Effects of Walking and Heating on Vascular Function in Diabetic Patients

Restoring Vasodilator Actions of Insulin in Patients With Type 2 Diabetes

The purpose of the present study is to determine the effects of increased walking and lower body heating on leg vascular function in patients with type 2 diabetes (T2D).

Study Overview

• Status: Completed
• Conditions: Obesity; Type 2 Diabetes Mellitus
• Intervention / Treatment: Behavioral: Walking: Intervention arm in diabetics; Other: Walking: No intervention in diabetics; Other: Walking: Healthy cohort as reference controls; Behavioral: Lower body heating: Intervention arm in healthy subjects; Behavioral: Lower body heating: Intervention arm in diabetics; Other: Lower body heating: Healthy cohort as reference controls

Detailed Description

The notion that habitual aerobic exercise increases insulin-induced vasodilation is largely founded on rodent studies, hence the urgent need for human studies, especially in patients with type 2 diabetes (T2D). For example, it remains unknown if increased walking, the most common form of physical activity, enhances skeletal muscle vasodilator actions of insulin in T2D. In addition, the molecular mechanisms by which exercise improves vasoreactivity to insulin have not been examined in humans. The investigators propose that in T2D patients who are sedentary (i.e., the vast majority), increased leg blood flow with walking or local heating signifies a vital strategy to correct vascular insulin resistance. This study will establish whether increased physical activity and associated hemodynamic forces (e.g., shear stress) are a direct form of vascular medicine in humans.

• Study Type: Interventional
• Enrollment (Actual): 99
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Missouri
    • Columbia, Missouri, United States, 65212
      • University of Missouri

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Patients with type 2 diabetes who are overweight and obese (BMI 25-50 kg/m2), 35 to 65 years of age, and sedentary (<60 minutes structured exercise/week). Healthy volunteers without type 2 diabetes: 18 to 65 years of age.

Exclusion Criteria:

1. Cardiovascular disease including myocardial infraction, heart failure, coronary artery disease, stroke;
2. renal or hepatic diseases;
3. active cancer;
4. autoimmune diseases;
5. immunosuppressant therapy;
6. excessive alcohol consumption (>14 drinks/week for men; >7 drinks/week for women);
7. current tobacco use;
8. pregnancy;
9. mobility limitations;
10. foot ulcers;
11. diabetic neuropathy
12. uncontrolled hypertension (>=180 systolic / 100 diastolic mmHg)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Walking: Intervention arm in diabetics; The walking program will consist of 45 minutes of walking (at a moderate pace) 5 days per week for 8 weeks.	Behavioral: Walking: Intervention arm in diabetics; The walking program will consist of 45 minutes of walking (at a moderate pace) 5 days per week for 8 weeks.
Experimental: Walking: No intervention in diabetics; Subjects will be instructed to continue their usual lifestyle for 8 weeks.	Other: Walking: No intervention in diabetics; Subjects will be instructed to continue their usual lifestyle for 8 weeks.
Other: Walking: Healthy cohort as reference controls; Subjects will be studied at one time only.	Other: Walking: Healthy cohort as reference controls; Subjects will be studied at one time only.
Experimental: Lower body heating: Intervention arm in healthy subjects; This intervention consists of 60 minutes of lower body heating (40-42 degree C).	Behavioral: Lower body heating: Intervention arm in healthy subjects; This intervention consists of 60 minutes of lower body heating (40-42 degree C).
Experimental: Lower body heating: Intervention arm in diabetics; This intervention consists of 60 minutes of lower body heating (40-42 degree C) 7 days per week for 7 days.	Behavioral: Lower body heating: Intervention arm in diabetics; This intervention consists of 60 minutes of lower body heating (40-42 degree C) 7 days per week for 7 days.
Other: Lower body heating: Healthy cohort as reference controls; Subjects will be studied at one time only.	Other: Lower body heating: Healthy cohort as reference controls; Subjects will be studied at one time only.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin-stimulated Leg Blood Flow Calculated as Percent Change (t0, t60)	Measure of blood flow in response to insulin. Blood flow is measured via Doppler ultrasound at the femoral artery. Measurements are performed at baseline (t0) and after 60 minutes of insulin stimulation (t60).	Percent change from baseline leg blood flow during 60 minutes of insulin stimulation.
Net Change in Insulin-stimulated Leg Blood Flow Calculated as Percent Change From Pre-intervention (t0,t60) to Post-intervention (t0,t60).	Measure of blood flow in response to insulin. Blood flow is measured via Doppler ultrasound at the femoral artery. Measurements are performed pre-intervention and post-intervention at baseline (t0) and after 60 minutes of insulin stimulation (t60). Outcome measure indicates whether percent change in insulin-stimulated blood flow increased or decreased following intervention. Interventions that show an increase demonstrate an improvement in insulin-stimulated blood flow.	Change from baseline insulin-stimulated leg blood flow following 1 heating session, 7 days of heating intervention, or 8 weeks of walking intervention/no intervention.

Collaborators and Investigators

• Sponsor: University of Missouri-Columbia
• Investigators: Principal Investigator: Jaume Padilla, PhD, University of Missouri-Columbia

Study record dates

Study Major Dates

• Study Start (Actual): December 4, 2017
• Primary Completion (Actual): March 10, 2022
• Study Completion (Actual): March 10, 2022

Study Registration Dates

• First Submitted: June 23, 2017
• First Submitted That Met QC Criteria: June 26, 2017
• First Posted (Actual): June 29, 2017

Study Record Updates

• Last Update Posted (Actual): April 4, 2024
• Last Update Submitted That Met QC Criteria: April 1, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 2008181

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No