Acupoint catgut embedding versus acupuncture for simple obesity: a systematic review and Meta-analysis of randomized controlled trials

Abstract

OBJECTIVE:

To evaluate the clinical effectiveness and safety of acupoint catgut embedding and acupuncture on simple obesity by Meta-analysis.

METHODS:

Studies on clinical randomized controlled trials of acupoint catgut embedding for simple obesity which were published from January 2015 to November 2020 were searched in Cochrane Central Register of Control Trials (Central), PubMed, China Science and Technology Journal Database, China National Knowledge Infrastructure Database and Wanfang data-bases. And those that met the inclusion criteria were screened. RevMan5.3 was used for Meta-analysis. The “Risk of Bias” tool was used to evaluate the quality of included studies. R studio software was used for the measurement of publication bias.

RESULTS:

A total of 33 studies were included for Meta-analysis, including 2685 patients with simple obesity. Meta-analysis results showed the comparison of effectiveness rate was relative risk (RR) = 1.12, 95%CI (1.08, 1.16), body mass index (BMI) was mean difference (MD) = –1.12, 95%CI (–2.09, –0.14), waist circumference was MD = –2.14, 95%CI (–4.22, –0.06), and body mass was MD = –2.36, 95%CI (–3.99, –0.73). On the basis of diet and exercise intervention, the effectiveness rate [RR = 1.12, 95%CI (1.05, 1.19)], BMI [MD = –0.88, 95%CI (–1.35, –0.40)], waist circumference [MD = –1.10, 95%CI (–4.27, 2.07)], and body mass [MD = –0.68, 95%CI (–2.90, 1.54)]. The risk of bias of included literatures was low.

CONCLUSIONS:

Acupoint catgut embedding therapy was slightly better than acupuncture therapy in most of the outcomes. Moreover, the treatment frequency of acupoint catgut embedding is less with larger stimulation intensity, which is more conducive to clinical promotion.

1. INTRODUCTION

Simple obesity is a common form of obesity,which is predominantly caused by a greater intake of calories than that expended by human body. Patients with simple obesity do not have underlying endocrine disorders or related diseases of metabolic illnesses and the fat distribution throughout the body is relatively even, rather than being concentrated in particular areas such as the abdomen. From 1985 to 2017, the global average Body Mass Index (BMI) increased by more than 55%¹ indicating an increasingly prevalent and serious issue worldwide. Nowadays, there are about 630 million obesity people worldwide. Obese population is close to 100 million in China, which is the world's largest, accounting for nearly 10% of the country's population.² This demonstrates that obesity becomes an important public health matter in China.

At present, the treatment of simple obesity consists mainly of diet and exercise therapy, biomedical treatments such as weight loss medications or surgical treatment and Traditional Chinese Medicine (TCM) therapy. Although diet and exercise therapy can be extremely effective, adherence to treatment is notoriously poor and typically requires a significant treatment course of more than 4 months. Biomedical approaches such as weight loss medications and surgical intervention can bring about rapid weight loss but can unfortunately be associated with serious side-effects affecting gastrointestinal function or even nervous system issues.³

TCM for simple obesity include acupuncture and specialized acupuncture techniques such as electro-acupuncture (EA) and acupoint catgut embedding (ACE). Acupuncture can support weight management through its effects on the endocrine, gastrointestinal and nervous systems. For example, studies have shown that ACE can increase insulin sensitivity to make patients feel full to reduce food intake.⁴ Acupuncture can also have a good effect. This is further supported by evidence from clinical research. The results of recent randomized controlled trials (RCTs) have demonstrated that patients with simple obesity treated with electroacupuncture combined with diet and exercise experienced (5 ± 7) kg greater weight loss when compared with patients undergoing diet and exercise alone.⁵ Another specialized acu-puncture technique, ACE, has also shown promising results for abdominal obesity. A recent Meta-analysis showed that the average weight loss of patients in the group treated with ACE was 1.35 kg greater than that in the electroacupuncture group.⁶ When considering the external validity of these results, however, electro-acupuncture typically requires multiple treatment sessions a week which can affect the overall acceptability of the intervention. In contrast, ACE treatment is carried out once every 7 to 10 d and which could result in considerably greater patient adherence and therefore greater overall effectiveness. We aimed to review the clinical evidence comparing ACE against acupuncture for simple obesity and conducted a systematic review and Meta-analysis of the available evidence to date.

2. METHODS

2.1. Inclusion criteria

We included RCTs involving patients diagnosed with simple obesity, which is predominantly caused by a greater intake of calories than that expended by human body. Studies were eligible if the treatment group received ACE and the control group received whether manual acupuncture (MA) or electroacupuncture (EA). Diet and exercise interventions were permitted if they were administered to both groups. RCTs were eligible if they evaluated relevant outcomes such as effectiveness rate, BMI, waist circumference and body mass.

2.2. Study review and screening

We conducted a search of literature published between January 2015 and November 2020 across Cochrane Central Register of Control Trials (Central), China National Knowledge Infrastructure Database (CNKI), China Science and Technology Journal Database (VIP), China Wanfang Database (Wanfang) and PubMed. We used search terms for literature search. For example, “Search ((((simple obesity [Title/Abstract] OR simple obese [Title/Abstract] OR obesity [Title/Abstract] OR obese [Title/Abstract)])) AND (acupoint catgut embedding [Title/Abstract)]”were used in PubMed. We excluded duplicate publications, studies that evaluated other obese populations and studies that did not involve ACE as the treatment intervention. Preliminary screening was carried out using NoteExpress by reading the titles and abstracts. Full texts of the remaining literature were then retrieved for final screening. Screening was carried out by Lin Zhechao and Han Mei with disagreements resolved by a third author Lai Lily if necessary.

2.3. Data extraction

We established a data collection form and data was extracted independently by two reviewers Wei Jiali and Han Mei. We extracted information such as the general characteristics of the studies, characteristics of the participants, details of interventions, outcome measures used and research findings.

2.4. Quality assessment

We evaluated the methodological quality using the Risk of Bias tool and according to the standards recommended by the Cochrane Handbook for Systematic Reviews of Interventions. We completed an assessment evaluating risk of bias according to the following categories: random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and any other bias. Due to the particularity of the interventions, we deemed it almost impossible to blind practitioners and participants. Therefore, if the data statistician was blinded, we assessed the study as being at low risk of bias. Studies reporting on reasons for withdrawals or dropouts and with comparable dropout rates between groups were also assessed as being at low risk.

BMI and waist circumference are the most objective indicators for evaluating simple obesity.⁷ Therefore, if these two outcomes were not reported, the study was evaluated as being at high risk of bias. The risk of bias was also evaluated independently by two reviewers Liu Jianping and Lin Zhechao and assessments were compared. Any disagreements were resolved through discussion with a third reviewer Lai Lily.

2.5. Statistics analysis

We used Review Manager 5.3 to conduct the quantitative synthesis of the review data. Relative risk (RR) was used for dichotomous data. The remaining outcome indicators were continuous and the mean difference (MD) was calculated for these measures.

Heterogeneity between RCTs was evaluated using χ² and I ² . When I ² ≤ 50%, we used a fixed effects model for analysis. When 50% ≤ I ² ≤ 75%, a random effects model was used for analysis. High heterogeneity was determined when I ² ≥ 75%, and in this case, it would be temporarily abandoned. A 95% confidence interval (CI) was calculated for each analysis and P < 0.05 considered statistically significant.

2.6. Measurement of publication bias

Metabias function in meta package of R studio software for the measurement of publication bias.

2.7. Quality evaluation of evidence

Grading of Recommendations Assessment, Deve-lopment and Evaluation criteria (GRADE; https://www.Gradeworkinggroup.org/) was used to evaluate the quality of evidence of Meta-analysis results from five downgrades including risk of bias, inconsistency, indirectness, imprecision and publication bias. According to the evaluation results, the grade of final evidence evaluation is high, medium, low and extremely low.

2.8. Informed consent and ethical review

This study is a review of literature, not a clinical trial. So informed consent or ethical review is not required in our study.

3. RESULTS

3.1. Studies searching and screening procedure

A total of 484 studies were obtained of which 87 were duplicates and which were excluded. After screening, 40 full text studies were obtained. After full-text screening, 33 were eligible for inclusion and 7 studies were excluded. 33 RCTs were eventually included in this Meta-analysis. The screening process is illustrated in Figure 1.

Figure 1. Flowchart of study searches and screening.

CNKI: China National Knowledge Infrastructure Database; VIP: China Science and Technology Journal Database.

3.2. Characteristics of included studies

All 33 studies included ACE in the treatment group. ACE was compared against MA in 19 studies and against EA in 14 studies. Adjunctive treatment of diet and exercise was adopted in 8 RCTs.^{11,14,15,25,28,29,35,39} The 33 included studies enrolled a total of 2685 participants, including 1349 in the ACE group and 1336 in the MA/EA group. The frequency of treatment and characteristics of the participants in each included RCT were very similar, with patients of similar age. The treatment duration was between 4-12 weeks. Among the included studies, the most frequently used acupoints were Zhongwan (CV12), Tianshu (ST25), Fenglong (ST40), Qihai (CV6), Daheng (SP15), Zusanli (ST36), Daimai (GB26), Liangmen (ST21), Yinlingquan (SP9), Guanyuan (CV4), Quchi (LI11) and Shuifen (CV9). Further information regarding the characteristics of the studies can be found in Table 1.

Table 1.

Characteristics of included studies

ID	Sample size（T/C）	Age (years)	Interventions			Treatment frequency					Treatment duration				Diet and Exercise
			T	C			T	C				T	C
Chen RZ 20168	47/47	42.8±2.9	ACE	MA		1/1 w			6/1 w		8 w		8 w	NO
Chen YY et al 20159	40/40	29	ACE	MA		1/3 w			4/1 w		12 w		10 w	NO
Di YL 201610	41/41	31.5±6.8	ACE	MA		1/1 w			4/1 w		8 w		8 w	NO
Duan YQ et al 201811	25/25	18-45	ACE	MA		1/15 d			7/1 w		8 w		8 w	YES
He LY et al 201712	30/28	38.2±2.8	ACE	EA		1/2 w			5/1 w		12 w		12 w	NO
Huang Q 202013	39/39	38.3±2.5	ACE	MA		1/1 w			4/1 w		12 w		12 w	NO
Huang W et al 201714	40/40	20-45	ACE	EA		1/10 d			4/1 w		8 w		8 w	YES
Jin WW, Chen ZL 201615	80/80	39.2±4.8	ACE	EA		1/2 w			5/1 w		6 w		6 w	YES
Li MM et al 201716	30/30	37.43	ACE	EA		1/2 w			2/1 w		8 w		8 w	NO
Li MM et al 201817	33/33	31.61	ACE	EA		1/2 w			2/1 w		8 w		8 w	NO
Li QL 201618	40/40	33.4±2.4	ACE	EA		1/15 d			2/1 w		12 w		12 w	NO
Liu Y 201919	31/31	37.3±11.8	ACE	EA		1/2 w			3/1 w		8 w		8 w	NO
Qiao L 201620	30/30	18-60	ACE	MA		1/1 w			7/1 w		8 w		8 w	NO
Ren CC, Ge BH 201621	36/36	32±9	ACE	EA		1/1 w			4/1 w		8 w		8 w	NO
Sun FJ 202022	25/25	26.2±5.9	ACE	MA		1/21 d			4/1 w		8 w		8 w	NO
Wang Z, Pang XH, Ma M 202023	56/56	43.5±2.7	ACE	MA		1/4 w			2/1 w		4 w		4 w	NO
Wu XM, Zheng YS, Zhou HN 201524	32/30	33.0±11.0	ACE	EA		1/10 d			1/1 w		6 w		6 w	NO
Wu XN 201525	80/80	41.1±12.0	ACE	EA		1/1 w			1/1 w		12 w		12 w	YES
Wu XN et al 201726	76/73	43.2±11.0	ACE	EA		1/1 w			4/1 w		12 w		12 w	NO
Xu DJ 201927	30/30	29.6±4.4	ACE	MA		1/15 d			7/1 w		12 w		12 w	NO
Xu WZ 201728	30/30	30.4±6.6	ACE	MA		1/1 w			3/1 w		8 w		8 w	YES
Yan XR 201529	27/27	32.4±11.9	ACE	EA		1/10 d			4/1 w		4 w		6 w	YES
Yang Q 201530	39/33	41.4	ACE	MA		1/1 w			4/1 w		10 w		10 w	NO
Yang YF 201531	65/65	35.5±6.3	ACE	MA		1/1 w			5/1 w		8 w		8 w	NO
Zhang H, Ding TH 201732	40/40	18-55	ACE	MA		1/1 w			4/1 w		12 w		12 w	NO
Zhang HT 201533	30/30	18-60	ACE	MA		1/2 w			4/1 w		6 w		6 w	NO
Zhang Y 201734	33/33	42.8±12.2	ACE	MA		1/15 d			7/1 w		12 w		12 w	NO
Zhao HY, Ai BW 201535	50/50	42.21	ACE	EA		1/10 d			5/1 w		6 w		6 w	YES
Zheng X, Ji HC 201536	40/40	15-56	ACE	MA		1/2 w			4/1 w		12 w		12 w	NO
Zheng X et al 201837	43/43	41.0±5.0	ACE	EA		1/1 w			4/1 w		8 w		8 w	NO
Zhou L et al 201738	33/33	18-60	ACE	MA		1/4 w			2/1 w		4 w		4 w	NO
Zhou W et al 201939	45/45	21-45	ACE	MA		1/10 d			4/1 w		8 w		8 w	YES
Zhu Q 201740	33/33	18-60	ACE	MA		1/2 w			4/1 w		8 w		8 w	NO

Notes: T: treatment group; C: control group; MA: manual acupuncture; EA: electroacupuncture; ACE: acupoint catgut embedding; w: week; d: day.

3.3. Quality assessment

Figure 2 provides a summary of the risk of bias evaluation of eligible studies across the 7 specific areas of bias mentioned earlier. 12 studies ^{10,17,19,21,22,25,30,34} were randomly assigned by random number table method and 2 studies ^14,39 used opaque envelopes. Blinding was not adopted in any of the 33 studies in this review. There were 2 studies^{27, 34} with safety outcome report and 6 studies^{17, 25, 29,30,33,35} reported on withdrawals. There was no conflict of interest.

Figure 2. Risk of bias evaluation of included studies.

3.4. Results of Meta-analysis

3.4.1. Effectiveness rate

The nationally recognized method of obesity assessment³⁴ was adopted to define the effectiveness rate. Significant effect: Body Mass decreases at least 5 kilograms or Waist Circumference decreases at least 5 centimeters. Effective: Body Mass decreases at least 3 kilograms or Waist Circumference decreases at least 3 centimeters. The ratio of the number of significant and effective patients with the total number of patients in this group is the effectiveness rate. Most of the studies included in this study adopted this definition of effectiveness rate.

In the comparison of ACE versus acupuncture, 24 studies reported effectiveness rate. Quantitative synthesis of the results showed that ACE performed slightly better than acupuncture in terms of the effectiveness rate [RR = 1.12, 95%CI (1.08, 1.16)] (Figure 3A).

Figure 3. Comparison between ACE and Acupuncture.

A: forest plot of effectiveness rate; B: forest plot of BMI; C: forest plot of waist circumference; D: forest plot of body mass. ACE: acupoint catgut embedding; BMI: body mass index.

Eight studies reported the effectiveness rate for the comparison of ACE plus diet and exercise versus acupuncture plus diet and exercise. Meta-analysis showed a better effect in ACE plus diet and exercise when compared with acupuncture plus diet and exercise [RR = 1.12, 95%CI (1.05, 1.19)] (Figure 4A).

Figure 4. Comparison between ACE and acupuncture (plus diet and exercise).

A: forest plot of effectiveness rate; B: forest plot of BMI; C: forest plot of waist circumference; D: forest plot of body mass. ACE: acupoint catgut embedding; BMI: body mass index.

3.4.2. BMI

When looking at studies reporting on BMI as an outcome, 17 studies compared ACE against acupuncture. Meta-analysis showed that BMI was statistically significantly reduced in the ACE group compared with acupuncture [MD = –1.12, 95%CI (–2.09, –0.14)] (Figure 3B).

Six studies comparing ACE plus diet and exercise against acupuncture plus diet and exercise reported on BMI as an outcome measure. Quantitative synthesis showed no significant difference between the two groups [MD = –0.88, 95%CI (–1.35, –0.40)] (Figure 4B).

3.4.3. Waist Circumference

A total of 12 studies comparing ACE against acupuncture used waist circumference as an outcome measure. Meta-analysis showed that WC was statistically significantly reduced in the ACE group compared with acupuncture [MD = –2.14, 95%CI (–4.22, –0.06)] (Figure 3C).

When comparing ACE plus diet and exercise against acupuncture plus diet and exercise, 5 studies reported waist circumference as an outcome. The combined analysis showed that ACE plus diet and exercise had a slight advantage over acupuncture plus diet and exercise [MD = –1.10, 95%CI (–4.27, 2.07)] for this outcome (Figure 4C).

3.4.4. Body Mass

14 studies reporting on body mass compared ACE against acupuncture. Our quantitative synthesis found a statistically significant difference favoring ACE for body mass [MD = –2.26, 95%CI (–3.99, –0.73)] (Figure 3D).

When comparing ACE plus diet and exercise against acupuncture plus diet and exercise (Figure 4D), we pooled data from four studies using body mass as an outcome. Our analysis showed ACE plus diet and exercise had a little advantage compared with Acupuncture plus diet and exercise for the outcome of body mass [MD = –0.68, 95%CI (–2.90, 1.54)] (Figure 4D).

3.4.5. Fasting plasma glucose (FPG), fasting serum lisulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR)

Only one study reported the outcome indexes of FPG, FINS and HOMA-IR. When comparing ACE plus diet and exercise against acupuncture plus diet and exercise, the corresponding values of ACE group were lower than acupuncture group in three outcomes.

3.4.6. Total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C)

Three studies reported the outcome indicators of TC, TG, HDL-C and LDL-C for ACE compared with acupuncture, and Meta-analysis results showed the comparison of TC was MD = –0.23, 95%CI (–0.84, 0.37), TG was MD = 0.05, 95%CI (–0.07, 0.17), HDL-C was MD = 0.33, 95%CI (–0.34, 1.00), LDL-C was MD = –0.43, 95%CI (–1.68, –0.81). There wasn’t significant difference between the two groups in TC, TG and HDL-C. On the outcome index of LDL-C, the effect of ACE was a little greater than acupuncture.

Based on diet and exercise intervention, one study reported the outcome indicators of TC, TG, HDL-C and LDL-C, and the corresponding values of the ACE group were lower than acupuncture group of TC, TG and LDL-C, in the outcome of HDL-C, ACE was a little higher than acupuncture group.

3.5. Measurement of publication bias

According to the results of Egger test, t = 0.17933, P value = 0.8599 > 0.05, suggesting that the included studies were likely to be free from publication bias.

3.6. Analysis of GRADE evidence

This study mainly evaluated the outcome indicators of effectiveness rate, BMI and waist circumference with GRADE. The evidence was degraded according to the requirements of five downgrades. Finally, the evidence grade of effectiveness rate, effectiveness rate (plus diet and exercise), BMI, BMI (plus diet and exercise), WC, WC (plus diet and exercise) score of this study were rated as moderate, low, very low, low, very low and very low. This may be related to subjectivity, risk of bias (most of the included studies in this study did not describe the specific random method and allocation hiding in detail, blind method was rarely used) and high heterogeneity. Further information regarding the analysis of GRADE evidence can be found in Table 2.

Table 2.

Analysis of GRADE Evidence

Outcome	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	No of participants (studies)	Certainty of the evidence (GRADE)
	Risk with acupuncture	Risk with ACE
Effectiveness rate	802 per 1000	96 per 1000 (64 to 128)	RR 1.12 (1.08 to 1.16)	1837 (24 RCTs)	⨁⨁⨁◯ MODERATEa
Effectiveness rate (plus diet and exercise)	802 per 1000	96 per 1000 (152 to 281)	RR 1.12 (1.35 to 1.19)	707 (8 RCTs)	⨁⨁◯◯ LOWa,b
BMI	The mean BMI was 0	MD 1.12 lower (–2.09 to–0.14)	-	1305 (17 RCTs)	⨁◯◯◯ VERY LOWa,b,c
BMI (plus diet and exercise)	The mean BMI (plus diet and exercise) was 0	MD 0.88 lower (–1.35 to –0.4)	-	624 (6 RCTs)	⨁⨁◯◯ LOWa,b
WC	The mean WC was 0	MD 2.14 lower (–4.22 to –0.06)	-	935 (12 RCTs)	⨁◯◯◯ VERY LOWa,b,c
WC (plus diet and exercise)	The mean WC (plus diet and exercise) was 0	MD 1.1 lower (–4.27 to 2.07)	-	464 (5 RCTs)	⨁◯◯◯ VERY LOWa,b,c

Notes: ^aMost of the included studies did not describe the specific random method and allocation hiding in detail, blind method was rarely used. ^bThe range of confidence interval is wide. ^cHeterogeneity between RCTs was evaluated using χ² and I². High heterogeneity was determined when I ² ≥ 75%. *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). GRADE: Grading of Recommendations, Assessment, Development, and Evaluation; CI: confidence interval; ACE: acupoint catgut embedding; BMI: body mass index; MD: mean difference; WC: waist circumference; RCT: randomized controlled trial.

3.7. Adverse events

Two studies^27,34 reported on safety. Some participants reported pain at the ACE site lasting for one week. Some participants reported mild pain at the embedding site which subsided after 2-3 days. Some participants experienced ecchymosis under the skin of the embedding site, which dissipated after symptomatic treatment. There were 6 studies ^{17, 25, 29,30,33,35} reported on withdrawals as a result of treatment-related pain and a lack of knowledge about simple obesity.

4. DISCUSSION

4.1. Principal Findings

This Meta-analysis of RCTs showed that ACE was statistically significantly better than acupuncture in terms of effectiveness rate, BMI, waist circumference and body mass. ACE plus diet and exercise provide significant benefits compared with acupuncture plus diet and exercise in terms of effectiveness rate and waist circumference. Based on the component differences of different outcome indicators after diet and exercise, we can know that diet and exercise intervention may play a complementary role in the treatment of simple obesity.

4.2. Comparison of similar studies

After searching the subject of ACE for obesity, we obtained 3 Meta-Analyses, including 1 study published in 2020⁴¹ 1 in 2019⁴² and 1 in 2015⁴³ suggesting that researchers had lots of attention on ACE for obesity recently.

Compared with the study of 2015, we included the latest randomized controlled trial studies from January 2015 to November 2020.We conducted a systematic evaluation of relevant studies in recent five years. Compared with the article of 2019, we included 18 more studies, and we focused on the outcome indicators in addition to BMI, body mass and waist circumference, as well as effectiveness rate, blood glucose and blood lipid series. When compared with the studies of 2020, we included 20 more literatures, focusing on outcome indicators in addition to effectiveness rate, BMI and waist circumference, as well as blood glucose and blood lipid series. In addition, a subgroup analysis was conducted in this paper with or without diet and exercise intervention to analyze the supplementary effect of diet and exercise intervention in the treatment of simple obesity. Moreover, diet and exercise subgroup analysis was not performed in the previous three literatures.

4.3. Limitations of the study

Some of the included studies failed to provide clear details regarding participants who withdrew or who were lost-to-follow-up. As studies in this review were published in Chinese and conducted in China which may make the results of this review less generalizable to non-Chinese populations.

4.4. Implications for clinical practice

The results of our review demonstrate that ACE has a statistically significant benefit when compared with acupuncture for simple obesity, for the outcomes of effectiveness rate, BMI, waist circumference and body mass. When with diet and exercise, ACE shows a significant benefit than acupuncture in the outcomes of effectiveness rate and waist circumference. As an extension of acupuncture therapy, acupoint catgut is placed in ACE to achieve lasting stimulation of the acupoints. ACE can speed up the flow of Qi and blood and enhance the metabolism of the body to achieve the purpose of treating obesity.¹⁹ Modern medicine believes that the mechanism of ACE may be increasing the expression of peroxisome proliferators-activated receptorγ PPAR-γ mRNA in adipose tissue and inhibiting the expression of visfatin in visceral adipose tissue so as to achieve multiple biological functions such as producing insulin, regulating immune and inflammatory responses, and promoting adipogenic differentiation and synthesis.It also can reduce uric acid levels in the blood of the obese patients and increase insulin sensitivity making the patients feel full to reduce food intake.⁴⁰

Since ACE treatment is administered on a less frequent basis compared with acupuncture, patients are likely to find ACE treatment more acceptable and easier to comply with. ACE treatment also requires a shorter course of treatment, meaning that patients are likely to observe clinical benefits sooner than with diet and exercise and which in turn is likely to increase patient adherence and thus overall effectiveness. This review also found few adverse events associated with ACE treatment which provides additional advantage over biomedical options such as medications and surgical intervention which can be associated with serious adverse outcomes. In summary, our findings appear to suggest that ACE is clinically effective for important parameters in obesity and could be considered as first-line therapy for the management of simple obesity in adults.

4.5. Implications for future research

The results of our review highlight the poor methodological quality of the included studies. Future RCTs involving participants with simple obesity should consider reducing bias in particular by providing further details regarding participants’ lost-to-follow-up.

In conclusion, in our Meta-analysis, ACE appeared to provide statistically significant benefits compared with acupuncture for the outcomes of effectiveness rate, BMI, waist circumference and body mass. ACE plus diet and exercise provides significant benefits compared with acupuncture plus diet and exercise for the outcomes of effectiveness rate and waist circumference. However, these findings need to be interpreted with caution owing to the poor methodological quality of the studies. More methodologically rigorous RCTs are required so that the effects of ACE for simple obesity can be understood more clearly.