Impact of Obesity on Microvascular Insulin Action and Cardiorespiratory Fitness in Type 1 Diabetes

NCT07573228 | Recruiting

• 2 other identifiers: 302809R01DK141617
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is:

• To see if insulin resistance (how sensitive your muscle tissue is to insulin) is associated with lower cardio fitness in people with Type 1 diabetes compared to healthy controls, before and after a High Intensity Interval Training (HIIT) exercise program.
• To see if being overweight and having Type 1 diabetes is associated with lower cardio fitness compared to overweight healthy controls, before and after a HIIT exercise program.

Conditions

Type 1 Diabetes; Overweight

Keywords

Type 1 diabetes; Exercise training; healthy controls; overweight

Outcome Measures

Primary Outcomes (2)

• Microvascular blood volume in skeletal and cardiac muscle - changes from baseline

  insulin-mediated changes in skeletal and cardiac muscle as determined by insulin clamp

  Before and after 15 weeks of exercise training

• maximal aerobic exercise capacity

  change in VO2max

  before and after 15 weeks of exercise training

Secondary Outcomes (2)

• insulin-mediated whole body glucose disposal

  before and after 15 weeks of exercise training

• Muscle capillary density and satellite cells

  before and after 15 weeks of exercise training

Study Arms (4)

Type 1 diabetes - normal weight

ACTIVE COMPARATOR

Type 1 diabetes normal weight

Other: Exercise training

Control - normal weight

ACTIVE COMPARATOR

healthy control - normal weight

Other: Exercise training

Overweight control

ACTIVE COMPARATOR

Overweight, otherwise healthy

Other: Exercise training

Type 1 diabetes - overweight

ACTIVE COMPARATOR

Type 1 diabetes - overweight

Other: Exercise training

Interventions

Exercise training OTHER

15 weeks of HIIT exercise training

Control - normal weight; Overweight control; Type 1 diabetes - normal weight; Type 1 diabetes - overweight

Eligibility Criteria

• Age: 21 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male or female ≥21 and ≤50 years old
• For persons with T1D: Disease duration ≥ 5 years and HbA1c ≤ 8.5% on multiple daily insulin injection or insulin pump
• Body mass index: ≥19 and ≤27 kg/m2 for control and T1D, ≥30 and ≤40 kg/m2 (27.5 to 37.5 for Asian Americans) for obesity and T1D + obesity. BMI is limited to ≤40 kg/m2 (37.5 for Asian Americans) for easier vascular access and cardiac imaging.
• Stable use of non-insulin medications for over 6 months other than estrogen/progesterone containing medications which must be discontinued at least 3 months prior to the study (intrauterine devices may be continued due to limited systemic absorption)

You may not qualify if:

• Acute or chronic disease other than T1D or obesity
• History of microvascular or macrovascular diabetes complications
• History of diabetic ketoacidosis in the past 24 months
• History of hypoglycemia unawareness
• Recently active (\>20 min of moderate/high intensity exercise, 2 times/week)
• Subjects who are smokers or who have quit smoking \<5 years
• Subjects with hypertriglyceridemia (\>400 mg/dl)
• Current use of vasoactive medications (i.e. calcium channel blockers, angiotensin-converting enzyme or renin inhibitors, angiotensin-receptor blockers, nitrates, alpha- or beta-blockers, or diuretics).
• Females taking oral contraceptives in the past 3 months
• Subjects with a history of significant metabolic, cardiac, cerebrovascular, hematological, pulmonary, gastrointestinal, liver, renal, or endocrine disease or malignancy
• Pregnant (as evidenced by positive pregnancy test) or nursing women
• Musculoskeletal condition preventing participation in exercise testing or exercise training
• History of gastroparesis
• Pulse oximetry \<90%

Sponsors & Collaborators

• University of Virginia: lead

Study Sites (1)

University of Virginia

Charlottesville, Virginia, 22908, United States

RECRUITING

MeSH Terms

Conditions

Diabetes Mellitus, Type 1; Overweight

Interventions

Exercise

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Zhenqi Liu, MD

  University of Virginia

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lee Hartline, MEd

CONTACT

434-924-5247; lmh9d@virginia.edu

Zhenqi Liu, MD

CONTACT

zl3e@UVAhealth.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: May 7, 2026
• Study Start: February 23, 2026
• Primary Completion (Estimated): June 30, 2030
• Study Completion (Estimated): June 30, 2030
• Last Updated: May 7, 2026

Record last verified: 2026-05

Locations

US (1)