Exercise Training and Fat Metabolism in Postmenopausal Women

July 25, 2023 updated by: Michael J. Ormsbee, Florida State University

Resistance Training Modulation of Fat Metabolism in Obese Postmenopausal Women

Adipose tissue turnover plays a critical role in body weight maintenance, and obesity is underscored by the dysregulated balance between fat breakdown and synthesis. Although there are clear health-related benefits of physical activity, little is known about how resistance exercise, as opposed to endurance exercise, can reduce the risk of metabolic disorders, particularly in women. The goal of the proposed study is to investigate the effectiveness of resistance training to improve basal and stimulated fat metabolism in postmenopausal women with obesity and pre-diabetes, potentially serving as a viable and practical approach to prevent the onset of type 2 diabetes.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The primary objective is to compare the effects of 12 weeks of resistance training to endurance training with respect to whole-body and regional lipolytic (fat breakdown) responses to acute walking exercise, (Aim 1), local adrenergic receptor blockade (Aim 2) and in response to insulin during a hyperinsulinemic-euglycemic clamp (Aim 3). The investigators will study the lipolytic response in the context of acute exercise, whole-body fat oxidation and resting energy expenditure data. The investigators will collect data on chronic lipogenesis (fat synthesis) and adipogenesis (fat cell formation), as well as on ambulatory blood glucose control. Microdialysis techniques will be utilized to determine the lipolytic rate in subcutaneous abdominal and gluteal adipose tissue at rest, as well as during and after physical activity (walking) or during a hyperinsulinemiceuglycemic clamp (including thigh muscle), before and after 12 weeks of either resistance training or endurance training. To investigate the adrenergic regulation of lipolysis before, during, and after exercise, a saline/ ethanol solution will be perfused (to monitor blood flow) through three separate microdialysis probes in subcutaneous abdominal and gluteal adipose tissue. The perfusate in the probes will consist of either: 1) no additional substances (control probe) to address Aim 1; or 2) phentolamine, an alpha adrenoreceptor blocker (treatment probe), and 3) propranolol, a beta adrenoreceptor blocker (second treatment probe) to address Aim 2. Hyperinsulinemic-euglycemic clamps will be performed to study the whole-body (with stable isotope tracers) and regional (with microdialysis) antilipolytic effect of insulin, as well as to measure insulin sensitivity with respect to glucose metabolism, before and after the training programs for Aim 3. Immediately following the controlled laboratory experiments, glycerol profiles (index of lipolysis) and glucose profiles (index of glucose control) will continue to be monitored in the participant's free-living environment over the ensuing 18 hours until the following morning. Additionally, at weeks 4 and 12 participants will come to the lab for adipose tissue biopsies of the abdominal and gluteal adipose tissue for determination of adipogenesis and lipogenesis using stable-isotope-labeled water they will drink daily over this eight-week labeling period. Additional measures of fat oxidation as well as chronic and acute fat deposition will allow interpretation of lipolysis in the context of fat oxidation and fat accumulation, while 24-hour lipolysis and glucose profile measures will allow investigation of fat metabolism and glucose control in a free-living condition. These studies will provide a greater understanding of how these exercise modalities affect metabolism in women with obesity and prediabetes, allowing practitioners to make more evidence based exercise prescriptions intended to improve body composition, glycemic control, and weight management.

The sample size for these studies will consist of 120 participants that will be randomly assigned via computer randomization to either resistance training (n=60) or endurance training (n=60) for 12 weeks. This sample size gives sufficient statistical power to detect differences in lipolytic rate and other outcome variables, as determined by previous studies examining similar outcome measures. A combination of stable tracers will be infused into the bloodstream to examine various measures of fat metabolism under resting and exercise conditions, as well as during a procedure that mimics a meal (hyperinsulinemic-euglycemic clamp). However, these various tracers can interfere with each other if studied altogether. Therefore these respective isotope tracer measures will be run in only one-half of the participants from each Aim. 30 participants in the endurance training group and 30 participants in the resistance training group will complete Aims 1 and 2. A different 30 participants in the endurance training group and 30 in the resistance training group will complete Aim 3. Among the 60 participants (30 from each exercise training group) completing Aims 1 and 2, there will be 15 individuals from each exercise training group who will be randomized to undergo the tracer measures during exercise while the other 15 from each exercise training group addressing Aims 1 and 2 will complete the exercise protocol without the tracer methods. These randomization methods will also be applied to the 60 participants completing Aim 3, although these participants will undergo a hyperinsulinemic-euglycemic clamp with or without the tracer methods.

Participants will be recruited, screened, enrolled, and tested during months 4-55 of this grant. Participant recruitment procedures and procurement of needed supplies will occur during the first 3 months of the project. Additional recruitment, as well as screening and testing of participants will occur at 1-2 per month over the ensuing 52 months. Two microdialysis experiments will be performed on participants, one before and one after 12 weeks of exercise training, for a total of 240 microdialysis experiments. This plan will therefore require 4-5 microdialysis tests per month on average during the testing months. Stable label palmitate and glycerol isotope experiments will be conducted in 30 of the 60 participants undergoing the acute walking microdialysis experiments and in 30 of the 60 participants undergoing the clamp experiment. Deuterium water isotope experiments (studies of lipogenesis and adipogenesis) will be conducted in 60 of the participants.

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Robert C Hickner, PhD
  • Phone Number: 850-644-1375
  • Email: rhickner@fsu.edu

Study Contact Backup

  • Name: Michael J Ormsbee, PhD
  • Phone Number: 850-644-2194
  • Email: mormsbee@fsu.edu

Study Locations

  • United States
    • Florida
      • Tallahassee, Florida, United States, 32306
        • Recruiting
        • Florida State University
        • Principal Investigator:
          • Michael J Ormsbee, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Women
  • Postmenopausal (50-70 yrs.)
  • Obese (BMI 30-39.9 kg/m2)
  • Prediabetes (HbA1c 5.7 - 6.4% or fasting blood glucose 100 to 125 mg/dL, or 2hr OGTT blood glucose 140 to 199 mg/dL)
  • Sedentary (not performing purposeful exercise training more than 20 minutes per day twice a week)
  • Non-smokers
  • No hormone replacement therapy for at least the past two years.

Exclusion Criteria:

  • Engaging in purposeful resistance training or endurance training (> 20min/day, > 2 days/week)
  • Resting blood pressure above 140 mmHg systolic or 90 mmHg diastolic
  • Type 1 or type 2 diabetes
  • Medical problems in which exercise is contraindicated, such as chronic infections
  • History of, or currently presentation with, cancer, cardiovascular or respiratory disease
  • Uncontrolled thyroid dysfunction, liver or renal dysfunction
  • Taking any medication affecting lipid metabolism
  • Musculoskeletal disease or injury that would otherwise prevent engagement in resistance and endurance training
  • Smokers and those with diagnosed eating disorders

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Resistance Exercise
Participants do regular resistance exercise for 12 weeks.
Behavioral: Resistance Exercise
300 Kcal worth of weight lifting, 3 times/week for 12 weeks
Other Names:
  • Weight Lifting
Experimental: Endurance Exercise
Participants do regular endurance exercise for 12 weeks.
Behavioral: Endurance Exercise
300 Kcal worth of treadmill walking, 3 times/week for 12 weeks
Other Names:
  • Aerobic Exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline subcutaneous abdominal adipose tissue glycerol concentration at 12 weeks
Time Frame: 12 weeks of resistance or endurance training
Changes in physical activity (walking)-stimulated lipolysis will be assessed as measured by glycerol concentration in dialysate samples from subcutaneous abdominal adipose tissue utilizing a powerful in-vivo microdialysis methodology
12 weeks of resistance or endurance training
Change from baseline gluteal adipose tissue glycerol concentration at 12 weeks
Time Frame: 12 weeks of resistance or endurance training
Changes in physical activity (walking)-stimulated lipolysis will be assessed as measured by glycerol concentration in dialysate samples from gluteal adipose tissue utilizing a powerful in-vivo microdialysis methodology
12 weeks of resistance or endurance training
Change from baseline whole-body lipolysis at 12 weeks
Time Frame: 12 weeks of resistance or endurance training
Whole body lipolysis will be measured using whole body rate of appearance of 2H5-glycerol in blood samples collected at rest, during walking exercise, and for 120 minutes after exercise.
12 weeks of resistance or endurance training

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in blood flow as measured by ethanol concentrations in dialysate samples from subcutaneous abdominal adipose tissue
Time Frame: 12 weeks of resistance or endurance training
Ethanol (~10 mM) will be included with the perfusion medium through the microdialysis probe. Blood flow will be expressed as a ratio of the ethanol concentration in the dialysate (outflow) and the ethanol concentration in the perfusate (inflow)
12 weeks of resistance or endurance training
Change in dialysate ethanol data in subcutaneous gluteal adipose tissue
Time Frame: 12 weeks of resistance or endurance training
Ethanol (~10 mM) will be included with the perfusion medium through the microdialysis probe. Blood flow will be expressed as a ratio of the ethanol concentration in the dialysate (outflow) and the ethanol concentration in the perfusate (inflow)
12 weeks of resistance or endurance training
Change in the ratio of 13CO2 to 12CO2 in breath samples
Time Frame: 12 weeks of resistance or endurance training
This measure will allow for the calculation of whole-body fat oxidation under conditions of rest, walking exercise, and hyperinsulinemiceuglycemic clamp.
12 weeks of resistance or endurance training
change in body composition
Time Frame: 12 weeks of resistance or endurance training
Body composition (body mass, lean mass, fat mass, visceral fat) will be measured before and after 12 weeks of resistance or endurance training.
12 weeks of resistance or endurance training
Change in blood growth hormone concentrations
Time Frame: 12 weeks of resistance or endurance training
Concentrations of growth hormone in plasma samples will be measured before and after 12 weeks of resistance or endurance training.
12 weeks of resistance or endurance training
Change in lipogenesis
Time Frame: 12 weeks of resistance or endurance training
Fat synthesis will be assessed in fat biopsies from subcutaneous abdominal and gluteal adipose tissue using deuterium labeled fatty acids following deuterated water administration in the free-living setting.
12 weeks of resistance or endurance training
Change in adipogenesis
Time Frame: 12 weeks of resistance or endurance training
New fat cell formation/proliferation will be assessed in fat biopsies from subcutaneous abdominal and gluteal adipose tissue via adipocytes and preadipocytes DNA quantification using deuterated water in the free-living setting.
12 weeks of resistance or endurance training

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Florida State University

Collaborators

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Pennington Biomedical Research Center
University of Arkansas

Investigators

  • Principal Investigator: Michael J Ormsbee, PhD, Florida State University
  • Principal Investigator: Robert C Hickner, PhD, Florida State University
  • Study Director: Mostafa M Ali, PhD, Florida State University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 20, 2022

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

April 4, 2022

First Submitted That Met QC Criteria

April 22, 2022

First Posted (Actual)

April 28, 2022

Study Record Updates

Last Update Posted (Actual)

July 27, 2023

Last Update Submitted That Met QC Criteria

July 25, 2023

Last Verified

July 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00001939
  • R01DK125728 (U.S. NIH Grant/Contract)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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