Protocol Number: 04-DK-0061

Title:

A Comparison of Free Fatty Acid Flux in African Americans and Caucasians

Number:

04-DK-0061

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 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.

Sponsoring Institute:

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Participants currently recruited/enrolled

Gender: Male & Female

Referral Letter Required: No

Population Exclusion(s): Asian/Pacific Islander

Hispanic

American Indian or Alaskan Native

Children

Eligibility Criteria:

INCLUSION CRITERIA - Population:

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.

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.

EXCLUSION CRITERIA:

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.

Special Instructions:

Currently Not Provided

Keywords:

Obesity

Resting Energy Expenditure

Metabolic Rate

Visceral Fat

Body Fat Distribution

Recruitment Keyword(s):

None

Condition(s):

Obesity

Investigational Drug(s):

None

Investigational Device(s):

None

Intervention(s):

None

Supporting Site:

National Institute of Diabetes and Digestive and Kidney Diseases

Contact(s):

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citation(s):

Flegal KM, et al. Prevalence and trends in obesity among US adults, 1999-2000. JAMA. 2002 Oct 9;288(14):1723-7.

Groop LC, et al. 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.

Bergman RN, et al. Free fatty acids and pathogenesis of type 2 diabetes mellitus. Trends Endocrinol Metab. 2000 Nov; 11(9):351-6. Review.

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