Effect of Caloric Restriction on Fat Oxidation in Obese Men and Women (Magellan II) (MagellanII)

Effect of Caloric Restriction on Metabolic Biomarkers and Fat Oxidation in Obese Men and Women (Magellan II)

The purpose of this study is to better understand the different ways our bodies burn fat which may be important for obesity, diabetes, and cardiovascular disease.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

In this study the investigators will examine the hypothesis that overweight/obese individuals that are unable to meet target weight loss goals on a low calorie diet (LCD) are intrinsically less metabolically flexible than their weight-losing counterparts. The investigators expect that this 'inflexibility' will be characterized by impaired fat oxidation (as determined by indirect calorimetry) in response to caloric restriction. If this were the case, these subjects may represent a population of 'super-responders' likely to demonstrate a robust response to approaches to increase fat oxidation. The investigators will also measure lipid concentrations in skeletal muscle and liver by hydrogen 1 magnetic resonance (1H-MRS) to determine both the stability of these measurements as well as the magnitude of changes that can be seen during LCD.

Study Type

Interventional

Enrollment (Actual)

39

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 Locations

    • Florida
      • Orlando, Florida, United States, 32804
        • Translational Research Institute for Metabolism and Diabetes

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

14 years to 51 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Male or female subjects between the ages of 18 and 55 years, inclusive
  • Body Mass Index (BMI) 27-30 kg/m2, inclusive, with hypertension, controlled (<140 / <90) either by diet or medication.
  • BMI 30-40 kg/m2, inclusive.
  • An informed consent document signed and dated by the subject or a legally acceptable representative.
  • Subjects who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.

Exclusion Criteria:

  • Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular (hypertension controlled (<140 / <90) either by diet or medication is acceptable), hepatic, psychiatric, neurologic, allergic, (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at time of dosing), muscle disease, diabetes, or severe uncontrolled hypertension.
  • Known hypersensitivity to phentermine, lidocaine, bupivicaine or any medication component of the study procedure.
  • Presence of cardiac pacemaker, implanted cardiac defibrillator, or brain aneurysm clips.
  • Any significant bleeding diathesis which could preclude recovery from the biopsy procedure. ASA, ibuprofen, and any other oral anti platelet agent will be discontinued at least 7 days prior to procedure.
  • Abnormal CK as per site laboratory ranges.
  • Subjects with either a medical history of or physical evidence of keloid scar formation upon physical examination.
  • 12-lead electrocardiogram (ECG) demonstrating a clinically significant abnormality.
  • Pregnant or nursing females or females less than 6 months postpartum from the scheduled date of collection.
  • Participation in non-routine rigorous exercise (e.g., road races, heavy lifting, etc.) within one week prior to the muscle biopsy procedures.
  • Presence of any condition in the investigator's opinion that may negatively affect subject safety or protocol adherence.
  • Females of childbearing potential (any female except those with tubal ligation, hysterectomy, or absence of menses > 2years) unwilling to use an approved method of contraception (condom, diaphragm, implantable uterine device (IUD) that does not release hormones).
  • Prior participation in the Magellan I study at the Translational Research Institute for Metabolism and Diabetes.

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: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Overwight/Obese with no drug
After screening, overweight/obese subjects (BMI >27 - ≤40.0) subjects will be started on a low calorie diet (approximately 900-1000 kcal/d) until a target weight loss is achieved.
A Diet History Questionnaire was completed and subjects had dietary counseling and were provided shakes. The low calorie diet began, to continued for a period of 8 weeks.
Active Comparator: Overweight/obese with Phentermine
After screening, overweight/obese (BMI >27.0 - ≤40.0) subjects will be started on a low calorie diet (approximately 900-1000 kcal/d) until a target weight loss is achieved. Individuals not on track to achieve their target weight by four weeks will receive the drug Phentermine to promote weight loss. Then, following eight weeks LCD (or four weeks LCD + four weeks LCD+Phentermine), in the event that they did not achieve the target weight loss, subjects will be given the option to continue with the LCD + Phentermine for up to an additional 12 weeks, under a doctor's supervision.
A Diet History Questionnaire was completed and subjects had dietary counseling and were provided shakes. The low calorie diet began, to continued for a period of 8 weeks.

Individuals not on track to achieve their target weight by four weeks received the drug Phentermine to promote weight loss. Then, following eight weeks LCD (or four weeks LCD + four weeks LCD+Phentermine), in the event that they did not achieve the target weight loss, subjects were given the option to continue with the LCD + Phentermine for up to an additional 12 weeks, under a doctor's supervision.

Protection Against Risk:

  • Prior to administering any phentermine, a history and physical including EKG will be conducted (at the screening visit) and will be used to determine whether the participant is clear to receive the medication.
  • Participants will see the study doctor or nurse practitioner at every study visit after the drug is initiated.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline Amount of Fat Oxidation at 14 Days
Time Frame: Days 0, 14

Measured with respiratory quotient obtained with indirect calorimetry

Expected Results

  • Overweight and obese subjects will show a wide variation in fat oxidation in response to the low calorie diet
  • Approximately one-third of study participants will not meet target weight loss by four weeks
  • Following an overnight fast (prior to and during LCD) individuals that fail to meet the target weight loss will be characterized by decreased whole body fat oxidation and increased carbohydrate oxidation (measured by indirect calorimetry)
Days 0, 14
Fat Oxidation Rates at 1 Week Intervals
Time Frame: Days 0, 7, 14, 28, 49, 56

Measured with respiratory quotient using indirect calorimetry

Expected Results

  • Overweight and obese subjects will show a wide variation in fat oxidation in response to the low calorie diet
  • Approximately one-third of study participants will not meet target weight loss by four weeks
  • Following an overnight fast (prior to and during LCD) individuals that fail to meet the target weight loss will be charaterized by decreased whole body fat oxidation and increased carbohydrate oxidation (measured by indirect calorimetry)
Days 0, 7, 14, 28, 49, 56

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Soleus IMCL Content
Time Frame: Days -7, -1, 14, 56

Measured with magnetic resonance spectroscopy (MRS)

Expected results

  • 1H-MRS can measure skeletal muscle (intramyocellular lipid) IMCL content with low test-retest variability
  • 1H-MRS can sensitively monitor reductions (or lack thereof) in skeletal muscle IMCL during caloric restriction
  • Reductions in IMCL will be higher in subjects with lower fasting respiratory quotients (RQ) at baseline/during LCD
Days -7, -1, 14, 56

Collaborators and Investigators

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

Sponsor

Collaborators

Investigators

  • Principal Investigator: Steven R Smith, MD, Translational Research Institute for Metabolism and Diabetes

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

September 1, 2011

Primary Completion (Actual)

November 1, 2012

Study Completion (Actual)

November 1, 2012

Study Registration Dates

First Submitted

June 4, 2012

First Submitted That Met QC Criteria

June 8, 2012

First Posted (Estimate)

June 11, 2012

Study Record Updates

Last Update Posted (Actual)

November 13, 2020

Last Update Submitted That Met QC Criteria

October 21, 2020

Last Verified

October 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

  • TRIMDFH 266040
  • 266040 (Other Identifier: Florida Hospital IRB)

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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