Fat Metabolism and Melanocortin 3 Receptors in African Americans
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|ClinicalTrials.gov Identifier: NCT01851421|
Recruitment Status : Terminated (Slow/Insufficient accrual)
First Posted : May 10, 2013
Last Update Posted : June 30, 2021
- Melanocortin receptors are proteins in the body that help send messages between body systems. One such receptor, the melanocortin 3 receptor (MC3R), is important for regulating body weight. Differences in MC3R can affect fat metabolism - or how the body handles fat. Some people who have changes in the MC3R genetic code are heavier than those who do not have these changes. These changes are found more often in African Americans. Researchers want to study the MC3R in African American adults to see how these changes may affect fat metabolism. They will look at overweight adults with either the most common genetic code for the MC3R or a rare variant.
- To study the role of the MC3R in body weight and fat metabolism.
- Healthy African American volunteers between 18 and 55 years of age.
- Volunteers must be overweight (body mass index at least 30 kg/m2) but weigh less than 450 lbs.
- The study consists of an outpatient screening visit and a 7-day inpatient visit with dietary studies.
- Participants will be screened with a physical exam and medical history. Blood samples will be collected. (Participants will need to fast for 10 hours before giving blood samples.) A body scan will be given to determine fat, bone, and muscle content. Participants will complete a 3-day dietary assessment to record their food and drink consumption. They will also have an exercise test to look at heart and lung function.
- Participants will have a 7-day inpatient stay. They will have a regular diet for the first 3 days of the study. For the final 4 days, they will have a diet with a higher fat content.
- During the inpatient visit, participants will have the following study procedures:
- Body measurements
- Daily exercise routine
- Imaging studies of the body
- Measurement of a whole day s energy expenditure (spending one day in metabolic chamber-day 5)
- Frequent blood samples
- Urine collection for 24 hours (days 3 and 7)
- Fat biopsy (collection of a small sample of fat tissue from under the skin on the abdomen)
- Insulin and metabolism tests while eating the two different diets (day 4 and day 7).
- After the final insulin and metabolism test, participants will be discharged from the study.
|Condition or disease|
|Obesity Healthy Volunteers|
|Study Type :||Observational|
|Actual Enrollment :||88 participants|
|Official Title:||Fat Metabolism and Function Altering Polymorphisms in MC3R|
|Actual Study Start Date :||September 23, 2013|
|Actual Primary Completion Date :||October 13, 2020|
|Actual Study Completion Date :||June 28, 2021|
Volunteers with homozygous polymorphisms causing protein changes to T6K and V81I.
Wild Type MC3R
Volunteers with no polymorphisms in MC3R gene.
- Free fatty acid reflux rate measured on a high- fat diet during the hyperinsulinemic state [ Time Frame: 3 hours ]FFA flux by isotopic study
- Free fatty acid flux rate in the post-absorptive state and estimates of whole body glucose disposal and endogenous glucose production assessed during postabsorptive and hyperinsulinemic states on both diets [ Time Frame: 4 days ]FFA flux by isotopic study
Biospecimen Retention: Samples With DNA
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01851421
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|
|Principal Investigator:||Jack A Yanovski, M.D.||Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)|