This subproject is one of many research subprojects utilizing theresources provided by a Center grant funded by NIH/NCRR. The subproject andinvestigator (PI) may have received primary funding from another NIH source,and thus could be represented in other CRISP entries. The institution listed isfor the Center, which is not necessarily the institution for the investigator.A culturally- designed community -based prevention program will be effective in reducing risk of cardiovascular disease in African Americans. This hypothesis applies to the following study aims.
Aims, specific hypotheses and rationale are described in detail below.
Specific Aim 1 : To reduce physiological risk factors for cardiovascular disease by decreasing blood pressure, waist circumference, and body mass index. Hypothesis: Reduction in obesity through lifestyle changes in diet and physical activity will result in decreased blood pressure, body mass index, waist circumference and cardiovascular disease risk.Rationale: Obesity is associated with increased cardiovascular disease morbidity and mortality apparently mediated through its effect on insulin resistance, glucose intolerance, hypertriglyceridemia, HDL cholesterol and hypertension. More specifically, visceral adiposity appears to be the most hazardous and atherogenic. Waist circumference provides an excellent tool for assessing visceral adipose tissue and correlates better with cardiovascular disease than both body mass index (BMI) and waist/hip ratio (1-5). Regular physical activity has been shown to improve blood cholesterol, blood glucose and blood pressure, in addition to promoting weight loss.
Specific Aim 2 : To reduce biochemical risk factors for cardiovascular disease by decreasing total and LDL cholesterol. Hypothesis: Adherence to a diet high in fiber and low in total and saturated fat (DASH diet) will result in a decrease in total and LDL cholesterol and cardiovascular risk.Rationale: Elevated triglycerides, small dense LDLc and low HDLc are important risk factors for cardiovascular disease. The beneficial effects of high dietary fiber on cardiovascular disease have been previously demonstrated by Liu and associates (6-7). It has been suggested that adequate amounts of fiber-rich carbohydrates will prevent carbohydrate-induced hypertriglyceridemia. The DASH diet is rich in fruits, vegetables and whole grains, which provide a substantial amount of phytochemicals and dietary fiber. In particular, the DASH diet is significantly higher in phytosterols, carotenoids, and flavanones than the typical US diet. These bioactive phytochemicals may reduce the risk of cardiovascular disease through antioxidant activities (8). The DASH diet also features a high carbohydrate, low fat plan. The carbohydrate sources in the DASH diet are from high dietary fiber rich foods. At 31 grams dietary fiber, the DASH diet meets the current recommendation for fiber intake of 25-35 grams per day, exceeding the typical daily U.S. diet, which contains only nine grams of fiber.
Specific Aim 3 : To reduce sociological risk factors for cardiovascular disease by decreasing or eliminating habitual smoking and by increasing regular physical activity. Hypothesis: Reduction of cigarette smoking through education will decrease risk of coronary artery disease and stroke in African Americans. Increased physical activity will improve the efficiency of the heart, promote weight loss and reduce stress associated with the urge to smoke. Rationale: A smoker's risk of heart attack is more than double that of nonsmokers. Taylor and co-workers found in the Coronary Artery Surgery Study (CASS) that during 16 years of follow-up, cigarette smoking alone accounted for a higher mortality rate among African Americans, regardless of type of therapy (9). B. Background and Significance: Disparities in healthcare in the Black or African American U.S. population, including recent immigrants from Africa, the Caribbean and the West Indies, are well-documented and cardiovascular disease remains the number one killer, claiming 37% of deaths each year. About four in every 10 non-Hispanic black adults have cardiovascular disease. Some 41% of non-Hispanic black males and 40% of black females have cardiovascular disease compared to 30% of non-Hispanic white men and 24% of white women (10). The rate of high blood pressure in U.S. blacks is among the highest in the world. African Americans have both a greater prevalence and severity of hypertension, and an earlier age of onset compared with whites (11, 12). Recent data have demonstrated a decrease in cardiovascular events in diabetic patients through primary prevention with lipid lowering and aggressive blood pressure-lowering therapy in the African American population (13). The U.S. Census Bureau projects that the African American population will increase from 12% in 2000 to 14.3% in 2035, representing more than 50 million individuals. Health disparities between African Americans and other racial groups, due to discrimination, cultural barriers and lack of access to health care continue to contribute to the disproportionate level of death and disability from cardiovascular disease. Goals set for eliminating disparities by 2010 include a reduction in deaths among African Americans from heart disease by 30 percent and deaths from strokes by 47 percent. Reducing risk factors such as high blood pressure, high cholesterol, smoking tobacco, blood glucose control, excessive body weight and physical inactivity offer the greatest potential strategies for reducing cardiovascular disease mortality. Community- based prevention programs such as the NHLBI 'Salud Para Su Corazon' aimed at Latino Americans have recently proven successful in educating the Latino community about lifestyle changes that can improve their health. Recent testing of 'Salud Para Su Corazon' in 223 families at seven sites (n=320) resulted in heart-healthy behavioral changes among the families (14). A similar program aimed at the African American community could provide like results. Developed materials could be disseminated to health organizations, and primary care practices in the African American community (15). An abundance of information exists concerning positive effects of behavioral change on heart disease morbidity and mortality (16). However, there have been health disparities in access to this information. When educational materials are developed to serve the general population, language and cultural differences can impact the ability of cardiovascular disease prevention messages from being understood and providing benefit. Sheats and colleagues found that even when healthcare treatment intensity was similar for Caucasians and African Americans in a medically underserved healthcare setting, higher prevalence and less control of hypertension still exist in African Americans (17). In addition, perception of heart disease as a cause of death may not be well understood, especially in African American females. Mosca and associates determined that less than 33% of U.S. females surveyed (13% African American) identified heart disease as the leading cause of death (18). Some community-based programs aimed at eliminating barriers to care for African Americans have previously been shown to be effective. A community-based multiple risk factor intervention program designed for black families with a history of premature coronary heart disease was recently conducted by Becker and co-workers. When compared with 'enhanced' primary care (EPC), the community-based care (CBC), consisting of a nurse practitioner and community health worker in a community setting, resulted in the CBC group achieving a significant reduction in coronary heart disease risk (p0.0001). No risk reduction was found in the EPC group (19). The proposed 'Hearts of Humanity Project' cultural- based lifestyle intervention program to reduce cardiovascular disease risk in African Americans will be centered around the effect of migration to the United States on dietary habits and lifestyle behavior of present day African Americans. The majority of the African American population has the greatest concentration in the Southeast and mid-Atlantic regions, such as Louisiana, Mississippi, Alabama, Georgia, South Carolina and Maryland. Georgia could serve as a representative testing site for piloting the program. In particular, metro-Atlanta Georgia is home to a large number of immigrants from Africa, the Caribbean and the West Indies, which present unique migratory acculturating habits in diet and lifestyle that have not been previously addressed in African American prevention programs. The adaptation to westernized lifestyles of the present, second and third generations of these migrants needs to be determined in relationship to its potential impact on cardiovascular disease risk. Cultural specific strategies and African/African American history incorporated into the African American intervention model can help break barriers to learning, may enhance knowledge and facilitate motivation to reduce risk of cardiovascular disease in this high risk population. The study will be conducted in the Clinical Research Center at Morehouse School of Medicine. The study is a randomized experimental design intervention study comparing the effect of a culturally- enriched intense educational program with standard care for patients at risk for cardiovascular disease. Subjects participating in a focus group to assess existing educational materials will be randomized to receive either continued standard care at their primary care facility or the intense education program. The program components of increased fruits, vegetables, low fat dairy products and nuts (DASH diet) will result in improved blood pressure and decreased total and LDL cholesterol (Aim 1 and 2). Increase in physical activity and decreased or cessation of habitual smoking will result in improvement in cardiovascular fitness (Aim 3).
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