Acupuncture for obesity: study protocol for a randomised controlled trial

Abstract

Background

Obesity is a major public health issue in China and around the world. While acupuncture is often used in clinical practice, there is a lack of conclusive evidence for its weight-loss effect. Thus we will conduct a parallel, randomised, sham-controlled trial to evaluate the efficacy and safety of acupuncture for treating obesity.

Methods and analysis

A total of 160 eligible participants with obesity will be randomly assigned to the verum acupuncture group or sham acupuncture group at a ratio of 1:1. All participants will be treated three times a week for a duration of 12 weeks, and followed up for another 16 weeks. The primary outcome is the percentage change in body weight from baseline to Week 12. The secondary outcomes include body mass index (BMI), waist circumference (WC), body fat percentage (BF%), blood pressure, fasting blood glucose, insulin, glycosylated haemoglobin A1c, blood lipids, and physical functioning score on the Short Form 36 Health Survey. Other secondary outcomes including psychological and social functions will also be evaluated using the body image scale, psychological function scale, and social function scale of the BODY-Q, Rosenberg Self-Esteem Scale, Patient Health Questionnaire-9, and Dutch Eating Behaviour Questionnaire. BMI, WC, BF% and blood pressure will be evaluated at Week 0, 4, 8, 12 and 28. Other secondary outcomes will be measured at Week 0, 12 and 28, respectively. Adverse events will be recorded in detail during the trial.

Ethics and dissemination

Ethical approval of this trial was granted by the Ethics Committee of Chengdu Sport University (2023–102). Written informed consent will be obtained from study participants before enrolment. The findings will be disseminated through peer-reviewed journals.

Trial registration number

Chinese Clinical Trial Registry (ChiCTR2200062092).

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This is a large parallel, randomised, sham-controlled trial to evaluate the efficacy and safety of acupuncture for obesity in China.

• Psychological and social functions will be evaluated in addition to physiological measures to confirm the therapeutic effects of acupuncture.

• The 12-week treatment and an ensuing 16-week follow-up will allow us to understand the long-term effects of acupuncture.

• The long duration of the trial may compromise the participants’ compliance.

• The generalisability may be limited as all participants will be recruited from Chengdu, China.

Introduction

Obesity is defined as abnormal or excessive fat accumulation that is potentially harmful to health. Nearly 880 million adults and 159 million children and adolescents are living with obesity globally.¹ In China, the prevalence is approximately 34.3% for overweight and 16.4% for obesity in adults.² Obesity is not only a chronic metabolic disease but also an independent risk factor for multiple non-communicable diseases, such as cardiovascular disease and type 2 diabetes mellitus, and psychosocial and social impairments.³ The management of obesity is crucial for addressing the burden of non-communicable diseases.

Several treatments are advised for obesity. Behavioural interventions, including diet changes and physical activities, are regarded as the first-line treatment for reducing body weight. However, the effect of behavioural interventions is weak and slow; at least 6 months is needed to achieve significant improvement.^{4 5} Pharmacotherapy is commonly used in the USA and Europe, but most weight-loss medications have adverse effects of varying degrees, such as headache, nausea, insomnia and diarrhoea.^{6 7} While bariatric surgery has long-term positive effects on weight loss with evident cardiovascular benefits, it is mostly recommended for severe obesity. Thus, the identification of safe, effective and low-cost therapies for obesity is still imperative.

Emerging evidence points to the potential weight-loss effects of acupuncture as a traditional Chinese medicine therapy. In a systematic review of eight randomised controlled trials (RCTs) among 403 participants, acupuncture was reported to lead to mean reductions of 1.85 kg and 1.0 kg/m² in body weight and body mass index (BMI), as compared with sham acupuncture.⁸ In addition, another systematic review of 23 trials among 1808 participants showed that acupuncture was more effective than sham acupuncture or no treatment for weight reduction, with or without lifestyle modification.⁹ Despite the collective evidence, there are still controversies over the efficacy of acupuncture, mainly due to a lack of high-quality data.¹⁰ The included trials generally had small sample sizes with short treatment periods and follow-ups, and in particular, the placebo effect of acupuncture could not be excluded in most cases because an appropriate placebo is not readily available. As non-penetrating acupuncture is emerging as a sham control in clinical research,^{11 12} it could be potentially used to remove the non-specific effect of acupuncture in trials for obesity management. While multiple lines of evidence supported the effects of acupuncture in improving psychological symptoms and social function,^{13 14} most trials on acupuncture for obesity only focused on physical health improvement; the effect on psychological and social functions is less examined. Based on the bio-psycho-social model, psychological and social impairments should be captured in such obesity trials.¹⁵

To address the knowledge gap, we intend to conduct an RCT with non-penetrating acupuncture at acupoints as control, to investigate the efficacy and safety of acupuncture for obesity treatment. Physiological outcomes, psychological and social functions, as well as adverse events, will be assessed in the follow-up. Our trial will be one of the most rigorous RCTs on the relation between acupuncture and weight loss, thus providing evidence for its utility for clinical weight management.

Methods and analyses

Study design

We will conduct a parallel, randomised and sham-controlled clinical trial at Chengdu Sport University and Chengdu University of Traditional Chinese Medicine. A total of 160 participants with obesity will be recruited and randomly assigned to verum acupuncture or sham acupuncture at a ratio of 1:1. Participants in the verum acupuncture group will receive normal acupuncture treatment at specific meridians and acupoints, while those in the sham acupuncture group will receive non-penetrating needling at these acupoints. All participants will receive treatment three times per week during the 12-week treatment period, and then followed up for a 16-week post-treatment period. Besides, both groups will receive lifestyle guidance (including diet and physical activity consultation) during the whole period. The flowchart of the whole trial is shown in figure 1, while the schedule is outlined in table 1. The protocol is developed under the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013¹⁶ (online supplemental file 1) and the SPIRIT-TCM (traditional Chinese medicine) Extension 2018.¹⁷

Figure 1. Flowchart of the trial. BF%, body fat percentage; BMI, body mass index; WC, waist circumference.

Table 1. Schedule of enrolment, interventions and assessments.

Timepoint	Enrolment	Baseline	Treatment period			Follow-up period
	Week -1	Week 0	Week 4 Week 8 Week 12			Week 16 Week 20 Week 24 Week 28
Enrolment
Eligibility screening	×
Informed consent	×
Randomisation		×
Interventions
Verum acupuncture group			×	×	×
Sham acupuncture group			×	×	×
Assessments
Body weight	×	×	×	×	×				×
BMI	×	×	×	×	×				×
WC		×	×	×	×				×
BF%		×	×	×	×				×
Blood pressure		×	×	×	×				×
Fasting blood glucose		×			×				×
Insulin		×			×				×
HbA1c		×			×				×
Blood lipids		×			×				×
SF-36		×			×				×
BIS of the BODY-Q		×			×				×
PFS of the BODY-Q		×			×				×
SFS of the BODY-Q		×			×				×
RSES		×			×				×
PHQ-9		×			×				×
DEBQ		×			×				×
Adverse events			×	×	×	×	×	×	×
Blinding assessment					×

BF%body fat percentageBISbody image scaleBMIbody mass indexDEBQDutch Eating Behavior QuestionnaireHbA1cglycosylated haemoglobin A1CPFSpsychological function scalePHQ-9Patient Health Questionnaire-9RSESRosenberg Self-Esteem ScaleSF-3636-Item Short Form Health SurveySFSsocial function scaleWCwaist circumference

Sample size estimation

Based on data from the literature,18,22 we expected that the difference in the percentage of weight loss was 4% (standard deviation, 8%) between verum acupuncture and sham acupuncture groups after 12-week treatment. With the aforementioned statistics, to achieve a statistical power of 80% (1 - β=0.8) with a two-sided significance level of 0.05, 160 participants are needed (80 participants in each group) if a dropout rate of 20% is assumed. PASS software V.15.0 (Kaysville, Utah, USA) is used to calculate the sample size.

Recruitment and informed consent

Participants in the RCT are recruited through social media platforms or offline advertisements (eg, posters or leaflets) at Chengdu Sport University and Chengdu University of Traditional Chinese Medicine from June 2023 to December 2026. Adults who are eligible will be invited to participate. All participants will be given information of the research procedure and the benefits and risks of the study. Informed consent will be obtained from all participants before randomisation. Ethics approval was obtained from the Ethics Committee of Chengdu Sport University (2023–102).

Inclusion criteria

Participants will be recruited if they meet the following criteria:

1. BMI ≥28 kg/m² (based on the obesity criteria in Chinese adults).²

2. Adults aged 18–35 years.

3. Having not received any weight-loss measures in the past 3 months.

4. Voluntarily participating in the trial and signing informed consent.

Exclusion criteria

Participants will be excluded if they meet any of the following criteria:

1. Secondary obesity caused by drugs or other diseases.

2. Psychosis, liver and kidney dysfunctions or other relevant diseases.

3. Skin diseases, severe allergic or scar constitution.

4. Pregnant or lactating women or those planning to conceive during the trial.

5. Having participated in other clinical trials.

Randomisation and allocation concealment

After enrolment, participants will be randomised into the treatment or control group by research personnel who are not involved in the treatment or data collection but are familiar with administrative work. Stata software V.17.0 will be used to generate random numbers and serial numbers, which are sealed in opaque paper envelopes. All participants allotted with specific serial numbers will be randomly assigned to verum acupuncture or sham acupuncture according to the random numbers.

Blinding

The study is a single-blinded trial, in which participants remain unknown about the group assignment throughout the study. Recruiters, acupuncturists, data collectors, outcome evaluators and data managers will work independently throughout the study. Only the acupuncturists know the grouping details. Participants will wear opaque eye masks during the treatment. To evaluate the quality of blinding, participants will be asked to answer a question after treatment at Week 12: which acupuncture do you think you have received? The participants will be provided with two options to answer this question: verum acupuncture or sham acupuncture.

Intervention

All participants will receive verum acupuncture or sham acupuncture every other day, three times per week for 12 weeks (4 weeks per session). Treatment will be performed by licensed acupuncturists, who receive standard training in advance. A stick adhesive pad will be placed on each acupoint before acupuncture administration, through which the needles are/are not inserted into the skin (figure 2). During treatment, two groups of participants will be treated in separate rooms and asked to wear an opaque eye mask. Besides, all participants will receive lifestyle guidance for diet control, physical activity and sufficient sleep at baseline (Week 0), and Week 4, 8 and 12.

Figure 2. Diagram of verum acupuncture versus sham acupuncture.

Verum acupuncture

Based on the traditional Chinese medicine theory and literature,^{23 24} CV4 (Guanyuan), CV6 (Qihai), CV12 (Zhongwan), bilateral SP6 (Sanyinjiao), SP9 (Yinlingquan), SP15 (Daheng), ST25 (Tianshu), ST36 (Zusanli) and ST40 (Fenglong) are included in the acupuncture prescription, the locations of which are presented in figure 3. The depths of needle insertion are shown in table 2.

Figure 3. Locations of acupoints. (A) abdomen; (B) front side of right leg; (C) inner side of right leg.

Table 2. Acupoints used in the treatment.

Acupoints	Locations*	Depth of insertion
CV4(Guanyuan)	On the lower abdomen, anterior median line, 3 cun below the navel	1.0–1.5 cun
CV6(Qihai)	On the lower abdomen, anterior median line, 1.5 cun below the navel	1.0–1.5 cun
CV12(Zhongwan)	On the upper abdomen, anterior median line, 4 cun above the navel	1.0–1.5 cun
SP6(Sanyinjiao)	On the inner side of the calf, 3 cun above the tip of the medial malleolus, by the posterior border of the tibia	1.0–1.5 cun
SP9(Yinlingquan)	On the inner side of the calf, in the depression between the inferior border of the medial condyle of the tibia and the medial border of the tibia	1.0–1.5 cun
SP15(Daheng)	On the abdomen, 4 cun beside the navel	1.0–1.5 cun
ST25(Tianshu)	On the abdomen, horizontal to the umbilicus, 2 cun lateral to the anterior midline	1.0–1.5 cun
ST36(Zusanli)	On the anterior lateral side of the calf, 3 cun below Dubi (ST35)†, one horizontally placed finger distance lateral to the anterior border of the tibia (the middle finger)	1.0–1.5 cun
ST40(Fenglong)	Outside the calf, 8 cun above the tip of the lateral malleolus, the outer border of the tibialis anterior muscle	1.0–1.5 cun

^*The cun is a measure of length in traditional Chinese medicine. 1 cun (≈20 mm) is defined as the width of the interphalangeal joint of patient’s thumb.

^†ST35 is located on the lateral depression of the patellar ligament.

After sterilisation, acupuncturists will use stainless steel needles (0.30×40 mm, Hwato, Suzhou, China) to penetrate the skin and insert them into acupoints at different depths through the stick adhesive pad. Afterwards, the needles will be manipulated by twirling, lifting and thrusting to generate the sensation of de qi, which is a complicated feeling of mixed numbness, heaviness and distension. Electrical stimulation will be applied using an electronic acupunctoscope (SDZ-III Suzhou Medical Appliance Factory, China) for 30 min. One pair of electrodes will connect acupoint ST25 to SP15, while another pair will connect ST36 to ST40. The power source offers a disperse-dense wave, which we ensure that all participants can tolerate.

Sham acupuncture

The selected acupoints are the same as those for the verum acupuncture group. After sterilisation, non-invasive acupuncture needles with blunt tips (0.30×40 mm, Hwato, Suzhou, China) will be used to penetrate the sterile stick adhesive pad but not into the skin, so a de qi sensation is not achieved. In addition, the acupoints will be connected to an electronic acupunctoscope but no electrical stimulation will be provided.

Outcomes

Outcome assessors will independently measure the outcomes for the two groups of participants.

Primary outcome

The primary outcome is the percentage change in body weight from baseline to Week 12.

Secondary outcomes

Extensive effects of acupuncture on obesity, including psychological and social functions will be assessed in addition to physiological outcomes.

Physiological outcomes include BMI, waist circumference (WC), body fat percentage (BF%), blood pressure, fasting blood glucose, insulin, glycosylated haemoglobin A1c, blood lipids, and physical functioning score on the Short Form 36 Health Survey.²⁵

Psychological and social functions will be evaluated using the body image scale, psychological function scale, and social function scale of the BODY-Q, ²⁶ Rosenberg Self-Esteem Scale,²⁷ Patient Health Questionnaire-9,²⁸ and Dutch Eating Behaviour Questionnaire.²⁹

For these outcomes, BMI, WC, BF% and blood pressure will be evaluated at Week 0, 4, 8, 12 and 28. Other secondary outcomes will be measured at Week 0, 12 and 28, respectively.

Safety outcomes

Acupuncture-related adverse events including serious pain, bleeding, subcutaneous haemorrhage, fainting, palpitation, and local infections will be recorded after each 4-week acupuncture session. All adverse events that occur during the study will be properly handled. In case of serious adverse events (SAEs), research personnel shall take all necessary measures to ensure patient safety. Treatment costs and corresponding financial compensations for these SAEs will be covered by the trial. SAEs should be reported within 24 hours to the research ethics committee, which has the right to terminate the trial if necessary.

Quality control

Prior to participant recruitment, standard operation procedures (SOPs) will be established. All research personnel will receive SOP training to understand the design, implementation and regulations of this study. A data monitoring plan will also be developed. Quality assurance monitors will check all research documents for completeness and compliance with SOPs. The Ethics Committee of Chengdu Sport University will regularly arrange quality control inspections.

Statistical analysis

Data from the trial will be managed and monitored by specific data managers. Intention-to-treat analyses will be used to evaluate all outcome measures, for which the analysis set is composed of all randomised participants. Missing data will be imputed using the last observation-carried-forward method. Continuous data will be reported as mean and standard deviation if they meet the normal distribution; otherwise, they will be presented as median and interquartile range. Categorical variables will be expressed in terms of frequency and percentage. For demographic and clinical information at baseline, χ² test or Fisher’s exact test will be used to compare categorical data, while two-sample t-test or Mann-Whitney U test will be used for continuous data. To compare changes within a group, paired t-test or Wilcoxon signed-rank test will be used. Net differences in mean weight (or BMI) changes between the verum acupuncture group and sham acupuncture group will be tested using a linear mixed effects model. Subgroup analyses will be performed by stratifying variables including sex (male and female), baseline BMI (28–29.9 kg/m², 30–31.9 kg/m² and ≥32 kg/m²) and family history of obesity (yes and no). Interactions between verum acupuncture and stratifying variables will be assessed using a likelihood-ratio test. A p<0.05 is considered statistically significant. All data will be analysed using Stata V.17.0 (StataCorp LLC).

Patient and public involvement

Patients and/or the public will not be involved in the design, conduct, reporting or dissemination plans of this research.

Discussion

Acupuncture is increasingly used in clinical practice for obesity treatment. Although the collective evidence indicates a potential weight-loss effect from acupuncture, such evidence is weak due to methodological and statistical weaknesses, such as small sample sizes and short treatment durations and follow-ups.^{2 8} Our study is conducted in such a context to consolidate the effect of acupuncture on obesity in the adult population.

Our trial will recruit 160 participants who will undergo a 12-week treatment and 16-week post-treatment follow-up. Previous trials on this topic included 30–70 participants in most cases.^{8 30 31} Our larger trial will improve the statistical power to identify the potential weight-loss effect. Weight regain is always a concern for weight-loss interventions, so a long-term follow-up is necessary to assess this regain in participants who receive acupuncture. Our trial has a longer follow-up than any others (4–12 weeks) on weight control through acupuncture as identified in the literature.^{10 22 24 32} The long follow-up with repeated observations of body weight in our work will help us to understand the long-term effects of acupuncture on obesity, particularly the weight dynamics after treatment. Moreover, the effect of acupuncture on obesity is mostly only assessed in terms of weight loss or BMI in other trials, which could be problematic as acupuncture itself has multiple effects on health such as improvement in psychological and social functions. To our knowledge, our trial will be one of the first ones to include these outcomes as secondary endpoints in participants with obesity. Although many adults with obesity could have psychological and social dysfunctions, these dysfunctions are often ignored in trials on obesity. Our trial can comprehensively assess the effect of acupuncture in the framework of a bio-psycho-social model for obesity. Moreover, the use of sham acupuncture as the control and the use of lifestyle guidance in both groups make it possible to differentiate the specific from non-specific effects of acupuncture, which is rarely addressed in other trials.

We acknowledge certain limitations in our trial. First, study participants will be primarily enrolled from university students in Chengdu, China. This participant composition may affect the generalisability of our findings. However, we believe that such enrolment could increase compliance. Second, as the follow-up is 16 weeks long after treatment, selection and information bias due to loss to follow-up could be expected. We plan to use various strategies such as close contact with participants through social media to improve the follow-up rate. Third, acupoints and electrostimulation are standardised for all participants without considerations of participant characteristics in our trial. Such an arrangement facilitates the implementation of the trial but may miss the chance of evaluating tailored treatments that are applied in clinical practice. Fourth, it is likely that some participants have received acupuncture for obesity or other conditions before, which may affect the effect of the blinding procedure in the trial. However, as most study participants will be university students, they are expected to receive acupuncture treatment for the first time.

Our large trial with a long follow-up and comprehensive assessments of endpoints will improve the current evidence base for the weight-loss effect of acupuncture. Our findings may contribute to the use of acupuncture for obesity management and control in clinical practice.

Ethics and dissemination

This study was approved by the Ethics Committee of Chengdu Sport University (2023–102) on 30 May 2023 and conformed to the Declaration of Helsinki. Registration was completed on 11 June 2023, in the Chinese Clinical Trial Registry (ChiCTR2200062092). All participants must provide written informed consent before participating in the trial (online supplemental material 2). All personal information from potential and enrolled participants out of the scope of this trial will not be collected, shared or maintained to protect confidentiality before, during and after the trial. Trial results will be published in peer-reviewed journals and will be disseminated to the media and the public.

The funding agencies has no role in the design, implementation, data analysis and manuscript writing of the trial.