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Biomedical subjects

G W Heath

Publications and source records attributed to G W Heath.

At least 37 records · Page 2Linked to original sources

Endurance exercise training improves body composition and plasma insulin responses in 70- to 79-year-old men and women.

Forty-two men and women aged 70 to 79 years were studied to assess the effects of 6 months of endurance or resistance training and subsequent cessation of training on glucose tolerance, plasma insulin responses, serum triglyceride and cholesterol levels, and plasma dehydroepiandrosterone (DHEA) levels. The endurance training group (n = 16) exercised at 75% to 85% heart rate reserve for 35 to 45 minutes three times per week; the resistance training group (n = 17) completed one set of eight to 12 repetitions on 10 Nautilus machines three times per week. No significant changes in any variables occurred in a control group (n = 9). Maximal oxygen consumption (VO2max) increased by 20% with endurance training, but did not change with resistance training. Upper- and lower-body strength increased in the resistance training group, but did not change with endurance training. Neither group changed their body weight with training, but the endurance training group elicited a significant reduction in their sum of seven skinfolds and percent body fat. Neither group altered their glucose tolerance with training; however, the endurance training group had lower plasma insulin responses after training compared with the other two groups. Serum lipid and plasma DHEA levels did not change in either the endurance or resistance training groups. Ten days of no exercise following training did not significantly alter body weight or composition, glucose tolerance, plasma insulin responses, or plasma DHEA levels in either the endurance training (n = 10) or resistance training (n = 14) group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Physical activity patterns among adults in Georgia: results from the 1990 Behavioral Risk Factor Surveillance System.

Regular physical activity increases a person's ability to perform daily activities more efficiently, reduces the risk of specific chronic diseases, including coronary artery disease, and lowers death rates in general. The Healthy People 2000 Physical Activity and Fitness Objectives underscored the importance of monitoring and tracking the prevalence of physical activity and fitness in the United States population for the purpose of planning, implementing, and evaluating efforts to improve the public's physical activity habits. This report examines the prevalence of self-reported leisure-time physical activity (LTPA) among southeastern adults aged 18 years and older living in the state of Georgia. Using data from the 1990 Behavioral Risk Factor Surveillance System (BRFSS) surveys from Georgia, we describe the LTPA patterns of Georgia adults aged 18 years and older. A total of 1,723 adults were interviewed during 1990. Results show the following: women are less active than men, blacks are less active than whites, persons of lower socioeconomic status (SES) are less active than those of higher SES, and older adults are less active than younger adults. These results suggest that a more concerted effort needs to be made in promoting physical activity for women, persons of lower SES, and older adults.

Adolescent↗

Correlates of high-density lipoprotein cholesterol in black and white women.

The relationships of high-density lipoprotein (HDL) cholesterol with body composition, leisure-time physical activity, cigarette smoking, and education were examined in a community-based sample of 480 Black and 1337 White women. Univariate and multivariate analyses indicated inverse associations of HDL with body mass index and waist-to-hip ratio in both groups, and with cigarette smoking and low educational attainment among White women only. Since correlates of HDL cholesterol differ for Black and White women, further investigation of the differences in these correlates is warranted.

Adult↗

Physical activity of public housing residents in Birmingham, Alabama.

OBJECTIVES: Because few data are available concerning physical activity among minority and low-income persons, we characterized physical activity patterns among public housing residents. METHODS: Two separate cross-sectional surveys were conducted 1 year apart of randomly selected residents of eight rental communities administered by the housing authority of Birmingham, Ala. Indigenous interviewers completed 687 interviews in survey 1 and 599 in survey 2. RESULTS: In both surveys, respondents were most frequently young adult African-American women, reflecting the predominance of women in these communities. Participants were generally poorly educated and either unemployed or working in service occupations. Thirty percent of the respondents in both surveys reported no participation in any of 13 physical activities in the previous year; approximately half reported activity levels equivalent to or less than walking 4 hours per week for 8 months of the year. Respondents who were younger and male were significantly more likely to have higher activity levels. CONCLUSIONS: A sedentary life-style is common among this low-income minority group, and, thus, interventions to promote exercise in these communities are needed.

Adolescent↗

Hypertension and blood pressure awareness among American Indians of the northern plains.

This study compared self-reported and measured blood pressure among American Indians of the northern plains. In 1986, a group of American Indians from the northern plains was administered the Centers for Disease Control Behavioral Risk Factor Survey (which included a question about previous blood pressure measurements) and a health risk appraisal (which included blood pressure measurement). Approximately 18% of the respondents reported being told by a doctor, nurse, or other health professional that they had high blood pressure, and 11% actually had measured blood pressures of at least 140/90 mm Hg. Overall, only 50% of hypertensive participants correctly identified themselves as hypertensive (sensitivity); specificity was 92%, predictive value positive was 43%, predictive value negative was 94%, and efficiency (the proportion of individuals who correctly classified their blood pressure status as high or normal) was 87%. These findings agree with similar studies of hypertension awareness, and they indicate that lack of this awareness remains a significant problem in the fight against cardiovascular diseases and premature death among American Indians.

Adolescent↗

Realistic outcomes: lessons from community-based research and demonstration programs for the prevention of cardiovascular diseases.

Public health departments nation-wide are implementing community-based cardiovascular disease (CVD) prevention programs. Many such programs are turning for guidance to three research and demonstration projects: the Stanford Five City Project, the Pawtucket Heart Health Program, and the Minnesota Heart Health Program. This article summarizes some of the lessons learned in these projects and recommends strategies for the new generation of CVD prevention programs. The core of a successful program is the community organization process. This involves identification and activation of key community leaders, stimulation of citizens and organizations to volunteer time and offer resources to CVD prevention, and the promotion of prevention as a community theme. A wide range of intervention settings are available for health promotion. As is true for the workplace, places of worship are receptive to health promotion programs and have access to large numbers of people. Mass media are effective when used in conjunction with complementary messages delivered through other channels, such as school programs, adult education programs, and self-help programs. Community health professionals play a vital role in providing program endorsement and stimulating the participation of other community leaders. School-based programs promote long-term behavior change and reach beyond the school to actively involve parents. Innovative health promotion contests have widespread appeal and promote participation in other community interventions. In the area of evaluation, health program participation rates are appropriate primary outcome measures in most community-oriented prevention programs. Other program evaluation priorities include community analysis and formative evaluation, providing data to fine-tune interventions and define the needs and preferences of the community. It is premature to comment conclusively on the effectiveness of community-based CVD prevention programs in reducing population risk factor levels. However, it has been demonstrated that a broad range of intervention strategies can favorably modify the health behaviors of specific groups in communities such as employees and school children.

Cardiovascular Diseases↗

Promoting physical activity in low-income African-American communities: the PARR project.

Data suggest that low-income and minority individuals are less physically active than the general population. We conducted a constituency-based physical activity promotion program, the Physical Activity for Risk Reduction (PARR) project, from 1988 to 1991, with residents of rental communities administered by the Housing Authority of the Birmingham District in Birmingham, Alabama. Data collected through focus groups and by survey of randomly selected residents' exercise practices, beliefs, barriers to and facilitators of physical activity were used to develop specific intervention programs that were implemented and evaluated in six intervention and two control communities through surveys and process evaluations. Trained community residents conducted data collection and interventions. Ninety-nine percent of respondents in the baseline survey were African Americans. Thirty-one percent reported no participation in any of 13 physical activities in the previous year. Significant differences (P < .05) in average attendance by community at group exercise sessions indicated substantial variability in effectiveness of the intervention, due at least in part to factors related to both the communities and the leaders. This variability appeared to explain patterns of change in preintervention and postintervention physical activity scores in intervention communities. Data and experiences from PARR will be applicable to the delivery of similar types of health-related programs in undeserved communities.

Adolescent↗

Leisure-time physical activity and high-density lipoprotein cholesterol in a biracial community sample.

The purpose of this analysis was to describe the association of leisure-time physical activity and high-density lipoprotein cholesterol levels among a large community sample of African-American and white men and women. Physical assessment of high-density lipoprotein cholesterol, weight, height, waist, and hip measurements were obtained for 3121 randomly selected community participants (969 white men, 1409 white women, 205 African-American men, and 538 African-American women). Leisure-time physical activity was assessed from responses to a standard series of questions about participation in various leisure-time activities. We found an inverse relationship between leisure-time activities and high-density lipoprotein cholesterol levels in African Americans, in contrast to a positive association observed in whites; however, these associations failed to reach statistical significance after controlling for age and body composition. These results confirm a strong association of body composition with high-density lipoprotein cholesterol and support continued interventions designed to reduce overall body weight, particularly upper body weight. The results further suggest that the relationships between some life-style factors and HDL levels may be different among minorities.

Black or African American↗

Perceived morbidity as a determinant of health behavior.

It is hypothesized that perceived morbidity, a concept closely related to perceived vulnerability, is an important determinant of health behaviors. In this cross-sectional study (N = 2740), perceived morbidity was conceptualized as a categorical variable defining six distinct morbidity groups: the hypertension, high cholesterol, angina pectoris, heart attack, stroke and 'morbidity-free' groups. We used analyses of covariance to identify differences in health behaviors between the six groups; the analyses were done separately for middle-aged (40-60 years old) and older ( greater than 60 years old) respondents. Results show that perceived morbidity had a significant effect on fat consumption (P less than 0.001) and on physical activity (P < 0.01). In both age ranges, the morbidity-free group had the highest fat consumption; among the middle-aged respondents, the level of physical activity was significantly lower in the morbidity-free group than in the heart attack group. Furthermore, respondents in the high cholesterol group showed consistently a 'better' health behavior than people in the hypertension group. Overall, these results suggest that the concept of perceived morbidity may be useful in explaining inter-individual differences in health behaviors.

Adolescent↗

Physical activity behaviors in lower and higher socioeconomic status populations.

Few data on physical activity habits among populations of low socioeconomic status have been published. The authors studied physical activity habits--leisure-time physical activity, job-related physical activity, household physical activity, and walking--among 172 lower socioeconomic status women and 84 lower socioeconomic status men and compared their habits with those of 208 higher socioeconomic status women and 95 higher socioeconomic status men. All subjects resided in the greater Pittsburgh, Pennsylvania, area. Data collection occurred throughout 1986. Lower socioeconomic status women, the least active group, averaged 1,536 +/- 1,701 minutes/week (+/- standard deviation) of total physical activity, whereas higher socioeconomic status women, the most active group, averaged 2,079 +/- 1,807 minutes/week (p less than 0.0001). Higher socioeconomic status men averaged 1,952 +/- 1,799 minutes/week, and lower socioeconomic status men averaged 1,948 +/- 1,916 minutes/week. Higher socioeconomic status women spent significantly more time each week in leisure-time physical activity, job-related physical activity, and household physical activity than did lower socioeconomic status women. Lower socioeconomic status men spent significantly more time each week walking and doing household chores, whereas higher socioeconomic status men tended to be more active in leisure-time physical activity. These data suggest important quantitative and qualitative differences in physical activity among population subgroups. In view of the important role of physical activity in promoting physical and mental health, reasons for the differences among groups of varying socioeconomic status must be examined and elucidated.

Adult↗

Community-based exercise and weight control: diabetes risk reduction and glycemic control in Zuni Indians.

Cardiovascular disease is a significant health problem for the Zuni Indians of southwest New Mexico, in part because of high rates of non-insulin-dependent diabetes mellitus (NIDDM). The Zuni Diabetes Project was initiated in July 1983 to reduce rates of obesity and provide primary and secondary prevention of NIDDM. Two studies of the project's activities have been carried out to date. After 2 y of follow-up, diabetic participants in an exercise program compared with diabetic nonparticipants experienced weight loss, a drop in fasting blood glucose values, and reductions in the use of hypoglycemic medications. In a weight-loss competition, 45% (122/271) of the enrollees finished and lost greater than or equal to 2.3 kg. The results of these two studies demonstrate that 1) participation in a community-based exercise program can produce significant weight loss and improvement in glycemic control in Zuni Indians with NIDDM and 2) weight-loss competitions appear to be an important public health model for health-behavior change in communities similar to that of Zuni, NM.

Adult↗

Exercise and the incidence of upper respiratory tract infections.

We examined illness patterns in a cohort of 530 male and female runners who completed a monthly log for 12 months. The average number of upper respiratory tract infections (URTIs) per person per year for the cohort was 1.2. An upper respiratory tract infection was indicated by the report of any of the following symptoms; runny nose, sore throat, or cough. Using a multiple logistic regression model, the following factors were found to be associated with having one or more URTIs in the follow-up period: living alone (odds ratio = 2.27, 95% CI = 1.01, 5.09), running mileage (486-865 miles, odds ratio = 2.00, 95% CI = 1.01, 2.78; 866-1388 miles, odds ratio = 3.50, 95% CI = 1.52, 4.44; greater than 1388 miles, odds ratio = 2.96, 95% CI = 1.30, 3.68), body mass index greater than the 75th percentile (odds ratio = 0.58, 95% CI = 0.35, 0.94), and male gender (odds ratio = 0.14, 95% CI = 0.03, 0.68). A significant interaction was found to exist between gender and alcohol use, with the association between alcohol use and upper respiratory tract infections being positive in males and negative in females. These results suggest that running dosage (mileage) is a significant risk factor for upper respiratory tract infections in this group of exercisers.

Adolescent↗

Effect of exercise training on plasma catecholamines and haemodynamics of adolescent hypertensives during rest, submaximal exercise and orthostatic stress.

Twelve adolescents with essential hypertension were studied to determine the effect of exercise training on plasma catecholamine concentrations, blood pressure and cardiovascular haemodynamics at rest and during submaximal exercise and orthostatic stress. Maximal oxygen consumption (VO2max) increased 13% with training while body weight and body fat did not change. Resting systolic and diastolic blood pressures decreased significantly with training, while plasma norepinephrine and epinephrine levels were unchanged. The increase in systolic blood pressure in response to standing was significantly lower after training, while the plasma catecholamine response was not significantly different. At the same absolute work rate after training, the subjects' systolic and diastolic blood pressures, heart rates, and plasma norepinephrine and epinephrine levels were significantly lower than before training. At the same relative work rate after training, the blood pressure response was the same as before training despite significantly higher plasma norepinephrine levels. Thus, the training-induced changes in resting blood pressures and blood pressure responses to orthostatic and submaximal exercise stress cannot be attributed to decreases in plasma catecholamine levels.

Adaptation, Physiological↗

Effects of intense exercise training on plasma catecholamines in coronary patients.

This paper reports the effect of 12 mo of intense endurance exercise training on the plasma catecholamine response to exercise in 11 male patients [aged 50 +/- 8 yr (mean +/- SD)] with coronary artery disease. A substantial adaptation to training was attained as evidenced by a 42% increase in maximum O2 uptake capacity. At rest, heart rate was lower after training, but resting blood pressure and plasma catecholamines were unchanged. At the same absolute work rate, plasma norepinephrine and epinephrine levels, rate pressure product, and ischemic S-T segment depression were all significantly lower after training. A higher plasma norepinephrine level was attained at maximal exercise after training (2,049 +/- 654 before vs. 3,408 +/- 1,454 pg/ml after, P less than 0.025); this was associated with a higher systolic blood pressure (175 +/- 25 before vs. 188 +/- 22 mmHg after, P less than 0.025) and a higher rate-pressure product (25.3 X 10(3) +/- 4.5 X 10(3) before vs. 27.6 X 10(3) +/- 5.2 X 10(3) after, P less than 0.025). Despite the higher plasma norepinephrine level and rate pressure product, S-T segment depression at maximal exercise was unchanged. These findings suggest that some patients with coronary arterial disease can attain a higher myocardial O2 requirement, without electrocardiographic evidence of increased ischemia, after prolonged strenuous exercise training.

Adaptation, Physiological↗

Effect of exercise training on the blood pressure and hemodynamic features of hypertensive adolescents.

Twenty-five adolescents (aged 16 +/- 1 years) whose blood pressure (BP) was persistently above the 95th percentile for their age and sex were studied before and after 6 +/- 1 months of exercise training and again 9 +/- 1 months after the cessation of training. Maximal oxygen consumption (VO2) increased significantly with training. There was no change in body weight or sum of skinfolds. Both systolic and diastolic BP decreased significantly with training; however, complete BP normalization was not achieved. When the subjects were retested 9 +/- 1 months after cessation of training, systolic BP and VO2 max had returned to pretraining levels; however, diastolic BP was still below pretraining levels in the subjects who had diastolic hypertension initially. Except in subjects who initially had an elevated cardiac output, no consistent hemodynamic changes were found with training or cessation of training to account for the reductions in BP. The subjects whose resting cardiac outputs were high initially had significantly lower cardiac outputs after training as a result of decreases in both heart rate and stroke volume; however, vascular resistance remained unchanged. Sedentary control subjects with similar BP had no significant change in any of the variables measured over a similar period. These data indicate that moderate endurance exercise training can lower BP in otherwise healthy hypertensive adolescents as an initial therapeutic intervention.

Adolescent↗

Exercise training improves lipoprotein lipid profiles in patients with coronary artery disease.

The effects of endurance exercise training on plasma lipoprotein lipids were determined in 10 men, ages 46 to 62 years, with coronary artery disease (CAD). Patients maintained body weight, health-related behaviors, and stable diets throughout the program. Training was at 50% to 85% of maximal oxygen consumption (VO2 max) for 40 to 60 minutes, 3 to 5 days/week for 29 +/- 7 weeks. Training increased VO2 max (31 +/- 19%, p less than 0.001), reduced plasma cholesterol (C) (-8 +/- 4%, p less than 0.01), low-density lipoprotein-C (LDL-C) (-9 +/- 9%, p less than 0.01), and triglyceride (TG) (-13 +/- 32%, p less than 0.05) concentrations, and increased high-density lipoprotein-C (HDL-C) levels (11 +/- 13%, p less than 0.05) and HDL-C/LDL-C ratios (25 +/- 20%, p less than 0.01). Changes in LDL-C and VO2 max were correlated (r = -0.73, p +/- 0.01), while the changes in LDL-C and HDL-C each correlated inversely with pretraining lipoprotein levels (rLDL-C = -0.77, p less than 0.01; rHDL-C = -0.68, p less than 0.05). Thus potentially "antiatherogenic" benefits of exercise seem to be due to a training effect, since they correlate best with changes in VO2 max and are maximal in patients with initially low VO2 max, high LDL-C, and low HDL-C levels.

Cholesterol↗