ObesityNCT01336777
Regional Fat Depots and Insulin Resistance
An observational study of Obesity and Insulin Resistance, run by Stanford University at 1 site in United States.
Trial summary
The biological basis for insulin resistance associated with obesity is unknown. By studying equally-overweight/obese individuals who are either insulin resistant or insulin sensitive, the investigators will compare characteristics of fat tissue to test several hypotheses: 1) impaired differentiation and fat storage in… Read more about this study
- Who is it for?
- Ages 39 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Insulin Resistance, Diabetes Mellitus Type 2
- How many people
- 166 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2009to May 2013
- Phase
- Observational
- Are there results?
- None posted in the registry
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 39 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Healthy, nondiabetic volunteers will be recruited from Stanford's General Surgery Preoperative Clinic, Stanford's Bariatric Surgery Clinic, and nonsurgical volunteers who respond to local newspaper advertisements.
Who may be able to join
- No major organ disease
- Fasting blood glucose < 126 mg/dL
- BMI 25-35 kg/m2
- Nonpregnant/nonlactating
Who cannot join
- pregnancy/lactation
- major organ disease
- drugs that influence insulin resistance
- unstable body weight or active weight loss program
- outside BMI range or age range
- diabetic by fasting glucose criteria 126 mg/dL or higher
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Heterogeneity of Fat Depots
The biological basis for insulin resistance associated with obesity is unknown. By studying equally-overweight/obese individuals who are either insulin resistant or insulin sensitive, the investigators will compare characteristics of fat tissue to test several hypotheses: 1) impaired differentiation and fat storage in the subcutaneous fat depot characterize insulin resistant individuals, who have, as a result, fat in other tissues like liver and muscle, as well as more fat circulating in the blood; 2) inflammation is greater in visceral and/or subcutaneous adipose tissue depots in insulin resistant individuals as compared with insulin sensitive individuals.
Read the detailed description
Insulin resistance (IR) is a major contributor to obesity-related morbidities such as diabetes and cardiovascular disease. While obesity is associated with IR, the biological basis for this association is unclear, and not all obese individuals are IR. The once-popular portal hypothesis, which states that lipolysis from VAT in particular accounts for IR, has been questioned because VAT contributes only 15% of the total systemic free fatty acid (FFA) flux. Other proposed mechanisms linking obesity to IR include inflammation, adiponectin, and ectopic fat. It is unclear whether VAT mass is more closely linked to IR than is subcutaneous adipose tissue (SAT) mass. Furthermore, evidence linking differential biological activity to IR in VAT or SAT is indirect, largely derived from studies comparing lean to obese or VAT to SAT without evaluation of IR. Thus, the purpose of this study is to investigate the biological mechanisms by which SAT and/or VAT contribute to IR. Specifically, the investigators will explore two related hypotheses- that impaired adipocyte differentiation in SAT is related to IR, ectopic fat deposition and expansion of VAT depot, and that inflammation in VAT is associated with IR. Utilizing adipose cell size/distribution obtained by Beckman Coulter Multisizer, gene expression via quantitative PCR, in-vivo quantification of IR via a modified insulin suppression test, and CT scans of abdomen/thigh, our specific aims are to:
- Confirm that impairment of adipocyte differentiation in SAT is associated with IR by comparing cell size characteristics and differentiation markers in IR and IS subjects undergoing elective surgery;
- Test the hypothesis that the same relationship will not be seen in VAT;
- Demonstrate that VAT mass is expanded in the presence of impaired differentiation of adipocytes in SAT;
- Demonstrate that intramuscular fat is related to both IR and impaired differentiation of adipocytes in SAT using cell size characteristics and differentiation markers;
- Demonstrate that increased inflammation in omental fat is associated with IR independent of obesity using inflammation markers (gene and protein).
- Conditions
- Obesity, Insulin Resistance, Diabetes Mellitus Type 2
- Keywords
- obesity, adipocyte differentiation, inflammation, insulin resistance, visceral fat, regional fat depots
- Medical subject headings
- Obesity, Insulin Resistance, Diabetes Mellitus, Type 2, 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 |
|---|---|---|
| Insulin resistant group | there is no intervention | |
| Insulin sensitive group | There is no intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adipose Cell Size
Harvest adipose tissue from human biopsy. Prepare for cell size analysis using Beckman Multisizer Coulter Counter
Measured: 3 years
Secondary outcomes (2)
Macrophage density
Human adipose tissue will be formalin-fixed and paraffin-blocked for immunohistochemical analysis to identify macrophage number and pattern
Measured: 3 years
Gene Expression
Adipose tissue from humans will be frozen and RNA prepared for measurement of relative expression of genes related to adipose cell differentiation, fat storage, and inflammation
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2011 (estimated)
- Study startAug 2009
- Primary completionMay 2013
- Study completionMay 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 166 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Collaborators
- University of California, National Institutes of Health (NIH)
- Responsible party
- Principal investigator, Tracey McLaughlin, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01336777
- Sponsor's protocol ID
- 1R01DK080436
- Status last verified
- Dec 2024
- First submitted
- 30 Mar 2011
- Last updated
- 4 Dec 2024
- Results posted
- No
- Data monitoring committee
- Yes
Publications
McLaughlin T, Lamendola C, Liu A, Abbasi F. Preferential fat deposition in subcutaneous versus visceral depots is associated with insulin sensitivity. J Clin Endocrinol Metab. 2011 Nov;96(11):E1756-60. doi: 10.1210/jc.2011-0615. Epub 2011 Aug 24.
PubMed 21865361
Study at a glance
From the registry record, last updated by the sponsor on 4 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Heterogeneity of Fat Depots
- ClinicalTrials.gov ID
- NCT01336777
- Acronym / sponsor ID
- 1R01DK080436
- Conditions
- Obesity, Insulin Resistance, Diabetes Mellitus Type 2
- Keywords
- obesity, adipocyte differentiation, inflammation, insulin resistance, visceral fat, regional fat depots
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 166 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Collaborators
- University of California, National Institutes of Health (NIH)
- Study start
- Aug 2009 (actual)
- Primary completion
- May 2013 (actual)
- Study completion
- May 2013 (actual)
- First posted
- 18 Apr 2011 (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.
The biological basis for insulin resistance associated with obesity is unknown. By studying equally-overweight/obese individuals who are either insulin resistant or insulin sensitive, the investigators will compare characteristics of fat tissue to test several hypotheses: 1) impaired differentiation and fat storage in the subcutaneous fat depot characterize insulin resistant individuals, who have, as a result, fat in other tissues like liver and muscle, as well as more fat circulating in the blood; 2) inflammation is greater in visceral and/or subcutaneous adipose tissue depots in insulin resistant individuals as compared with insulin sensitive individuals.
Detailed description
Insulin resistance (IR) is a major contributor to obesity-related morbidities such as diabetes and cardiovascular disease. While obesity is associated with IR, the biological basis for this association is unclear, and not all obese individuals are IR. The once-popular portal hypothesis, which states that lipolysis from VAT in particular accounts for IR, has been questioned because VAT contributes only 15% of the total systemic free fatty acid (FFA) flux. Other proposed mechanisms linking obesity to IR include inflammation, adiponectin, and ectopic fat. It is unclear whether VAT mass is more closely linked to IR than is subcutaneous adipose tissue (SAT) mass. Furthermore, evidence linking differential biological activity to IR in VAT or SAT is indirect, largely derived from studies comparing lean to obese or VAT to SAT without evaluation of IR. Thus, the purpose of this study is to investigate the biological mechanisms by which SAT and/or VAT contribute to IR. Specifically, the investigators will explore two related hypotheses- that impaired adipocyte differentiation in SAT is related to IR, ectopic fat deposition and expansion of VAT depot, and that inflammation in VAT is associated with IR. Utilizing adipose cell size/distribution obtained by Beckman Coulter Multisizer, gene expression via quantitative PCR, in-vivo quantification of IR via a modified insulin suppression test, and CT scans of abdomen/thigh, our specific aims are to:
- Confirm that impairment of adipocyte differentiation in SAT is associated with IR by comparing cell size characteristics and differentiation markers in IR and IS subjects undergoing elective surgery;
- Test the hypothesis that the same relationship will not be seen in VAT;
- Demonstrate that VAT mass is expanded in the presence of impaired differentiation of adipocytes in SAT;
- Demonstrate that intramuscular fat is related to both IR and impaired differentiation of adipocytes in SAT using cell size characteristics and differentiation markers;
- Demonstrate that increased inflammation in omental fat is associated with IR independent of obesity using inflammation markers (gene and protein).
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Insulin resistant group | – | –there is no intervention |
| Insulin sensitive group | – | –There is no intervention |
Who may qualify
- Ages
- 39 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Healthy, nondiabetic volunteers will be recruited from Stanford's General Surgery Preoperative Clinic, Stanford's Bariatric Surgery Clinic, and nonsurgical volunteers who respond to local newspaper advertisements.
Key inclusion criteria (4 listed)
- No major organ disease
- Fasting blood glucose < 126 mg/dL
- BMI 25-35 kg/m2
- Nonpregnant/nonlactating
Key exclusion criteria (6 listed)
- pregnancy/lactation
- major organ disease
- drugs that influence insulin resistance
- unstable body weight or active weight loss program
- outside BMI range or age range
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
Adipose Cell Size
Time frame: 3 years
Harvest adipose tissue from human biopsy. Prepare for cell size analysis using Beckman Multisizer Coulter Counter
2 secondary outcomes
Macrophage density
Time frame: 3 years
Gene Expression
Time frame: 3 years
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Dec 2024.
- Derived from this study: PubMed 21865361McLaughlin T, Lamendola C, Liu A, Abbasi F. Preferential fat deposition in subcutaneous versus visceral depots is associated with insulin sensitivity. J Clin Endocrinol Metab. 2011 Nov;96(11):E1756-60. doi: 10.1210/jc.2011-0615. Epub 2011 Aug 24.
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 and Insulin Resistance, run by Stanford 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 4 inclusion and 6 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: finished, as of the sponsor's last update on 4 Dec 2024. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Adipose Cell Size (time frame: 3 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01336777, which also lists 1 linked publication.
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 4 Dec 2024.