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Biomedical subjects

L T Clark

Publications and source records attributed to L T Clark.

48 records · Page 3Linked to original sources
PubMed1986

Cholesterol and heart disease: current concepts in pathogenesis and treatment.

One of the modifiable risk factors associated with coronary heart disease (CHD) is hypercholesterolemia. This paper reviews the major plasma lipids and how they relate to coronary heart disease. Among blacks, CHD is the leading cause of death and disability. Blacks, in general, have been found to have lower low density lipoprotein (LDL), lower very low density lipoprotein (VLDL), and higher high density lipoprotein (HDL) levels than whites, but there is some evidence to suggest that lipid and lipoprotein profiles may differ in middle and upper socioeconomic subgroups of the black population from those reported for lower socioeconomic groups.The results of the Lipid Research Clinics Coronary Primary Prevention Trial and the National Heart, Lung and Blood Institute Type II Coronary Intervention Study have shown that lowering cholesterol levels in persons with high blood cholesterol will decrease the rate of coronary heart disease events.Diet therapy is the mainstay of treatment, and may lower blood cholesterol levels by 10 to 15 percent. For those unresponsive to diet therapy alone, a number of hypolipidemic drugs are available; some drugs (cholestyramine and colestipol) work by increasing the clearance of lipoprotein and others (clofibrate, nicotinic acid, and probucol) decrease the production of lipoproteins. The combination of diet and drugs may result in a decrease in cholesterol levels of 30 percent or more. For each 1 percent that cholesterol is decreased, there is a 2 percent decrease in coronary heart disease events.

Adult↗
PubMed1985

Alcohol-induced hypertension: mechanisms, complications, and clinical implications.

Alcohol abuse is a frequent contributor to elevated blood pressure and may be the most common cause of secondary hypertension. The mechanism of this association is unknown. In most cases, the blood pressure elevations are reversible and return to normal upon discontinuation of alcohol use. Even though transitory, such hypertension cannot be considered benign, or inconsequential, since it may be contributory to the increased prevalence of cardiovascular disease observed in problem drinkers.

Alcohol Drinking↗
PubMed1984

Alcohol use and hypertension. Clinical considerations and implications.

Alcohol abuse is a more frequent contributor to hypertension than is generally appreciated. Although hypertension is transitory in most alcoholics and may not be evident after a short period of abstinence, it is potentially dangerous. Paroxysms of hypertension might result in target-organ damage. Hypertension may be the causal link to the increased incidence of stroke and coronary heart disease observed in problem drinkers as well as a contributor to the pathogenesis of alcoholic cardiomyopathy. Because of its transitory nature, however, alcohol-associated hypertension may, regrettably , be dismissed as inconsequential. Thus, a major potential cause of cardiovascular morbidity may go untreated.

Adult↗
PubMed1983

Acute pulmonary edema due to ischemic heart disease without accompanying myocardial infarction. Natural history and clinical profile.

The natural history of acute cardiogenic pulmonary edema was studied in a group of patients who did not have acute myocardial infarction, cardiomyopathy, or valvular heart disease. Most of these patients had coronary artery disease. Cardiac catheterization in selected patients showed depressed contractility in some with segmental abnormalities. In the group older than 70 years, this carried a 70 percent two-year mortality rate. It is important to approach patients with this syndrome vigorously, both diagnostically and therapeutically. Acute, reversible segmental ischemia may be responsible for this syndrome and may respond to measures designed to prevent recurrent ischemia.

Acute Disease↗
PubMedDate not supplied

Relationship between cytokine levels and coronary artery disease in women.

Inflammation is thought to have a role in the pathogenesis of atherosclerotic coronary artery disease (CAD), and the measurement of markers of inflammation has been suggested to improve the identification of individuals at risk for this disease. The incidence of CAD in women is not accounted for by conventional risk factors, and the association of CAD and the antiinflammatory cytokine transforming growth factor beta1 (TGF-beta1) in this population is unknown. Associations among TGF-beta1, the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), and CAD severity in inner city women were examined. Fifty-three women requiring angiography (mean age, 60.7 years) were stratified as having on of the following conditions: 0 vessel disease (VD) (n = 20), 1 (VD) (n = 10), 2 VD (n = 9), or 3 VD (n = 14). Fasting serum cytokine levels were determined by enzyme-linked immunosorbent assay. Serum TGF-beta1 was lower in patients with extensive disease (2 and 3 VD versus 0 and 1 VD). The lowest TGF-beta1 levels (<30 ng/mL) were in the 2 and 3 VD groups. In contrast, in the 0 and 1 VD groups, TGF-beta1 was above 41 ng/mL. Serum TGF-beta1 correctly classified the severity of CAD in 62.3% of patients, with a predictive threshold of 58 ng/mL by discriminant function analysis. TGF-beta1 may be a determinant of clinical events and outcome in CAD in women.

Aged↗
PubMedDate not supplied

Coronary heart disease in African Americans.

African Americans have the highest overall mortality rate from coronary heart disease (CHD) of any ethnic group in the United States, particularly out-of-hospital deaths, and especially at younger ages. Although all of the reasons for the excess CHD mortality among African Americans have not been elucidated, it is clear that there is a high prevalence of certain coronary risk factors, delay in the recognition and treatment of high-risk individuals, and limited access to cardiovascular care. The clinical spectrum of acute and chronic CHD in African Americans is similar to that in whites. However, African Americans have a higher risk of sudden cardiac death and present more often with unstable angina and non-Q-wave myocardial infarction than whites. African Americans have less obstructive coronary artery disease on angiography, but may have a similar or greater total burden of coronary atherosclerosis. Ethnic differences in the clinical manifestations of CHD may be explained largely by the inherent heterogeneity of the coronary syndromes, and the disproportionately high prevalence and severity of hypertension and type 2 diabetes in African Americans. Identification of high-risk individuals for vigorous risk factor modification-especially control of hypertension, regression of left ventricular hypertrophy, control of diabetes, treatment of dyslipidemia, and smoking cessation--is key for successful risk reduction.

Age Factors↗
PubMedDate not supplied

Hypertension associated with alcohol withdrawal: assessment of mechanisms and complications.

Two hundred and fifty-six consecutive alcoholics admitted for detoxification, but not having delirium tremens, were evaluated for hypertension. Thirty-three per cent (84) of the alcoholics had a blood pressure greater than or equal to 160/95 mm Hg on or within 72 hr of admission. In 71% (60 of 84) of alcoholics with hypertension, pressure elevation was transitory, whereas 29% (24 of 84) required therapy. After 4 to 5 days of abstinence, alcoholics with transitory hypertension, whose blood pressure was no longer elevated, had a larger increment of pressure (p less than 0.001) with a cold pressor test than did normotensive alcoholics. Hypertensive alcoholics were older and tended to use greater amounts of alcohol, but their liver enzymes, alcohol levels on admission, and serum magnesium concentrations did not distinguish them from normotensive alcoholics. Basal plasma renin activity and epinephrine were elevated in both hypertensive and normotensive alcoholics, whereas plasma norepinephrine was normal. Although plasma renin activity (4.08 +/- 0.9 vs. 2.88 +/- 0.4 ng/ml/hr) and epinephrine (138 +/- 17 vs. 108 +/- 28 pg/ml) were higher in alcoholics with hypertension than in normotensive alcoholics, differences were not significant. However, elevated plasma epinephrine was found in 86% of alcoholics with hypertension, whereas only 44% of normotensive subjects had elevations (chi 2 = 5.49; p = 0.01). Although alcoholics with hypertension demonstrated an exaggerated catecholamine response with the cold pressor test, these changes per se did not explain the elevations in blood pressure. Thus, a transitory, reactive form of hypertension associated with increased catecholamines and vascular hyperresponsiveness is present in alcoholics.

Adult↗
PubMedDate not supplied

Gender and ethnic differences in health behaviors and risk factors for coronary disease among urban teenagers: the PATH program.

OBJECTIVE: To assess gender and ethnic differences among teenagers in heart health behaviors, risk factors for coronary heart disease (CHD), and cardiovascular fitness. DESIGN: Observations consist of cross-sectional data collected prior to a school-based health promotion intervention program. PARTICIPANTS: Teenage girls (N = 865) and boys (N = 497) from three New York City high schools. The ethnic composition of this sample was 20% Asian-American, 40% African-American, 25% Hispanic, and 15% white. METHOD: Subjects were compared on the following: height, weight, body mass index, percentage body fat, total cholesterol, blood pressure, heart health knowledge, family history, socioeconomic status, dietary habits, smoking, physical activity, and estimated aerobic capacity. Differences were assessed with independent t tests, analysis of variance, and chi-square statistical techniques. RESULTS: Compared with girls, boys were more active and had higher estimated aerobic capacity, higher systolic blood pressure, and better self-perception of health. Compared with boys, girls had higher cholesterol, percentage body fat, and heart health knowledge scores and ate fewer foods high in saturated fat, cholesterol, salt, and simple sugars. Among girls, African-Americans had the highest blood pressure, cholesterol, body mass index, and intake of foods high in saturated fat, cholesterol, and sugar. Among boys, Hispanics had the highest body mass index and percentage body fat and the lowest heart health knowledge scores. White girls and white boys were the most frequent smokers. CONCLUSIONS: Poor health behaviors and risk factors for CHD occurred frequently among urban teenagers. In general, teenage girls had poorer health behaviors and a greater prevalence of risk factors than teenage boys, even though they scored better in heart health knowledge testing. Ethnic comparisons revealed poorer health behaviors and higher prevalence of risk factors in African-American and Hispanic teens compared with white and Asian-American teens. Results support the need for health promotion intervention among urban teenagers.

Adolescent↗
PubMedDate not supplied

Health promotion in minority adolescents: a Healthy People 2000 pilot study.

PURPOSE: The purpose was to evaluate the effects of a health promotion curriculum on health knowledge, behavior, cardiovascular fitness, and cardiovascular risk factors. METHODS: A multi-ethnic, multi-cultural sample (n = 54) of 10th grade males and females participated in a study of cardiovascular health promotion and coronary risk factor reduction. The sample was comprised of Asian-Americans (39%), blacks (33%), Hispanics (11%), whites (2%), and others (15%). Intervention consisted of a 10-week health promotion curriculum of classroom education modules in physical activity, nutrition, smoking cessation, stress management and personal problem solving, and an exercise program of walking and running. A nonintervention control group served as a basis for comparison. Classroom and exercise sessions met on alternate days. RESULTS: Following intervention, a significant treatment effect (P = .007) was observed in lowered total cholesterol, and significant within group improvements (P < .01) were observed in diet habits, percent body fat, and cardiovascular health knowledge. Comparisons of knowledge and social effects revealed higher cardiovascular health knowledge (P < .05) in subjects of nonsmoking compared to smoking parents, higher self-perception of health (P < .01) in more active vs less active subjects and better dietary habits (P < .07) in children whose parents were college educated compared to parents who did not attend college. CONCLUSIONS: Preliminary findings suggest that a health promotion curriculum consisting of health education, behavior modification, and regular aerobic exercise lowers cholesterol, improves health behavior and increases health knowledge.

Adolescent↗