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ObesityNCT00802204

Dopamine and Insulin Resistance

A study testing PET scan, Oral glucose tolerance test and MRI in people with Obesity, run by Vanderbilt University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Obese individuals have fewer striatal dopamine type 2 receptors (DRD2) than normal weight individuals. Lower DRD2 levels are associated with addiction and a decreased sense of pleasure.Obesity is also associated with insulin resistance (poor insulin action).We propose that insulin resistance and low DRD2 are… Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Obesity
What is being tested?
PET scan, Oral glucose tolerance test and MRI
Could I receive a placebo?
No, everyone receives an active treatment
How many people
28 participants
Where
1 siteUnited States
Study dates
Dec 2008to Dec 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Ages 18-60 yrs
  • obese BMI > 30kg/m2 and Weight less than 350 lbs
  • lean control BMI 18-25kg/m2

Who cannot join

  • Structured exercise > equivalent to 30mins 5x week of walking times a week
  • History of Substance Abuse, including but exclusive to alcohol, cocaine, marijuana, heroin, nicotine
  • Current psychiatric disorder or significant h/o disorder
  • Use or any antidepressants or antipsychotics for last 3-6months or depot antipsychotics in the last 12 months
  • Any condition felt by PI or co-investigators to interfere with ability to complete the study
  • Inability to abstain from alcohol, physical exercise or > 1 cup of coffee or equivalent daily for 3 days prior to imaging studies
Show all 9Show fewer
  • Significant co-morbidities including atherosclerotic disease, metabolic disease, liver or renal insufficiency or abnormality found on MRI
  • Any condition which would interfere with MRI or PET studies, e.g. claustrophobia, cochlear implant, metal fragments in eyes, cardiac pacemaker, neural stimulator, tattoos with iron pigment and metallic body inclusions or other metal implanted in the body which may interfere with MRI scanning
  • Subjects on medications determined by PI, ex. sibutramine, frequent benzodiazepines or related drugs, which could affect quality of study for last 3 months.

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Vanderbilt University Medical Center

    Nashville, Tennessee, 37232

Other trials in United States

About this study

Official title: Dopamine Receptor Availability and Insulin Resistance

Obese individuals have fewer striatal dopamine type 2 receptors (DRD2) than normal weight individuals. Lower DRD2 levels are associated with addiction and a decreased sense of pleasure.Obesity is also associated with insulin resistance (poor insulin action).We propose that insulin resistance and low DRD2 are associated. Using PET imaging,we aim to determine DRD2 binding potential (BP) in the brain is associated with insulin resistance and neuroendocrine hormone levels. Obese participants will be compared to lean, gender and age similar participants. We also aim to determine the effect of caloric restriction on DRD2 BP in obese subjects

Read the detailed description

In has been reported obese individuals have fewer striatal dopamine type 2 receptors (DRD2) compared to normal weight individuals congruent with diet induced obese rodent models and similar to models of addiction. Lower DRD2 levels are associated with addiction and a decreased sense of pleasure. Excessive weight gain also contributes to the onset of impaired insulin signaling (insulin resistance). In the brain insulin regulates monoamines and has trophic effects. We propose that the previous reports of low DRD2 in individuals with obesity will be associated with the degree of insulin resistance. Using PET imaging, we aim to determine DRD2 binding potential (BP) in the striatum and hypothesize these measurements will be associated with insulin resistance and potentially other neuroendocrine hormone levels. Obese participants will be compared to lean, sex and age similar participants. We also aim to determine the effect of caloric restriction on DRD2 BP in obese subjects. We hypothesize the caloric restriction will improve insulin resistance and that changes in DRD2 binding will be associated with changes in insulin signaling.

Conditions
Obesity
Being tested
PET scan, Oral glucose tolerance test, MRI, Psychological scales to assess attitudes and behaviors related to eating and quality of life, Caloric Restriction
Keywords
Obesity, Insulin Resistance, Neuroendocrine regulation, Eating behaviors, Dopamine signaling
Medical subject headings
Obesity, Insulin Resistance, Feeding Behavior

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PET scanRadiation

    Both lean and obese undergo a PET scan of the brain using the radioligand,fallypride [18F] at baseline. Obese subjects who complete caloric restriction will have repeat scan after diet.

    Completed at baseline and post-VLCD

  • Oral glucose tolerance testProcedure or surgery

    Subjects will be required to drink a glucose solution; blood samples will be taken over a 5-hour time period Completed at baseline by both lean and obese and in obese post-VLCD

  • MRIProcedure or surgery

    An MRI of the brain and abdomen will be performed prior to PET scan One time at baseline in both lean and obese

  • Psychological scales to assess attitudes and behaviors related to eating and quality of lifeBehavioural

    A series of short psychological scales will be administered during the study. Completed at baseline

  • Caloric RestrictionOther

    Obese participants only complete a short-term (~10days) very low calorie diet

Study groups in NCT00802204
Study groupRoleWhat they receive
Lean controlsActive comparatorLean complete baseline outcome measures only
Receives: Radiation: PET scan; Procedure: Oral glucose tolerance test; Procedure: MRI; Behavioral: Psychological scales to assess attitudes and behaviors related to eating and quality of life
ObeseExperimentalObese completing baseline and post-VLCD outcome measures
Receives: Radiation: PET scan; Procedure: Oral glucose tolerance test; Procedure: MRI; Behavioral: Psychological scales to assess attitudes and behaviors related to eating and quality of life; Other: Caloric Restriction

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Striatal DRD2 Receptor Binding

    Region of interest compared to reference region to calculate binding potential

    Measured: Baseline and after 8-10days VLCD

  2. Insulin

    microU/ml

    Measured: Baseline to post 8-10days after VLCD

  3. Glucose

    Measured: Baseline to post 8-10days after VLCD

  4. Leptin

    Measured: Baseline to post 8-10days after VLCD

  5. Acyl Ghrelin

    Measured: Baseline to post 8-10days after VLCD

  6. Insulin Sensitivity From Oral Glucose Tolerance Test (OGTT_SI)

    Insulin Sensitivity from Oral Glucose Tolerance Test was estimated using the minimal model method

    Measured: Baseline to post 8-10days after VLCD

Secondary outcomes (1)

  1. Binge Eating Score Questionnaire

    Increased scores indicate increased binge eating behaviors. Score 0-46

    Measured: Baseline

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Dec 2008 (estimated)
  2. Study startDec 2008
  3. Primary completionApr 2011
  4. Study completionDec 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Non-randomised
Intervention model
Sequential
Model description
Lean who are age and sex similar to obese will complete baseline outcome measurements only. Obese will complete baseline outcome measurements then the VLCD intervention with post outcome measurements .
Masking
None (open label)
Enrolment
28 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00802204
Sponsor's protocol ID
IRB#080861 and 061246
Status last verified
Mar 2017
First submitted
2 Dec 2008
Last updated
10 May 2017
Data monitoring committee
No

Publications

  • Dunn JP, Abumrad NN, Patterson BW, Kessler RM, Tamboli RA. Brief communication: beta-cell function influences dopamine receptor availability. PLoS One. 2019 Mar 8;14(3):e0212738. doi: 10.1371/journal.pone.0212738. eCollection 2019.

    PubMed 30849082

  • Dunn JP, Abumrad NN, Kessler RM, Patterson BW, Li R, Marks-Shulman P, Tamboli RA. Caloric Restriction-Induced Decreases in Dopamine Receptor Availability are Associated with Leptin Concentration. Obesity (Silver Spring). 2017 Nov;25(11):1910-1915. doi: 10.1002/oby.22023. Epub 2017 Sep 25.

    PubMed 28944597

  • Garcia AE, Kasim N, Tamboli RA, Gonzalez RS, Antoun J, Eckert EA, Marks-Shulman PA, Dunn J, Wattacheril J, Wallen T, Abumrad NN, Flynn CR. Lipoprotein Profiles in Class III Obese Caucasian and African American Women with Nonalcoholic Fatty Liver Disease. PLoS One. 2015 Nov 23;10(11):e0142676. doi: 10.1371/journal.pone.0142676. eCollection 2015.

    PubMed 26599819

  • Dunn JP, Kessler RM, Feurer ID, Volkow ND, Patterson BW, Ansari MS, Li R, Marks-Shulman P, Abumrad NN. Relationship of dopamine type 2 receptor binding potential with fasting neuroendocrine hormones and insulin sensitivity in human obesity. Diabetes Care. 2012 May;35(5):1105-11. doi: 10.2337/dc11-2250. Epub 2012 Mar 19.

    PubMed 22432117

Questions about this trial

What is this clinical trial studying?

A study testing PET scan, Oral glucose tolerance test and MRI in people with 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 3 inclusion and 9 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 10 May 2017. 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?

Yes. Results are posted in the registry (first posted 10 May 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Striatal DRD2 Receptor Binding (time frame: Baseline and after 8-10days VLCD). The study lists 6 primary outcomes in all. 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 NCT00802204, which also lists 4 linked publications.

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 May 2017.

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Dopamine and Insulin Resistance (NCT00802204) | AzTrials