Protocol Number: 99-DK-0002

Title:

Heart Disease Risk Factors in African Americans

Number:

99-DK-0002

Summary:

It is unknown if obesity contributes to the development of heart disease in African American men and women.

This study was created to determine whether there is a relationship between sex and body size and the incidence of heart disease in African American men and women. Researchers will attempt to associate obesity with the presence of heart disease risk factors. Risk factors that will be studied include; total body fat, body fat distribution, fat content of the blood (triglyceride concentration, low density lipoproteins [LDL], and high density lipoproteins [HDL]), how fast fat is removed from the blood, and how well insulin works in the body.

Scientific studies have shown that obesity and increased levels of fat content in the blood are important risk factors for heart disease in Caucasian women. However, similar studies in African American women have failed to show the same correlation. In fact, it appears that African American women in all three body weight groupings, nonobese, overweight, and obese experience high death rates due to heart disease. In addition, prior research has shown that obese African American men tend to have elevated levels of fat in the blood while African American women have normal blood fat levels. Therefore, if high levels of triglycerides (fat found in the blood) are not seen in non-diabetic obese African American women, it cannot be considered a risk factor in this population. This suggests that studies conducted on Caucasian women may not provide insight into heart disease risk factors in African American women.

The study will take 120 healthy nondiabetic African American men and women (ages 18-50) grouped by sex (60 men and 60 women) and body mass index 3 subgroups; nonobese, overweight and obese). Diabetes undeniably increases the risk of heart disease. Therefore patients suffering from diabetes will not be included in the study. Candidates for the study will undergo a series of tests and examinations over 5 outpatient visits. Subjects will have body fat analyses, resting energy expenditure measurements, an EKG (electrocardiogram), and specific blood tests.

Researchers believe this study will provide significant insight into the causes of obesity and heart disease in African Americans.

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): American Indian or Alaskan Native

Asian/Pacific Islander

White (Not of Hispanic Origin)

Hispanic

Pacific Islander

Children

Eligibility Criteria:

INCLUSION CRITERIA:

Ethnicity: African Americans

This is a study of adult African Americans. As African American people are multi-ethnic, we will in this initial investigation, study two different groups of African American. To enroll participants must self-identify as African Americans and be born in the United States, with American born parents or be born in Africa with African born parents. In both groups we will study sex differences in the role of obesity and TG levels on cardiovascular disease. In the future, we plan to expand the study to include other groups which self-identify as African Americans (i.e. AfroCarribeans and Hispanic blacks).

Age:

The age range of the participants will be between 18 and 50 years.

EXCLUSION CRITERIA:

African American Ethnicity other than American or African ancestry. As stated in the inclusion criteria African American people are a multi-ethnic group.

Medications:

People who take medications that are known to alter the parameters which are under investigation in this study will be excluded. An example would be medications used to treat hyperlipidemia such as statins, niacin, bile acid sequestrants and fibric acid derivatives. Subjects on thyroid hormone replacement will be included if their TSH is normal. Because antihypertensive medication may affect both the lipid profile and insulin sensitivity, subjects receiving antihypertensive medication will not be enrolled.

Diabetes:

Breastfeeding:

Women who are breastfeeding or have an infant that is less than four months of age will be excluded.

Menstrual History:

Women with a history of irregular menstrual cycles in the year prior to the study will be excluded.

History of bleeding diathesis:

Special Instructions:

Currently Not Provided

Keywords:

Obesity

Insulin

African

African-Americans

Recruitment Keyword(s):

None

Condition(s):

Coronary Disease

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):

Obesity as an independent risk factor for cardiovascular disease: a 26-year follow-up of participants in the Framingham heart study

Body mass index and body girths as predictors of mortality in black and white women

The body mass index-mortality relationship in white and African American women

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