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Completed

NCT Number: NCT07078058

Low Level Laser VS 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

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Key information

Age range

45 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

out-patient clinic, faculty of physical therapy, Horus university

Damietta, Egypt

About this study

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

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

The patient selection will be according to the following criteria:

  • 30 patients diagnosed with diabetic neuropathy from both genders their ages will be ranged from 45-60 years old.
  • All patients are ambulant independently.
  • All patients are under full medical control
  • Glycated hemoglobin is ranged from 6.5: 7 %.
  • Patients have had diabetes for more than 5 or 10 years.
  • 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

  • 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).
  • Following the implantation of cardiac pacemakers or other electrical stimulation devices.
  • Patient had sinus bradycardia, long QT syndrome, or other arrhythmias or mental disorders.
  • Patients whose heart rate dropped below 50 beats/min after vagus nerve stimulation.
  • Nerve damage as a result of prior reconstructive or replacement knee surgery, back surgery, spinal stenosis, spinal compression or radiculopathy

Treatment and study plan

Low level laser

Device

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.

Transcutaneous Auricular Vagus Nerve Stimulation

Device

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.

Primary outcomes

  1. assessment of change of vascular blood flow

    Time frame: at baseline and after 8 weeks

    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.

Secondary outcomes

  1. Assessment of change of Neuropathic Pain

    Time frame: at baseline and after 8 weeks

    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.

  2. Assessment of change of Quality of life

    Time frame: at baseline and after 8 weeks

    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.

Sponsors and collaborators

Lead sponsor

Horus University

Other

Registry information

Official study title

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

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Jul 22, 2025
Registry last updated
May 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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