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In brief Active patients, with or without cardiovascular disease, are often concerned about the risk of serious heart complications brought on by exercise. What can physicians tell patients about the risks of exercise versus its benefits? How can physicians identify those at risk? How useful are stress tests? What exercise intensity is best? A panel of experts addresses these issues.

In most countries throughout the world, except those affected by the HIV-Aids epidemic, populations are increasing in size, rapidly getting older, and becoming more sedentary. This combination, along with the adoption of unhealthy habits such as cigarette smoking and consumption of an animal-based rather than a plant-based diet, will result in chronic degenerative diseases becoming the most common cause of disability and premature death throughout the world during the first twenty-five years of this new millennium. As more and more populations acquire the technology that reduces the need to exercise for transportation, occupation or maintaining a household, lack of activity quickly becomes a major risk for coronary heart disease, stroke, hypertension and noninsulin dependent diabetes mellitus. This lack of activity appears to contribute to other disorders such as osteoporosis and selected site-specific cancers. In older persons, inactivity can become a major reason for loss of physical independence and a reduction in their quality of life. Public health approaches will be needed to reverse this trend of increasing "hypokinetic" diseases as the computer/communication revolution becomes worldwide. These public health programs will need to be supported by government and corporate changes in policies that provide time, facilities and incentives for maintaining an appropriately active life-style. The goal should be for all adults to perform at least 30 minutes of moderate to vigorous intensity exercise on most days.

This study examined the relationship between perceived physical condition and measured physical fitness and activity levels in 40 patients with moderate heart failure (HF). Self rated physical condition, physical activity, self efficacy, and quality of life were evaluated by self administered questionnaires. Functional capacity was examined by cardiopulmonary exercise testing and 6 minute walk test. We found that physical activity levels were low. Participation in moderate intensity recreational activity and physical fitness were associated with self efficacy. Perceived physical condition was associated with emotional well being and levels of energy and fatigue. We conclude that self efficacy may reflect physical condition and physical activity levels in this sample of HF patients and may be a simple indicator of physical ability. Because of the association between perceived physical condition and emotional well being, caution must be taken when using self reports of physical condition. Further study is needed to explore these relationships.

To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships.The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California.All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates.Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.

The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal.kg-1.day-1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effect, and cost-effectiveness, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical setting, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.

Phytoestrogens represent a family of plant compounds that have been shown to have both estrogenic and antiestrogenic properties. A variety of these plant compounds and their mammalian metabolic products have been identified in various human body fluids and fall under two main categories: isoflavones and lignans. A wide range of commonly consumed foods contain appreciable amounts of these different phytoestrogens. For example, soy and flax products are particularly good sources of isoflavones and lignans, respectively. Accumulating evidence from molecular and cellular biology experiments, animal studies, and, to a limited extent, human clinical trials suggests that phytoestrogens may potentially confer health benefits related to cardiovascular diseases, cancer, osteoporosis, and menopausal symptoms. These potential health benefits are consistent with the epidemiological evidence that rates of heart disease, various cancers, osteoporotic fractures, and menopausal symptoms are more favorable among populations that consume plant-based diets, particularly among cultures with diets that are traditionally high in soy products. The evidence reviewed here will facilitate the identification of what is known in this area, the gaps that exist, and the future research that holds the most potential and promise.

A review of research on complementary and alternative treatments, specifically mind-body techniques, was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and to provide a rationale for future research concerning successful aging.Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet, and interviews conducted with practitioners. All studies since 1990 that examined mind-body treatments of cardiovascular disorders in the elderly were included. Mind-body practices evaluated were social support, cognitive-behavioral treatment, meditation, the placebo effect, hope, faith, imagery, spiritual healing, music therapy, hypnosis, yoga, t'ai chi, qigong and aikido. Studies conducted after 1990 were a priority, but when more recent literature was scarce, other studies using randomized, controlled trials were included.Mind-body techniques were found to be efficacious primarily as complementary and sometimes as stand-alone alternative treatments for cardiovascular disease-related conditions. Studies provided evidence for treatment efficacy, but the need for further controlled research was evident.Reviewers found only a handful of randomized, controlled research studies conducted in the United States. As a result, there is a lack of replicated studies with which to determine appropriate treatment dosage and the mechanisms by which many of the practices work. Compelling anecdotal evidence, the presence of some controlled research, overall cost effectiveness, and the lack of side effects resulting from mind-body treatments make further investigation a high priority.

Most studies of physical fitness change have been relatively small, not population-based, and lacking in women and nonwhites. The purpose of this analysis was to evaluate the 7-yr change in physical fitness in a biracial (black and white) population of young men and women.We evaluated change in exercise treadmill test performance in a biracial (black and white) population of 1,962 young adults, ages 18-30 yr at baseline, who completed symptom-limited graded exercise treadmill tests at the baseline (1985-1986) and year 7 (1992-1993) examinations of the CARDIA study.Mean test duration decreased 58 s (9.5%) over 7 yr (black men, 13.6% decrease, white men, 7.4%; black women, 11.1%; white women, 7.0%). Mean time to heart rate 130 (WL130), a measure of submaximal performance, decreased 31 s (11.3%) (black men, 16.9%; white men, 10.0%; black women, 12.3%; white women, 6.1%). Baseline body mass index (BMI) and physical activity were not statistically significant predictors of test duration change in any race-gender group, but change in BMI and activity were. Seven-year weight gain20 lbs (31% of cohort) was associated with a large decrease in fitness (18.5% decrease in mean duration, 21.8% decrease in WL130).These data suggest that fitness declines during young adulthood in blacks and whites and that fitness changes are related to changes in weight and physical activity.

To determine the effects of moderate-intensity exercise training on self-rated (subjective) sleep quality among healthy, sedentary older adults reporting moderate sleep complaints.Randomized controlled trial of 16 weeks' duration.General community.Volunteer sample of 29 women and 14 men (of 67 eligible subjects) aged 50 to 76 years who were sedentary, free of cardiovascular disease, and reported moderate sleep complaints. No participant was withdrawn for adverse effects.Randomized to 16 weeks of community-based, moderate-intensity exercise training or to a wait-listed control condition. Exercise consisted primarily of four 30- to 40-minute endurance training sessions (low-impact aerobics; brisk walking) prescribed per week at 60% to 75% of heart rate reserve based on peak treadmill exercise heart rate.Pittsburgh Sleep Quality Index (PSQI).Compared with controls (C), subjects in the exercise training condition (E) showed significant improvement in the PSQI global sleep score at 16 weeks (baseline and posttest values in mean [SD] for C=8.93 [3.1] and 8.8 [2.6]; baseline and posttest values for E=8.7 [3.0] and 5.4 [2.8]; mean posttest difference between conditions=3.4; P.001; 95% confidence interval, 1.9-5.4), as well as in the sleep parameters of rated sleep quality, sleep-onset latency (baseline and posttest values for C=26.1 [20.0] and 23.8 [15.3]; for E=28.4 [20.2] and 14.6 [13.0]; net improvement=11.5 minutes), and sleep duration baseline and posttest scores for C=5.8 [1.1] and 6.0 [1.0]; for E=6.0 [1.1] and 6.8 [1.2]; net improvement=42 minutes) assessed via PSQI and sleep diaries (P=.05).Older adults with moderate sleep complaints can improve self-rated sleep quality by initiating a regular moderate-intensity exercise program.

Previous studies have shown that alendronate can increase bone mineral density (BMD) and prevent radiographically defined (morphometric) vertebral fractures. The Fracture Intervention Trial aimed to investigate the effect of alendronate on the risk of morphometric as well as clinically evident fractures in postmenopausal women with low bone mass.Women aged 55-81 with low femoral-neck BMD were enrolled in two study groups based on presence or absence of an existing vertebral fracture. Results for women with at least one vertebral fracture at baseline are reported here. 2027 women were randomly assigned placebo (1005) or alendronate (1022) and followed up for 36 months. The dose of alendronate (initially 5 mg daily) was increased (to 10 mg daily) at 24 months, with maintenance of the double blind. Lateral spine radiography was done at baseline and at 24 and 36 months. New vertebral fractures, the primary endpoint, were defined by morphometry as a decrease of 20% (and at least 4 mm) in at least one vertebral height between the baseline and latest follow-up radiograph. Non-spine clinical fractures were confirmed by radiographic reports. New symptomatic vertebral fractures were based on self-report and confirmed by radiography.Follow-up radiographs were obtained for 1946 women (98% of surviving participants). 78 (8.0%) of women in the alendronate group had one or more new morphometric vertebral fractures compared with 145 (15.0%) in the placebo group (relative risk 0.53 [95% Cl 0.41-0.68]). For clinically apparent vertebral fractures, the corresponding numbers were 23 (2.3%) alendronate and 50 (5.0%) placebo (relative hazard 0.45 [0.27-0.72]). The risk of any clinical fracture, the main secondary endpoint, was lower in the alendronate than in the placebo group (139 [13.6%] vs 183 [18.2%]; relative hazard 0.72 [0.58-0.90]). The relative hazards for hip fracture and wrist fracture for alendronate versus placebo were 0.49 (0.23-0.99) and 0.52 (0.31-0.87). There was no significant difference between the groups in numbers of adverse experiences, including upper-gastrointestinal disorders.We conclude that among women with low bone mass and existing vertebral fractures, alendronate is well tolerated and substantially reduces the frequency of morphometric and clinical vertebral fractures, as well as other clinical fractures.

Physical activity performed by patients with coronary heart disease is a two-edged sword. A number of biological changes produced by regular exercise may reduce the risk of future cardiac events, while the increase in cardiac work produced by this same exercise can predispose the patient to sudden cardiac death. Data from observational studies as well as randomized clinical trials demonstrate a lower cardiac mortality rate for men participating in exercise rehabilitation programs vs nonparticipants. Overall, exercise program participants appear to experience a reduction of approximately 25% in cardiac and all-cause mortality, but no single study has provided definitive results. During medically supervised exercise, the risk of cardiac death based on reports of programs in the United States is approximately one event in every 60,000 participant-hours of exercise. At this rate, a typical rehabilitation program that has 95 patients exercising 3 h.wk-1 could expect a sudden cardiac death during an exercise session once every 4 yr. No data have been published on the morbidity or mortality benefits or risks of home-based exercise or for women participants. Also, the contribution of continuous electrocardiographic monitoring to the safety of exercise training of cardiac patients is yet to be defined.

The Guidelines for Exercise Training initially developed by the American College of Sports Medicine in 1978 and updated in 1990 have served as the foundation for most recommendations regarding physical activity program design for the general public. These guidelines have proven to be very useful by providing a specific regimen for enhancing aerobic capacity and body composition. As data supporting a causal link between increased activity or fitness and health status have evolved, questions have been raised about potential limitations of these guidelines for promoting physical activity to increase the health status of sedentary adults. The major issues have involved the necessity to achieve the values for each of the program parameters, especially the intensity, duration, and frequency of exercise, in order to improve health status. To address these issues, a paradigm shift from exercise training to promote physical fitness to physical activity to promote health has been introduced. This new paradigm is based on the results from numerous studies indicating that a generally active life style is associated with better health and performance and greater longevity and a certain set of assumptions, yet to be fully tested. The following article provides some background leading to the development of the ACSM guidelines and presents some of those issues we understand and some we do not regarding the characteristics of daily physical activity or exercise training that are likely to improve the physical health status of sedentary persons.

Symptom-limited, graded exercise treadmill testing was performed by 4,968 white and black adults, ages 18-30 yr, during the baseline examination for the Coronary Artery Risk Development in Young Adults (CARDIA) study. Compared with nonsmokers, the mean exercise test duration of smokers was 29-64 s shorter depending on race/gender group (all P0.001), but mean duration to heart rate 130 (beats.min-1) ranged from 20-50 s longer (P0.05). In each race/gender group, test duration to heart rates up to 150 was 15-35 s longer (P0.05) in smokers than in nonsmokers after adjustment for age, sum of skinfolds, hemoglobin, and physical activity score. The mean maximum heart rate was lower in smokers than in nonsmokers (difference ranging from 6.7 beats.min-1 in white men to 11.2 beats.min-1 lower in black women, P0.001), although maximum rating of perceived exertion was nearly identical in smokers and nonsmokers. Chronic smoking appears to blunt the heart rate response to exercise, so that exercise duration to submaximal heart rates is increased even though maximal performance is impaired. This may result from downloading of beta-receptors caused by smoking. Smoking status should be considered in the evaluation of physical fitness data utilizing submaximal test protocols, or else the fitness of smokers relative to nonsmokers is likely to be overestimated.

The 12-month effects of exercise training on psychological outcomes in adults ages 50-65 years were evaluated. Ss (N = 357) were randomly assigned to assessment-only control or to higher intensity group, higher intensity home, or lower intensity home exercise training. Exercisers showed reductions in perceived stress and anxiety in relation to controls (p.04). Reductions in stress were particularly notable in smokers. Regardless of program assignment, greater exercise participation was significantly related to less anxiety and fewer depressive symptoms, independent of changes in fitness or body weight (p.05). It was concluded that neither a group format nor vigorous activity was essential in attaining psychological benefits from exercise training in healthy adults.

A retrospective longitudinal analysis of fat distribution and cause-specific mortality was performed on data from 105,062 men discharged from the United States Army in 1946-47. Baseline height, weight, waist and hip girth, and 23-year follow-up mortality data were available for 84,910 white men. Proportional hazard survival analysis was performed by 5-year age group for waist/hip ratio (WHR) and for body mass index (BMI) in prediction of time to death from ischaemic heart disease (IHD) and stroke. Relative risk of IHD fatality per standard deviation (s.d.) of WHR ranged from 1.11 to 1.17, the higher values appearing in younger age groups. Relative risk due to BMI was not significant in the group aged 16-20 years at time of discharge from service, but ranged from 1.22 to 1.25 per s.d. among the 21-30 year olds. WHR was predictive of cerebrovascular disease mortality among 16-25 year olds, carrying a relative risk of 1.24 to 1.35 per s.d. BMI was not predictive of cerebrovascular disease mortality in any age group. Multivariate models indicated that WHR and BMI were related to subsequent IHD independently of each other in most age groups. WHR and BMI both contribute to risk of premature IHD mortality and WHR to risk of cerebrovascular disease mortality in an initially relatively healthy population of young men, although the effects are not equivalent in all age groups.

To determine the effectiveness of group- vs home-based exercise training of higher and lower intensities among healthy, sedentary older adults.--Year-long randomized, controlled trial comparing (1) higher-intensity group-based exercise training; (2) higher-intensity home-based exercise training; (3) lower-intensity home-based exercise training; or (4) assessment-only control.--General community located in northern California.--One hundred sixty women and 197 men 50 to 65 years of age who were sedentary and free of cardiovascular disease. One out of nine persons contacted through a community random-digit-dial telephone survey and citywide promotion were randomized.--For higher-intensity exercise training, three 40-minute endurance training sessions per week were prescribed at 73% to 88% of peak treadmill heart rate. For lower-intensity exercise training, five 30-minute endurance training sessions per week were prescribed at 60% to 73% of peak treadmill heart rate.--Treadmill exercise test performance, exercise participation rates, and heart disease risk factors.--Compared with controls, subjects in all three exercise training conditions showed significant improvements in treadmill exercise test performance at 6 and 12 months (P less than .03). Lower-intensity exercise training achieved changes comparable with those of higher-intensity exercise training. Twelve-month exercise adherence rates were better for the two home-based exercise training conditions relative to the group-based exercise training condition (P less than .0005). There were no significant training-induced changes in lipid levels, weight, or blood pressure.--We conclude that (1) this community-based exercise training program improved fitness but not heart disease risk factors among sedentary, healthy older adults; (2) home-based exercise was as effective as group exercise in producing these changes; (3) lower-intensity exercise training was as effective as higher-intensity exercise training in the home setting; and (4) the exercise programs were relatively safe.

We used heart rate and walking speed to calculate an energy expenditure index (EEI), the ratio of heart rate per meter walked, for 102 normal subjects, age 6-18 years. Heart rate was measured at self-selected slow, comfortable, and fast walking speeds on the floor and on a motor-driven treadmill. At slow walking speeds (37 +/- 10 m/min) the EEI was elevated (0.71 +/- 0.32 beats/m), indicating poor economy. At comfortable speeds (70 +/- 11 m/min) the EEI values decreased to the maximum economy (0.47 +/- 0.13 beats/m). At fast speeds (101 +/- 13 m/min), the EEI increased (0.61 +/- 0.17 beats/m), indicating poor economy relative to comfortable speeds. A graph of the EEI versus walking speed provides a way to evaluate and compare energy expenditure in a clinical setting.

The postprandial response to three test meals provided during a single day was investigated in subjects with either the apo E3/3 phenotype (n = 8), or the apo E4/3 phenotype (n = 4), who had LDL-C greater than 160 mg/dl. Vitamin A (60,000 U/m2) was ingested with the first meal and retinyl palmitate determined four hours later. Triglyceride and total cholesterol concentration were determined on whole plasma and total cholesterol and free cholesterol determined following single spin ultracentrifugation (d less than 1.006 g/ml) and dextran precipitation of the d greater than 1.006 fraction to separate apoprotein-B containing lipoproteins. Fasting values revealed significantly lower HDL-cholesterol ester (p less than 0.03) and HDL3-cholesterol ester (p less than 0.03) and significantly greater HDL-free cholesterol (p less than 0.03) and HDL3-free cholesterol (p less than 0.02) in subjects with the E4/3 phenotype. Four hour postprandial HDL and HDL3 cholesterol ester increased significantly more (p less than 0.05) in E4/3 patients and HDL and HDL3 free cholesterol decreased significantly more (p less than 0.05) in E4/3 subjects. Eight-hour postprandial change values maintained the significant HDL3-cholesterol ester and free cholesterol difference, and, revealed a significantly greater triglyceride rich lipoprotein cholesterol ester reduction (p less than 0.01) in the E4/3 group. Individuals with the apolipoprotein E4/3 phenotype reveal significant differences in postprandial lipemia compared to individuals with the E3/3 phenotype, and, postprandial lipemia following multiple meals reveals differences not apparent from responses to a single meal.

To test whether communitywide health education can reduce stroke and coronary heart disease, we compared two treatment cities (N = 122,800) and two control cities (N = 197,500) for changes in knowledge of risk factors, blood pressure, plasma cholesterol level, smoking rate, body weight, and resting pulse rate. Treatment cities received a 5-year, low-cost, comprehensive program using social learning theory, a communication-behavior change model, community organization principles, and social marketing methods that resulted in about 26 hours of exposure to multichannel and multifactor education. Risk factors were assessed in representative cohort and cross-sectional surveys at baseline and in three later surveys. After 30 to 64 months of education, significant net reductions in community averages favoring treatment occurred in plasma cholesterol level (2%), blood pressure (4%), resting pulse rate (3%), and smoking rate (13%) of the cohort sample. These risk factor changes resulted in important decreases in composite total mortality risk scores (15%) and coronary heart disease risk scores (16%). Thus, such low-cost programs can have an impact on risk factors in broad population groups.

Until relatively recently, clinical information regarding plasma lipoproteins and their association with human atherosclerosis had been based on epidemiologic evidence obtained from cross-sectional studies or prospective studies that used clinical events as end points. Authorities have cautioned against the interpretation of these results to imply that drug therapy be used to alter the high-density lipoprotein (HDL) fraction of total cholesterol. Several recent investigations strongly suggest that decreasing the low-density lipoprotein fraction of total cholesterol and increasing the HDL fraction may alter the progression of atherosclerosis. Appropriate exercise may be a viable tool to assist in elevating plasma HDL levels.

To determine the response to repeated treadmill exercise testing soon after uncomplicated myocardial infarction, 24 males (mean age 54 +/- 6 years) performed two symptom-limited tests several days apart 3, 7 and 11 weeks after the acute event. Significant within-week differences were noted for peak exercise tolerance (mets) and peak heart rate at 7 weeks (p less than 0.05). Significant within-week differences in these variables were not noted for other weeks or for systolic blood pressure or heart rate-systolic blood pressure product for any of the three test periods. No significant within-week differences were noted for any variable recorded at a submaximal work load of 4 mets. The frequency of exercise-induced ischemic ST-segment depression, angina pectoris and premature ventricular complexes did not change from visit to visit and was highly reproducible (p less than 0.01). All test variables measured at peak exercise increased significantly between 3 and 11 weeks after infarction. We conclude that cardiovascular responses to symptom-limited exercise testing are highly reproducible in the 3 months after uncomplicated myocardial infarction. Changes in the response to treadmill exercise tests performed several weeks apart reflect alterations in cardiovascular performance.

Medically directed at-home rehabilitation was compared with group rehabilitation which began 3 weeks after clinically uncomplicated acute myocardial infarction (AMI) in 127 men, mean age 53 ± 7 years. Between 3 and 26 weeks after AMI, adherence to individually prescribed exercise was equally high (at least 71%), the increase in functional capacity equally large (1.8 ± 1.0 METs) and nonfatal reinfarction and dropout rates equally low (both 3% or less) in the 66 men randomized to home training and the 61 men randomized to group training. No training-related complications occurred in either group. The low rate of reinfarction and death (5% and 1%, respectively) in the study as a whole, which included 34 patients with no training and 37 control patients, reflected a stepwise process of clinical evaluation, exercise testing at 3 weeks and frequent telephone surveillance of patients who underwent exercise training. Medically directed at-home rehabilitation has the potential to increase the availability and to decrease the cost of rehabilitating low-risk survivors of AMI.

The Stanford Five-City Project is a long-term field evaluation of the effects of community health education on cardiovascular disease risk factors and event rates. One major end point of the project is the difference between treatment and control group trends in morbidity and mortality rates ascertained through community-wide surveillance of deaths and hospital discharges. This surveillance system includes continuous review of death certificates and hospital discharge records, interviews with the families and physicians of decedents who died outside the hospital, abstraction of the hospital records of possible myocardial infarction and stroke cases (fatal and nonfatal), and systematic validation of diagnosis by the use of standard criteria. Initial experience with information access, availability of diagnostic information, costs, and reliability are described. This standardized approach to community surveillance of cardiovascular disease events rates, both fatal and nonfatal, is a feasible method for evaluating large-scale intervention programs and may be applicable to monitoring secular trends in the absence of intervention.

We investigated the circumstances of death and the medical and activity histories of 18 individuals who died during or immediately after jogging. Thirteen men died of coronary heart disease (CHD) and four men and one woman died of other causes. Six CHD subjects had medical histories relevant to the cardiovascular system, but only one had diagnosed CHD. Six CHD subjects experienced prodromal symptoms but continued vigorous exercise programs. Two subjects had exercised less than a month, but most had trained regularly for years. The CHD risk factors for the CHD cases did not differ significantly from those for other age-matched, physically active men. Superior physical fitness does not guarantee protection against exercise deaths. Physicians and exercising adults should be aware of this fact and give appropriate attention to possible prodromal symptoms.

During the Lipid Research Clinics North American Prevalence Study, plasma lipoprotien determinations and treadmill exercise testing were performed on 2319 white men and 2067 white women ages 20 years or older randomly selected from population surveys by nine clinics in the U.S. and Canada. Before exercise testing, participants were asked if they performed any strenuous physical activity on a regular basis. Data were analyzed to determine the relationship of plasma high-density lipoprotein (HDL) cholesterol to treadmill exercise test performance and a self-report of strenuous activity. Neither treadmill exercise test duration nor heart rate response to submaximal exercise was significantly related to HDL cholesterol levels for either men or women. However, participants who reported some strenuous physical activity generally had higher HDL cholesterol levels than those who reported none, and the more active men ages 30-49 years and active women ages 20-39 had significantly higher values (p0.05). When HDL cholesterol was adjusted for age, body mass index, alcohol use, cigarette smoking and interclinic population variation, more active men (47.1 vs 45.2 mg/dl; p = 0.0001) and more active women (59.6 vs 57.7 mg/dl; p = 0.02) had higher HDL cholesterol levels than their sedentary counterparts. Thus, the association between HDL cholesterol and reported physical activity was, at least in part, independent of other factors that influence HDL cholesterol concentration, but was not associated with exercise tolerance as determined by treadmill exercise testing.

The major classes of serum lipoproteins have been shown to be differentially affected not only by dietary factors but also by levels of physical activity. Individuals engaging in relatively higher amounts of physical activity tend to have lower levels of low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and higher levels of high-density lipoprotein cholesterol (HDL-C) than their sedentary counterparts. However, higher levels of physical activity are also associated with lower adiposity and elevated caloric intake, two factors that themselves have independent roles in the regulation of lipoprotein levels. Changes in adiposity appear to be responsible for some, but not all, of the lipoprotein change associated with exercise. A study in which 14 sedentary, middle-aged men engaged in a progressive running program over 2 years showed increased HDL-C and decreased LDL-C, both considered antiatherogenic. Adiposity, expressed as percent body fat, decreased during the study whereas caloric intake, notably in the form of carbohydrates, increased. Elevated physical activity levels alter the relationships among adiposity, dietary intake, and lipoproteins that prevail in the sedentary state.

Persons whose body fat is distributed predominantly in the abdomen compared with the hips are at increased risk of several chronic diseases. This study examined the cross-sectional relation of percent body fat, computed from skinfold thickness, and fat distribution, measured by the waist-to-hip girth ratio, to physiologic cardiovascular risk factors in a biracial sample (blacks and whites) of young adults aged 18-30 years. The subjects were persons who were examined at baseline (1984-1986) in the Coronary Artery Risk Development in Young Adults Study in four US metropolitan areas. The two hypotheses tested were that 1) after adjusting for percent body fat, waist-to-hip girth ratio is associated with several physiologic risk factors, and 2) fasting concentrations of serum insulin partly explain such association. Percent body fat was significantly associated with all measured blood lipids, lipoproteins, apolipoproteins, uric acid, and blood pressure. Waist-to-hip girth ratio was significantly, although more weakly, associated in multivariate models with blood concentrations of triglycerides, high density lipoprotein (HDL) cholesterol, HDL2 cholesterol, apolipoproteins A-I and B, low density lipoprotein cholesterol (in women only), uric acid, and systolic blood pressure, but was not associated in either sex with total cholesterol, HDL3 cholesterol, or diastolic blood pressure. Fasting serum insulin concentrations were significantly associated with percent body fat (Pearson r = 0.45-0.53), waist-to-hip girth ratio (Pearson r = 0.18-0.27), and most of the physiologic risk factors. Inclusion of fasting insulin in multivariate models reduced, but rarely eliminated, associations between waist-to-hip girth ratio and the physiologic risk factors. These findings suggest that obese young adults, especially those with abdominal fat preponderance, carry a physiologic profile that places them at higher risk of cardiovascular disease, and that fasting insulin concentrations are only partly explanatory.

Eighty-one healthy, sedentary men aged 30 to 55 years were randomly assigned to supervised running (n = 48) or to sedentary control groups (n = 33) and followed up in a one-year trial. Measurements of plasma lipoproteins, fitness, and percent body fat were made at three-month intervals. Results and conclusions from this study are (1) that cross-sectional studies of lipoprotein concentrations in exercisers may be biased by a self-selection effect, since study participants with initially higher high-density lipoprotein cholesterol (HDL-C) and lower triglyceride concentrations were more easily persuaded to run more miles; (2) that plasma concentrations of HDL-C and low-density lipoprotein cholesterol (LDL-C) generally did not begin to change until a threshold exercise level (ten miles run per week) was maintained for at least nine months; and (3) that fitness increased and percent body fat decreased sooner and at lower exercise levels than required for HDL-C and LDL-C concentration changes.

Medical supervision of cardiac exercise programs should be individualized to each patient's needs. In order for this to be done, several factors must be considered, including the nature of increased risk during exercise due to coronary heart disease, ways to minimize the risk of cardiovascular complications during exercise, the types of medical supervision available and their contributions to safety, and the other factors that are influenced by medical supervision, such as program availability and cost and patient reactivity and compliance.

To determine if multiple risk factor modification favorably alters the rate of progression of coronary atherosclerosis, 300 patients with established atherosclerosis have been randomized into a clinical trial; 155 to usual care and 145 to special intervention. All patients have medical/risk examinations at baseline and annually for 4 years. The special intervention patients undergo aggressive risk factor management with emphasis on lipoprotein modification, dietary management, smoking abatement, blood pressure control, weight loss and increased physical activity. To measure progression of atherosclerosis, a quantitative, computer-assisted coronary arteriographic system was developed to analyze the baseline and 4-year follow-up arteriograms. This procedure uses a catheter with a metallic calibration cylinder at its tip to determine absolute artery size and automated computer edge detection techniques to define the internal border of the artery. The analysis system detects artery borders using changes in cine film density and measures distances between these borders. For each segment the minimum, maximum and mean diameters are measured and percent stenosis and atheroma area calculated. This system provides precise and reproducible measures of coronary artery segment diameter. Using this technique, we estimate a 33% reduction in the rate of coronary artery progression over 4 years, defined as mean segment diameter, can be detected at a power of 0.80 and an alpha of 0.05 (one tailed test) with a sample size of 120 in each of 2 groups.

Exercise exerts both acute and chronic effects on plasma lipid and lipoprotein concentrations. Much of the triglyceride-lowering effect is an acute response, with the changes in cholesterol having a greater chronic component. The acute Tg decrease seems to be due to accelerated catabolism resulting from increased LPL activity. Following exercise, and on a more chronic basis, decreased VLDL-Tg synthesis may also occur in response to an increase in tissue insulin sensitivity. The low body fat content of endurance-trained athletes also contributes to lower Tg concentrations, through this same mechanism. The magnitude of the plasma Tg response to acute or chronic exercise is highly influenced by preexercise values--decreases in plasma Tg occur only when preexercise values are elevated. The major exercise effect on plasma cholesterol appears to be an increase in HDL-C as a result of endurance training, very likely related to the increase in LPL activity and Tg catabolism. This response is not always achieved with exercise training, and has been especially difficult to demonstrate in previously sedentary women. Exercise effects on HDL-C may be augmented by weight loss or changes in nutrient intake, but these interrelationships are not well established. A dose-response relationship exists, with the lower threshold influenced by baseline HDL-C values and exercise status. The higher HDL-C associated with endurance training is the result of increases in the less dense HDL2 subfraction, with elevations in both the lipid and protein components. Relatively small decreases in LDL-C occur with training. The biological mechanisms for these exercise effects have not been established.

The Sphygmetrics SR-2 Automatic Blood Pressure Recorder uses an infrasonic technique for detecting artery wall motion to estimate systemic arterial pressure and produces a permanent record of the results. It therefore is potentially useful in reducing observer bias in epidemiologic studies of blood pressure (BP). Two blood pressures were recorded in 21 men and 50 women using the SR-2 simultaneously with two auscultators using a biaural stethoscope and mercury syhgmomanometer. The SR-2 measured slightly higher systolic nd slightly lower diastolic pressures on average, but the differences were not significant. The two auscultators were highly correlated with one another (r = 0.99 systolic/0.97 diastolic) and with the SR-2 (0.93 and 0.92 for systolic, 0.84 and 0.85 for diastolic). The correlations were unrelated to sex, age, or antihypertensive medication status, but the correlations between th SR-2 and either auscultator for diastolic BP were quite low (0.36, 0.55) in subjects whose relative weight was below 1.0. Interpretation of the SR-2 disc was very reliable, with inter- and intra-reader correlations being 0.99 for systolic and 0.84 to 0.94 for diastolic. The SR-2 was found to be comparable to auscultation in estimating systolic BP in a heterogeneous population which has the advantages of reducing observer bias and producing a permanent record. Its use in estimating diastolic pressure in thin individuals and children needs further evaluation.

This paper presents the results of an analysis of dietary alcohol use and blood pressure in representative population samples from four northern California cities surveyed in 1979-1980 as part of the Stanford Five City Project. The pooled samples included 883 men and 959 women aged 20-74 who were not taking blood pressure medications. Blood pressure was obtained while seated using a standard manometer. Alcohol was assessed by self-report of usual intake. In men, age-specific analysis revealed a positive association between dietary alcohol and both systolic (SBP) and diastolic blood pressure (DBP). The association was linear in men aged 20-34 and 50-74 and was stronger in the oldest men. Both linear and quadratic terms were significant for men aged 35-49. This association remained significant in a linear regression model that included age, relative weight, income, education, physical activity, cigarette use, and untimed urinary sodium/creatinine; for alcohol in ml/day in men aged 50-74, beta = 0.21, p = 0.0001, R2 = 0.32 for SBP; beta = 0.09, p = 0.0002, R2 = 0.18 for DBP. In women, alcohol use was significantly associated with blood pressure only in those above age 49 and was more striking in those not taking estrogens; this association was also independent of the same variables listed above for men (beta = 0.43, p = 0.0001, R2 = 0.23 for SBP; beta = 0.17, p = 0.001, R2 = 0.13 for DBP). Multiple logistic analyses with hypertension as a dichotomous dependent variable and including all subjects showed similar results. These results could be due to any one or more of the following hypotheses: 1) a biologic response to alcohol in older men and in older women that is different from the response in younger persons; 2) a delayed effect of alcohol use on blood pressure; 3) effects of a different pattern of alcohol use in the different age groups; or 4) the presence of some unmeasured confounding factor in the older age groups.