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| Sponsored by: |
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) |
|---|---|
| Information provided by: | National Institutes of Health Clinical Center (CC) |
| ClinicalTrials.gov Identifier: | NCT00001853 |
Purpose
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....
| Condition |
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Coronary Disease Obesity |
This study is designed to investigate in African Americans the relationship of obesity to coronary artery disease risk factors, specifically fasting plasma triglyceride concentration and the triglyceride related risk factors of small dense low density lipoprotein (LDL), high density lipoprotein (HDL) and central obesity.
The Framingham Study demonstrated that obesity and elevated triglyceride levels are important risk factors for coronary artery disease in white women. However, studies that have had significant participation of African American women such as the Charleston Heart Study, failed to show a relationship of obesity or triglyceride to coronary artery disease mortality in African American women. In fact, African American women independent of body weight or triglyceride levels experience high mortality from coronary artery disease. Our earlier research has demonstrated that obese African American men have elevated triglyceride levels but obese African American women have normal triglyceride levels. Consequently if elevated triglyceride levels do not occur in obese nondiabetic African American women, then elevated triglyceride levels may not represent a major cardiovascular risk for African American women.
The study, Heart Disease Risk Factors in African Americans, is designed to determine the role of obesity and triglyceride on risk for heart disease in African Americans. For this initial study of African Americans, we will study 2 groups. In both groups all individuals must self-identify as African American. The first group will include people who were born in the United States and whose parents were born in the United States. The second group will be African Americans born in Africa.
We will recruit 532 healthy, non-diabetic individuals (196 men, 336 women), age range 18-50, and body mass index (3 subgroups: nonobese, overweight and obese). We need to recruit more women than men because triglyceride levels are lower in women than men. Therefore a larger number of women are needed to see an effect. In 3 outpatient visits to the Clinical Center, participants will have body fat analyses, resting energy expenditure measurements, an electrocardiogram, an oral glucose tolerance test, and an intravenous glucose tolerance test.
This study has the potential to provide significant insight into the pathophysiology of obesity, triglyceride and cardiovascular risk in African Americans.
Eligibility
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:
Contacts and Locations| Contact: Patient Recruitment and Public Liaison Office | (800) 411-1222 | prpl@mail.cc.nih.gov |
| Contact: TTY | 1-866-411-1010 |
| United States, Maryland | |
| National Institutes of Health Clinical Center, 9000 Rockville Pike | Recruiting |
| Bethesda, Maryland, United States, 20892 | |
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