Dose-Effect Response in Acupuncture for Functional Constipation

Official title

Response Characteristics of the Dose-Effect Relationship in Acupuncture Treatment for Functional Constipation: A Randomized Controlled Study

Overview

This is a single-center, randomized, parallel-group trial evaluating the dose-response relationship of two experimental interventions: manual acupuncture and electroacupuncture for functional constipation. A total of 72 participants with functional constipation (Rome IV criteria) will be randomly assigned in a 1:1 ratio to either the manual acupuncture group or the electroacupuncture group. Both groups receive acupuncture at bilateral Tianshu (ST25) and Shangjuxu (ST37) points, 30 minutes per session, three times per week for 12 weeks. The electroacupuncture group additionally receives electrical stimulation (continuous wave, 10 Hz, 0.5-4 mA). The primary outcome is the responder rate at week 12, defined as the percentage of participants with ≥3 complete spontaneous bowel movements (CSBMs) per week. Secondary outcomes include changes in gut microbiota, brain functional connectivity measured by multimodal MRI and fNIRS, and scales. The study aims to clarify the dose-response characteristics of different acupuncture modalities and their underlying biological mechanisms.

Interventions

• Other Manual Acupuncture
  Acupuncture at bilateral Tianshu (ST25) and Shangjuxu (ST37). Participant lies supine and rests for 5 minutes before treatment. After routine disinfection, the acupuncturist inserts needles vertically to a certain depth, followed by mild lifting, thrusting, and twisting for 10 seconds at each acupoint to induce deqi. Needles are retained for 30 minutes. After removal, needle holes are pressed to prevent bleeding. Treatment frequency: three sessions per week for 12 weeks.
• Device Electroacupuncture
  Acupuncture at bilateral Tianshu (ST25) and Shangjuxu (ST37). Participant lies supine and rests for 5 minutes before treatment. After routine disinfection, the acupuncturist inserts needles vertically to a certain depth, followed by mild lifting, thrusting, and twisting for 10 seconds at each acupoint to induce deqi. Then needles are connected to an electroacupuncture device (Hwato SDZ-III, Suzhou Medical Products Factory, China). Two pairs of electrodes are attached: one pair to bilateral Tians

Primary outcome measures

• Responder Rate at Week 12 [Time frame: Week 12]

Secondary outcome measures (9)

• Responder Rate at Week 16 [Time frame: Week 16]
• Changes in Blood Flow Measured by DCS [Time frame: Baseline, after deqi, weeks 2, 4, 6, 8, 10, 12, 16]
• Changes in Gut Microbiota [Time frame: Baseline, week 12, week 16, and at the time when CSBMs ≥3 per week is achieved]
• Changes in Brain Function [Time frame: Baseline, after deqi, week 12, week 16, and at the time when CSBMs ≥3 per week is achieved]
• Changes in Cortical Activity Measured by fNIRS [Time frame: Baseline, after deqi, weeks 2, 4, 6, 8, 10, 12, 16]
• Acupuncture Expectancy Scale [Time frame: Baseline]
• Patient Assessment of Constipation Quality of Life [Time frame: Baseline, weeks 2, 4, 6, 8, 10, 12, 16]
• Generalized Anxiety Disorder 7-item Scale [Time frame: Baseline, weeks 2, 4, 6, 8, 10, 12, 16]
• Patient Health Questionnaire-9 [Time frame: Baseline, weeks 2, 4, 6, 8, 10, 12, 16]

Eligibility criteria

Inclusion criteria

• Meet Rome IV diagnostic criteria for functional constipation
• Symptoms present for ≥6 months, meeting diagnostic criteria in the last 3 months
• Mean weekly complete spontaneous bowel movements (CSBMs) ≤2 during 14-day baseline period
• Age 18-75 years
• No use of constipation medications for at least 2 weeks prior to treatment (except rescue medication)
• No acupuncture treatment for constipation in the past 3 months
• Not currently participating in another clinical trial
• Willing and able to provide written informed consent

Exclusion criteria

• Constipation secondary to other causes (IBS, organic diseases, medications, endocrine disorders, metabolic disorders, neurological disorders, or gastrointestinal surgery)
• Loose or watery stools (Bristol type 6 or 7) >1 time during baseline without laxative use
• History of pelvic floor dysfunction
• Use of probiotics, fiber supplements, or laxatives within 2 weeks prior to treatment (2-week washout required)
• Severe hemorrhoids or anal fissures
• Severe or uncontrolled heart, liver, or kidney disease; abdominal aortic aneurysm; hepatosplenomegaly; cognitive impairment; or psychiatric disorders
• Dependence on opioids or anticholinergic drugs
• Red flags: unexplained weight loss >10% in 3 months, hematochezia or positive fecal occult blood, family history of colon cancer (first-degree relative diagnosed <50 years), anemia (Hb <110 g/L), or elevated inflammatory markers
• Contraindications to acupuncture: coagulation disorders or use of anticoagulants
• Pregnancy or breastfeeding
• Unable to comply with follow-up or contraindications to MRI (e.g., cardiac pacemaker, non-titanium aneurysm clips, metallic implants, claustrophobia)

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

China · 2 centers

• Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology — Wuhan
• Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology — Wuhan

Identifiers

NCT: NCT07506122 · TJ-IRB202603096

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗