusion criteria

(a) Study subjects: the subjects were patients with definite diagnostic criteria of abdominal obesity based on body mass index (BMI) and waist circumference (WC) that exceed the normal level without any limitation of gender. (b) Study design: the design was an RCT (cross-design or parallel design). (c) Intervention measures: Acupuncture or acupoint catgut embedding was the main intervention measure. The treatment arm was treated with acupuncture or catgut embedding as the intervention method, while the control group was treated with conventional Western Medicine, Traditional Chinese Medicine, sham acupuncture, or no treatment. (d) Outcome indicators: the primary outcome indicators were weight, WC and BMI. The secondary outcome indicators were hip circumference (HC), waist/hip ratio (WHR), and waist/height ratio (WtHR).

2.3. Exclusion criteria

(a) The patient’s obesity was a secondary or sudden obesity (caused by other diseases). (b) Obesity was combined with other, pre-existing diseases, such as mental diseases, severe hypertension, abnormal hepatic and kidney function, congenital heart disease, malignant cancer, blood system diseases or severe bleeding tendency, pregnancy, or lactation. (c) The publication lacked various key data, such as subject information or intervention measures. (d) The study reported results that could not be verified or could not be analyzed. (e) Duplicate publications.

2.4. Data compilation

2.4.1. Data screening

Papers were retrieved according to a predefined search strategy. First, two authors (Ye wujie and Xing Jingyu) entered the retrieved publications into EndNote X9.1 for deduplication and integration. Second, they excluded apparently irrelevant publications by reading headlines and abstracts. Then, they downloaded and read the remaining full publications to determine whether to include them in the analysis. Finally, if there was any disagreement, the authors first discussed it; then, if necessary, they consulted a third party (Yu Zekai) to resolve it.

2.4.2. Data extraction and management

The investigators (Ye Wujie and Xing Jingyu) extracted valid data from all included publications, including the basic information of the study (author, publication date), the basic characteristics of the subjects (sample size, sex, age, and course of disease), intervention measures (method, frequency, and time), course of treatment, primary outcome indicators and data, follow-up time, and adverse events. Two investigation personnel collated and checked the data independently and entered them into a standardized form. If there was any disagreement, the author resolved it through discussion and consulted another author (Yu Zekai) as needed. If the information was incomplete or unclear, the original author was contacted to obtain the needed information.

2.4.3. Quality assessment

The risk of bias in the included studies was assessed using the Chinese version of the Cochrane Handbook (2014). We evaluated seven study design domains, including the generation of random sequences, allocation concealment, the blinding of patients and investigators, the blinding of outcome evaluators, the integrity of the outcome data, selective reporting, and other deviations. According to the above evaluation basis, the quality of each publication was classified as low risk of bias, high risk of bias, or unknown risk of bias.

2.5. Data synthesis and statistical analysis

RevMan 5.4 software was used for the Meta-analysis of the data. Continuous data were calculated as the mean difference (MD) with a 95% confidence interval (CI) in the effect analysis. Categorical variable data were calculated as odds ratios (ORs) with 95% CIs. I² was calculated for the heterogeneity test. The studies with high heterogeneity (P ≤ 0.10 and/or I² ≥ 50%) were analyzed by a random-effect model for the combined effect value, and the studies with low heterogeneity (P > 0.10 and I² < 50%) were analyzed by a fixed-effect model. A difference was considered statistically significant when P ≤ 0.05. If enough studies were included in the Meta-analysis (n ≥10), RevMan software was used for funnel plot analysis to evaluate the publication bias. Using the MD and standard deviation before and after treatment, as specified in the Cochrane Handbook, the calculation method was as follows: Mean_change = Mean₁ - Mean₂; SD_change = √SD₁² + SD₂² -2 × Corr × SD₁ × SD₂, where Corr ranges between -1 and 1 (1 was used in this study per convention); Mean₁ is the baseline mean; Mean₂ is the endpoint mean; SD₁ is the baseline SD; and SD₂ is the endpoint SD.

2.6. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE)

The evidence of the main outcomes was further assessed with the GRADE system. We evaluated five domains of study design limitations: inconsistency, directness, imprecision and publication bias. Finally, five levels of evidence were identified as follows: high, moderate, low, very low quality of evidence and no evidence.

3. RESULT

3.1. Literature search and retrieval

A total of 93 English and 51 Chinese publications were retrieved from the major Chinese and English databases. The paper titles were exported to Excel tables, and 34 duplicate studies and 97 studies that did not meet the inclusion criteria were excluded, including case reports, reviews, Meta-analyses, noninterventional basic studies, and nonclinical controlled trials. Finally, 11 RCTs that met the criteria were included for Meta-analysis, including eight Chinese studies and three foreign studies. The flow chart of study screening is shown in Figure 1.

Figure 1. Flow chart.

CNKI: China National Knowledge Infrastructure Database; VIP: China Science and Technology Journal Database; RCT: randomized controlled trial.

3.2. Characteristics of clinical studies

A total of 13 studies^31-43 (1069 patients) were included in the systematic review. The subjects were 18.2% males and 81.8% females, with ages ranging from 30 to 50 years old. In the treatment arm, acupuncture or acupoint catgut embedding was the main intervention method. Ten publications^{31,32,35-38,40-43} involved catgut embedding therapy, and three publications^33,34,39 involved acu-puncture. Studies involved in sham acupuncture, tr-aditional Chinese medicine, Western medicine, or no treatment were assigned to the control group. In the included RCTs, acupuncture was performed 2-5 times/ week, and needles were retained for 20-30 minutes; acupoint catgut embedding was basically administered 7-14 days/time; and the overall course of treatment was 1-3 months. The acupoints were mainly in the abdomen, supplemented by acupoints along the spleen meridian and stomach meridian or front-mu points along the spleen meridian, stomach meridian, and large intestine meridian. The most frequently used acupoints were Zhongwan (RN12) and Tianshu (ST25), followed by Zusanli (ST36), Daheng (SP15), and Pishu (BL20). The details are as shown in Table 1.

Table 1.

Basic Characteristics of Included RCTs

Study	Patients		Gender	Average age	Interventions	Treatment time	Outcomes	Adverse Events			Follow-up
	(T/C)	(male/female)		(years)	Treatment / Control
Liang CM et al 201631	50/23		21/52	T: 47.7±11.0 C: 49.4±11.4	Acupuncture, 3 times a week Health education	8 weeks	weight; BMI; WC; HC		None	None
Qin WL et al 201632	58/54		33/79	T: 42.14±11.83 C: 39.13±11.13	Catgut embedding, once a week Sham acupuncture	4 weeks	weight; BMI; WC		None	None
Xiong W 201933	31/32		12/51	T: 33.16±6.99 C: 33.00±6.75	Acupuncture, once a day, 2 d off after 5 d Oral orlistat, 1 tablet each time, t.i.d	28 days	weight; WHR		Mentioned	None
Wu KQ 201934	33/33		35/31	T: 35.61±8.24 C: 32.24±6.58	Acupuncture, twice a week Auricular point bean	4 weeks	weight; WC; HC; BMI; WHR; WHtR		None	Mentioned
Zhang XH 202035	25/25		20/30	T: 36.6±8.1 C: 36.4±7.9	Catgut embedding, once every 2 weeks Oral Chinese medicine, 1 dose per day	6 weeks	weight; WC; HC; BMI; WHR;		None	None
Song YX et al 201836	200/100		0/300	T: 33.2±2.6 C: 33.5±2.5	Catgut embedding, once every 2 weeks Tuina, once a day	8 weeks	weight; WC; WHR; BMI		Mentioned	None
Jin YH 201937	33/32		13/52	T: 34.58±9.95 C: 35.47±8.89	Catgut embedding, once every 2 weeks Sham acupuncture	8 weeks	weight; WC; HC		Mentioned	None
Meng JQ 201938	35/34		10/59	T: 36.51±10.13 C: 36.44±9.66	Catgut embedding, once every 2 weeks Sham acupuncture	8 weeks	weight; BMI; WC; HC		Mentioned	None
Pan XW 201739	26/24		16/34	T: 35.88±8.65 C: 37.62±8.84	acupuncture, 3 times a week Sham acupuncture	12 weeks	weight; WC; HC; BMI; WHR		Mentioned	Mentioned
Deng LJ, et al 201440	30/30		5/55	T: 33±8 C: 32±7	Catgut embedding, once a week no treatment	9 weeks	weight; WC		None	None
Chen LS et al 201941	28/23		/	T: 34.43±7.63 C: 34.60±5.21	Catgut embedding, Once every 10 d no treatment	10 weeks	weight; BMI; WC; HC; WHR; WtHR		None	None
Chen IJ et al 201842	40/40		/	T: 39.9±9.8 C: 43.7±9.3	Catgut embedding, once a week Sham acupuncture	6 weeks	weight; WC; HC; WHR		None	None
Lei H et al 201743	15/15		/	T: 31.6±8.2 C: 31.4±8.4	Acupuncture, 3 times a week no treatment	12 weeks	BMI; WC		None	None

Notes: WC: waist circumference; BMI: body mass index; HC: hip circumference; WHR: waist/hip ratio; WtHR: waist/height ratio.

3.3. Risk of bias

The risk-of-bias assessment criteria in the Cochrane Handbook were used to assess the risk of bias of the included RCTs. In terms of the generation of random allocation sequences (selective bias), eleven studies^{32, 33-39, 41-43} adopted the random number method, one study⁴⁰ adopted the stratified random method, and one study³¹ adopted the block randomization method. In terms of allocation concealment, three studies^{32, 33, 39} used ordered and light-tight sealed envelopes to hide the random allocation protocol, and ten studies^{31, 34-38, 40-43} did not mention the allocation concealment method. The risks of bias are shown in Figures 2 and 3.

Figure 2. Risk of bias graph.

Figure 3. Risk of bias summary.

3.4. Meta-analysis

Finally, 11 RCTs^32-42 (966 patients) were available for Meta-analysis, and the results were as follows.

3.4.1. Weight

All studies^32-42 observed weight changes in patients by tracking weights before and after treatment. The acupuncture group^33,34,39 had high heterogeneity among studies (P < 0.000 01, I² = 97%). The random-effect model was adopted, and the results showed that the weight changes in the acupuncture group were greater than those of the control group, but the difference was not statistically significant [MD = 2.86, 95% CI (–0.87, 6.59), P = 0.13]. The catgut embedding group^{32, 35-38, 40-42} exhibited high heterogeneity among studies (P < 0.000 01, I² = 98%). The random-effect model was adopted, showing that the weight changes in the catgut embedding group were significantly greater than those of the control group [MD = 2.32, 95% CI (1.88, 2.76), P < 0.000 01, Figure 4A].

Figure 4. Meta-analysis.

A: weight: acupuncture or acupoint catgut embedding versus comparator; B: waist circumference: acupuncture or acupoint catgut embedding versus comparator; C: body mass index: acupuncture or acupoint catgut embedding versus comparator; D: hip circumference: acupuncture or acupoint catgut embedding versus comparator; E: Waist/Hip ratio: acupuncture or acupoint catgut embedding versus comparator; F: waist/height ratio: acupuncture or acupoint catgut embedding versus comparator.

3.4.2. Waist circumference

Ten studies^32,34-42 compared the waist circumference of patients before and after treatment. The acupuncture group^34,39 exhibited high heterogeneity among studies (P < 0.000 01, I² = 99%). The random-effect model was adopted, and the results showed that the changes in waist circumference in the acupuncture group were better than those in the control group, but the difference was not statistically significant [MD = 5.31, 95% CI (–0.03, 10.65), P = 0.05]. The catgut embedding group^{32,35-38,40-42} exhibited high heterogeneity among studies (P < 0.000 01, I² = 100%). The random-effect model was adopted, showing that the changes in waist circumference in the catgut embedding group were significantly greater than those in the control group [MD = 3.47, 95% CI (1.99, 4.94), P < 0.000 01, Figure 4B].

3.4.3. Body mass index

Seven studies^{32,34-36,38,39,41} compared the BMI before and after treatment. The acupuncture group^34,39 exhi-bited high heterogeneity among studies (P < 0.000 01, I² = 98%). The random-effect model was adopted, and the results showed that the improvement of BMI in the acupuncture group was better than that in the control group, but the difference was not statistically significant [MD = 1.60, 95% CI (–0.19, 3.39), P = 0.08]. The catgut embedding group^{32,35,36,38,41} exhibited high heterogeneity among studies (P < 0.000 01, I² = 99%). The random-effect model was adopted, and the results showed that the improvement of BMI in the catgut embedding group was better than that in the control group, but the diff-erence was not statis-tically significant [MD = 1.28, 95% CI (–0.19, 2.74), P = 0.09, Figure 4C].

3.4.4. Hip circumference

Seven studies^{34,35,37-39,41,42} compared the hip cir-cumferences of patients before and after treatment. The acupuncture group^34,39 exhibited high heterogeneity among studies (P < 0.007, I² = 86%). The random-effect model was adopted, showing that the changes in hip circumference in the acupuncture group were higher than those in the control group [MD = 0.89, 95% CI (0.12, 1.66), P = 0.02]. The catgut embedding group^{35,37,38,41,42} exhibited high heterogeneity among studies (P < 0.000 01, I² = 98%). The adopted random-effect model showed that the changes in hip circumference in the catgut embedding group were greater than those in the control group, but the difference was not statistically significant [MD = 0.37, 95% CI (–0.55, 1.30), P = 0.43, Figure 4D].

3.4.5. Waist/hip ratio

Seven studies^{33-36,39,41,42} compared the WHR of patients before and after treatment. The acupuncture group^33,34,39 exhibited high heterogeneity among studies (P = 0.001, I² = 85%). The random-effect model was adopted, and the changes in WHR in the acupuncture group were better than those in the control group, but the difference was not statistically significant [MD = 0.00, 95% CI (–0.02, 0.03), P = 0.71]. The catgut embedding group^35,36,41,42 exhibited high heterogeneity between studies (P < 0.000 01, I² = 99%). The random-effect model was adopted, and the changes in WHR in the catgut embedding group were found to be better than those in the control group, but the difference was not statistically significant [MD = 0.07, 95% CI (–0.03, 0.17), P = 0.16, Figure 4E].

3.4.6. Waist/height ratio

Three studies^32,34,41 compared the waist/height ratio of patients before and after treatment. There was high heterogeneity exhibited studies (P < 0.000 01, I² = 100%). The random-effect model was adopted, showing that the improvement of the waist/height ratio in the treatment arm was better than that in the control group, but the difference was not statistically significant [MD = 0.07, 95% CI (–0.04, 0.19), P = 0.21, Figure 4F].

3.5. Adverse events

Five studies^33,36-39 mentioned adverse reactions. In Xiong’s study³³ , a small amount of bleeding from a pinhole occurred in the acupuncture group, and this problem was resolved by prolonged pressure; 7 cases of adverse reactions occurred, including 3 cases of steatosis, 2 cases of increased gastrointestinal flatus, and 2 cases of abnormal stool. In Song’s study,³⁶ both the treatment group and the control group had mild adverse reactions, such as fever, subcutaneous congestion, and induration, but these reactions did not affect the treatment. During Jin’s study,³⁷ 12 patients had induration at surgical sites, and 4 patients had hematoma in both groups. After hot compression or ceasing treatment, the above adverse reactions disappeared within 2 weeks without sequelae. In Meng’s study,³⁸ seven patients had hematoma, which dissipated within 1-2 weeks, and four patients had induration, which dissipated within 2 weeks in the two groups. In Pan’s study,³⁹ nine of 50 patients had acupoint bleeding, which was resolved by pressing for hemostasis; three patients had acupoint congestion with mild tenderness in two groups. These patients were instructed to apply a hot compress on it, and the sites of involvement were avoided in subsequent sessions, resolving on their own 2 weeks later.

3.6. GRADE analysis and explanation

The detailed GRADE assessment is shown in Table 2. When patients were treated with acupuncture or acupoint catgut embedding, there was low-quality evidence of benefit for weight, waist circumference and BMI, as the domain of inconsistency was not met. There was very low-quality evidence that acupuncture or acupoint catgut embedding improved the hip circumference, WHR and WtHR of patients because of imprecision and lack of consistency.

Table 2.

GRADE analysis: acupuncture or acupoint catgut embedding for abdominal obesity

Quality assessment							No of patients		Effect
No of studies	Design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	Summary	Control	Relative (95%CI)				Absolute	Quality	Importance
Weight (better indicated by lower values)
11	Randomized Trials	No serious risk of bias	Very seriousa	No serious indirectness	No serious imprecision	None	539	427	-		MD 1.45 higher (1.4 to 1.5 higher)			LOW	IMPORTANT
Waist circumference (better indicated by lower values)
10	Randomized Trials	no serious risk of bias	Very seriousa	No serious indirectness	No serious imprecision	None	508	395	-		MD 3.9 higher (2.43 to 5.36 higher)			LOW	IMPORTANT
Hip circumference (better indicated by lower values)
7	Randomized Trials	no serious risk of bias	Very seriousa	No serious indirectness	Seriousb	None	220	211	-		MD 0.54 higher (0.2 lower to 1.27 higher)			VERY LOW	IMPORTANT
BMI (better indicated by lower values)
7	Randomized Trials	no serious risk of bias	Very seriousa	No serious indirectness	No serious imprecision	None	405	293	-			MD 1.37 higher (0.2 to 2.54 higher)		LOW	IMPORTANT
WHR (better indicated by lower values)
7	Randomized Trials	no serious risk of bias	Very seriousa	No serious indirectness	Seriousb	None	383	277	-	MD 0.03 higher (0.03 to 0.04 higher)				VERY LOW	NOT IMPORTANT
WtHR (better indicated by lower values)
3	Randomized Trials	no serious risk of bias	Very seriousa	No serious indirectness	Very seriousb	None	119	110	-	MD 0.07 higher (0.04 lower to 0.19 higher)				VERY LOW	NOT IMPORTANT

Notes: GRADE: Grading of Recommendations, Assessment, Development, and Evaluation; CI: confidence interval; BMI: body mass index; WHR: waist/hip ratio; WtHR: waist/height ratio; MD: mean difference. ^aI ² ≥ 75%; ^bCross the equivalent line or the sample size is too small.

4. DISCUSSION

A detailed description of obesity in Traditional Chinese Medicine was first recorded in Huang Di Nei Jing.^44,45 Traditional Chinese medicine holds that the essence of “grease” is sputum, dampness, and turbidity, which accumulate in the abdomen and affect the Qi activities of abdominal-related organs and the movement of meridians.^46,47 There were five meridians at the abdomen from the inside to the outside: Ren meridian, kidney meridian of foot-Shaoyin, stomach meridian of foot-Yangming, spleen meridian of foot-Taiyin, and liver meridian of foot-Jueyin. Therefore, acupuncture or acupoint catgut embedding in the treatment of abdominal obesity usually selects many acupoints along these meridians.

Modern science has shown that obesity is closely related to the hypothalamic feeding center and many hormones such as leptin and adipose cell cytokines. These substances affect the appetite via the hypothalamus, influencing individual feeding behavior and ultimately leading to metabolic and endocrine disorders.^{48,⇓,⇓-51} Some experiments have observed that rats in the acupuncture group had significantly higher spontaneous discharge frequencies from the ventral contralateral hypothalamic nucleus than others, indicating that acupuncture can activate the hypothalamic satiety center and promote the effective formation of weight loss channels.^52,53 Leptin is a hormone encoded by the obesity (ob) gene that can inhibit appetite, reduce food consumption, and increase energy consumption by increasing the activity of the sympathetic nervous system.^54,⇓-56 Acupuncture can promote the aggregation of leptin in the hypothalamus, increase energy consumption and significantly reduce the levels of serum glycerol and cholesterol.⁵⁷

Acupoint catgut embedding can promote the signal transduction of leptin after it binds to the receptor in the hypothalamus to promote its biological effects.⁵⁸ The body’s heat production capacity depends mainly on the mitochondrial UCP gene, which controls the degree of “proton leak” at transmembrane proteins located in the mitochondrial inner membrane, so UCP can affect obesity by regulating energy balance and substrate metabolism.^{59,⇓,⇓-62}

After acupoint catgut embedding therapy, the gene expressions of UCP2 and UCP3 in rats were significantly increased in obese rats, indicating that acupoint catgut embedding can significantly increase the expression levels of UCP2 and UCP3 mRNA in skeletal muscle, thereby increasing peripheral heat production and metabolism in obese rats and ultimately achieving weight loss⁵⁸ .⁶³

This study is the evidence-update Meta-analysis focused on the effect of acupuncture and acupoint catgut embedding in the treatment of abdominal obesity. Eleven RCTs were included in this study to compare the efficacy of acupuncture and sham acupuncture or no treatment on abdominal obesity. Meta-analysis was used to explore the effect of acupuncture and catgut embedding on parameters related to abdominal obesity. The results showed that acupuncture and catgut embedding have certain advantages in the treatment of abdominal obesity in terms of weight, waist circumference, hip circumference and but with no significant differences between groups in BMI, WHR, WtHR. Moreover, the results of subgroup analysis reveal that acupuncture has obvious efficacy with respect to hip circumference in improving abdominal obesity, while catgut embedding shows significant efficacy regarding weight and waist circumference. Five RCTs reported adverse reactions. Regardless, the adverse reactions to acupuncture were relatively mild, and their incidence was significantly lower in patients treated with acupuncture or catgut embedding than in those treated with western medicine. There was low-quality evidence of benefit for weight, waist circumference and BMI, and very low-quality evidence of improving hip circumference, WHR and WtHR when patients were treated with acupuncture or acupoint catgut embedding. In summary, our review and Meta-analysis of their findings showed that acupuncture and catgut embedding are the most common acupuncture therapies for abdominal obesity, and their efficacy is worthy of attention.^{25,26,64,⇓,⇓-67}

Due to the differences in the experimental design protocol of each study and the small number of included studies, our study has the following shortcomings. (a) It included several reference diagnoses, which were outdated, and new diagnostic criteria have not yet appeared. (b) Regarding the selection of control measures, the inconsistent direction of each investigator and the absence of authoritative criteria may be the major reasons for the high heterogeneity of the analysis. (c) Although there were records of adverse reactions, only some studies described the adverse reactions for observation group and control group separately, so the safety of acupuncture and catgut embedding could not be objectively assessed. (d) The courses of treatment included in the studies were relatively short, and most of them were not followed up. The long-term effects of acupuncture and catgut embedding on abdominal obesity are not known. To draw more objective conclusions, large, multicenter, high-quality, and well-designed RCTs are needed. Researchers should adopt the correct method of randomization, random sequence generation, and allocation concealment and the diagnostic criteria and the intervention measures of the control group need to be more unified and standardized. At the same time, it is necessary to follow up the patients and evaluate the long-term effects of the interventions for a more thorough and accurate determination of the value of acupuncture and acupoint catgut embedding in the treatment of abdominal obesity.In conclusion, acupuncture and acupoint catgut embedding are effective methods of treating abdominal obesity. These two methods are feasible and have lasting effects, so they can be recommended to clinicians. Acupuncture and acupoint catgut embedding have significant advantages in improving weight, waist circumference, and hip circumference. They can also avoid adverse reactions related to western medicine and improve the patient’s quality of life. Compared to lifestyle changes such as diet regulation and exercise, these interventions can support higher compliance and maintain health status more effectively and permanently.