NCT05145452

Brief Summary

Sensorimotor neuropathy (SMN) and cardiovascular autonomic neuropathy (CAN) are the most common complications of type 2 diabetes (T2D). SMN affects \~30% of people with T2D and CAN \~20%. SMN causes pain, impairs and limits physical activity, and increases the risk for physical disability, complications (such as foot ulcerations), and premature mortality. Moreover, both motor and sensory nerve function are important regulators of muscle function; impaired myofiber innervation causes myofiber loss, muscle fat infiltration, and increases the risk of age-associated sarcopenia and falls. CAN often goes unrecognized because it presents with non-specific symptoms, such as resting tachycardia and fixed heart rate, exercise intolerance, and orthostatic hypotension. However, CAN is a serious problem because it increases the risk for cardiovascular events and mortality several-fold. Both SMN and CAN have long been considered a consequence of T2D, but it is now becoming clear that they precede the diagnosis of T2D and are already detectable in people with prediabetes, especially those with impaired glucose tolerance. Treatments for both SMN and CAN focus on symptom management because there are no effective therapeutics that target the underlying neuropathy. The results from studies conducted in animal models suggest fish oil-derived n-3 polyunsaturated fatty acids (n-3 PUFA) may have therapeutic effects for people with SMN and CAN. The purpose of this proposal is to conduct a randomized controlled trial to test the hypothesis that dietary supplementation with fish oil-derived n-3 PUFA improves sensorimotor and cardiovascular autonomic functions in people with impaired glucose tolerance. Forty 55-80 year old men and women with impaired glucose tolerance (plasma glucose 2 h after a 75 g glucose challenge ≥140 mg/dl) and evidence of SMN (assessed as epidermal nerve fiber density) will be randomized to either receive fish oil-derived n-3 PUFA (4.2 g per day; n=20) or placebo (n=20) for six months. Sensorimotor and cardiovascular autonomic function will be evaluated after three and 6 months of the interventions.

Trial Health

57
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
31

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Jan 2021

Typical duration for not_applicable

Geographic Reach
1 country

2 active sites

Status
terminated

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

July 9, 2020

Completed
6 months until next milestone

Study Start

First participant enrolled

January 14, 2021

Completed
11 months until next milestone

First Posted

Study publicly available on registry

December 6, 2021

Completed
1.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 26, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 26, 2023

Completed
Last Updated

March 11, 2026

Status Verified

February 1, 2024

Enrollment Period

2.4 years

First QC Date

July 9, 2020

Last Update Submit

March 9, 2026

Conditions

Outcome Measures

Primary Outcomes (3)

  • Sensorimotor function

    Nerve conduction velocity

    Change from baseline to 6 months

  • Cardiovascular autonomic function

    Heart rate variability

    Change from baseline to 6 months

  • Muscle endurance

    Decline in torque during repeat muscle contraction

    Change from baseline to 6 months

Secondary Outcomes (6)

  • Glucose tolerance

    Change from baseline to 6 months

  • Insulin sensitivity

    Change from baseline to 6 months

  • Beta cell function

    Change from baseline to 6 months

  • Plasma triglyceride concentration

    Change from baseline to 6 months

  • Muscle strength

    Change from baseline to 6 months

  • +1 more secondary outcomes

Study Arms (3)

Intervention Group

EXPERIMENTAL

Subjects randomized to n-3 PUFA will receive a total of 4.2 g/d of fish oil.

Dietary Supplement: Fish-oil derived n-3 polyunsaturated fatty acids

Placebo Group

PLACEBO COMPARATOR

Subjects randomized to placebo will receive 4.2 g/d sunflower oil.

Dietary Supplement: Fish-oil derived n-3 polyunsaturated fatty acids

Control group

NO INTERVENTION

Subjects assigned to the control group will be tested once

Interventions

4.2 g/d (7 pills with 600 mg each)

Intervention GroupPlacebo Group

Eligibility Criteria

Age55 Years - 80 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • age: ≥55 and ≤80 years
  • BMI: ≥25.0 and ≤39.9 kg/m2;
  • normal plasma glucose (fasting plasma glucose \<100 mg/dl and plasma glucose 2 h after a 75 g glucose challenge \<140 mg/dl) for the control group and impaired fasting plasma glucose (≥100 mg/dl) or impaired glucose tolerance (plasma glucose 2 h after a 75 g glucose challenge ≥140 mg/dl) or both for the intervention groups

You may not qualify if:

  • age: \<55 and \>80 years
  • BMI: \<25.0 and \>39.9 kg/m2
  • fasting plasma glucose ≥100 mg/dl or plasma glucose 2 h after a 75 g glucose challenge ≥140 mg/dl for the control group and normal plasma glucose (fasting plasma glucose \<100 mg/dl, plasma glucose at 2 h after 75 g glucose ingestion \<140 mg/dl) for the intervention groups
  • treatment for T2D, except for metformin
  • regular structured high-intensity exercise \>150 min total per week
  • significant neurological or other organ system dysfunction (e.g., progressive neuromuscular disease, unstable angina, vasculitis, certain cardiopulmonary diseases, cancer that has been in remission for \<5 years, dementia, allergies to the dietary supplement) or significant ambulatory impairments (e.g., limb amputations, being wheelchair-bound)
  • use of certain medications that are incompatible with the study procedures (e.g., certain anticoagulants) or could confound the study outcomes (e.g., anabolic steroids, metronidazole, etc) alcohol use disorder as defined by the NIAAA or use of controlled substances or smoking \>20 cigarettes per week
  • regular consumption of fish oil supplements or \>2 servings of fatty fish per week
  • x) prisoners, and persons who are unable to grant voluntary informed consent.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Washington University School of Medicine

St Louis, Missouri, 63110, United States

Location

Washington University

St Louis, Missouri, 63110, United States

Location

MeSH Terms

Conditions

Diabetic Neuropathies

Condition Hierarchy (Ancestors)

Peripheral Nervous System DiseasesNeuromuscular DiseasesNervous System DiseasesDiabetes ComplicationsDiabetes MellitusEndocrine System Diseases

Study Officials

  • Bettina Mittendorfer

    Washington University School of Medicine

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Masking Details
double-blind, randomized controlled trial in men and women
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Senior Associate Dean for Research

Study Record Dates

First Submitted

July 9, 2020

First Posted

December 6, 2021

Study Start

January 14, 2021

Primary Completion

June 26, 2023

Study Completion

June 26, 2023

Last Updated

March 11, 2026

Record last verified: 2024-02

Data Sharing

IPD Sharing
Will not share

Locations