Low Level Laser VS Transcutaneous Vagus Nerve Stimulation on Vascular Changes in Patients With Diabetic Polyneuropathy

Low Level Laser Versus Transcutaneous Vagus Nerve Stimulation on Vascular Changes in Patients With Diabetic Polyneuropathy

To compare the effect of both low-level laser versus transcutaneous vagus nerve stimulation on vascular changes in patients with diabetic polyneuropathy

Study Overview

• Status: Completed
• Conditions: Diabetic Peripheral Neuropathy; Transcutaneous Vagus Nerve Stimulation
• Intervention / Treatment: Device: Low level laser; Device: Transcutaneous auricular Vagus nerve stimulation

Detailed Description

Diabetic polyneuropathy is a prevalent and severe diabetes-related complication linked to cardiovascular mortality and disease events, even after accounting for risk factors and diabetes status.

Diabetic polyneuropathy affects the peripheral nervous system, leading to dysfunctions in sensory, motor, and autonomic nervous systems. It predisposes diabetics to refractory neuropathic pain, foot ulcers, and amputation, lowering quality of life, increasing mortality, and prompting patients with diabetes to seek medical attention.

Over half of diabetes patients experienced painful diabetic polyneuropathy over the past few decades Painful diabetic polyneuropathy therapy uses various drugs for symptom relief, but they often have systemic side effects and do not slow neuropathy progression. Therefore, investigating non-pharmacological interventions like low-level laser and transcutaneous auricular vagus nerve stimulation is crucial for developing more effective and potentially safer pain management options.

low-level laser therapy and transcutaneous auricular vagus nerve stimulation are emerging non-invasive interventions that have shown potential in alleviating pain associated with diabetic polyneuropathy, a common diabetes complication affecting quality of life.

The effectiveness of conservative treatment options for painful diabetic polyneuropathy needs further investigation. If one method proves superior in reducing pain, improving macrovascular health, and quality of life, it could guide clinical decisions

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Damietta, Egypt
    • out-patient clinic, faculty of physical therapy, Horus university

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

The patient selection will be according to the following criteria:

1. 30 patients diagnosed with diabetic neuropathy from both genders their ages will be ranged from 45-60 years old.
2. All patients are ambulant independently.
3. All patients are under full medical control
4. Glycated hemoglobin is ranged from 6.5: 7 %.
5. Patients have had diabetes for more than 5 or 10 years.
6. patients experiencing painful peripheral neuropathic symptoms for more than 6 months involving both lower extremities and complained of burning pain with paresthesia in both legs.

7 Neurological examination revealed abnormal sensation appeared at the ends of the extremities.

Exclusion Criteria:

1. Patients had unstable glycemic control and/or medical conditions that would confound assessment of neuropathy such as malignancy, active/untreated thyroid disease, peripheral vascular diseases, vascular insufficiency (claudication, skin discoloration, ulceration).
2. Following the implantation of cardiac pacemakers or other electrical stimulation devices.
3. Patient had sinus bradycardia, long QT syndrome, or other arrhythmias or mental disorders.
4. Patients whose heart rate dropped below 50 beats/min after vagus nerve stimulation.
5. Nerve damage as a result of prior reconstructive or replacement knee surgery, back surgery, spinal stenosis, spinal compression or radiculopathy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low Level Laser; Patients will receive Low Level Laser irradiated with two wavelengths of visible 630 nm and near infra-red 810 nm for 15 min on entire surface of each foot three times a week for 2 months	Device: Low level laser; Patients in the low level laser group will be irradiated with visible and near-infra-red lasers at a pulsed mode with a frequency of 35 Hz, peak power of 100 mW, and a spot diameter of 5 mm. The 15-minute sessions were performed three times a week for two months, with each laser having a power density of 0.35 mW/cm2 and an energy density of 32.08 J/cm2.
Active Comparator: Transcutaneous auricular Vagus nerve stimulation; Patients will receive 30 minutes Transcutaneous auricular Vagus nerve stimulation 3 sessions per week for 2 months.	Device: Transcutaneous auricular Vagus nerve stimulation; Patients will receive 30 minutes of transcutaneous vagus nerve stimulation for 2 months, with 5 sessions per week. The antihelix and cymba concha will be sterilized with 75% alcohol, and the electrode will be attached. The device parameters include a wave width of 0.2 ms ± 30%, pulse frequency of 20 Hz, gradually increasing intensity to a tolerable intensity (4-6 mA), and duration of 30 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
assessment of change of vascular blood flow	The study uses Duplex Doppler ultrasound to assess vascular changes in the posterior tibial and anterior tibial, assessing anteroposterior diameter, Tunica intima thickness, and resistive index and peak systolic velocity using a variable frequency range.	at baseline and after 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessment of change of Neuropathic Pain	The Douleur Neuropathique en 4 (DN4) is a screening questionnaire that consists of interview questions and physical tests to identify possible neuropathic pain. It has high test-retest and inter-rater reliability, with an ICC of 0.8 and a Cohen's kappa of 0.8. A total score is calculated as the sum of the 10 items. Scores _ 4 out 10 of indicate that neuropathic pain is likely.	at baseline and after 8 weeks
Assessment of change of Quality of life	The 12-Item Short Form Health Survey is a validated instrument used to assess health-related quality of life in clinical and research settings. It evaluates both physical and mental health through 12 questions derived from the short form-36 questionnaire, covering domains such as physical functioning, pain, general health, vitality, social functioning, and emotional well-being. The questionnaire generates two summary scores: the Physical Component Summary and the Mental Component Summary. Scoring is based on weighted responses to each item, with scores transformed to a standardized scale ranging from 0 to 100, where higher scores indicate better health status and quality of life. Due to its brevity, reliability, and ease of administration, the short form-12 is widely used for rapid assessment of overall patient health outcomes.	at baseline and after 8 weeks

Collaborators and Investigators

• Sponsor: Horus University

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2025
• Primary Completion (Actual): October 1, 2025
• Study Completion (Actual): March 1, 2026

Study Registration Dates

• First Submitted: July 12, 2025
• First Submitted That Met QC Criteria: July 12, 2025
• First Posted (Actual): July 22, 2025

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Nervous System Diseases; Neuromuscular Diseases; Diabetes Mellitus; Diabetes Complications; Polyneuropathies; Peripheral Nervous System Diseases; Diabetic Neuropathies; Therapeutics; Laser Therapy; Phototherapy; Low-Level Light Therapy
• Other Study ID Numbers: Manar-005515

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No