Recruiting

Observational Study

Sponsor:

University of Michigan

Code:

NCT04442451

Conditions

Pre-diabetes

Type 2 Diabetes

Eligibility Criteria

Sex: All

Age: 30 - 70+

Healthy Volunteers: Not accepted

Interventions

Control Exercise

Blood Flow Restriction Exercise

Study Details

Brief 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.

Conditions

Pre-diabetes

Type 2 Diabetes

Study ID

NCT04442451

Start date

Sep 1, 2022

Status verified date

Oct, 2025

Completion date

Aug 31, 2027

Anticipated

Primary completion date

Jul 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 30 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Men and women adults 30 years to 85 years or less
  • Pre-diabetes \[glycosylated hemoglobin (HbA1c) of 5.7-6.4% and fasting plasma glucose 100-125 mg/dL at the time of initial screening\]
  • 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:

  • Signs or symptoms of neuropathy
  • Medications associated with advanced stages of T2D including insulin
  • Poor glycemic control (HbA1c>10%)
  • Peripheral edema
  • Severe obesity (BMI, >45kg·m-2)
  • Untreated hypothyroidism
  • Smoking
  • Hypertension
  • Cardiovascular or musculoskeletal disease that preclude exercise testing
  • Hormone replacement drugs or vasoactive medications

Study Design

Enrollment

80 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

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.

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.

Interventions

Control 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.

Blood 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.

Primary outcome measure

  • Fatigability - Reduction in Power [ Time Frame: One session before and then after 8 weeks of training ]
  • Strength - 1 Repetition Maximum [ Time Frame: One session before and then after 8 weeks of training ]
  • Strength - Maximal Voluntary Contraction (MVC) [ Time Frame: One session before and then after 8 weeks of training ]
  • Leg Blood Flow [ Time Frame: One session before and then after 8 weeks of training ]

Central Contacts and Locations

Central contacts

Sandra Hunter, PhD

(734) 647-9819sandrahu@umich.edu

Sarah Lessila, MSc

slessila@umich.edu

Locations

University of Michigan

Recruiting

Ann Arbor, Michigan, United States, 48109

Contacts

Sandra Hunter, PhD

(734) 647-9819sandrahu@umich.edu

Sarah Lessila, MS

(734) 647-6019slessila@umich.edu

More Information

Sponsor

University of Michigan

Last update posted

Sep 1, 2026

Last verified

Oct, 2025

Keywords

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Michigan on 2026-09-01.