N/A
N=140
Effect of Exercise and Surgical Weight Loss on Polyneuropathy
Polyneuropathies · Obesity · Bariatric Surgery Candidate
Bottom Line
View on ClinicalTrials.gov: NCT03617185 ↗Enrolled (actual)
140
Serious AEs
0.0%
Results posted
Oct 2025
Primary outcome: Primary: Intraepidermal Nerve Fiber Density (IENFD) at the Proximal Thigh — 11.9; 12.7; 9.8; 11 fibers/mm — p=0.15
Study Design & Population
- Study type
- Interventional
- Phase
- N/A
- Interventions
- High Intensity Interval Training (HIIT) (Other); Routine Exercise (Other); Bariatric surgery (Procedure)
- Age
- Adult, Older Adult · 40+ yrs
- Sex
- All
- Sponsor
- University of Michigan
- Primary completion
- Aug 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Intraepidermal Nerve Fiber Density (IENFD) at the Proximal Thigh |
11.9; 12.7; 9.8; 11; 12.6; 14.3 | 0.15 |
| SECONDARY Intraepidermal Nerve Fiber Density (IENFD) at Distal Leg. |
6.3; 6.8; 7.3; 5.7; 7.3; 6.2 | 0.27 |
| SECONDARY Corneal Confocal Microscopy (CCM) - Fiber Density |
22.1; 19.5; 19.5; 22.4; 20; 19.9 | 0.97 |
| SECONDARY Corneal Confocal Microscopy (CCM) - Branch Density |
56.4; 57.1; 53.6; 54.7; 62.2; 72.6 | 0.62 |
| SECONDARY Corneal Confocal Microscopy (CCM) - Fiber Length |
18.6; 18.9; 17.9; 19.3; 19; 20.6 | 0.89 |
| SECONDARY Corneal Confocal Microscopy (CCM) - Tortuosity Coefficient |
19.4; 19; 18.6; 19.2; 17.8; 19.9 | 0.82 |
| SECONDARY 24-2 Frequency Doubling Technology (FDT) - Mean Deviation |
-1.6; -1.6; -2; -2.5; -1; -1.5 | 0.98 |
| SECONDARY 24-2 Frequency Doubling Technology (FDT) - Foveal Sensitivity dB |
27.7; 28.3; 26.9; 25.4; 28.3; 28.3 | 0.26 |
| SECONDARY 24-2 Frequency Doubling Technology (FDT) - Pattern SD |
3.4; 3.1; 3.3; 3.7; 3.1; 3.2 | 0.25 |
| SECONDARY Retinal Fundus Photography |
0; 1; 1; 1; 0; 0 | 1 |
| SECONDARY Nerve Conduction Study (NCS) - Latency |
4.6; 4.4; 4.4; 4.5; 3.8; 3.7 | 0.83 |
| SECONDARY Nerve Conduction Study (NCS) - Motor Amplitude |
5.21; 5.95; 5.18; 6.25; 9.4; 9.16 | 0.48 |
| SECONDARY Nerve Conduction Study (NCS) - Sensory Amplitude |
12.4; 10.8; 10.6; 9.1; 12.4; 14.2 | 0.82 |
| SECONDARY Nerve Conduction Study (NCS) - CV |
46.91; 45.37; 46.49; 45.47; 46.96; 47.48 | 0.82 |
| SECONDARY Nerve Conduction Study (NCS) - F Wave Index |
48.29; 49.57; 49.28; 48.91; 50.84; 51.92 | 0.32 |
| SECONDARY Cardiac Autonomic Neuropathy Testing-Deep Breathing/Exhalation to Inhalation (E:I) Ratio |
1.3; 1.2; 1.3; 1.2; 1.2; 1.3 | 0.79 |
| SECONDARY Cardiac Autonomic Neuropathy Testing (30:15 Ratio) |
1.1; 1.1; 1.1; 1.1; 1.2; 1.2 | 0.07 |
| SECONDARY Cardiac Autonomic Neuropathy Testing (Valsalva Ratio) |
1.5; 1.5; 1.4; 1.4; 1.3; 1.4 | 0.46 |
| SECONDARY Participants With Probable Polyneuropathy as Defined by the Toronto Definition of Probable Neuropathy |
6; 5; 9; 11; 9; 7 | 0.07 |
| SECONDARY Michigan Neuropathy Screening Instrument (MNSI) |
2.5; 2.5; 2.4; 2.8; 2.5; 2 | 0.21 |
| SECONDARY Michigan Neuropathy Screening Instrument (MNSI) - Exam |
1; 0.9; 1.1; 1.3; 1; 0.4 | 0.01 sig |
| SECONDARY Michigan Neuropathy Screening Instrument (MNSI) - Index |
1.6; 1.5; 1.4; 1.8; 1.6; 1.1 | 0.20 |
| SECONDARY Utah Early Neuropathy Score (UENS) |
2.4; 1.6; 2.4; 3.5; 1.7; 1.8 | 0.44 |
| SECONDARY Modified Toronto Neuropathy Score (mTNS) |
3.8; 1.5; 2.1; 3.5; 2.1; 1.3 | 0.78 |
| SECONDARY Survey of Autonomic Symptoms (SAS) |
4.7; 5; 5.1; 5.1; 8.2; 4.9 | 0.84 |
| SECONDARY Diabetic Neuropathy Score (DNS) |
1.1; 0.9; 0.8; 1.1; 1.1; 0.6 | 0.69 |
| SECONDARY Short Form McGill Pain Questionnaire |
3.7; 3.1; 2.7; 3.5; 3.8; 2.1 | 0.09 |
| SECONDARY Numerical Rating Scale for Pain |
2.2; 2.7; 2.5; 3.8; 3.3; 2.7 | 0.62 |
| SECONDARY Neuropathy Quality of Life (NeuroQOL) |
2.62; 2.13; 2.1; 2.71; 2.49; 1.62 | 0.83 |
| SECONDARY 8 Foot Get Up and Go Test |
6.2; 6.1; 6.4; 6.6; 6; 5.9 | 0.58 |
| SECONDARY Berg Balance Scale |
55.41; 55.53; 55.41; 54.57; 55.48; 55.47 | 0.38 |
| SECONDARY Modified Falls Efficacy Scale - Fall Evaluation |
8; 9; 9; 12; 8; 8 | 0.54 |
| SECONDARY Neurothesiometer |
8.7; 10.2; 21.1; 20.2; 9.7; 8 | 0.36 |
| SECONDARY NIH Toolbox Cognitive Battery |
42.6; 44; 42.7; 43; 51.6; 54.6 | 0.16 |
| SECONDARY Rey Auditory Verbal Learning Test |
0.1; 0.3; 0.4; 0.4; 0; -0.2 | 0.57 |
Summary
The purpose of this research study is to evaluate how exercise and surgical weight loss affect how likely an individual is to develop peripheral neuropathy and other neurologic complications.
Eligibility Criteria
Inclusion Criteria
- Attending a bariatric surgery clinic
- BMI > 35 with one comorbid condition present or BMI > 40 without comorbid conditions present
- Willing and capable to sign the Institutional Review Board (IRB) approved consent form and cooperate with the medical procedures for the study duration
- Willing to accept random treatment assignment to HIIT or routine exercise counseling
Exclusion Criteria
- History of distal symmetric polyneuropathy (DSP) from causes other than diabetes and/or the metabolic syndrome as determined through medical history, family history, history of medications, occupational history, history of exposure to toxins, physical and neurological examinations;
- Use of warfarin, heparin, or other anticoagulants, which would increase the risk of complications from skin biopsy
- Contraindication to HIIT participation including a failed exercise stress test
- Participation in an experimental medication trial within 3 months of starting the study
- Undergoing therapy for malignant disease other than basal-cell or squamous-cell skin cancer
- Medical or psychiatric reason for not being a surgical candidate
- Requiring a walking assist device;
- Currently smoking
Data sourced from ClinicalTrials.gov (NCT03617185). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.