Exercise Effects on Adipose Tissue Structure and Function (LG)

Participants will be randomized into one of two different experimental groups: 1) Exercise group and 2) No exercise (control group). Subject participation in the study will involve a series of metabolic tests before and after participants undergo a 10% weight loss program (with or without exercise training depending on group randomization). After completing this weight loss portion of the study, participants will then be required to adhere to a high calorie diet program to regain half of the weight the participant lost - followed by the same series of metabolic tests.

Study Overview

• Status: Recruiting
• Conditions: Obesity; Metabolic Syndrome; Insulin Resistance; Weight Loss; Weight Gain; Metabolic Disease
• Intervention / Treatment: Behavioral: Exercise; Behavioral: No exercise

Detailed Description

Exercise is among the first line treatments for obesity and obesity-related diseases, yet it is shocking how little is known about how exercise works to improve health. Expanding the knowledge about novel exercise-induced adaptations in fat tissue of obese individuals and furthering the understanding about mechanisms underlying these adaptations could lead to innovative approaches for preventing and treating insulin resistance and obesity-related diseases.

Overall, the researchers believe that exercise training modifies key processes in subcutaneous fat tissue that may contribute to an increase body fat storage capacity (without increasing fat mass). The research team anticipates that exercise will evoke an even more potent adaptive response when fat tissue is dynamically changing in response to alterations in nutritional status (i.e., weight loss and weight regain).

Participants will be randomized into one of two different experimental groups: 1) Exercise group and 2) No exercise (control group). Subject participation in the study will involve a series of metabolic tests before and after participants undergo a 10% weight loss program (with or without exercise training depending on group randomization). After completing this weight loss portion of the study, participants will then be required to adhere to a high calorie diet program to regain half of the weight the participant lost - followed by the same series of metabolic tests. After the participant completes the study, the study team will help the participant to lose more weight. Total involvement in the study for each participant will likely be about 8-10 months.

• Study Type: Interventional
• Enrollment (Estimated): 46
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Suzette Howton; Phone Number: 734-647-9850; Email: smlstudies@umich.edu

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • Recruiting
      • University of Michigan
      • Contact: Jeffrey F Horowitz; Phone Number: 734-647-1076; Email: jeffhoro@umich.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age: 18-40
• Body Mass Index: 27-45 kg/m2
• No regularly planned exercise/physical activity for at least 6 months
• Women must have regularly occurring menses and must be premenopausal

Exclusion Criteria:

• Evidence/history of cardiovascular or metabolic disease
• Medications known to affect lipid or glucose metabolism, or inflammation
• Weight instability ≥ ± 6 pounds in the last 3 months
• Tobacco or e-cigarette users
• Women must not be pregnant or actively lactating

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exercise; This exercise prescription represents a common or "conventional" form of physical activity (e.g., moderate/brisk walking). If assigned to this group, participants will perform 45 minutes of moderate intensity continuous steady-state exercise at 70% maximal heart rate (HRmax) to expend 250 calories 4 days per week.	Behavioral: Exercise; Participants will complete a moderate intensity continuous exercise 4 days/week.
Experimental: No exercise; Subjects assigned to this group are to remain sedentary (no planned physical exercise) throughout the duration of the study.	Behavioral: No exercise; Participants will remain sedentary throughout the duration of the study.; Other Names: Control group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oral Glucose Tolerance Test (OGTT)	A test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood will be completed at each clinical visit appointment..	2 hours
Adipose Tissue Fibrosis	measured histologically using Sirus Red Staining, quantified using ImageJ software at each clinical visit appointment.	30 minutes
Muscle Capillarization	measured immunohistochemically using an antibody for CD31, quantified using ImageJ software at each clinical visit appointment.	30 minutes
Adipose Capillarization	measured immunohistochemically using an antibody for CD31, quantified using ImageJ software at each clinical visit appointment.	30 minutes
Fat Cell Size	measured histologically using Hematoxylin and eosin (H & E) staining, quantified using ImageJ software at each clinical visit appointment.	3 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood Lipid Profile	A panel of blood tests that screens for abnormalities in blood lipids will be measured at each clinical visit appointment.	15 minutes
Blood Pressure	The pressure of circulating blood against the walls of blood vessels will be measured at screening and each clinical visit appointment.	10 minutes

Collaborators and Investigators

• Sponsor: University of Michigan
• Investigators: Principal Investigator: Jeffrey F Horowitz, PhD, University of Michigan, School of Kinesiology

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2021
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): March 1, 2030

Study Registration Dates

• First Submitted: March 19, 2021
• First Submitted That Met QC Criteria: March 19, 2021
• First Posted (Actual): March 23, 2021

Study Record Updates

• Last Update Posted (Estimated): June 16, 2023
• Last Update Submitted That Met QC Criteria: June 15, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Hyperinsulinism; Body Weight Changes; Metabolic Syndrome; Weight Loss; Insulin Resistance; Body Weight; Weight Gain; Metabolic Diseases
• Other Study ID Numbers: HUM00175528

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is not a plan to make IPD available.

Drug and device information, study documents

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