Investigation of Ultrasonographic Measurements of Lower Extremity Nerves in Type 2 Diabetes Patients with Peripheral Polyneuropathy

The aim of this study is to quantitatively evaluate ultrasonographic measurements of the lower extremity nerves in patients diagnosed with diabetic polyneuropathy and to investigate the relationship with gait, static and dynamic balance performance.

In this study, we aimed to investigate the effect of ultrasonographic findings of lower extremity nerves on quality of daily life, physical activity, gait and balance in patients with diabetic peripheral polyneuropathy.

Diabetes is a chronic metabolic disorder characterized by hyperglycemia and the body's inability to adequately utilize carbohydrates, fats, and proteins due to a reduction in insulin secretion or insulin action. It requires continuous medical care.

One of the most common complications associated with diabetes is diabetic neuropathy, which affects the autonomic, motor, and sensory nerves of the peripheral nervous system. The most frequent form of diabetic neuropathy is peripheral sensorimotor polyneuropathy. Clinical and electrophysiological findings typically begin in the distal lower extremities.

While nerve conduction studies remain the gold standard for diagnosing diabetic neuropathy, they are time-consuming, require a separate patient visit, and are too costly to recommend for routine screening. Various methods can be employed to assess the morphological changes in nerves associated with diabetic peripheral neuropathy. With advancing technology in recent years, ultrasonography (US) has emerged as an affordable, reproducible, and more comfortable technique. It can be utilized as an effective method to evaluate structural changes in nerves. Diabetic neuropathy is a significant contributor to the severe morbidity, increased mortality, and reduced quality of life in diabetic patients. Therefore, the early detection of nerve dysfunction through ultrasonography is essential for providing appropriate care to patients with diabetic neuropathy.

The study will be conducted as a cross-sectional and single-center research involving patients with peripheral polyneuropathy secondary to type 2 diabetes and healthy volunteers who present to the Physical Medicine and Rehabilitation Clinic at the Health Sciences University Sultan 2nd Abdülhamid Han Training and Research Hospital.

As part of the study, demographic data collected from participants will include age, gender, height, weight, body mass index, smoking and alcohol usage, marital status, occupation, educational level, fasting blood glucose, HbA1c levels, vitamin B12, ALT, AST, creatinine levels, duration of diabetes, duration of diabetic peripheral polyneuropathy (DPP) complaints, current antidiabetic medications, presence of comorbidities, and neuropathic pain treatment and duration. Patients will be evaluated once, and the assessment will include ultrasonography, the Biodex balance system, the Douleur Neuropathique 4 (DN4) pain scale, numeric pain scale, Toronto Clinical Neuropathy Score, diapason vibration sensitivity test, 6-minute walk test, SF-12 quality of life scale, International Physical Activity Questionnaire-Short Form, Timed Up and Go Test (TUG), and motor and sensory examination.

The sample size for the study was calculated using G-Power version 3.1, based on ultrasonographic measurement data from a similar study conducted by Breiner et al. in 2016. The calculated sample size includes Group 1: 17 healthy participants of similar age and gender, and Group 2: 69 participants diagnosed with peripheral polyneuropathy and type 2 diabetes, amounting to a total of 86 participants. The study is planned to be conducted between December 2024 and May 2025.

Eligibility Criteria:
Inclusion Criteria (Group 1):

* Being between the ages of 18-65
* Being literate
* Signed a voluntary consent form agreeing to participate in the study

Inclusion Criteria (Group 2):

* Diagnosed with Type 2 Diabetes based on at least one of the following diagnostic criteria: fasting plasma glucose ≥ 126 mg/dl, 2-hour plasma glucose ≥ 200 mg/dl in an oral glucose tolerance test, HbA1c ≥ 6.5%, or diabetes symptoms (excessive thirst, eating, urination, and weight loss) + random plasma glucose ≥ 200 mg/dl. (14)
* Diagnosed with diabetic peripheral polyneuropathy through EMG evaluation in addition to Type 2 Diabetes.
* Being between the ages of 18-65
* Being literate
* Signed a voluntary consent form agreeing to participate in the study.

Exclusion Criteria:

* Individuals under 18 years old and over 65 years old
* Diagnosed with Type 1 diabetes
* Use of medications that can cause polyneuropathy
* Other causes of neuropathic pain (lumbar radiculopathy, spinal stenosis, -hereditary, inflammatory, entrapment neuropathies)
* Undergoing lower extremity surgery (spine/hip/knee/foot) in the last 6 months
* Having peripheral artery disease
* B12 vitamin deficiency
* Active foot ulcer
* History of lower extremity amputation
* Severe cardiopulmonary insufficiency (stage 3-4)
* History of myocardial infarction within the last 1 month
* History of unstable angina
* Active systemic inflammatory diseases and active malignancy
* Presence of vestibular disorders
* Presence of cognitive impairment
* Osteoarthritis in the lower extremity
* Pregnancy
* Body Mass Index (BMI) of 30 or higher