ObesityNCT00074945
Obesity and Fatty Acid Flux Comparison Trials
An observational study of Obesity, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
This study will explore factors that affect obesity and obesity-related diseases in both Caucasians and African Americans. By looking at the rate at which the human body burns calories while at rest (resting energy expenditure, or REE) and at the rate at which fat travels through the blood (fatty acid flux), this… Read more about this study
- Who is it for?
- Ages 18 to 49 years
- Conditions the study is for
- Obesity
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Dec 2003to 28 Feb 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 18 to 49 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- A total of 134 subjects, age range 18 to 49 will be recruited.
- 64 African-Americans (32 men, 32 women)
- 56 Caucasians (35 men, 35 women)
- Within each racial group equal numbers of normal weight, overweight and obese subjects will be recruited.
- African-Americans: Individuals will be considered to be African-American if they self-identify as African-American and were born in the United States. Further they must describe both parents as being African-American and born in the United States.
- Age: We will recruit subjects between the ages of 18 and 49 years.
Show all 10Show fewer
- Weight: Enrollees must weigh less than 136 kg (300 lbs) and have a BMI less than 36 kg/m(2).
- Screening Blood Work: To enroll subjects must have normal hemoglobin levels, electrolyte panel and normal kidney, thyroid and liver function tests.
- Hysterectomy: Women who have had hysterectomies may participate as long as they are less than or equal to 49 years of age and have normal gonadotropin levels.
- Weight and Exercise Regimens: Subjects must report that they have been weight stable for at least 3 months and will not initiate a rigorous exercise regimen during participation in the study.
Who cannot join
- Age: As above, subjects less than 18 years or greater than 49 years will not be enrolled.
- Weight: Subjects greater than 136 kg (300 lbs) or BMI greater than 36 kg/m(2) will not be enrolled.
- Medications: Subjects taking medications that are known to affect the parameters under investigation will be excluded. Some examples of such medications are: oral contraceptives, depoprovera, antihyperglycemic medications, antihypertensives, hypolipidemics, steroids or antiobesity agents.
- Medical conditions, specifically: Diabetes, Hypertension and Hyperlipidemia.
- Breastfeeding: Women who are breastfeeding or have an infant less than four months of age will be excluded.
- Pregnancy: Pregnant women will be excluded from participating.
- Minority Status other than African-American: After the sample size necessary to achieve clinically relevant data is calculated, the plan is to seek permission from the IRB to expand this study by the enrollment of other minorities.
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, 20892
About this study
Official title: A Comparison of Free Fatty Acid Flux in African Americans and Caucasians
This study will explore factors that affect obesity and obesity-related diseases in both Caucasians and African Americans. By looking at the rate at which the human body burns calories while at rest (resting energy expenditure, or REE) and at the rate at which fat travels through the blood (fatty acid flux), this study will examine the relationship between REE and fatty acid flux, both of which are determinants of obesity. Researchers will compare the test results of Caucasians and African Americans to determine if race has an effect on the relationship between REE and fatty acid flux.
Volunteers must be between 18 and 49 years of age. Equal numbers of typical weight, overweight, and obese participants will be recruited. Candidates will be screened with a physical examination, electrocardiogram, and blood tests, and will be interviewed about diet and exercise habits, family and medical history, and employment.
Participants will be placed on a two-week maintenance diet (prepared by a dietician to regulate and maintain calorie consumption) and must visit an outpatient clinic for weight measurement for 10 consecutive weekdays. During the two-week diet, participants will also undergo two 20-minute computerized scans to measure abdominal and body fat. At the end of the two weeks, participants will then be hospitalized for two days to allow researchers to conduct blood tests, oral glucose tests, and a physical examination to measure REE and fatty acid flux levels for comparison.
Read the detailed description
Thirty percent of Americans are obese. Women are more severely affected than men. African-Americans are more severely affected than Caucasians.
To understand the metabolic consequences of obesity, it is essential to know the rate at which free fatty acids (FFA) are released from adipose tissue. Circulating FFA contribute to the complications of obesity particularly diabetes and heart disease. As there are sex and race differences in the prevalence of all these conditions there may be sex and race differences in FFA flux. FFA flux represents the rate at which FFA circulate. FFA flux is the result of three processes going on at the same time, (1) the rate FFA are released from adipose tissue, (2) the rate circulating FFA are used for energy, and (3) the rate FFA leaves the circulation to re-enter adipose tissue. No data is available on whether sex and race differences in FFA flux exist. Further, when comparing subjects of different size, sex and race, it is unknown whether FFA flux should be corrected for lean body mass or resting energy expenditure.
To determine if there are sex and race differences in FFA flux and to ensure adequate enrollment of both African American and Caucasians, this investigation is a collaborative effort between the National Institutes of Health (NIH) in Bethesda, Maryland and the Mayo Clinic in Olmsted County, Minnesota. The greater Washington, DC, metropolitan area, where NIH is located, has a large African-American community whereas over 90 percent of residents of Olmsted County are Caucasians. Therefore, sex differences in FFA flux in African Americans will be mainly studied at the National Institutes of Health. Sex differences in FFA flux in Caucasians will be mainly studied at the Mayo Clinic. But, to confirm the ability to combine data from two different sites, some Caucasians will be enrolled at NIH and some African Americans will be enrolled at the Mayo Clinic. The results of the two studies will be combined to determine if there are race differences in FFA flux.
At NIH, 50 African-Americans (25M, 25W, age range 18-49 years) and 14 Caucasians (7M, 7W age range 18-49 years) will be enrolled. Equal numbers of normal weight, overweight and obese subjects will be recruited. As outpatients, participants will be placed on weight maintaining diets for two weeks and then admitted for a two-day hospital stay. On each in-hospital morning, resting energy expenditure will be measured and stable isotopes infused to measure FFA flux. Stable isotopes are naturally occurring forms of elements, which are safe and non-radioactive.
From the study of African-Americans at NIH it will be possible to determine if (a) the rate of FFA release in African-Americans is more highly related to lean body mass or to resting energy expenditure, and (b) if there is a sex difference in this relationship. Then as described above, the results from the Mayo Clinic and NIH will be combined to determine if there are race differences in the FFA flux.
- Conditions
- Obesity
- Keywords
- Obesity, Resting Energy Expenditure, Metabolic Rate, Visceral Fat, Body Fat Distribution
- Medical subject headings
- Obesity
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Dec 2003 (estimated)
- Study start19 Dec 2003
- Study completion28 Feb 2013
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The 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
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Investigators
- Anne E Sumner, M.D., Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00074945
- Sponsor's protocol ID
- 040061
- Other IDs
- 04-DK-0061
- Status last verified
- 28 Feb 2013
- First submitted
- 23 Dec 2003
- Last updated
- 6 Oct 2017
- Results posted
- No
Publications
Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA. 2002 Oct 9;288(14):1723-7. doi: 10.1001/jama.288.14.1723.
PubMed 12365955Groop LC, Bonadonna RC, Simonson DC, Petrides AS, Shank M, DeFronzo RA. Effect of insulin on oxidative and nonoxidative pathways of free fatty acid metabolism in human obesity. Am J Physiol. 1992 Jul;263(1 Pt 1):E79-84. doi: 10.1152/ajpendo.1992.263.1.E79.
PubMed 1636701Bergman RN, Ader M. Free fatty acids and pathogenesis of type 2 diabetes mellitus. Trends Endocrinol Metab. 2000 Nov;11(9):351-6. doi: 10.1016/s1043-2760(00)00323-4.
PubMed 11042464
Study at a glance
From the registry record, last updated by the sponsor on 6 Oct 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Comparison of Free Fatty Acid Flux in African Americans and Caucasians
- ClinicalTrials.gov ID
- NCT00074945
- Acronym / sponsor ID
- 040061
- Conditions
- Obesity
- Keywords
- Obesity, Resting Energy Expenditure, Metabolic Rate, Visceral Fat, Body Fat Distribution
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- 19 Dec 2003
- Study completion
- 28 Feb 2013
- First posted
- 24 Dec 2003 (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.
This study will explore factors that affect obesity and obesity-related diseases in both Caucasians and African Americans. By looking at the rate at which the human body burns calories while at rest (resting energy expenditure, or REE) and at the rate at which fat travels through the blood (fatty acid flux), this study will examine the relationship between REE and fatty acid flux, both of which are determinants of obesity. Researchers will compare the test results of Caucasians and African Americans to determine if race has an effect on the relationship between REE and fatty acid flux.
Volunteers must be between 18 and 49 years of age. Equal numbers of typical weight, overweight, and obese participants will be recruited. Candidates will be screened with a physical examination, electrocardiogram, and blood tests, and will be interviewed about diet and exercise habits, family and medical history, and employment.
Participants will be placed on a two-week maintenance diet (prepared by a dietician to regulate and maintain calorie consumption) and must visit an outpatient clinic for weight measurement for 10 consecutive weekdays. During the two-week diet, participants will also undergo two 20-minute computerized scans to measure abdominal and body fat. At the end of the two weeks, participants will then be hospitalized for two days to allow researchers to conduct blood tests, oral glucose tests, and a physical examination to measure REE and fatty acid flux levels for comparison.
Detailed description
Thirty percent of Americans are obese. Women are more severely affected than men. African-Americans are more severely affected than Caucasians.
To understand the metabolic consequences of obesity, it is essential to know the rate at which free fatty acids (FFA) are released from adipose tissue. Circulating FFA contribute to the complications of obesity particularly diabetes and heart disease. As there are sex and race differences in the prevalence of all these conditions there may be sex and race differences in FFA flux. FFA flux represents the rate at which FFA circulate. FFA flux is the result of three processes going on at the same time, (1) the rate FFA are released from adipose tissue, (2) the rate circulating FFA are used for energy, and (3) the rate FFA leaves the circulation to re-enter adipose tissue. No data is available on whether sex and race differences in FFA flux exist. Further, when comparing subjects of different size, sex and race, it is unknown whether FFA flux should be corrected for lean body mass or resting energy expenditure.
To determine if there are sex and race differences in FFA flux and to ensure adequate enrollment of both African American and Caucasians, this investigation is a collaborative effort between the National Institutes of Health (NIH) in Bethesda, Maryland and the Mayo Clinic in Olmsted County, Minnesota. The greater Washington, DC, metropolitan area, where NIH is located, has a large African-American community whereas over 90 percent of residents of Olmsted County are Caucasians. Therefore, sex differences in FFA flux in African Americans will be mainly studied at the National Institutes of Health. Sex differences in FFA flux in Caucasians will be mainly studied at the Mayo Clinic. But, to confirm the ability to combine data from two different sites, some Caucasians will be enrolled at NIH and some African Americans will be enrolled at the Mayo Clinic. The results of the two studies will be combined to determine if there are race differences in FFA flux.
At NIH, 50 African-Americans (25M, 25W, age range 18-49 years) and 14 Caucasians (7M, 7W age range 18-49 years) will be enrolled. Equal numbers of normal weight, overweight and obese subjects will be recruited. As outpatients, participants will be placed on weight maintaining diets for two weeks and then admitted for a two-day hospital stay. On each in-hospital morning, resting energy expenditure will be measured and stable isotopes infused to measure FFA flux. Stable isotopes are naturally occurring forms of elements, which are safe and non-radioactive.
From the study of African-Americans at NIH it will be possible to determine if (a) the rate of FFA release in African-Americans is more highly related to lean body mass or to resting energy expenditure, and (b) if there is a sex difference in this relationship. Then as described above, the results from the Mayo Clinic and NIH will be combined to determine if there are race differences in the FFA flux.
Study design
Who may qualify
- Ages
- 18 to 49 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (10 listed)
- A total of 134 subjects, age range 18 to 49 will be recruited.
- 64 African-Americans (32 men, 32 women)
- 56 Caucasians (35 men, 35 women)
- Within each racial group equal numbers of normal weight, overweight and obese subjects will be recruited.
- African-Americans: Individuals will be considered to be African-American if they self-identify as African-American and were born in the United States. Further they must describe both parents as being African-American and born in the United States.
Key exclusion criteria (7 listed)
- Age: As above, subjects less than 18 years or greater than 49 years will not be enrolled.
- Weight: Subjects greater than 136 kg (300 lbs) or BMI greater than 36 kg/m(2) will not be enrolled.
- Medications: Subjects taking medications that are known to affect the parameters under investigation will be excluded. Some examples of such medications are: oral contraceptives, depoprovera, antihyperglycemic medications, antihypertensives, hypolipidemics, steroids or antiobesity agents.
- Medical conditions, specifically: Diabetes, Hypertension and Hyperlipidemia.
- Breastfeeding: Women who are breastfeeding or have an infant less than four months of age will be excluded.
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
Not reported in the source record.
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 6 Oct 2017.
- Background: PubMed 12365955Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA. 2002 Oct 9;288(14):1723-7. doi: 10.1001/jama.288.14.1723.
- Background: PubMed 1636701Groop LC, Bonadonna RC, Simonson DC, Petrides AS, Shank M, DeFronzo RA. Effect of insulin on oxidative and nonoxidative pathways of free fatty acid metabolism in human obesity. Am J Physiol. 1992 Jul;263(1 Pt 1):E79-84. doi: 10.1152/ajpendo.1992.263.1.E79.
- Background: PubMed 11042464Bergman RN, Ader M. Free fatty acids and pathogenesis of type 2 diabetes mellitus. Trends Endocrinol Metab. 2000 Nov;11(9):351-6. doi: 10.1016/s1043-2760(00)00323-4.
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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.
Anne E Sumner, M.D. principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
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 National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) 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: finished, as of the sponsor's last update on 6 Oct 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?
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.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00074945, which also lists 3 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 6 Oct 2017.