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Not yet recruitingNCT07642518Updated Jun 11, 2026

Transcutaneous Auricular Vagus Nerve Stimulation in Type 2 Diabetes With Mild Cognitive Impairment

An interventional study of active transcutaneous auricular vagus nerve stimulation and sham transcutaneous auricular vagus nerve stimulation in Type 2 Diabetes and Mild Cognitive Impairment, sponsored by The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School. Not yet recruiting. Open to participants aged 40 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-06-11.

Sponsored by The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
38
Allocation
Randomized
Ages
40 Years to 75 Years
Sex
All
01

Study summary

This study is a 24-week, single-center, randomized, double-blind, sham-controlled, parallel-group clinical trial. A total of 38 patients with type 2 diabetes and mild cognitive impairment were enrolled and randomly assigned in a 1:1 ratio to either the treatment group (receiving active transcutaneous auricular vagus nerve stimulation) or the sham control group (receiving sham transcutaneous auricular vagus nerve stimulation). The primary objective of this study is to evaluate the potential disease-modifying effects of transcutaneous auricular vagus nerve stimulation on cognitive impairment in patients with type 2 diabetes.

Read the detailed description

This study is a 24-week, single-center, randomized, double-blind, sham-controlled, parallel-group clinical trial aimed at investigating the potential disease-modifying effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive impairment in 38 patients with type 2 diabetes mellitus (T2DM) complicated by mild cognitive impairment. Participants will be randomly assigned in a 1:1 ratio to receive either active taVNS (stimulation frequency: 20 Hz pulses for 10 seconds and 100 Hz pulses for 50 seconds per minute; 30 minutes per session, twice daily) or sham stimulation for 5 days per week. All participants will continue to receive treatment based on their original glucose-lowering therapies. The primary objective of the study is to evaluate improvements in cognitive function, while secondary endpoints include structural and functional brain changes, metabolic improvements, neurodegenerative biomarkers, and safety outcomes.

Participants will undergo comprehensive cognitive and metabolic assessments at baseline, followed by a safety visit at Week 12 to monitor adverse events, treatment adherence, and metabolic parameters. The comprehensive evaluation at Week 24 will include cognitive assessments, neuroimaging, and metabolic profiling. During the study period, investigators will conduct weekly follow-ups via telephone or WeChat, and participants will attend monthly in-clinic visits to complete examinations such as capillary blood glucose, blood pressure, and heart rate, as well as to be inquired about treatment adherence and adverse reactions. All rationales for decision-making and efficacy evaluations must be thoroughly documented.

02

Conditions studied

  • Type 2 Diabetes
  • Mild Cognitive Impairment

Keywords

  • Type 2 Diabetes
  • Mild Cognitive Impairment
  • Cognitive Impairment
  • Transcutaneous Auricular Vagus Nerve Stimulation
03

In context

Diabetes Mellitus, Type 2

9,359 studies on the registry are indexed under Diabetes Mellitus, Type 2; 1,318 are open to participants now.

This study's planned enrollment of 38 is below the median of 80 across 7,525 interventional studies indexed under Diabetes Mellitus, Type 2.

Browse Diabetes Mellitus, Type 2 studies →

Lead sponsor

The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School is the lead sponsor of 242 studies on the registry; 144 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
40 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  1. Type 2 diabetes mellitus
  2. Meets criteria for mild cognitive impairment
  3. Aged 40 to 75 years, with no gender restrictions
  4. HbA1c levels between 6.5% and 9.0%
  5. At least 6 years of formal education
  6. Able to cooperate with and complete all cognitive and functional assessments
  7. Right-handed
  8. Voluntary provision of written informed consent

Exclusion criteria

Exclusion Criteria:

  1. Concomitant use of GLP-1 receptor agonists, Alzheimer's disease medications, anti-Parkinson's medications, antiepileptic drugs, or antipsychotic drugs within 3 months prior to screening
  2. Presence of dementia-related neurological disorders; current or history of clinically significant psychiatric disorders within the past 2 years (e.g., schizophrenia, bipolar disorder, major depressive disorder, generalized anxiety disorder, personality disorders)
  3. CNS diseases, including traumatic brain injury, intracranial hemorrhage, acute cerebral infarction, etc
  4. Severe sinusitis, nasal and sinus polyps, space-occupying lesions such as skull base or nasopharyngeal tumors; congenital diseases or history of trauma of the nose, maxillofacial region, or skull base that affect olfactory function; presence of upper respiratory tract infection symptoms (e.g., nasal congestion, rhinorrhea, fever) on the day of the MRI scan
  5. Acute complications of diabetes, including diabetic ketoacidosis, hyperglycemic hyperosmolar state, hypoglycemic coma, etc
  6. Severe impairment of major organ function (e.g., heart, liver, kidneys), including any of the following: ALT and/or AST > 3×ULN. eGFR \< 45 mL/min/1.72 m² (CKD-EPI). History of unstable angina, myocardial infarction, or NYHA Class II or higher heart failure within 3 months prior to screening
  7. Concurrent major illnesses, such as active or untreated malignancies, or malignancies in clinical remission for less than 5 years.
  8. Contraindications for MRI scans (e.g., implanted metallic prostheses, claustrophobia); presence of cardiac pacemakers or other implantable medical devices; severe infection or ulceration of the auricular skin
  9. Pregnant or lactating women
  10. History of alcohol abuse, defined as an average weekly alcohol consumption exceeding 21 units for males and 14 units for females (1 unit = 360 mL of beer, 150 mL of wine, or 45 mL of distilled spirits/liquor)
  11. Any other conditions or factors that, in the opinion of the investigator, may confound the efficacy or safety evaluation of the study, making the participant unsuitable for enrollment
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
38 participants (estimated)

Study arms

  • Experimental
    active taVNS

    After disinfecting the stimulation sites (cymba conchae, cavum conchae, and earlobe), the auricular stimulation electrodes will be attached. For the active stimulation group, the actual functional electrodes delivering the current are positioned at the cymba conchae and cavum conchae. The stimulation parameters are set as follows:(1) Dense-disperse wave, with a stimulation frequency consisting of 20 Hz pulses for 10 seconds and 100 Hz pulses for 50 seconds per minute, and a pulse width of 0.2 ms ± 30%;(2) Stimulation intensity ranging from 4 to 6 mA, adjusted according to the individual patient's tolerance;(3) 30 minutes per session, twice daily;(4) 5 days per week, for 24 weeks.

    Device: active transcutaneous auricular vagus nerve stimulation

  • Sham comparator
    sham taVNS

    After disinfecting the stimulation sites (cymba conchae, cavum conchae, and earlobe), the auricular stimulation electrodes will be attached. For the sham stimulation group, the actual functional electrodes delivering the current are positioned at the earlobe. The stimulation parameters are set as follows:(1) Dense-disperse wave, with a stimulation frequency consisting of 20 Hz pulses for 10 seconds and 100 Hz pulses for 50 seconds per minute, and a pulse width of 0.2 ms ± 30%;(2) Stimulation intensity ranging from 4 to 6 mA, adjusted according to the individual patient's tolerance;(3) 30 minutes per session, twice daily;(4) 5 days per week, for 24 weeks.

    Device: sham transcutaneous auricular vagus nerve stimulation

Interventions

  • Deviceactive transcutaneous auricular vagus nerve stimulation

    After disinfecting the stimulation sites (cymba conchae, cavum conchae, and earlobe), the auricular stimulation electrodes will be attached. For the active stimulation group, the actual functional electrodes delivering the current are positioned at the cymba conchae and cavum conchae. The stimulation parameters are set as follows:(1) Dense-disperse wave, with a stimulation frequency consisting of 20 Hz pulses for 10 seconds and 100 Hz pulses for 50 seconds per minute, and a pulse width of 0.2 ms ± 30%;(2) Stimulation intensity ranging from 4 to 6 mA, adjusted according to the individual patient's tolerance;(3) 30 minutes per session, twice daily;(4) 5 days per week, for 24 weeks.

  • Devicesham transcutaneous auricular vagus nerve stimulation

    After disinfecting the stimulation sites (cymba conchae, cavum conchae, and earlobe), the auricular stimulation electrodes will be attached. For the sham stimulation group, the actual functional electrodes delivering the current are positioned at the earlobe. The stimulation parameters are set as follows:(1) Dense-disperse wave, with a stimulation frequency consisting of 20 Hz pulses for 10 seconds and 100 Hz pulses for 50 seconds per minute, and a pulse width of 0.2 ms ± 30%;(2) Stimulation intensity ranging from 4 to 6 mA, adjusted according to the individual patient's tolerance;(3) 30 minutes per session, twice daily;(4) 5 days per week, for 24 weeks.

06

What researchers measure

Primary outcomes

  1. Montreal Cognitive Assessment Scale (MoCA) score

    The MoCA is a comprehensive endpoint focusing on the cognitive domain. It integrates multidimensional assessments of core cognitive functions (including subscale scores for visuospatial/executive function, naming, attention, language, abstraction, delayed recall, and orientation), yielding a total score range of 0-30.The calculation formula is:MoCA Score = Subscale Scores+ Educational Correction(Note: If the participant's formal education is ≤12 years, 1 point is added to the sum of the subscale scores, with the maximum total score capped at 30).Lower MoCA scores indicate more severe global cognitive impairment in the participant.

    Time frame: Baseline, and Week 24

Secondary outcomes

  1. Change in score of Mini-Mental State Examination (MMSE)

    The MMSE contains a total of 30 items that assess orientation, registration, attention and calculation, recall, and language, with a score range from 0 to 30. Generally, a higher MMSE score reflects a better cognitive function.

    Time frame: from baseline to week 24 of treatment

  2. Changes in total score of RBANS

    The RBANS (Chinese version) is a brief neuropsychological screening battery with established test-retest reliability and age-appropriate normative data, which consists of 12 task tests assessing 5 cognitive domains, namely immediate memory, visuospatial/ constructional, language, attention and delayed memory, with a score range from 40 to 160. A higher RBANS score reflects a better global cognitive function.

    Time frame: from baseline to week 24 of treatment

  3. Change in the RBANS index score of immediate memory

    The RBANS (Chinese version) is a brief neuropsychological screening battery with established test-retest reliability and age-appropriate normative data. The RBANS includes 12 sub-tests that generate five age-adjusted index scores and a total score. The five indices include immediate memory (consisting of list learning and story memory tests), visuospatial/constructional domain (consisting of figure copying and line orientation tests), language (consisting of picture naming and semantic fluency tests), attention (consisting of digit span and coding tests) and delayed memory (consisting of list recall, story recall, figure recall and list recognition tests). Generally, a higher index score reflects a better cognitive subdomain function.

    Time frame: from baseline to week 24 of treatment

  4. Change in the RBANS index score of visuospatial/constructional

    Measurements and instruments are the same as the RBANS index score of immediate memory.

    Time frame: from baseline to week 24 of treatment

  5. Change in the RBANS index score of language

    Measurements and instruments are the same as the RBANS index score of immediate memory.

    Time frame: from baseline to week 24 of treatment

  6. Change in the RBANS index score of attention

    Measurements and instruments are the same as the RBANS index score of immediate memory.

    Time frame: from baseline to week 24 of treatment

  7. Change in the RBANS index score of delayed memory

    Measurements and instruments are the same as the RBANS index score of immediate memory.

    Time frame: from baseline to week 24 of treatment

  8. Change in aggregate time to test completion for Trail Making Test (TMT)

    The TMT is a validated timed measure of processing speed, which consists of part A and part B (TMT-A and TMT-B). The time limits for performing the TMT-A and TMT-B are 180 and 300 seconds, respectively. Processing speed is estimated by the aggregate time in seconds to complete TMT-A and TMT-B such that less time indicate faster processing speed.

    Time frame: from baseline to week 24 of treatment

  9. Change in aggregate time to test completion for Victoria Stroop Color-Word Test

    The Victoria Stroop Color-Word Test is a well-known measure of executive function. There are three indices including Stroop-dot, Stroop-word and Stroop-color word in the test. The color task consists of colored dots; the word task comprises ordinary words that are unrelated to the meaning of color; the color-word task consists of words written in color that indicate the meaning of the color, but the color of these words differs from the meaning of the word itself. The participants were asked to quickly read the color of the dots or Chinese words on the cards. The sum of consuming time taken to read the three cards is used as an index of executive function performance. Less time indicates better executive function.

    Time frame: from baseline to week 24 of treatment

  10. Change in Total Brain Volume

    The change in total brain volume evaluated by structural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from baseline to week 24 of treatment

  11. Change in Total White Matter Volume

    The change in total white matter volume evaluated by structural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  12. Change in Total Gray Matter Volume

    The change in total gray matter volume evaluated by structural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  13. Change in Total White Matter Lesion Volume

    The change in total white matter lesion volume evaluated by sturctural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  14. Change in Cortical Gray Matter Lobar Volumes

    The change in cortical gray matter lobar volumes evaluated by sturctural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  15. Change in Subcortical Nuclei Volumes

    The change in subcortical nuclei volumes evaluated by stuctural MRI from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  16. Change in Blood-Based Neurodegeneration Biomarkers

    The change in blood-based neurodegeneration biomarkers (includingAmyloid-β (Aβ42/40 ratio), Phosphorylated tau (p-tau217), Glial fibrillary acidic protein (GFAP), and Neurofilament light chain (NfL), etc.)evaluated by Simoa from baseline to Week 76 will be compared between the treatment group and the placebo group.

    Time frame: from Baseline to Week 24 of treatment

  17. Change in Heart Rate Variability

    Change in heart rate variability from baseline to Week 24 will be assessed using time-domain and/or frequency-domain heart rate variability analysis

    Time frame: from Baseline to Week 24 of treatment

  18. Change in Cardiovascular Autonomic Reflex Test Result

    Change in cardiovascular autonomic reflex function from baseline to Week 24 will be assessed using standardized cardiovascular autonomic reflex testing

    Time frame: from Baseline to Week 24 of treatment

  19. Change in Glycated Haemoglobin (HbA1c) Levels

    Change in HbA1c levels from baseline to weeks 24

    Time frame: from Baseline to Week 24 of treatment

  20. Change in fasting insulin

    Fasting insulin

    Time frame: from baseline to weeks 24 of treatment

07

Study locations

No study locations are listed for this record.

08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 11, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07642518
Lead sponsor
The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School
Responsible party
Ruan jianguo (associate chief physician, The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School) — Principal investigator
First posted
Jun 11, 2026
Start date
May 20, 2026 (estimated)
Primary completion
Dec 31, 2027 (estimated)
Completion
Dec 31, 2027 (estimated)
Last update
Jun 11, 2026

Study contacts

Jianguo Ruan, MD
Contact
medrjg@163.com
86-25-83-106666

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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