Glycemic Load & Resistance Training on Endothelial Function & Insulin Sensitivity (GET FIT)

This project is prompted by the urgent public health need to identify novel strategies to prevent cardiovascular disease (CVD) and type 2 diabetes (T2D). The higher prevalence of CVD, T2D, and metabolic syndrome in obese individuals is a major healthcare concern. Therefore, finding optimal intervention strategies to combat these growing epidemics is imperative.

Study Overview

• Status: Completed
• Conditions: 160 Participants Aged 18-35 Years and Obese (BMI ≥30) Open to Men and Women of All Ethnicity
• Intervention / Treatment: Other: Resistance Training; Other: Glycemic Load

Detailed Description

At present, the extent to which dietary components can modify endothelial function, monocyte inflammation and glycemic variations is not well defined, although different carbohydrates are known to vary in their abilities to induce plasma glucose and insulin responses. Epidemiologic work suggests that high dietary glycemic load (GL) is associated with increased concentrations of inflammatory cytokines, endothelial dysfunction markers, and increased risk of T2D and coronary heart disease (CHD). We are examining using randomized control trials low vs. high-GL diet to determine if low-GL diets induce improvements in endothelial function or monocyte inflammation. Furthermore, resistance training is an alternate form of exercise from conventional aerobic training. Resistance Training has the potential to improve endothelial function or monocyte phenotype, but there is very little data in this area. We hypothesize that resistance training may augment the beneficial effects of a low-GL diet in improving metabolic health.

• Study Type: Interventional
• Enrollment (Actual): 88
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90095
      • University of California, Los Angeles

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 18-35 with BMI≥30 and/or your waist circumference ≥40 inches for males or ≥35 inches for females
• In good health as determined by the screening visit and review of medical history

Exclusion Criteria:

• Have a known heart arrhythmia and/or abnormalities found in electrocardiogram (ECG) reading or use of medications that influence CV function
• Have been in a weight loss or exercise program in the 6 months prior to participation
• Use tobacco products
• Have a syndrome or are prescribed medications that may influence body composition, insulin action, or CVD (e.g. PCOS, prednisone, methylphenidate, etc.)
• Have intolerance to lactose or gluten
• Pregnant

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low Glycemic Load + Resistance Training; 12-week intervention diet + resistance training (1 hour, 3 times per week)	Other: Resistance Training; Other: Glycemic Load
Experimental: High Glycemic Load + Resistance Training; 12-week control diet + resistance training (1 hour, 3 times per week)	Other: Resistance Training; Other: Glycemic Load
Experimental: Low Glycemic Load; 12-week intervention diet	Other: Glycemic Load
Other: High Glycemic Load; 12-week control diet	Other: Glycemic Load

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Endothelial function as determined by brachial artery FMD	12 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
monocyte inflammation	12 weeks
Insulin Sensitivity by Oral Glucose Tolerance Test	12 weeks
MAGE via Continuous Glucose Monitoring System	12 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
body composition (total fat mass, visceral fat, HFF, LBM) via DXA and MRI		12 weeks
plasma and cellular biomarkers post pre and post 12 week intervention	Monocytes will be isolated from subject whole blood and will be phenotyped in 2 ways: 1) as pro- or anti-inflammatory based on flow-activated cell sorting (FACS) analysis of monocyte-specific markers TLR-4, CD14 and CD16. Serum-Stimulated Cell Culture. Subject serum will be incubated with L6 cells as we have previously performed in monocytes and adipocytes as well as endothelial cells 18, 130. Following 48 hr incubation, cellular insulin-stimulated glucose transport will be assayed as described 129 and conditioned medium assayed for myokine levels (ex. IL-15, 1L-6, etc). Fasting plasma (and conditioned media where appropriate) will be taken to determine a panel of adipokines and hormones (e.g. insulin, adiponectin, HSP-72, IL-4, IL-6, IL-10, MCP-1, CRP, 8-iso PGF2α) will be measured using the Millipore Multiplex assay kit or with specific ELISA kits	12 weeks
RNA/protein levels via muscle and fat tissue collection	Approximately 300 mg of muscle tissue from the superficial portion of the vastus lateralis and approximately 3-5 g of subcutaneous adipose tissue from the periumbilical portion of the abdomen will be obtained.	12 weeks

Collaborators and Investigators

• Sponsor: University of California, Los Angeles
• Investigators: Principal Investigator: Catherine Carpenter, PhD, MPH, University of California, Los Angeles

Study record dates

Study Major Dates

• Study Start: April 1, 2012
• Primary Completion (Actual): December 14, 2017
• Study Completion (Actual): December 14, 2017

Study Registration Dates

• First Submitted: October 11, 2012
• First Submitted That Met QC Criteria: December 19, 2012
• First Posted (Estimate): December 24, 2012

Study Record Updates

• Last Update Posted (Actual): November 16, 2020
• Last Update Submitted That Met QC Criteria: November 12, 2020
• Last Verified: November 1, 2020

More Information

Terms related to this study

• Keywords: exercise; overweight; nutrition; body composition; diet; obese; resistance training; lifestyle; weight training; glycemic load
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Insulin Resistance
• Other Study ID Numbers: 546464