Comparison of the Acute Effects of Non-Invasive Transcutaneous Auricular Vagus Nerve Stimulation Applied at Different Durations on the Autonomic Nervous System in Healthy Adults: A Sham-Controlled Study
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 发起方
- 入组人数
- 44
- 试验地点
- 1
- 主要终点
- Change in RMSSD
研究概览
简要总结
This randomized, participant-blinded, sham-controlled interventional study aims to compare the acute effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) applied at different durations on autonomic nervous system responses in healthy adults. Participants will be assigned to either an active taVNS group or a sham stimulation group. Within each group, participants will complete three separate study visits in which stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits. Heart rate variability, heart rate, blood pressure, respiratory rate, and subjective discomfort will be assessed immediately before and after each intervention session. The study is designed to determine whether the acute autonomic effects of taVNS vary according to stimulation duration and whether a duration-related response pattern can be identified.
详细描述
Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation method in which electrical stimulation is applied to auricular regions innervated by the auricular branch of the vagus nerve. Because of its low-risk profile, non-surgical application, and potential autonomic regulatory effects, taVNS has attracted increasing interest in autonomic physiology and cardiovascular research.
Previous studies in healthy individuals suggest that taVNS may influence autonomic balance, particularly through changes in heart rate variability (HRV), heart rate, and related physiological parameters. However, substantial heterogeneity remains across published taVNS studies with regard to stimulation parameters such as frequency, pulse width, current intensity, and intervention duration. Among these parameters, stimulation duration is one of the least standardized, and sham-controlled comparisons of different application durations remain limited.
This study is designed to investigate whether the acute autonomic effects of taVNS differ according to stimulation duration. The study uses a randomized, participant-blinded, sham-controlled mixed design. Healthy adults aged 18 to 40 years will be randomized to either an active taVNS group or a sham stimulation group. Participants will remain in their assigned group throughout the study. Within each group, each participant will attend three separate visits and receive stimulation for 5, 10, and 15 minutes in randomized order. Visits will be separated by 48- to 72-hour washout intervals.
Active taVNS will be applied bilaterally to the cymba conchae region using non-invasive stimulation parameters consistent with the study protocol. Sham stimulation will be delivered under visually and procedurally similar conditions to minimize expectancy effects. Before and immediately after each intervention session, autonomic and physiological outcomes will be assessed, including heart rate variability derived from RR interval recordings, heart rate, systolic and diastolic blood pressure, respiratory rate, and subjective discomfort measured by a visual analog scale.
The primary objective is to compare the acute autonomic responses to active taVNS and sham stimulation across different stimulation durations. The study also aims to explore whether a duration-response relationship exists for autonomic outcomes in healthy adults. Findings from this trial may help inform duration selection in future experimental and clinical taVNS research.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
盲法说明
Participants will be blinded to whether they are assigned to active taVNS or sham stimulation. Investigators and care providers cannot be blinded because of the technical requirements of device setup and application.
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy adults aged 18 to 40 years No known chronic systemic disease Non-smoker No regular medication use, including medications that may affect autonomic or cardiovascular function Able to understand the study procedures and provide written informed consent Willing to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise
排除标准
- •Any known chronic systemic disease Current smoker Regular medication use, including medications that may affect autonomic or cardiovascular function Inability to understand the study procedures or provide written informed consent Unwillingness or inability to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise
研究组 & 干预措施
Active taVNS
Participants assigned to this arm will receive active transcutaneous auricular vagus nerve stimulation during three separate study visits. Stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.
干预措施: Active taVNS (Device)
Sham stimulation
Participants assigned to this arm will receive sham stimulation during three separate study visits. Sham stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.
干预措施: Sham stimulation (Device)
结局指标
主要结局
Change in RMSSD
时间窗: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]
Change in the root mean square of successive differences (RMSSD), derived from RR interval recordings, from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.
Change in high-frequency heart rate variability (HF-HRV)
时间窗: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]
Change in high-frequency heart rate variability (HF-HRV) from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.
次要结局
- Change in heart rate([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in systolic blood pressure([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in diastolic blood pressure([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in respiratory rate([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in subjective discomfort assessed by visual analog scale (VAS)([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in SDNN([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
- Change in LF/HF ratio([Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)])
研究者
SEFA HAKTAN HATIK
Assistant Professor
Sinop University