ObesityNCT00993460
Study of Changes in Skeletal Muscle After Caloric Restriction
An observational study of Obesity, run by Vanderbilt University at 1 site in United States.
Trial summary
Research has shown that fat stored within muscles affects the muscle's sensitivity to insulin and ability to handle blood glucose. The purpose of this study is to examine the effects of weight loss surgery-induced caloric restriction on the accumulation and types of fats within skeletal muscle, as well as the effects… Read more about this study
- Who is it for?
- Ages 21 to 65 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Obesity
- How many people
- 24 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2011to Nov 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 65 years
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Study population: Female subjects approved for Roux-en-Y gastric bypass surgery at Vanderbilt University Medical Center.
Who may be able to join
- For Normal Weight Subjects:
- Age 21-65 years
- BMI of 21 to 27 kg/m2
- Normal glucose tolerance as determined by OGTT on day of screening
- No family history of diabetes
- For Morbidly Obese Subjects:
Show all 10Show fewer
- Age 21-65 years
- BMI of 30 to 65 kg/m2
- Scheduled for Roux-en-Y gastric bypass at Vanderbilt Medical Center
- Insulin resistant as determined by OGTT on day of screening
Who cannot join
- Clinically significant heart disease
- Clinically significant hepatic or renal disease
- Pregnancy
- Breastfeeding
- Any abnormality that would preclude safe completion of study
- Use of statins
- Use of thiazide or furosemide diuretics, beta blockers, or other chronic medications with known adverse effects on glucose tolerance levels unless subject has been on stable dose of such medications for the past 3 months before entering the study
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
Official title: Diacylglycerols and Insulin Action in Skeletal Muscle Upon Caloric Restriction
Research has shown that fat stored within muscles affects the muscle's sensitivity to insulin and ability to handle blood glucose. The purpose of this study is to examine the effects of weight loss surgery-induced caloric restriction on the accumulation and types of fats within skeletal muscle, as well as the effects of such caloric restriction on insulin sensitivity and inflammatory responses in skeletal muscle. The investigator proposes that caloric restriction will result in decreases in diacylglycerols enriched with saturated fat and increases in diacylglycerols enriched with monounsaturated fats.
Read the detailed description
We hypothesize that in a setting of surgically-induced weight loss decrements in select DAGs result in improved glucose utilization, altered insulin signaling and decreased inflammatory responses. We propose to examine the impact of molecular DAG species accumulation on glucose utilization, insulin signaling and inflammation in skeletal muscle from morbidly obese subjects before/after 10% weight loss facilitated by Roux-en-Y Gastric Bypass (RYGB). We will compare these results to those from a control, normal weight cohort
The detected differences in DAG molecular species, insulin action, inflammatory responses between normal and obese subjects (before/after weight loss) will emphasize pathways coordinately altered as a consequence of adiposity and RYGB surgery. The primary endpoints for this study will be: Insulin sensitivity (glucose Rd, insulin levels, DAG mass, DAG species amounts).Secondary endpoints will be: FFA levels, inflammatory cytokine production, and insulin signaling in skeletal muscle.
- Conditions
- Obesity
- Keywords
- Obesity, Insulin sensitivity, Inflammation
- Medical subject headings
- Obesity, Insulin Resistance, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Normal body weight | Female subjects, ages 21-65 yrs, with BMI of 21-27 kg/m2 with normal glucose tolerance. | |
| Roux-en-Y gastric bypass | Female subjects ages 21-65 with insulin resistance and scheduled for Roux-en-Y gastric bypass at Vanderbilt University Medical Center will be studied before and 4-6 weeks after surgery. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Diacylglycerol content and composition
Muscle lipid will be analyzed by LC-MS/MS
Measured: after 10% body weight loss
Secondary outcomes (2)
Insulin sensitivity and glucose disposal
Peripheral insulin sensitivity and glucose disposal will be determined by euglycemic-hyperinsulinemic clamp
Measured: after 10% body weight loss
Muscle gene expression
Housekeeping-gene normalized fold-change
Measured: after 10% body weight loss
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Oct 2009 (estimated)
- Study startMar 2011
- Primary completionNov 2013
- Study completionNov 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Charles R. Flynn, Vanderbilt University
- Investigators
- Charles R Flynn, PhD, Principal investigator, Vanderbilt University Medical CenterNaji Abumrad, MD, Study chair, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00993460
- Sponsor's protocol ID
- IRB #091145
- Status last verified
- Jul 2026
- First submitted
- 7 Oct 2009
- Last updated
- 10 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diacylglycerols and Insulin Action in Skeletal Muscle Upon Caloric Restriction
- ClinicalTrials.gov ID
- NCT00993460
- Acronym / sponsor ID
- IRB #091145
- Conditions
- Obesity
- Keywords
- Obesity, Insulin sensitivity, Inflammation
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- Vanderbilt UniversityUniversity, hospital or other
- Study start
- Mar 2011
- Primary completion
- Nov 2013 (actual)
- Study completion
- Nov 2026 (estimated)
- First posted
- 12 Oct 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Research has shown that fat stored within muscles affects the muscle's sensitivity to insulin and ability to handle blood glucose. The purpose of this study is to examine the effects of weight loss surgery-induced caloric restriction on the accumulation and types of fats within skeletal muscle, as well as the effects of such caloric restriction on insulin sensitivity and inflammatory responses in skeletal muscle. The investigator proposes that caloric restriction will result in decreases in diacylglycerols enriched with saturated fat and increases in diacylglycerols enriched with monounsaturated fats.
Detailed description
We hypothesize that in a setting of surgically-induced weight loss decrements in select DAGs result in improved glucose utilization, altered insulin signaling and decreased inflammatory responses. We propose to examine the impact of molecular DAG species accumulation on glucose utilization, insulin signaling and inflammation in skeletal muscle from morbidly obese subjects before/after 10% weight loss facilitated by Roux-en-Y Gastric Bypass (RYGB). We will compare these results to those from a control, normal weight cohort
The detected differences in DAG molecular species, insulin action, inflammatory responses between normal and obese subjects (before/after weight loss) will emphasize pathways coordinately altered as a consequence of adiposity and RYGB surgery. The primary endpoints for this study will be: Insulin sensitivity (glucose Rd, insulin levels, DAG mass, DAG species amounts).Secondary endpoints will be: FFA levels, inflammatory cytokine production, and insulin signaling in skeletal muscle.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normal body weight | – | –Female subjects, ages 21-65 yrs, with BMI of 21-27 kg/m2 with normal glucose tolerance. |
| Roux-en-Y gastric bypass | – | –Female subjects ages 21-65 with insulin resistance and scheduled for Roux-en-Y gastric bypass at Vanderbilt University Medical Center will be studied before and 4-6 weeks after surgery. |
Who may qualify
- Ages
- 21 to 65 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Female subjects approved for Roux-en-Y gastric bypass surgery at Vanderbilt University Medical Center.
Key inclusion criteria (10 listed)
- For Normal Weight Subjects:
- For Morbidly Obese Subjects:
Key exclusion criteria (7 listed)
- Clinically significant heart disease
- Clinically significant hepatic or renal disease
- Pregnancy
- Breastfeeding
- Any abnormality that would preclude safe completion of study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Diacylglycerol content and composition
Time frame: after 10% body weight loss
Muscle lipid will be analyzed by LC-MS/MS
2 secondary outcomes
Insulin sensitivity and glucose disposal
Time frame: after 10% body weight loss
Muscle gene expression
Time frame: after 10% body weight loss
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jul 2026.
Related trials for Obesity
RecruitingObservational study
Endoscopic Sleeve Gastroplasty (ESG) Prospective Trial for Obesity (EGO-Trial)
Obesity
Active, not recruitingPhase 4
Effects of Sequential Therapy With Mexidol® (Intravenous) and Mexidol® FORTE 250 (Oral) on Functional Brain Activity Assessed by Functional Magnetic Resonance Imaging and Biochemical Parameters in Patients With Chronic Cerebral Ischemia: A Comparison of Patients With and Without Metabolic Disorders
Metabolic Abnormalities, Obesity & Overweight
Recruiting
Exercise Training and Vitamin D Metabolism
Obesity & Overweight, Vitamin D
Recruiting
Metabolic Health, Bones and Nuts During Weight Loss in Adults
Weight Loss, Bone Density
Active, not recruiting
Effect of Probiotics on Insulin Sensitivity in Overweight and Obese Pregnancy
Obesity & Overweight, Gestational Diabetes Mellitus (GDM)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Charles R Flynn, PhD principal investigator
Vanderbilt University Medical Center
Naji Abumrad, MD study chair
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity, run by Vanderbilt University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 10 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 10 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Diacylglycerol content and composition (time frame: after 10% body weight loss). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jul 2026.