Adipocyte DifferentiationNCT00560469
Impaired Adipogenesis in Insulin Resistance: Pilot Clinical and In Vitro Studies
An observational study of Adipocyte Differentiation and Insulin Resistance, run by University of Vermont at 1 site in United States.
Trial summary
Obesity is a strong risk factor for developing type 2 diabetes (T2DM), but the reasons for this are not fully understood. In particular, it is not known why some obese people develop T2DM while other obese individuals do not. This study tests whether differences in fat cells (adipocytes) are to blame. Read more about this study
- Who is it for?
- Ages 40 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Adipocyte Differentiation, Insulin Resistance
- What is being tested?
- Administration of 70% deuterated water
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2008to Jul 2010
- 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 40 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Community sample
Who may be able to join
- Men and women age 40-65 who are obese (BMI>30)and weight stable for 6 months prior to enrollment.
Who cannot join
- Acute or chronic medical conditions that would contraindicate participation in the research testing
- Pregnant or nursing women
- HbA1c>6.5%
- Active alcohol or drug abuse
- Weight >300 pounds.
- Smoking
Trial locations and contacts
1 site in 1 country.
United States1 site
Fletcher Allen Health Care
South Burlington, Vermont, 05403
About this study
Obesity is a strong risk factor for developing type 2 diabetes (T2DM), but the reasons for this are not fully understood. In particular, it is not known why some obese people develop T2DM while other obese individuals do not. This study tests whether differences in fat cells (adipocytes) are to blame. Even in adults, fat cells are constantly being formed to replace old fat cells and to respond to the body's need to store excess energy. The ability to form new fat cells may be diminished in some individuals, leading to larger fat cells. These large fat cells secrete hormones that may increase risk for T2DM. This study tests whether fat cells from obese insulin resistant subjects (who are at risk for developing T2DM) form at a slower rate than those from insulin sensitive subjects (who are at lower risk for developing T2DM).
To address this question we will recruit and study two groups of obese subjects, selected to be similar in age, gender and degree of obesity. One group of subjects will be obese and insulin resistant (the OIR group), while the other will be comparably obese, but insulin sensitive (OIS). Subjects will undergo a series of studies to characterize their metabolism including measurement of body fat by DEXA scanning, oral glucose tolerance (a test used to diagnose diabetes) and measurement of insulin sensitivity in response to an infusion of insulin (a research study used to classify patients into the OIR and OIS groups). Small samples of fat (from just under the skin of the belly and the buttocks) will obtained using a needle on two occasions over 12 weeks. During these 12 weeks, subjects will drink a small amount of water that contains a non-radioactive label. This labeled water will allow us to measure the rate of growth of new fat cells in the body. We will also look at the rate of growth of fat cells obtained from these biopsies in the laboratory.
The results of this study may tell us more about why certain obese people develop diabetes and why others do not. This might lead to new ways to prevent or treat T2DM.
Read the detailed description
Overview of design: To address the specific aims of this study we will recruit and study two groups of obese subjects, selected to be similar in age, gender and BMI. Based on the results of an oral glucose tolerance test (OGTT) and hyperinsulinemic-glucose clamp, one group will be obese and insulin resistant (OIR) and one will be obese and insulin sensitive (OIS). Subjects will undergo measurement of body fat and fat distribution, oral glucose tolerance, in vivo insulin sensitivity, percutaneous needle biopsies of subcutaneous abdominal and gluteal fat and in vivo measurement of SVC and adipocyte turnover using the D2O DNA labeling technique. Adipocyte size and the expression of pro-inflammatory cytokines and adipokines will be compared in the two groups. Primary cultures of preadipocytes will be derived from subjects and proliferation and differentiation measured in vitro and compared to in vivo measures.
Measurement of adipocyte proliferation and differentiation in vivo: The stable isotope technique of Hellerstein et al. for the measurement of slowly dividing cells is based on the incorporation of deuterium oxide (D2O) into DNA. This method has been used to estimate rates of turnover of adipocytes and stromal vascular cells in healthy normal volunteers. It has not, to date, been employed to compare groups of subjects who may differ in their adipogenic propensity. A major objective of the study, therefore, is to evaluate the utility of this approach for quantifying in vivo differences in adipocyte and SVC turnover between groups that vary by insulin sensitivity and to compare the in vivo measures obtained using this technique with in vitro measures of adipogenesis.
- Conditions
- Adipocyte Differentiation, Insulin Resistance
- Being tested
- Administration of 70% deuterated water
- Keywords
- Adipokines, Inflammation, Metabolic syndrome
- Medical subject headings
- Insulin Resistance, Inflammation, Metabolic Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Administration of 70% deuterated waterOther
Subjects will drink 70% deuterated water daily for 8 weeks.
| Study group | Role | What they receive |
|---|---|---|
| 1 | Men and Women over age 40 who are obese (BMI>30) and insulin-resistant. Receives: Other: Administration of 70% deuterated water | |
| 2 | Men and women over age 40 who are obese (BMI>30) and insulin-sensitive. Receives: Other: Administration of 70% deuterated water |
What is being measured
The primary outcome is the main question the study is designed to answer.
In vitro rates of adipocyte turnover
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Nov 2007 (estimated)
- Study startJan 2008
- Primary completionJul 2010
- Study completionJul 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Adipocyte DifferentiationStudies 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Vermont
- Sponsor type
- University, hospital or other
- Investigators
- Richard E Pratley, MD, Principal investigator, University of Vermont
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00560469
- Sponsor's protocol ID
- R21DK080386
- Other IDs
- R21DK080386, 1R21DK80386-1, 958
- Status last verified
- Sep 2010
- First submitted
- 16 Nov 2007
- Last updated
- 2 Feb 2011
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Feb 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impaired Adipogenesis in Insulin Resistance: Pilot Clinical and In Vitro Studies
- ClinicalTrials.gov ID
- NCT00560469
- Acronym / sponsor ID
- R21DK080386
- Conditions
- Adipocyte Differentiation, Insulin Resistance
- Keywords
- Adipokines, Inflammation, Metabolic syndrome
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of VermontUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- Jan 2008
- Primary completion
- Jul 2010 (actual)
- Study completion
- Jul 2010 (actual)
- First posted
- 19 Nov 2007 (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.
Obesity is a strong risk factor for developing type 2 diabetes (T2DM), but the reasons for this are not fully understood. In particular, it is not known why some obese people develop T2DM while other obese individuals do not. This study tests whether differences in fat cells (adipocytes) are to blame. Even in adults, fat cells are constantly being formed to replace old fat cells and to respond to the body's need to store excess energy. The ability to form new fat cells may be diminished in some individuals, leading to larger fat cells. These large fat cells secrete hormones that may increase risk for T2DM. This study tests whether fat cells from obese insulin resistant subjects (who are at risk for developing T2DM) form at a slower rate than those from insulin sensitive subjects (who are at lower risk for developing T2DM).
To address this question we will recruit and study two groups of obese subjects, selected to be similar in age, gender and degree of obesity. One group of subjects will be obese and insulin resistant (the OIR group), while the other will be comparably obese, but insulin sensitive (OIS). Subjects will undergo a series of studies to characterize their metabolism including measurement of body fat by DEXA scanning, oral glucose tolerance (a test used to diagnose diabetes) and measurement of insulin sensitivity in response to an infusion of insulin (a research study used to classify patients into the OIR and OIS groups). Small samples of fat (from just under the skin of the belly and the buttocks) will obtained using a needle on two occasions over 12 weeks. During these 12 weeks, subjects will drink a small amount of water that contains a non-radioactive label. This labeled water will allow us to measure the rate of growth of new fat cells in the body. We will also look at the rate of growth of fat cells obtained from these biopsies in the laboratory.
The results of this study may tell us more about why certain obese people develop diabetes and why others do not. This might lead to new ways to prevent or treat T2DM.
Detailed description
Overview of design: To address the specific aims of this study we will recruit and study two groups of obese subjects, selected to be similar in age, gender and BMI. Based on the results of an oral glucose tolerance test (OGTT) and hyperinsulinemic-glucose clamp, one group will be obese and insulin resistant (OIR) and one will be obese and insulin sensitive (OIS). Subjects will undergo measurement of body fat and fat distribution, oral glucose tolerance, in vivo insulin sensitivity, percutaneous needle biopsies of subcutaneous abdominal and gluteal fat and in vivo measurement of SVC and adipocyte turnover using the D2O DNA labeling technique. Adipocyte size and the expression of pro-inflammatory cytokines and adipokines will be compared in the two groups. Primary cultures of preadipocytes will be derived from subjects and proliferation and differentiation measured in vitro and compared to in vivo measures.
Measurement of adipocyte proliferation and differentiation in vivo: The stable isotope technique of Hellerstein et al. for the measurement of slowly dividing cells is based on the incorporation of deuterium oxide (D2O) into DNA. This method has been used to estimate rates of turnover of adipocytes and stromal vascular cells in healthy normal volunteers. It has not, to date, been employed to compare groups of subjects who may differ in their adipogenic propensity. A major objective of the study, therefore, is to evaluate the utility of this approach for quantifying in vivo differences in adipocyte and SVC turnover between groups that vary by insulin sensitivity and to compare the in vivo measures obtained using this technique with in vitro measures of adipogenesis.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | – | Other: Administration of 70% deuterated waterMen and Women over age 40 who are obese (BMI>30) and insulin-resistant. |
| 2 | – | Other: Administration of 70% deuterated waterMen and women over age 40 who are obese (BMI>30) and insulin-sensitive. |
Who may qualify
- Ages
- 40 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Community sample
Key inclusion criteria (1 listed)
- Men and women age 40-65 who are obese (BMI>30)and weight stable for 6 months prior to enrollment.
Key exclusion criteria (6 listed)
- Acute or chronic medical conditions that would contraindicate participation in the research testing
- Pregnant or nursing women
- HbA1c>6.5%
- Active alcohol or drug abuse
- Weight >300 pounds.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Administration of 70% deuterated waterSubjects will drink 70% deuterated water daily for 8 weeks. | Other | 1, 2 |
Primary outcome
In vitro rates of adipocyte turnover
Time frame: 8 weeks
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 2 Feb 2011.
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Recruiting
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Differenciation of Stromal-vascular Fraction Cells
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.
Richard E Pratley, MD principal investigator
University of Vermont
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 Adipocyte Differentiation and Insulin Resistance, run by University of Vermont 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 1 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 2 Feb 2011. 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?
In vitro rates of adipocyte turnover (time frame: 8 weeks). 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 2 Feb 2011.