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RecruitingNCT04442451Updated Sep 1, 2026

Mechanisms of Fatigability With Diabetes

An interventional study of Control Exercise and Blood Flow Restriction Exercise in Pre-diabetes and Type 2 Diabetes, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to participants aged 30 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-09-01.

Sponsored by University of Michigan · Not applicable, Interventional, and Basic science

From the registry’s dates

  • Started Sep 2022; still recruiting 4 years 2 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
80
Allocation
Randomized
Ages
30 Years to 85 Years
Sex
All
01

Study summary

Pre-diabetes (Pre-D) is a precursor to type 2 diabetes (T2D) and characterized by increased exercise fatigability of lower limb muscles, that can impede exercise performance. The cause for the increased fatigability in people with Pre-D is not known. Given the profound vascular disease present in people who have had uncontrolled diabetes for several years, we will determine whether dynamic, fatiguing contractions of the lower limb muscles in people with Pre-D are limited by vascular dysfunction at multiple levels along the vascular tree including the artery, arteriole, and/or capillary. This clinical trial involves a novel exercise training regime involving blood flow restriction to the exercising limb will be used as a probe to further understand the vascular mechanisms for increased fatigability in people with Pre-D and T2D. The long-term goal is to better understand what limits exercise and functional performance in people with diabetes to help develop targeted, more effective exercise programs.

Read the detailed description

The aim of the clinical trial is to determine the effectiveness of dynamic resistance exercise training coupled with blood flow restriction to improve fatigability and vascular function in people with Pre-D and T2D. People with Pre-D and T2D from Aim 1 will perform 8 weeks of dynamic unilateral resistance exercise training in which one leg is exercised with freely perfused conditions and the other leg with blood flow restriction.

We will assess fatigability, skeletal muscle metabolism, capillary density, and vascular function in people with Pre-D and T2D before and after a novel training intervention that couples dynamic resistance training with blood flow restriction to the exercising limb. This novel intervention has been shown to improve vascular function in young and older adults but has not been investigated in people with Pre-D and T2D. Endothelial function in intact large conduit arteries and arterioles isolated from skeletal muscle biopsies will be measured before and after the training intervention to assess whether the novel training improves vascular function along multiple levels of the vascular tree in people with Pre-D and T2D. Skeletal muscle blood flow through the femoral artery will be quantified with Doppler ultrasonography and skeletal muscle oxygenation will be measured with near infrared spectroscopy (NIRS) during a dynamic fatiguing knee extension exercise. We will closely match participant groups for physical activity levels, age, sex, and body mass index (BMI), because these confounders are not typically controlled for in other human studies.

02

Conditions studied

  • Pre-diabetes
  • Type 2 Diabetes

Keywords

  • Diabetes
  • Pre-diabetes
  • Fatigability
  • Blood Flow Restriction Training
  • Vascular Function
  • Muscle Fatigue
03

In context

Glucose Intolerance

793 studies on the registry are indexed under Glucose Intolerance; 115 are open to participants now.

This study's planned enrollment of 80 is above the median of 56 across 661 interventional studies indexed under Glucose Intolerance.

Browse Glucose Intolerance studies →

Lead sponsor

University of Michigan is the lead sponsor of 1,506 studies on the registry; 192 are open to participants now.

Of its 169 completed or terminated interventional studies of FDA-regulated products, 133 (79%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
30 Years to 85 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Men and women adults 30 years to 85 years or less
  • Pre-diabetes [glycosylated () of 5.7-6.4% and fasting plasma glucose 100-125 mg/dL at the time of initial screening]
  • Controls [normoglycemic with a HbA1c level ≤5.6% and fasting blood glucose ≤ 99 mg/dL (5.5 mmol/L)]
  • Type 2 Diabetes Mellitus [elevated glycosylated hemoglobin (HbA1c) >6.5% and \<10%]

Exclusion criteria

Exclusion Criteria:

  • Signs or symptoms of neuropathy
  • Medications associated with advanced stages of T2D including insulin
  • Poor glycemic control (>10%)
  • Peripheral edema
  • Severe obesity (, >45kg·m-2)
  • Untreated hypothyroidism
  • Smoking
  • Hypertension
  • Cardiovascular or musculoskeletal disease that preclude exercise testing
  • Hormone replacement drugs or vasoactive medications
Terms in these criteria, in plain language(3)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Hemoglobin (Hb)

The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).

HbA1c

A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
80 participants (estimated)

Study arms

  • Experimental
    Control Exercise

    Low-load knee extension resistance training (20% of 1-RM) without blood flow restriction. A 10-cm wide inflatable cuff will be placed around the upper portion of the thigh but not inflated.

    Other: Control Exercise

  • Experimental
    Blood Flow Restriction Exercise

    Low-load knee extension resistance training (20% of 1-RM) with blood flow restriction using a 10-cm wide inflatable cuff placed around the most proximal part of the exercising thigh. Blood flow will be restricted in the BFR leg at above the limb occlusion pressure of the and this will be determined prior to the exercise while the participant is seated in the knee extensor machine. The cuff pressure during the BFR protocol will be 10 mmHg above limb occlusion pressure.

    Other: Blood Flow Restriction Exercise

Interventions

  • OtherControl Exercise

    Each participant will attend 3 sessions per week for 8 weeks. Participants will perform low-load knee extension resistance training (20% of 1-RM) without blood flow restriction on the designated leg for 4 sets of contractions with 15 contractions per set of contractions with a 30 second rest between each set of contractions.

  • OtherBlood Flow Restriction Exercise

    Each participant will attend 3 sessions per week for 8 weeks. Participants will perform low-load knee extension resistance training (20% of 1-RM) with blood flow restriction on the designated leg for 4 sets of contractions with 15 contractions per set of contractions with a 30 second rest between each set of contractions.

06

What researchers measure

Primary outcomes

  1. Fatigability - Reduction in Power

    Reduction in limb power and maximal force in response to a dynamic fatiguing contraction.

    Time frame: One session before and then after 8 weeks of training

  2. Strength - 1 Repetition Maximum

    Reduction in limb power and maximal force in response to a dynamic fatiguing contraction

    Time frame: One session before and then after 8 weeks of training

  3. Strength - Maximal Voluntary Contraction (MVC)

    Changes in MVC after 8 weeks resistance training. MVC is the greatest force generated during a brief isometric contraction.

    Time frame: One session before and then after 8 weeks of training

  4. Leg Blood Flow

    Femoral artery mean blood velocity and femoral artery diameter will be measured using Doppler ultrasonography before and immediately after the fatiguing task in each leg.

    Time frame: One session before and then after 8 weeks of training

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: No — No data will be shared

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Sep 2022 (actual). Primary completion is estimated for Jul 2027, 58 months after the start.

Of 254 non-industry interventional studies with no phase under Glucose Intolerance, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 44. This study's planned 58 months is above that.

Counting every sponsor, half of 286 studies reached it within 26 months; a quarter within 10 and three quarters within 44.

How these figures are worked out, and which studies are left out of them.

Registered
Jun 18, 2020
First posted
Jun 22, 2020
StartActual
Sep 1, 2022
Primary completionEst.
Jul 1, 2027
CompletionEst.
Aug 31, 2027
Last update
Sep 1, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Sep 1, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04442451
Responsible party
Sandra Hunter (Francie Kraker Goodridge Collegiate Professor of Kinesiology and Professor of Kinesiology, School of Kinesiology, University of Michigan) — Principal investigator
First posted
Jun 22, 2020
Start date
Sep 1, 2022
Primary completion
Jul 1, 2027 (estimated)
Completion
Aug 31, 2027 (estimated)
Last update
Sep 1, 2026

Study contacts

Sandra Hunter, PhD
Contact
sandrahu@umich.edu
(734) 647-9819
Sarah Lessila, MSc
Contact
slessila@umich.edu

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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