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Biomedical subjects

R J Garrison

Publications and source records attributed to R J Garrison.

At least 19 recordsLinked to original sources
PubMed2002

Health Opportunities with Physical Exercise (HOPE): social contextual interventions to reduce sedentary behavior in urban settings.

Physical activity interventions targeting social and physical environments of the urban poor hold promise in improving health outcomes in underserved communities. This study randomly assigned overweight, sedentary, economically disadvantaged adults to one of three intervention conditions at The Hope and Healing Center, a large inner-city health facility providing numerous options for exercise. Within the tenets of Social Action Theory, the Health Opportunities with Physical Exercise (HOPE) trial will test the efficacy of two behavior change models, social support and patient-provider interaction, to increase physical activity. In addition to a standard care condition, in which patients have open access to Hope and Healing physical activity programming, patients were assigned to one of two behavior change interventions. Those assigned to patient-peer receive face-to-face, systematic and scheduled encouragement from study-trained 'peer' interventionists at the facility. Patients assigned to patient-provider receive face-to-face, systematic and scheduled encouragement provided by study-trained 'provider' interventionists also at the facility. The primary outcomes of change in exercise behavior will be documented by self-reported physical activity and confirmed by fitness testing at baseline, 6, 12 and 24 months during the 1 year of active intervention and 1 year of relapse prevention follow-up. Intervention conditions will be compared on psychosocial mediators including motivational appraisals, ratings of social support, rapport, problem solving and self-efficacy for overcoming barriers to increased physical activity. Novel aspects of this intervention include: (1) delivery of socially based physical activity interventions to an economically disadvantaged urban population, (2) reduction of environmental barriers to be physically active and (3) emphasis on social interactions influencing health habit change. Results of this study have the potential to identify mechanisms of behavior change that could be adopted by physical activity interventions aimed at reducing sedentary behavior and health disparities in high-risk, underserved populations.

Exercise↗
PubMed1999

Emerging noninvasive biochemical measures to predict cardiovascular risk.

New predictors of cardiovascular events are needed to improve the accuracy of risk stratification. Such predictors should be easily measurable in the population and potentially modifiable. This review reports on new biomarkers that are closely linked to the pathogenic mechanisms underlying the progression of the atherosclerotic plaque leading to rupture and thrombosis that ultimately precipitate acute clinical events, such as stroke and myocardial infarction. These risk factors have been associated with subclinical or clinical cardiovascular disease in large populations and include markers of lipoprotein and lipid metabolism, vitamin B12 metabolism, fibrinolysis, coagulation, inflammation, infection, endothelial dysfunction, the angiotensin system, and oxidative stress. For other key processes of atherosclerosis and cardiac disease, such as apoptosis or programmed cell death, there are currently no markers that can be measured noninvasively. Atherosclerosis is a multifactorial condition and possibly only a subset of factors are the main determinants of disease in a given patient. A better definition of the cardiovascular risk profile will help to better target primary and secondary prevention. Further epidemiological studies are needed to characterize the actual predictive and clinical value of these new emerging cardiovascular biomarkers.

Biomarkers↗
PubMed1996

Obesity and coronary heart disease.

Obesity carries a penalty of an associated adverse cardiovascular risk profile. Largely as a consequence of this, it is associated with an excess occurrence of cardiovascular disease morbidity and mortality. It is concluded on the basis of data from the Framingham study and other large prospective studies that the rate of development of cardiovascular disease rises rapidly in relation to even modest amounts of adiposity. The abdominal pattern of adiposity, and specifically visceral adiposity, appears to be the most hazardous. First identified as a cause of glucose intolerance, abdominal adiposity has been identified as promoting insulin resistance, hypertension and dyslipidemia, as well as CHD. While the impact of epidemic obesity on the health of white Americans is becoming more fully understood, there are important gaps in the knowledge about the nature of influence of adiposity on CHD in large subgroups of the population. The dearth of detailed and long term prospective studies of African-Americans is the most conspicuous shortcoming of the research base. Finally, because there is a great potential benefit of remaining lean or achieving a sustained weight loss when indicated, and given the high prevalence of obesity, research on adiposity prevention and more effective weight reduction methodology are urgently needed.

Adult↗
PubMed1993

Educational attainment and coronary heart disease risk: the Framingham Offspring Study.

BACKGROUND: Efforts to control the continuing epidemic of coronary heart disease in the United States have been successful according to certain criteria, such as mortality, but by others, such as morbidity, the picture is less clear. Documenting whether various subgroups of the population have adopted healthier lifestyles that are likely to reduce coronary heart disease risk is essential to understanding the status of the epidemic and, most importantly, to formulating prevention and health education strategies that will ameliorate its effects. METHODS: The Framingham Offspring Study cohort participated in extensive health screening protocols to determine their cardiovascular risk. The 2,846 men and women who were between the ages of 25 and 64 years and who reported their educational attainment level are the subject of this report. RESULTS: Both body mass index and cigarette smoking showed inverse relationships to educational attainment among both men and women, while reported vigorous leisure time physical activity showed a positive relationship to educational attainment. However, fitness levels as assessed by treadmill duration were directly related to educational attainment only the women. With the exception of total plasma cholesterol among women, all coronary heart disease risk factors had most adverse levels in the least educated study participants. CONCLUSIONS: This study indicates that most components of the coronary heart disease risk profile show adverse levels in individuals with low educational attainment.

Adult↗
PubMed1993

Secular blood pressure trends in normotensive persons: the Framingham Study.

Trends in hypertension prevalence are difficult to assess because of a massive increase in the prevalence of antihypertensive treatment. Over the past three decades mean blood pressure levels among the 5209 members of the Framingham Study cohort have declined, and elevated blood pressure is only one third as prevalent. However, if those receiving treatment who have normalized blood pressures are defined as hypertensive, in addition to those with elevated blood pressure, the prevalence of hypertension has increased. No consistent secular trend in the incidence of hypertension was noted over three decades, but high blood pressure eventually developed in two thirds of the study cohort. To determine whether untreated blood pressure levels are changing over time, trends in mean blood pressure were examined in normotensive subjects over three decades. Only a 1 mm Hg decline in mean systolic and diastolic pressure over each 10-year interval was noted (p < 0.001). Thus blood pressure in the normotensive segment of the population has been quite stable. Because the incidence of hypertension is very high and future hypertension arises from the upper end of the normal blood pressure distribution, there is an urgent need for primary prevention. Preventive measures such as exercise, avoidance of salt and alcohol, and especially weight control deserve a high priority.

Adult↗
PubMed1993

Healthy adiposity in women: the Framingham Offspring Study.

This report estimates a threshold for "healthy adiposity" by determining the relationship between subscapular skinfolds thickness, a direct measure of adiposity, and cardiovascular disease risk factors in 1254 nonsmoking adult women who participated in the Framingham Offspring Study. Cardiovascular disease risk factors, including blood pressure, fasting plasma lipoprotein cholesterol, plasma glucose and echocardiographically measured left ventricular mass, were included. The optimal subscapular skinfold for 20-39-year-old women was determined to be < 15 mm. Women aged 20-59 whose subscapular skinfolds were below this level had a mean body mass index (BMI) of 21.1 kg/M2. Weight-for-height estimates for these women corresponded closely to the 1959 Metropolitan Life Insurance Company Desirable Weight table. The probability of having unhealthy adiposity was estimated for all women aged 20-59 for each (rounded) integer value grouping of BMI. The probability of being above the healthy adiposity threshold rises rapidly across BMI levels > 20 and plateaus > 24. Thus, only women with BMI < 24 need assessment for adiposity status.

Adipose Tissue↗
PubMed1993

A new approach for estimating healthy body weights.

Optimal body weight standards have most often been based on the relationship of relative weight to all cause mortality. This report proposes a strategy based on a more direct measure of adiposity, subscapular skinfolds and cardiovascular disease risk factors, rather than mortality. This approach provides a means for determining standards that are consistent with optimum cardiovascular health without the lengthy follow-up required for mortality studies. The report utilizes data on 2447 non-smoking men and women aged 20-59 years. Seven cardiovascular disease risk factors were significantly related to subscapular skinfold thickness in both sexes in an unfavourable direction. The optimal subscapular skinfolds based on these risk factors for 20-39 year olds were determined to be below 12 mm for men and 15 mm for women. Men and women who had subscapular skinfolds at or below the optimal level had a mean body mass index of 22.6 kg/m2 and 21.1 kg/m2 for men and women, respectively. The probability of being above the optimum adiposity rises rapidly across body mass index levels above 20 kg/m2 and plateaus at above 0.90 in both men and women with body mass index above 24 kg/m2. Thus, screening for above optimal adiposity is necessary only in individuals with body mass index at or below 24 kg/m2.

Adipose Tissue↗
PubMed1991

Relation of alcohol intake to left ventricular mass: The Framingham Study.

Alcohol has direct toxic effects on the myocardium and is associated with elevated blood pressure, but its relation to left ventricular mass independent of blood pressure level has not been assessed. Reported alcohol intake and left ventricular mass measured by echocardiography were evaluated in 1,980 men and 2,511 women 17 to 90 years of age and free of cardiovascular disease in the Framingham offspring and cohort study. The relation of reported alcohol intake to left ventricular mass was assessed by gender-specific multivariate regression analysis adjusting for age, height, body mass index, systolic blood pressure, history of hypertension and cigarette smoking. Alcohol intake was positively associated with left ventricular mass in men (p less than 0.01) but not in women (p = 0.64). When stratified by beverage type, beer and wine in both men and women and liquor in men were positively related to left ventricular mass. The lack of association of total alcohol intake to left ventricular mass in women appeared to be due to a negative association (p less than 0.01) with liquor. The strongest positive associations were with wine in men (p less than 0.001) and beer in women (p less than 0.05). Alcohol use is independently associated with left ventricular mass; this association may vary by beverage type. In persons with unexplained left ventricular hypertrophy, excessive alcohol intake should be considered.

Adolescent↗
PubMed1990

Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study.

A pattern of left ventricular hypertrophy evident on the electrocardiogram is a harbinger of morbidity and mortality from cardiovascular disease. Echocardiography permits the noninvasive determination of left ventricular mass and the examination of its role as a precursor of morbidity and mortality. We examined the relation of left ventricular mass to the incidence of cardiovascular disease, mortality from cardiovascular disease, and mortality from all causes in 3220 subjects enrolled in the Framingham Heart Study who were 40 years of age or older and free of clinically apparent cardiovascular disease, in whom left ventricular mass was determined echocardiographically. During a four-year follow-up period, there were 208 incident cardiovascular events, 37 deaths from cardiovascular disease, and 124 deaths from all causes. Left ventricular mass, determined echocardiographically, was associated with all outcome events. This relation persisted after we adjusted for age, diastolic blood pressure, pulse pressure, treatment for hypertension, cigarette smoking, diabetes, obesity, the ratio of total cholesterol to high-density lipoprotein cholesterol, and electrocardiographic evidence of left ventricular hypertrophy. In men, the risk factor-adjusted relative risk of cardiovascular disease was 1.49 for each increment of 50 g per meter in left ventricular mass corrected for the subject's height (95 percent confidence interval, 1.20 to 1.85); in women, it was 1.57 (95 percent confidence interval, 1.20 to 2.04). Left ventricular mass (corrected for height) was also associated with the incidence of death from cardiovascular disease (relative risk, 1.73 [95 percent confidence interval, 1.19 to 2.52] in men and 2.12 [95 percent confidence interval, 1.28 to 3.49] in women). Left ventricular mass (corrected for height) was associated with death from all causes (relative risk, 1.49 [95 percent confidence interval, 1.14 to 1.94] in men and 2.01 [95 percent confidence interval, 1.44 to 2.81] in women). We conclude that the estimation of left ventricular mass by echocardiography offers prognostic information beyond that provided by the evaluation of traditional cardiovascular risk factors. An increase in left ventricular mass predicts a higher incidence of clinical events, including death, attributable to cardiovascular disease.

Blood Pressure↗
PubMed1990

Association of echocardiographic left ventricular mass with body size, blood pressure and physical activity (the Framingham Study).

Left ventricular (LV) hypertrophy has been found to predispose to increased cardiovascular morbidity and mortality. To assess the clinical correlates and potential determinants of LV mass, the relation of echocardiographically determined LV mass to a variety of clinical parameters was examined in a general population. From 1979 to 1983 Framingham Heart Study participants underwent routine evaluation including medical history, physical examination and M-mode echocardiography. LV mass was determined using an anatomically validated formula that incorporates measurements of LV wall thickness and LV internal diameter. The study population consisted of 2,226 men and 2,746 women (mean age 51 years, range 17 to 90). Age, height, systolic blood pressure and body mass index (a measure of obesity) were statistically significant and independent correlates of LV mass in both sexes (p less than 0.001). In men under age 50, leisure-time physical activity was associated with LV mass (p less than 0.05), but this was not observed in women. Results from multivariate analyses in which body mass index and subscapular skinfold thickness were included suggest that lean body mass is correlated with LV mass. Maintenance of ideal body weight and normal blood pressure, weight reduction in obese persons and blood pressure control in hypertensive patients may contribute to the primary and secondary prevention of LV hypertrophy and its sequelae. Clinical interpretation of echocardiograms should include consideration of the correlates of LV mass to gain better insight into the pathogenesis of LV hypertrophy.

Age Factors↗
PubMed1990

Is obesity-related hypertension less of a cardiovascular risk? The Framingham Study.

The hypothesis that obesity-related hypertension is relatively innocuous was explored by an examination of cardiovascular events over 34 years of follow-up when related to biennially measured weights and blood pressures using time-dependent covariate proportional hazards analysis. The 5209 participants were also classified by age, cigarette smoking, and antihypertensive treatment at each of four baseline examinations with 8-year follow-up periods. Over the period of follow-up, there were 978 cardiovascular events in men and 836 in women. Risk of cardiovascular morbidity and mortality in general and of CHD in particular was as strongly related to hypertension at all levels of body mass index. This was also found to apply when adjustment was made for possible confounding by cigarette smoking. Age and smoking-adjusted absolute risks of cardiovascular events were found to be higher in hypertensive individuals with high than with low BMIs. Furthermore, the relative risk of cardiovascular disease did not vary significantly with BMI. Thus hypertension is at least as dangerous in obese as in lean persons at all ages in either sex, providing no support for the hypothesis that hypertension in the obese is more benign. This is important, since obesity predisposes to hypertension and most who have hypertension are obese. This report examines the hypothesis for CVD outcomes considered by previous reports and also the subcategories of CVD disease such as myocardial infarction and stroke, and includes data on both men and women and on young and old.

Adult↗
PubMed1989

Cardiovascular risk factors and graded treadmill exercise endurance in healthy adults: The Framingham Offspring Study.

To help describe the association between exercise endurance and cardiovascular risk factor profiles, 2,606 young and middle-aged healthy adults in the Framingham Offspring Study were given submaximal treadmill tests. For both men and women, exercise endurance was inversely related to resting heart rate (p less than 0.001), body mass index (p less than 0.001), systolic blood pressure (p less than 0.001) and blood glucose (p less than 0.01), and positively related to high density lipoprotein (HDL) cholesterol (p less than 0.05). In men, cigarette smoking (p less than 0.05), high levels of total cholesterol (p less than 0.01) and very low density lipoprotein (VLDL) cholesterol (p less than 0.001) were also associated with poor exercise endurance. After adjusting for age, resting heart rate and body mass index, significant independent associations persisted for HDL cholesterol (p less than 0.05) in both sexes and for systolic blood pressure, VLDL cholesterol, blood glucose and cigarette smoking in men (p less than 0.05). Risk factors associated with overt cardiovascular disease in older individuals are also associated with poor exercise endurance in those who are younger and asymptomatic.

Adolescent↗
PubMed1989

Left ventricular mass and incidence of coronary heart disease in an elderly cohort. The Framingham Heart Study.

OBJECTIVE: To examine the association of echocardiographically determined left ventricular mass with incidence of coronary heart disease in an elderly cohort. DESIGN: Cohort study with a follow-up period of 4 years. SETTING: Population-based. SUBJECTS: Elderly original volunteer subjects of the Framingham Heart Study who were free of clinically apparent coronary heart disease. This group included 406 men (mean age, 68 years: range, 60 to 90) and 735 women (mean age, 69 years: range, 59 to 90). MEASUREMENTS AND MAIN RESULTS: During 4 years of follow-up, coronary heart disease events occurred in 37 men and 33 women. Baseline echocardiographically determined left ventricular mass was associated with incidence of coronary disease in both sexes (P less than 0.01). After adjusting for age, systolic blood pressure, smoking, and the ratio of total/high density lipoprotein cholesterol, the relative risk for a coronary event, per 50 g/m increment in left ventricular mass/height, was 1.67 in men (95% CI, 1.24 to 2.23) and 1.60 in women (95% CI, 1.10 to 2.32). CONCLUSIONS: Echocardiographic assessment of left ventricular mass offers prognostic information beyond that provided by traditional risk factors, which can improve our ability to identify individuals at high risk for coronary heart disease. These findings may have widespread implications regarding the applications of echocardiography in clinical practice.

Age Factors↗
PubMed1989

High-density lipoprotein cholesterol and cardiovascular disease. Four prospective American studies.

The British Regional Heart Study (BRHS) reported in 1986 that much of the inverse relation of high-density lipoprotein cholesterol (HDLC) and incidence of coronary heart disease was eliminated by covariance adjustment. Using the proportional hazards model and adjusting for age, blood pressure, smoking, body mass index, and low-density lipoprotein cholesterol, we analyzed this relation separately in the Framingham Heart Study (FHS), Lipid Research Clinics Prevalence Mortality Follow-up Study (LRCF) and Coronary Primary Prevention Trial (CPPT), and Multiple Risk Factor Intervention Trial (MRFIT). In CPPT and MRFIT (both randomized trials in middle-age high-risk men), only the control groups were analyzed. A 1-mg/dl (0.026 mM) increment in HDLC was associated with a significant coronary heart disease risk decrement of 2% in men (FHS, CPPT, and MRFIT) and 3% in women (FHS). In LRCF, where only fatal outcomes were documented, a 1-mg/dl increment in HDLC was associated with significant 3.7% (men) and 4.7% (women) decrements in cardiovascular disease mortality rates. The 95% confidence intervals for these decrements in coronary heart and cardiovascular disease risk in the four studies overlapped considerably, and all contained the range 1.9-2.9%. HDLC levels were essentially unrelated to non-cardiovascular disease mortality. When differences in analytic methodology were eliminated, a consistent inverse relation of HDLC levels and coronary heart disease event rates was apparent in BRHS as well as in the four American studies.

Adult↗