Exercise and the heart. Good, benign, or evil?

The Influence of the Group with Elderly Exercisers

This study examined the relationship of group cohesion to attitude and control beliefs toward exercise in a sample of older adults within the broader framework of the theory of planned behavior (N = 179, 27% male, average age = 67 years, SD = 7.77). Perceptions of task and social cohesion were assessed as well as attitude toward exercise, perceptions of control over attendance, and exercise intention. Following the assessment of the cognitive variables, exercise attendance was monitored for 4 weeks. Results revealed that task cohesion was related to perceptions of control (p < .05), whereas social cohesion was related to attitude toward exercise (p < .05). In turn, perceptions of control were related to intention to exercise (p < .01), and intention to exercise and perceptions of control were related to exercise class attendance (p < .01). Contrary to predictions, task cohesion did add to the prediction of attitude, but attitude was not related to exercise intentions.

Disparate effects of improving aerobic exercise capacity and quality of life after cardiac rehabilitation in young and elderly coronary patients

PURPOSE

Although cardiopulmonary exercise variables predict prognosis, functional capacity, and quality of life (QoL) in patients with coronary artery disease (CAD), these variables have not been assessed fully before and after exercise training in elderly with CAD. Therefore, the purpose of this study was to determine the impact of formal Phase II cardiac rehabilitation and exercise training programs on cardiopulmonary variables and QoL in elderly and younger CAD patients.

METHODS

The authors analyzed consecutive patients before and after Phase II cardiac rehabilitation and exercise training programs, and compared exercise cardiopulmonary data and data from validated questionnaires assessing QoL (MOS SF-36) and function in 125 younger patients (< 55 years; mean 48 +/- 6 years) and 57 elderly (> 70 years; mean 78 +/- 3 years).

RESULTS

At baseline, elderly patients had lower estimated aerobic exercise capacity (-27%; P < 0.001), peak oxygen consumption (VO2) (-19%; P < 0.01), and anaerobic threshold (-10%; P < 0.05), as well as total function scores (-11%; P < 0.01) and total QoL scores (-5%; P = 0.06). Commonly used prediction equations greatly overestimated aerobic exercise capacity compared with precise measurements using cardiopulmonary testing both before (+23% and +12% in younger and elderly patients, respectively) and after the exercise training programs (+51% and +31% in younger and elderly patients, respectively), and more so in younger compared with older patients. After rehabilitation, the elderly had significant improvements in estimated aerobic exercise capacity (+32%; P < 0.0001), peak VO2 (+13%; P < 0.0001), anaerobic threshold (+11%; P = 0.03), total function scores (+27%; P < 0.0001), and total QoL scores (+20%; P < 0.0001). Although younger patients had greater improvements in estimated aerobic exercise capacity (+44% versus +32%; P = 0.08), peak VO2 (+18% versus +13%; P < 0.01), and anaerobic threshold (+17% versus +11%; P = 0.07), the elderly had statistically greater improvements in both function scores (+27% versus +20%; P = 0.02), and total QoL scores (+20% versus +14%; P = 0.03).

CONCLUSIONS

These data confirm the benefits of precisely determining aerobic exercise capacity by cardiopulmonary function, especially to determine the benefits of an exercise training program. In addition, these data using cardiopulmonary exercise tests and validated assessments of quality of life demonstrate the disparate effects of cardiac rehabilitation programs on improvements in aerobic exercise capacity and QoL in young and elderly with CAD.

Group cohesion in older adult exercisers: prediction and intervention effects

Two studies were conducted to examine the relationship between class cohesion and exercise adherence in older adult exercisers. Study 1 examined the predictive ability of four dimensions of cohesion on exercise participation at 1, 6, and 12 months following the initial assessment of cohesion. Study 2 examined the effectiveness of a team-building intervention, designed to enhance class cohesion (and based on Study 1 results), on improving exercise adherence and return rates. Participants were assigned to a team-building, placebo, or control condition. Study 1 showed that three measures of cohesion, Individual attractions to the group-social, Group integration-social, and Group integration-task, were all significantly related to exercise class attendance following a 1-month interval. Group integration-task was significantly related to class attendance following a 6- and a 12-month interval. Study 2 showed that participants in the team-building condition (a) attended more classes than the control and placebo conditions and (b) had a higher return rate following a 10-week hiatus than the control condition. It was concluded that (a) class cohesion plays a significant role in exercise class participation, both short- and long-term, and (b) samples of older adult exercisers are appropriate groups for interventions based on developing class cohesion.

Cardiac rehabilitation and preventive cardiology in the elderly

This article reviews data demonstrating the benefits of cardiac rehabilitation and exercise training programs in the elderly. Other risk factor interventions, including cessation of smoking, treatment of diabetes, and lipid therapy, are very beneficial for the elderly with coronary heart disease or strong risk of coronary heart disease. Also briefly reviewed are current data suggesting the benefits of antioxidant vitamins, and folic acid to reduce levels of homocysteine for the primary and secondary prevention of coronary heart disease in the elderly.

The conceptualization and effect of control beliefs on exercise attendance in the elderly

The purpose of the study was to compare the relative merits of two approaches to the measurement of perceived behavioral control for the prediction of attendance in an exercise program in an elderly population. The first approach was to conceptualize perceived behavioral control in the traditional manner outlined by Ajzen (1987). The second approach was to conceptualize control beliefs as two distinct constructs: scheduling self-efficacy and perceived barriers to exercise. Participants (N = 157, average age = 68 years +/-7.87, 74% female) were volunteers from elderly exercise classes. Participants were asked to complete questionnaires assessing the constructs at Weeks 5 and 9 of a 16-week exercise program. Attendance was monitored and used as the dependent variable. Results revealed that in an active elderly sample, (a) scheduling self-efficacy is a superior conceptualization for control beliefs than perceived behavioral control, (b) neither attitude nor subjective norm predict intention or attendance in an exercise program, and (c) perceived barriers to exercise are not related to exercise intention or attendance.

Causes of sudden death in young and middle-aged competitive athletes

The incidence of sudden death in athletes is low. Some pathologic conditions may predispose to sudden death during exercise in young athletes. In older individuals, exercise may trigger terminal arrhythmias in patients with severe coronary atherosclerosis. Screening programs with a history and a physical examination are recommended for high school and collegiate sports participants. For older individuals who are likely to have undetected or overt coronary heart disease and are exercising for physical fitness, caution regarding the level of activity and type of symptoms that are frequently associated with coronary disease may help prevent sudden death.

Behavioral differences and effects of cardiac rehabilitation in diabetic patients following cardiac events

PURPOSE

To describe the incidence of depression and other behavioral disorders in diabetic coronary patients following major cardiac events and to assess the impact of cardiac rehabilitation.

PATIENTS

291 consecutive coronary patients (70 with diabetes mellitus).

METHODS

Patients were prospectively enrolled in comprehensive phase II cardiac rehabilitation 4 to 6 weeks following a major cardiac event. Depressive symptoms and other behavioral characteristics (anxiety, somatization, hostility), as well as parameters of quality of life, were assessed by validated questionnaires at entry and upon completion (12 weeks, 36 sessions) of cardiac rehabilitation.

RESULTS

Diabetic patients made up 24% of the cohort and were more likely to be female (P = 0.08), hypertensive (P = 0.05), and obese (P = 0.08). Additionally, diabetic patients had a reduced exercise capacity (P = 0.008), lower high-density lipoprotein cholesterol (P = 0.008), lower low-density lipoprotein cholesterol (P = 0.02), and increased triglyceride (P = 0.04) levels. Diabetic patients had a higher incidence of depression (26% versus 14%; P < 0.03), demonstrated more symptoms of somatization (P < 0.06), and exhibited lower scores for components of quality of life. Following cardiac rehabilitation, the incidence of depression was reduced in diabetic patients by 67% (P = 0.01) and ultimately equaled the 9% prevalence found in the non-diabetic group.

CONCLUSIONS

Diabetic coronary patients demonstrate a higher incidence of depression than non-diabetic patients following major cardiac events. In addition to improving traditional cardiac risk factors, cardiac rehabilitation reduces depression in this high-risk group.

Effects of cardiac rehabilitation and exercise training in obese patients with coronary artery disease

STUDY OBJECTIVE

To determine the effects of cardiac rehabilitation and exercise training in obese coronary patients.

DESIGN

We compared data before and after cardiac rehabilitation between obese and nonobese patients.

SETTING

Two large teaching institutions.

PATIENTS

116 obese (body mass index [BMI] > or = 27.8 kg/m2 for men and > or = 27.3 kg/m2 for women; mean, 31.2 +/- 3.2 kg/m2] and 198 (mean BMI, 24.6 +/- 2.1 kg/m2) nonobese patients with recent cardiac events.

INTERVENTIONS

A 3-month (36-session) formal, outpatient phase 2 cardiac rehabilitation and supervised exercise training program.

MEASUREMENTS AND RESULTS

At baseline, obese patients had higher levels of total cholesterol (p < 0.01), low-density lipoprotein-cholesterol (LDL-C [p < 0.01]), LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio (p < 0.01), percentage body fat (p < 0.02), and a higher prevalence of hypertension (p < 0.05) than the nonobese patients, but the prevalence of diabetes mellitus and of other coronary risk factors was similar. After cardiac rehabilitation, there were modest reductions in the prevalence of obesity (116 patients [37%] vs 104 patients [33%]) and severe obesity (BMI > or = 35 kg/m2 [3.5 vs 2.5%]), although these improvements were not statistically significant. The obese patients had improvements in exercise capacity (+24%; p < 0.001), BMI (-3%; p < 0.0001), LDL-C (-4%; p = 0.07), HDL-C (+6%; p < 0.001), and LDL-C/HDL-C ratio (-10%; p < 0.01). Although reduction in BMI was greater in the obese patients (-3 vs 0%; p < 0.0001), improvement in exercise capacity was greater in the nonobese (+36 vs +24%; p < 0.01); improvements in lipid fractions and percentage body fat were statistically similar between the groups.

CONCLUSION

Modest reductions in BMI, obesity, and severe obesity occur after cardiac rehabilitation. In addition, obese patients demonstrate significant improvements in most coronary risk factors after rehabilitation, although improvements in exercise capacity are greater in nonobese patients. Potentially, more significant improvements in exercise capacity and lipid values may occur by specifically targeting obese patients for further weight reduction and exercise training after major cardiac events.

Insights into the pathogenesis and prevention of coronary artery disease

OBJECTIVE

To present information about risk factor clustering and the oxidation hypothesis of atherosclerosis and attempt to synthesize these facts into a clinically relevant approach to patients with or at risk for coronary artery disease (CAD).

MATERIAL AND METHODS

The total cholesterol level is a relatively weak marker for the risk of CAD. The levels of both high-density lipoprotein (HDL) cholesterol and remnants of triglyceride-rich lipoproteins and the inherent susceptibility of the low-density lipoprotein (LDL) particles to oxidative modification may be as important as the total or LDL cholesterol levels. LDL cholesterol must undergo oxidative modification by means of oxygen free radical processes before it becomes atherogenic. Patients with high levels of oxidative stress include those with risk factor clustering or insulin resistance (or both). Such patients are characterized by hypertension, truncal obesity, hypertriglyceridemia, depressed HDL cholesterol levels, and increased insulin levels. They also have increased levels of triglyceride-rich remnant lipoproteins and LDL particles that are characterized by their small dense nature and pronounced predisposition to oxidative modification.

RESULTS

Biologic antioxidants seem to be promising therapy for the prevention of atherogenesis. Although long-term prospective data are not yet available, vitamin E has been shown to be effective in both animal and human models in preventing LDL oxidation, and it may have a role in the prevention of CAD. A healthy diet of fresh fruits, vegetables, and whole grains is beneficial because it improves the lipid levels and provides high levels of natural antioxidants. The atherogenic potential of hydrogenated polyunsaturated fats is approximately equivalent to that of saturated fats. Monounsaturated fat is inherently resistant to oxidation and may be protective against CAD. Niacin may be effective in patients with clustered risk factors. It has been found to convert the easily oxidized small dense LDL pattern to the large buoyant oxidation-resistant particles. Hydroxymethylglutaryl-coenzyme A reductase inhibitors are well tolerated and highly effective in decreasing LDL cholesterol, but they are expensive. Estrogen has multiple potentially beneficial effects relative to cardiovascular disease.

CONCLUSION

Persons with or at high risk for CAD should be identified early and aggressively treated with a program that involves lifestyle changes, alterations in dietary intake, and pharmacologic therapy.

Patients with high baseline exercise capacity benefit from cardiac rehabilitation and exercise training programs

Despite the well-proven benefits of cardiac rehabilitation and exercise training, no data are available on the benefits of this therapy in patients with preserved baseline exercise capacity. Therefore we assessed data before and after phase II cardiac rehabilitation and exercise programs at two large teaching institutions to determine the benefits in 163 patients with high baseline exercise capacity (> or = 6 estimated [mean 8.8 +/- 2.4] metabolic equivalents [METs]) compared with 125 patients with low baseline functional capacity (< 6 estimated [mean 4.6 +/- 0.8] METs). After cardiac rehabilitation and exercise training, patients with high baseline exercise capacity had significant improvements in triglyceride (-10%; p < 0.05), high-density lipoprotein cholesterol (+7%; p < 0.001), and low-density lipoprotein cholesterol (-4%; p = 0.09) levels; low-density lipoprotein/high-density lipoprotein ratio (-10%; p < 0.01); body mass index (-1.5%; (p < 0.001); percent body fat (-6%; p < 0.0001); and exercise capacity (+22%; p < 0.0001). Patients with high baseline exercise capacity had less relative improvement in exercise capacity (p < 0.0001) after cardiac rehabilitation but had greater relative improvement in low-density lipoprotein cholesterol level (p < 0.05) and low-density lipoprotein/high-density lipoprotein ratio (p < 0.05) than did patients with low baseline exercise capacity. These data demonstrate the benefits of cardiac rehabilitation and exercise training in patients with preserved exercise capacity and support routine referral of these patients to these programs after major cardiac events.

Sudden Death During Exercise

Sudden death during exertion is extremely rare. Among adults older than 30, coronary artery disease is the predominant cause of sudden death. Attention to risk factors and premonitory symptoms is the best prevention. Doing the appropriate testing, tailoring exercise programs, and discouraging denial help minimize the risk. But above all, physicians can help keep patients' fears in check so as not to deprive patients of the unquestionable benefits of exercise.

Benefits of cardiac rehabilitation and exercise training in secondary coronary prevention in the elderly

OBJECTIVES

The aim of this study was to determine the effects of cardiac rehabilitation and exercise training on plasma lipids, indexes of obesity and exercise capacity in the elderly and to compare the benefits in elderly patients with coronary heart disease with benefits in a younger cohort.

BACKGROUND

Despite the well proved benefits of cardiac rehabilitation and exercise training, elderly patients with coronary heart disease are frequently not referred or vigorously encouraged to pursue this therapy. In addition, only limited data are available for these elderly patients on the benefits of cardiac rehabilitation on plasma lipids, indexes of obesity and exercise capacity.

METHODS

At two large multispecialty teaching institutions, baseline and post-rehabilitation data including plasma lipids, indexes of obesity and exercise capacity were compared in 92 elderly patients (> or = 65 years, mean age 70.1 +/- 4.1 years) and 182 younger patients (< 65 years, mean 53.9 +/- 7.4 years) enrolled in phase II cardiac rehabilitation and exercise programs after a major cardiac event.

RESULTS

At baseline, body mass index (26.0 +/- 3.9 vs. 27.8 +/- 4.2 kg/m2, p < 0.001), triglycerides (141 +/- 55 vs. 178 +/- 105 mg/dl, p < 0.01) and estimated metabolic equivalents (METs) (5.6 +/- 1.6 vs. 7.7 +/- 3.0, p < 0.0001) were lower and high density lipoprotein cholesterol was greater (40.4 +/- 12.1 vs. 37.5 +/- 10.4 mg/dl, p < 0.05) in the elderly than in younger patients. After rehabilitation, the elderly demonstrated significant improvements in METs (5.6 +/- 1.6 vs. 7.5 +/- 2.3, p < 0.0001), body mass index (26.0 +/- 3.9 vs. 25.6 +/- 3.8 kg/m2, p < 0.01), percent body fat (24.4 +/- 7.0 vs. 22.9 +/- 7.2%, p < 0.0001), high density lipoprotein cholesterol (40.4 +/- 12.1 vs. 43.0 +/- 11.4 mg/dl, p < 0.001) and the ratio of low density to high density lipoprotein cholesterol (3.6 +/- 1.3 vs. 3.3 +/- 1.0, p < 0.01) and a decrease in triglycerides that approached statistical significance (141 +/- 55 vs. 130 +/- 76 mg/dl, p = 0.14) but not in total cholesterol or low density lipoprotein cholesterol. Improvements in functional capacity, percent body fat and body mass index, as well as lipids, were statistically similar in the older and younger patients.

CONCLUSIONS

Despite baseline differences, improvements in exercise capacity, obesity indexes and lipids were very similar in older and younger patients enrolled in cardiac rehabilitation and exercise training. These data emphasize that elderly patients should not be categorically denied the psychosocial, physical and risk factor benefits of secondary coronary prevention including formal cardiac rehabilitation and supervised exercise training.

Left ventricular hypertrophy. Its relationship to obesity and hypertension

Hypertension and obesity are closely related. Obese patients tend to have increased intravascular volume and cardiac output and decreased total peripheral vascular resistance and plasma renin activity. Lean patients with essential hypertension usually have increased total peripheral resistance. Left ventricular adaptation in obesity consists of eccentric left ventricular hypertrophy (LVH), regardless of the level of arterial pressure. Obesity and hypertension occurring together place a dual burden on the left ventricle and are associated with systolic and diastolic dysfunction, lipid abnormalities, insulin resistance, and a propensity for frequent, complex ventricular arrhythmias. Congestive heart failure and sudden death are common sequelae of obesity-hypertension and LVH. Treatment should include vigorous efforts at weight reduction and sodium restriction. Diuretics are ideal agents from a hemodynamic standpoint but often do not improve the total risk profile, with the possible exception of indapamide (Lozol). Calcium blockers may be ideal agents because of their favorable effects on both hemodynamics and total cardiovascular risk profile.