The Effect of Bariatric Surgery on Peripheral Nerve Function and Axonal Regeneration (BAR)

• ClinicalTrials.gov Identifier: NCT02218866
• Recruitment Status: Completed
• First Posted: August 18, 2014
• Last Update Posted: April 10, 2018
• Sponsor: University of Utah
• Collaborator: American Diabetes Association
• Information provided by (Responsible Party): Gordon Smith, University of Utah

Study Description

Brief Summary:

The goal of this research is understand if obesity is a major factor for neuropathy development in patients with and without Type 2 diabetes. This study will examine the relationship between weight, metabolism, and nerve function and regeneration.

Condition or disease
Peripheral Neuropathy; Obesity

Detailed Description:

Peripheral neuropathy causes progressive injury to the longest nerves of the body, starting in the toes, then progressing slowly up the leg. Neuropathy often causes pain, numbness, and weakness if the feet and can lead to reduced mobility, foot ulcers, and even amputation. The most common cause is diabetes, but work at the University of Utah finds that prediabetes and other consequences of obesity, including abnormal cholesterol levels, may be associated with neuropathy. Research has shown that these risk factors may damage nerves and interfere with the ability of nerves to grow back after an injury.

This study aims to

1. characterize peripheral nerve function and cutaneous nerve structure in obese bariatric surgery candidates;
2. evaluate peripheral nerve regeneration capacity (and other nerve function measures) before and after bariatric surgery in obese subjects with no or mild neuropathy;
3. examine the relationship between ectopic lipid accumulation, lipotoxic mediators, neuropathy and regeneration capacity in surgical candidates before and one year after surgery.

Study Design

• Study Type: Observational
• Actual Enrollment: 205 participants
• Observational Model: Case-Control
• Time Perspective: Prospective
• Official Title: The Effect of Bariatric Surgery on Peripheral Nerve Function and Axonal Regeneration
• Study Start Date: January 2012
• Actual Primary Completion Date: December 31, 2017
• Actual Study Completion Date: December 31, 2017

Groups and Cohorts

Group/Cohort
Group 1; All participants will be examined by a neurologist to test sensation, reflexes, and strength and complete a few questionnaires. Tests will be performed to measure nerve function and small punch skin biopsies will be taken to assess nerve fiber density. Blood and urine tests will measure various markers of interest. Participants will be seen before and after their bariatric surgery.
Group 2; In addition to the procedures described for Group 1, participants in Group 2 will have the following procedures: During bariatric surgery, a small biopsy from the liver and abdominal fat will be taken to examine how fat is processed within the body.; At the first visit, after a skin biopsy is taken, a small capsaicin patch will be placed on the lower thigh. The patch will remain in place for 48 hours and will cause the nerves in the immediate area to pull back from the skin. A biopsy will be taken from the patch area 48 hours, 1 month, and 3 months after the initial biopsy. This procedure will be repeated after surgery.; MRIs may be performed before and after bariatic surgery.; Participants may be asked to complete additional tests to evaluate nerve function
Group 3; Group 3 will comprise of individuals who are not overweight. Participants in this group will undergo a similar evaluation to Group 2.

Outcome Measures

Primary Outcome Measures :

1. Change in reinnervation capacity [ Time Frame: 4 - 1 months prior to bariatric surgery, compared to 9 - 12 months after surgery ]

Secondary Outcome Measures :

1. Change in Utah Early Neuropathy Scale (UENS) [ Time Frame: Baseline to 12 months after bariatric surgery ]
2. Change in Nerve Conduction Study measures [ Time Frame: Baseline to 12 months after bariatric surgery ]
   Nerve Conduction Study is a procedure routinely used in the diagnosis of neuropathy. Measures will include Sural sensory and Peroneal motor amplitudes and conduction velocities.
3. Change in nerve fiber density [ Time Frame: Baseline to 12 months after bariatric surgery ]

Biospecimen Retention:   Samples With DNA

DNA, serum, tissue

Eligibility Criteria

• Ages Eligible for Study: 18 Years to 80 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes
• Sampling Method: Non-Probability Sample

Study Population

Participants will be recruited through bariatric surgery clinics in the local area.

Criteria

Inclusion Criteria:

• Age 18-80 years old
• Subjects must fulfill criteria for bariatric surgery.

Exclusion Criteria:

• History of foot ulceration or neurogenic arthropathy
• Family history of non-diabetic neuropathy in a first-degree family member.
• Presence of any disease known to be associated with peripheral neuropathy including but not limited to vitamin deficiency, toxin exposure, paraproteinemia, heavy alcohol use, hepatitis C, HIV.
• Coumadin use.
• Inability to understand or cooperate with the procedures of the trial.
• Known history of sensitivity to capsaicin products.

Contacts and Locations

Locations

United States, Utah

University of Utah

Salt Lake City, Utah, United States, 84132

Sponsors and Collaborators

University of Utah

American Diabetes Association

Investigators

• Principal Investigator: A. Gordon Smith, MD; University of Utah

More Information

• Responsible Party: Gordon Smith, Professor, University of Utah
• ClinicalTrials.gov Identifier: NCT02218866
• Other Study ID Numbers: BAR-UofU
• First Posted: August 18, 2014
• Last Update Posted: April 10, 2018
• Last Verified: August 2016

Keywords provided by Gordon Smith, University of Utah:

Bariatric surgery; Obesity; Neuropathy

Additional relevant MeSH terms:

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases