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A one-year lifestyle intervention improves myocardial function in patients with chronic kidney disease
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
adaptation to exercise using supervised intensive longitudinal exercise interventions. In contrast with textbook dogma, we observed no evidence in healthy, young and relatively inactive subjects to support the notion that resistance training induces concentric cardiac hypertrophy. Our data are consistent with previous echocardiographic evidence which suggests that endurance training results in increased LVM and EDV, although echo data underestimates LVM relative to MRI possibly exaggerating the magnitude of this effect. These adaptations were maintained for 6 weeks following exercise cessation. In conclusion, endurance exercise induces cardiac morphological adaptations whereas resistance exercise does not, despite the presence of physiological adaptations in strength and body composition. Our data overturns previous assumptions that have been widely adopted in the literature. doi:10.1016/j.jsams.2011.11.042 41 Acute versus chronic exposure to androgen suppression for prostate cancer: Impact on the exercise response D. Galvao 1,∗ , D. Newton 1
Taaffe 2 , N.
Spry 3 , D.
Joseph 3 , R.
1 Edith
Cowan University Health and Wellness Institute, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Australia 2 School of Environmental and Life Sciences, University of Newcastle, Australia 3 Sir Charles Gairdner Hospital, Radiation Oncology, Australia Introduction: Exercise has been proposed as an effective countermeasure for androgen suppression therapy (AST) induced side effects. Given that the magnitude of fat gain and muscle loss are most pronounced during the early phases of AST, it is possible that the exercise response may differ according to the duration of AST. We investigated whether the exercise response might vary according to the prior length of exposure to AST; acute (<6 months) versus later (≥6 months). Methods: Fifty men (55–84 years) undergoing AST for non-bone metastases prostate cancer completed a progressive resistance and cardiovascular exercise program for 12 weeks – acute (n = 16) or chronic AST exposure (n = 34). The resistance exercises included 8 exercises and was designed to progress from 12 to 6-repetition maximum for 2 to 4 sets per exercise The aerobic component of the training program included 15–20 min of cardiovascular exercises (cycling and walking/jogging) at 65–80% maximum heart rate and perceived exertion at 11–13 (6–20 point, Borg scale). Fat and lean mass (dual-energy X-ray absorptiometry), muscle strength, functional performance, quality of life, and blood biomarkers were assessed. Results: Acute AST patients showed an increase in total body fat (0.9 kg, p = 0.018) compared to chronic AST
e21
although both groups experienced an increase in appendicular skeletal muscle (∼0.5 kg, p < 0.01). Triglycerides decreased in the chronic and increased in the acute AST groups (p = 0.027) with change in triglycerides associated with change in total body fat (r = 0.411, p = 0.004). There were no differences between groups for PSA, testosterone, glucose, insulin, total cholesterol, LDL and HDL cholesterol, CRP, homocysteine or quality of life and both groups showed similar improvement in muscle strength and function, and cardiovascular fitness. Conclusions: Apart from differences in body fat and triglycerides, the beneficial effects of exercise are similar in patients on acute or chronic AST. These results suggest that exercise training should be initiated when AST commences to enhance physical function, and improve the patient’s acceptance of hormone therapy. Future trials are warranted examining the role of physical exercise implemented at the onset of androgen suppression therapy on physical and physiological function, as well as quality of life. doi:10.1016/j.jsams.2011.11.043 42 A one-year lifestyle intervention improves myocardial function in patients with chronic kidney disease E. Howden 1,2,3,∗ , R. Leano 2,3 , W. Isbel 2,3,4 , J. Coombes 1,3 , T. Marwick 2,3
Petchey 2,3,4 , N.
1 School of Human Movement Studies, University of Queens-
land, Australia 2 School of Medicine, University of Queensland, Australia 3 Centre for Clinical Research Excellence – Vascular and Metabolic Health, University of Queensland, Australia 4 Department of Nephrology, Princess Alexandra Hospital, Brisbane, Australia Introduction: Myocardial dysfunction is common in patients with chronic kidney disease (CKD). Cardiovascular event rate is high is this population and effective management strategies are lacking. Therefore we sought to determine effect of a lifestyle intervention that included exercise training on myocardial function in patients with CKD. Methods: Eighty four patients, stages 3–4 CKD were randomised to either standard medical care (control) or lifestyle intervention (LI). LI involved 8 weeks of gym-based individualised exercise training under supervision of an accredited exercise physiologist followed by home based training with ongoing telephone support and gym refresher sessions for the remaining 12 months. In addition, patients attended 4 week behaviour and lifestyle change program led by a psychologist and dietician. LI included access to multidisciplinary care through a nurse practitioner led CKD clinic, which included a nephrologist, social worker and diabetes educator. Myocardial function was assessed at baseline and 12 months using standard echocardiography techniques and tissue Dopplerderived myocardial velocities. Anthropometric, biochemical
e22
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
and fitness data were collected at both time points. Data was analysed by intention to treat with effect of intervention compared to controls determined using analysis of covariance (ANCOVA). Results: 12 patients were lost to follow-up (LI = 34, control = 38). Baseline characteristics were similar (p > 0.05) between groups (LI = 67% male, age 60.7 ± 9.1, eGFR 39.4 ± 8.9; control = 56% male, age 58.7 ± 10.5 years, eGFR 39.7 ± 8.8). There were no baseline differences (Table 1). The intervention resulted in a significant 13.3% increase in exercise capacity, with decreases in weight and BMI in LI group. This group also showed improved diastolic function (increased E ). There was no significant change in systolic function or blood pressure. There were no changes in any biochemical parameters between groups. Conclusion: The lifestyle intervention significantly improved exercise capacity and diastolic function in CKD patients. Lifestyle and exercise interventions may assist in managing the deleterious effects of reduced kidney function on the myocardium. doi:10.1016/j.jsams.2011.11.044 43 Fitness and body composition: Which factors influence heart morphology? C. Buck 1,∗ , A. Spence 1 , H. Carter 1 , L. Dembo 2 , L. Naylor 1 , D. Green 1,3
surface area (BSA) and fitness on left ventricular cardiac morphology. Results: Left ventricular mass at end diastole (LVMed) was significantly correlated with VO2 peak (r = 0.73, p < 0.01), lean body mass (LBM) (r = 0.83, p < 0.01) and fat mass (r = 0.46, p < 0.05). Regression analysis revealed that total LBM was a more significant contributor to LVMed (t = 7.19, p < 0.01) and left ventricular end diastolic volume (LVEDv) (t = 3.22, p < 0.01) than BSA, fat mass and fitness. Analysis of regional components of body composition showed that LBM located around the hips and thighs (gynoid LBM) had the strongest correlation to LVMed (r = 0.84, p < 0.01), whilst the LBM of the legs had the strongest correlation to LVEDv (r = 0.86, p < 0.01). Conclusion: Fitness, fat mass, BSA and total LBM were all significantly correlated to LVMed. However, total LBM was the most significant contributor to cardiac morphology. Furthermore, gynoid and leg LBM were identified as stronger correlates to cardiac morphology than total LBM. Together these findings indicate that LBM located specifically in the gynoid and leg region may be the most appropriate scaling factors for cardiac morphology. Thus, scaling cardiac morphology by leg LBM may be particularly useful in resolving some of the disparities observed in studies investigating the Morganroth hypothesis. A potential physiological explanation for the strong relationship between LBM and cardiac morphology is likely to come from the strong influence of the muscle component of LBM on blood flow and hemodynamic loading of the heart.
1 University
of Western Australia, Australia Perth Hospital, Australia 3 Research Institute for Sports and Exercise Sciences (Liverpool), Australia 2 Royal
Background: There is considerable inconsistency regarding the methods used to scale cardiac morphology for the influence of body size in studies investigating the Morganroth hypothesis. This has led to disparities on observations and the interpretation of data on athlete’s heart. It has been suggested that body composition and cardiorespiratory fitness level are between participant factors that influence cardiac morphology. However, very little research has been done on body composition and fitness as cardiac morphology scaling factors. Therefore, we investigated the relationships between body composition, fitness and cardiac morphology to provide a starting point for future research on cardiac scaling. Methods: Fitness level, cardiac morphology and body composition was assessed in 25 recreationally active males (mean 27 years, range 20–36). Fitness was assessed in response to a maximal incremental treadmill exercise test, cardiac morphology using cardiac magnetic resonance imaging and body composition using dual-energy X-ray absorptiometry. Pearson correlations were performed between all variables and backwards regression analysis was used to assess the influence of body composition, body
doi:10.1016/j.jsams.2011.11.045 44 The effects of eccentrically biased versus conventional resistance training in older adults I. Selva Raj 1,∗ , S. Bird 1 , B. Westfold 1 , A. Shield 2 1 RMIT
University, Australia University of Technology, Australia
2 Queensland
Introduction: We hypothesised that eccentrically biased resistance training (ECC) would lead to greater strength, muscle architectural and functional gains than conventional training (CONV) in older adults. Methods: Twelve participants were randomly assigned to CONV (seven males and five females; mean age 67.8 years, range 60–74), 13 to ECC (eight males and five females; mean age 68.2 years, range 60–75) and 13 to wait-list control (7 males and 6 females; mean age 66.5 years, range 60–74). Training was performed twice a week for 16 weeks. Exercises were leg press, toe press, bench press and latissimus pulldown. Participants in ECC performed three sets of 10 bilateral concentric lifts at 50% of one repetition maximum (1RM). Following each concentric lift, the eccentric phase was performed unilaterally, alternating between each leg or arm with each repetition, thus performing five unilat-
adaptation to exercise using supervised intensive longitudinal exercise interventions. In contrast with textbook dogma, we observed no evidence in healthy, young and relatively inactive subjects to support the notion that resistance training induces concentric cardiac hypertrophy. Our data are consistent with previous echocardiographic evidence which suggests that endurance training results in increased LVM and EDV, although echo data underestimates LVM relative to MRI possibly exaggerating the magnitude of this effect. These adaptations were maintained for 6 weeks following exercise cessation. In conclusion, endurance exercise induces cardiac morphological adaptations whereas resistance exercise does not, despite the presence of physiological adaptations in strength and body composition. Our data overturns previous assumptions that have been widely adopted in the literature. doi:10.1016/j.jsams.2011.11.042 41 Acute versus chronic exposure to androgen suppression for prostate cancer: Impact on the exercise response D. Galvao 1,∗ , D. Newton 1
Taaffe 2 , N.
Spry 3 , D.
Joseph 3 , R.
1 Edith
Cowan University Health and Wellness Institute, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Australia 2 School of Environmental and Life Sciences, University of Newcastle, Australia 3 Sir Charles Gairdner Hospital, Radiation Oncology, Australia Introduction: Exercise has been proposed as an effective countermeasure for androgen suppression therapy (AST) induced side effects. Given that the magnitude of fat gain and muscle loss are most pronounced during the early phases of AST, it is possible that the exercise response may differ according to the duration of AST. We investigated whether the exercise response might vary according to the prior length of exposure to AST; acute (<6 months) versus later (≥6 months). Methods: Fifty men (55–84 years) undergoing AST for non-bone metastases prostate cancer completed a progressive resistance and cardiovascular exercise program for 12 weeks – acute (n = 16) or chronic AST exposure (n = 34). The resistance exercises included 8 exercises and was designed to progress from 12 to 6-repetition maximum for 2 to 4 sets per exercise The aerobic component of the training program included 15–20 min of cardiovascular exercises (cycling and walking/jogging) at 65–80% maximum heart rate and perceived exertion at 11–13 (6–20 point, Borg scale). Fat and lean mass (dual-energy X-ray absorptiometry), muscle strength, functional performance, quality of life, and blood biomarkers were assessed. Results: Acute AST patients showed an increase in total body fat (0.9 kg, p = 0.018) compared to chronic AST
e21
although both groups experienced an increase in appendicular skeletal muscle (∼0.5 kg, p < 0.01). Triglycerides decreased in the chronic and increased in the acute AST groups (p = 0.027) with change in triglycerides associated with change in total body fat (r = 0.411, p = 0.004). There were no differences between groups for PSA, testosterone, glucose, insulin, total cholesterol, LDL and HDL cholesterol, CRP, homocysteine or quality of life and both groups showed similar improvement in muscle strength and function, and cardiovascular fitness. Conclusions: Apart from differences in body fat and triglycerides, the beneficial effects of exercise are similar in patients on acute or chronic AST. These results suggest that exercise training should be initiated when AST commences to enhance physical function, and improve the patient’s acceptance of hormone therapy. Future trials are warranted examining the role of physical exercise implemented at the onset of androgen suppression therapy on physical and physiological function, as well as quality of life. doi:10.1016/j.jsams.2011.11.043 42 A one-year lifestyle intervention improves myocardial function in patients with chronic kidney disease E. Howden 1,2,3,∗ , R. Leano 2,3 , W. Isbel 2,3,4 , J. Coombes 1,3 , T. Marwick 2,3
Petchey 2,3,4 , N.
1 School of Human Movement Studies, University of Queens-
land, Australia 2 School of Medicine, University of Queensland, Australia 3 Centre for Clinical Research Excellence – Vascular and Metabolic Health, University of Queensland, Australia 4 Department of Nephrology, Princess Alexandra Hospital, Brisbane, Australia Introduction: Myocardial dysfunction is common in patients with chronic kidney disease (CKD). Cardiovascular event rate is high is this population and effective management strategies are lacking. Therefore we sought to determine effect of a lifestyle intervention that included exercise training on myocardial function in patients with CKD. Methods: Eighty four patients, stages 3–4 CKD were randomised to either standard medical care (control) or lifestyle intervention (LI). LI involved 8 weeks of gym-based individualised exercise training under supervision of an accredited exercise physiologist followed by home based training with ongoing telephone support and gym refresher sessions for the remaining 12 months. In addition, patients attended 4 week behaviour and lifestyle change program led by a psychologist and dietician. LI included access to multidisciplinary care through a nurse practitioner led CKD clinic, which included a nephrologist, social worker and diabetes educator. Myocardial function was assessed at baseline and 12 months using standard echocardiography techniques and tissue Dopplerderived myocardial velocities. Anthropometric, biochemical
e22
Abstracts / Journal of Science and Medicine in Sport 14S (2011) e1–e119
and fitness data were collected at both time points. Data was analysed by intention to treat with effect of intervention compared to controls determined using analysis of covariance (ANCOVA). Results: 12 patients were lost to follow-up (LI = 34, control = 38). Baseline characteristics were similar (p > 0.05) between groups (LI = 67% male, age 60.7 ± 9.1, eGFR 39.4 ± 8.9; control = 56% male, age 58.7 ± 10.5 years, eGFR 39.7 ± 8.8). There were no baseline differences (Table 1). The intervention resulted in a significant 13.3% increase in exercise capacity, with decreases in weight and BMI in LI group. This group also showed improved diastolic function (increased E ). There was no significant change in systolic function or blood pressure. There were no changes in any biochemical parameters between groups. Conclusion: The lifestyle intervention significantly improved exercise capacity and diastolic function in CKD patients. Lifestyle and exercise interventions may assist in managing the deleterious effects of reduced kidney function on the myocardium. doi:10.1016/j.jsams.2011.11.044 43 Fitness and body composition: Which factors influence heart morphology? C. Buck 1,∗ , A. Spence 1 , H. Carter 1 , L. Dembo 2 , L. Naylor 1 , D. Green 1,3
surface area (BSA) and fitness on left ventricular cardiac morphology. Results: Left ventricular mass at end diastole (LVMed) was significantly correlated with VO2 peak (r = 0.73, p < 0.01), lean body mass (LBM) (r = 0.83, p < 0.01) and fat mass (r = 0.46, p < 0.05). Regression analysis revealed that total LBM was a more significant contributor to LVMed (t = 7.19, p < 0.01) and left ventricular end diastolic volume (LVEDv) (t = 3.22, p < 0.01) than BSA, fat mass and fitness. Analysis of regional components of body composition showed that LBM located around the hips and thighs (gynoid LBM) had the strongest correlation to LVMed (r = 0.84, p < 0.01), whilst the LBM of the legs had the strongest correlation to LVEDv (r = 0.86, p < 0.01). Conclusion: Fitness, fat mass, BSA and total LBM were all significantly correlated to LVMed. However, total LBM was the most significant contributor to cardiac morphology. Furthermore, gynoid and leg LBM were identified as stronger correlates to cardiac morphology than total LBM. Together these findings indicate that LBM located specifically in the gynoid and leg region may be the most appropriate scaling factors for cardiac morphology. Thus, scaling cardiac morphology by leg LBM may be particularly useful in resolving some of the disparities observed in studies investigating the Morganroth hypothesis. A potential physiological explanation for the strong relationship between LBM and cardiac morphology is likely to come from the strong influence of the muscle component of LBM on blood flow and hemodynamic loading of the heart.
1 University
of Western Australia, Australia Perth Hospital, Australia 3 Research Institute for Sports and Exercise Sciences (Liverpool), Australia 2 Royal
Background: There is considerable inconsistency regarding the methods used to scale cardiac morphology for the influence of body size in studies investigating the Morganroth hypothesis. This has led to disparities on observations and the interpretation of data on athlete’s heart. It has been suggested that body composition and cardiorespiratory fitness level are between participant factors that influence cardiac morphology. However, very little research has been done on body composition and fitness as cardiac morphology scaling factors. Therefore, we investigated the relationships between body composition, fitness and cardiac morphology to provide a starting point for future research on cardiac scaling. Methods: Fitness level, cardiac morphology and body composition was assessed in 25 recreationally active males (mean 27 years, range 20–36). Fitness was assessed in response to a maximal incremental treadmill exercise test, cardiac morphology using cardiac magnetic resonance imaging and body composition using dual-energy X-ray absorptiometry. Pearson correlations were performed between all variables and backwards regression analysis was used to assess the influence of body composition, body
doi:10.1016/j.jsams.2011.11.045 44 The effects of eccentrically biased versus conventional resistance training in older adults I. Selva Raj 1,∗ , S. Bird 1 , B. Westfold 1 , A. Shield 2 1 RMIT
University, Australia University of Technology, Australia
2 Queensland
Introduction: We hypothesised that eccentrically biased resistance training (ECC) would lead to greater strength, muscle architectural and functional gains than conventional training (CONV) in older adults. Methods: Twelve participants were randomly assigned to CONV (seven males and five females; mean age 67.8 years, range 60–74), 13 to ECC (eight males and five females; mean age 68.2 years, range 60–75) and 13 to wait-list control (7 males and 6 females; mean age 66.5 years, range 60–74). Training was performed twice a week for 16 weeks. Exercises were leg press, toe press, bench press and latissimus pulldown. Participants in ECC performed three sets of 10 bilateral concentric lifts at 50% of one repetition maximum (1RM). Following each concentric lift, the eccentric phase was performed unilaterally, alternating between each leg or arm with each repetition, thus performing five unilat-