Carole M. Schneider

Effects of supervised exercise training on cardiopulmonary function and fatigue in breast cancer survivors during and after treatment

Cancer treatments have serious physiological and psychological side effects in cancer survivors. This investigation examined cardiopulmonary function and fatigue in breast cancer survivors during and after treatment by using similar exercise assessments, prescriptions, individualized interventions, and reassessments.

Exercise training attenuates acute doxorubicin-induced cardiac dysfunction.

The use of doxorubicin, a highly effective antitumor antibiotic, is limited by a dose-dependent cardiotoxicity. The purpose of this study was to determine whether chronic exercise training (ET) prior to doxorubicin treatment would preserve cardiac function and reduce myocardial oxidative stress following treatment. Rats were exercise trained on a motorized treadmill or confined to sedentary cage activity for 12 weeks, then administered an intraperitoneal injection of doxorubicin (15 mg/kg) or 0.9% saline. Five days following the injections, hearts were isolated and Langendorf perfused to assess cardiac function and then processed for biochemical analyses. Doxorubicin treatment induced significant inotropic, lusitropic, and chronotropic cardiac dysfunction, reduced coronary flow, and increased cardiac lipid peroxidation in the sedentary animals. Doxorubicin treatment was also associated with a decrease in cardiac manganese superoxide dismutase protein expression and an increase in heat shock protein-72 (Hsp72) compared with saline-treated animals. Exercise training attenuated doxorubicin-induced cardiac dysfunction, and lipid peroxidation, and led to a greater cardiac expression of Hsp72 compared with the sedentary animals. The results of this study demonstrate for the first time that chronic exercise training before doxorubicin treatment protects against cardiac dysfunction following treatment, and provide evidence for a sustained increase in myocardial Hsp72 following exercise training and doxorubicin treatment in vivo.

Exercise Preconditioning Protects against Doxorubicin-Induced Cardiac Dysfunction

UNLABELLED The clinical use of the chemotherapeutic drug doxorubicin (DOX) is limited due to a dose-dependent cardiotoxicity. Evidence is mounting that exercise protects against DOX-related cardiac dysfunction, and as such, it may be possible that prior endurance training promotes defense against DOX cardiotoxicity. PURPOSE To examine the effects of exercise preconditioning on acute DOX-induced cardiotoxicity, and to determine whether any observed cardioprotection was associated with myosin heavy chain (MHC) isoform alterations. METHODS Male Sprague-Dawley rats trained on a motorized treadmill, had access to voluntary running wheels, or remained sedentary for 10 wk prior to being injected with either saline or 10 mg.kg(-1) DOX. Left ventricular function was then assessed in vivo using transthoracic echocardiography and ex vivo using the isolated working heart at 5 and 10 d after injection. Additionally, left ventricular MHC isoform expression was analyzed as a possible mechanism to explain exercise-induced cardioprotection. RESULTS DOX treatment promoted significant in vivo and ex vivo cardiac dysfunction at 5 and 10 d after injection in sedentary animals, and this dysfunction was associated with an upregulation of the beta-MHC isoform. Exercise preconditioning protected against DOX-induced cardiac dysfunction at 5 and 10 d after injection by attenuating beta-MHC upregulation. CONCLUSION Endurance training prior to DOX treatment protects against acute DOX cardiotoxicity for up to 10 d, and this protection can potentially be explained by a preservation of MHC isoform distribution.

Acute Exercise Protects Against Doxorubicin Cardiotoxicity

Numerous methods have been used to minimize the cardiotoxic effects of the chemotherapeutic agent doxorubicin (DOX), and most have had limited success. Chronic endurance exercise has been shown to protect against DOX cardiotoxicity, but little is known regarding the effects of acute exercise on DOX-induced cardiac dysfunction. Purpose. The purpose of this study was to determine the effects of a single bout of acute endurance exercise on the cardiac dysfunction associated with DOX treatment. Methods. Male Sprague-Dawley rats either performed an acute exercise bout on a motorized treadmill for 60 minutes at a maximal speed of 25 m/min with a 5% grade (EX) or remained sedentary (SED) 24 hours before receiving either a 15-mg/kg DOX bolus dose or saline (SAL). Cardiac function was then analyzed 5 days post injection using a Langendorff isolated perfused heart model. In addition, myocardial lipid peroxidation was analyzed as an indicator of oxidative stress. Results. Doxorubicin treatment alone (SED+DOX) promoted a significant decline in end-systolic pressure (—35%), left ventricular developed pressure (—59%), and the maximal rate of left ventricular pressure development (—43%) as well as a 45% increase in lipid peroxidation products when compared with SED+SAL (P < .05). Acute exercise 24 hours before DOX treatment, however, had a cardioprotective effect, as end-systolic pressure, left ventricular developed pressure, and the maximal rate of left ventricular pressure development were significantly higher in EX+DOX compared with SED+DOX (P < .05) and EX+DOX had similar levels of lipid peroxidation products as SED+SAL Conclusions. An acute exercise bout performed 24 hours before DOX treatment protected against cardiac dysfunction, and this exercise-induced cardioprotection may partly be explained by a reduction in the generation of reactive oxygen species.

Effects of a Supervised Exercise Intervention on Recovery From Treatment Regimens in Breast Cancer Survivors

PURPOSE/OBJECTIVES To investigate the effects of supervised exercise training on cardiopulmonary function and fatigue in cancer survivors undergoing various clinical treatments. DESIGN Pretest and post-test quasiexperimental. SETTING Outpatient oncology rehabilitation center. SAMPLE 96 breast cancer survivors undergoing various clinical treatments. METHODS Subjects were divided into four groups based on the specific type of clinical treatment: surgery alone (n = 22); surgery and chemotherapy (n = 30); surgery and radiation (n = 17); and surgery, chemotherapy, and radiation (n = 27). Following a comprehensive screening and medical examination, cardiovascular endurance, pulmonary function, and fatigue were assessed, leading to the development of an individualized exercise prescription and a six-month exercise intervention. Repeated-measures analysis of variance and covariance were used to compare the effectiveness of the intervention and differences among treatment groups. MAIN RESEARCH VARIABLES Systolic and diastolic blood pressure, resting heart rate, forced vital capacity, forced expiratory volume, predicted oxygen consumption, time on treadmill, and fatigue. FINDINGS Cardiopulmonary function (predicted maximal oxygen consumption and time on treadmill) significantly increased in all groups after exercise training. In addition, resting heart rate and forced vital capacity significantly improved in those receiving surgery, chemotherapy, and radiation. Psychologically, the exercise intervention resulted in significant reductions in behavioral, affective, sensory, cognitive and mood, and total fatigue scale scores in all three groups who received treatment with surgery. The breast cancer survivors in the surgery-alone group showed significant reductions in behavioral, affective, and total fatigue scale scores but not in sensory and cognitive and mood fatigue scale scores. CONCLUSIONS The results suggest that moderate intensity, individualized, prescriptive exercise maintains or improves cardiopulmonary function with concomitant reductions in fatigue regardless of treatment type. Moreover, cancer survivors receiving combination chemotherapy and radiotherapy following surgery appear to benefit to a greater extent as a result of an individualized exercise intervention. IMPLICATIONS FOR NURSING Clinicians need to be aware of adjuvant therapies such as moderate exercise that attenuate negative side effects of cancer treatments. Symptom management recommendations should be given to cancer survivors concerning the effectiveness of exercise throughout the cancer continuum and the importance of participating in a cancer rehabilitation exercise program.

Exercise Training Manages Cardiopulmonary Function and Fatigue During and Following Cancer Treatment in Male Cancer Survivors

This investigation determined the cardiopulmonary function and fatigue alterations in male cancer survivors during treatment as well as following treatment utilizing similar exercise assessment protocols and individualized, prescriptive exercise interventions. The study included 45 male cancer survivors that were referred by local oncologists. Following a comprehensive screening and physical examination, cardiovascular endurance, pulmonary function, and fatigue were assessed leading to the development of 12-week individualized exercise prescriptions and exercise interventions. The cancer survivors were divided into during treatment (DTm) and following treatment (FTm) groups. Repeated-measures analysis of variance and analyses of covariance were used to compare pre- versus postintervention and between groups. Cardiopulmonary function was maintained in the DTm, whereas the FTm showed significant reductions in resting heart rate (P < .05) with concurrent increases in predicted VO2max and time on treadmill ( P < .05) postexercise intervention. Fatigue levels did not increase in the DTm group, whereas the FTm group showed significant reductions in behavioral fatigue, affective fatigue, sensory fatigue, cognitive/mood fatigue, and total fatigue (P < .05) after the exercise intervention. The results of the current study suggest that moderate intensity, individualized, prescriptive exercise intervention maintains or improves cardiovascular and pulmonary function with concomitant reductions in fatigue in cancer survivors during and following cancer treatment. Exercise appears to be a safe, efficacious strategy for improving physical fitness in cancer survivors during and following treatment.

Effects of physical activity on creatine phosphokinase and the isoenzyme creatine kinase-MB.

Creatine phosphokinase (CPK) and creatine kinase-MB (CK-MB) have been used extensively as diagnostic markers for myocardial infarction and skeletal muscle injury. Many factors affect the variability of serum CPK and serum CK-MB activity, especially physical activity. We discuss the influence of physical activity on muscle and serum CPK and CK-MB. The effect of acute and chronic exercise on CPK and CK-MB activity emphasizes the need to use measurements of serum CPK and CK-MB with caution when evaluating and diagnosing acute myocardial infarctions and skeletal muscle injury.

The Effects of Walking Poles on Shoulder Function in Breast Cancer Survivors

Breast cancer treatment often results in impaired shoulder function, in particular, decrements in muscular endurance and range of motion, which may lead to decreased quality of life. The purpose of this investigation was to determine the effects of walking pole use on shoulder function in female breast cancer survivors. Participants had previously been treated with 1 or a combination of the following: mastectomy, breast conservation therapy, axillary lymph node dissection, chemotherapy, or radiation. Participants were randomly placed in experimental (n = 6) and control (n = 6) groups and met with a cancer exercise specialist 2 times each week for 8 weeks. The experimental group used walking poles during the 20-minute aerobic portion of their workout, whereas the control group did not use walking poles but performed 20 minutes of aerobic exercise per workout session. Both groups participated in similar resistance training programs. Testing was done pre- and postexercise intervention to determine upper body muscular endurance and active range of motion at the glenohumeral joint. Repeated-measures analysis of variance (ANOVA) revealed significant improvements in muscular endurance as measured by the bench press ( P = .046) and lat pull down ( P = .013) in the walking pole group. No within-group improvements were found in the group that did not use walking poles. The data suggest that using a walking pole exercise routine for 8 weeks significantly improved muscular endurance of the upper body, which would clearly be beneficial in helping breast cancer survivors perform activities of daily living and regain an independent lifestyle.

Exercise Preconditioning Provides Long-Term Protection Against Early Chronic Doxorubicin Cardiotoxicity

Acute doxorubicin (DOX) cardiotoxicity can be attenuated by exercise preconditioning, but little is known of whether this cardioprotection continues beyond 10 days post-DOX administration. The purpose of this study was to determine the effects of exercise preconditioning on early chronic DOX-induced cardiotoxicity. Male rats were randomly assigned to sedentary, treadmill, or wheel running groups. Treadmill and wheel running animals participated in a progressive treadmill training protocol or voluntary wheel running, respectively, for 10 weeks. Following the intervention, animals were further randomized to receive either DOX (sedentary + DOX, treadmill + DOX, wheel running + DOX) or saline (sedentary + saline, treadmill + saline, wheel running + saline). All animals then remained sedentary for 4 weeks. A 22% reduction in fractional shortening was observed in left ventricles from previously sedentary animals receiving DOX when compared with sedentary + saline. This degree of decline was not observed in treadmill + DOX and wheel running + DOX. Sedentary + DOX possessed significantly depressed mitral and aortic valve blood flow velocities when compared with sedentary + saline, but these decrements were not observed in treadmill + DOX and wheel running + DOX. Ex vivo analysis revealed that left ventricular developed pressure and maximal rate of pressure development were significantly lower in sedentary + DOX when compared to sedentary + saline. Treadmill and wheel running prior to DOX treatment protected against these decrements. Exercise cardioprotection was associated with preserved myosin heavy chain but not sarcoendoplasmic reticulum Ca2+ ATPase 2a expression. In conclusion, 10 weeks of prior exercise protected against early chronic DOX cardiotoxicity suggesting that training status may be a determining factor in the degree of late-onset cardiotoxicity experienced by cancer patients undergoing treatment with DOX.

The relationship between physical activity and 2-hydroxyestrone, 16α-hydroxyestrone, and the 2/16 ratio in premenopausal women (United States)

Objectives: Estrogen is metabolized in the body through two mutually exclusive pathways yielding metabolites with different biological activities: the low estrogenic 2-hydroxyestrone (2-OHE1) and the highly estrogenic 16α-hydroxyestrone (16α-OHE1). The ratio of these metabolites (2/16) may be predictive of risk for developing breast cancer. Early evidence has demonstrated that exercise may alter estrogen metabolism to favor the weak estrogen, 2-OHE1. Methods : Seventy-seven eumenorrheic females completed physical activity logs for two weeks prior to providing a luteal phase urine sample. Concentrations of 2-OHE1 and 16α -OHE1 were measured and the 2/16 ratio computed. Hierarchical regression, controlling for age and body mass index (BMI), was used to determine relationships between estrogen metabolites and daily physical activity. Results : Regression analyses indicated significant positive relationships between physical activity and 2-OHE1 and the 2/16 ratio (p < 0.05) that appears to be independent of BMI. 16αOHE1 was not significantly related to physical activity. Conclusion : These results indicate that physical activity may modulate estrogen metabolism to favor the weak estrogen, 2-OHE1, thus producing a higher 2/16 ratio. This alteration in estrogen metabolism may represent one of the mechanisms by which increased physical activity reduces breast cancer risk.