Editorial Exercise in CKD: Why Is It important and How Should It Be Delivered? Related Article, p. 383
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n addition to substantial epidemiologic evidence for the role of physical activity in the prevention and treatment of disease, inactivity is linked to a higher incidence of noncommunicable diseases and reduced life expectancy. 1 Consequently, the American College of Sports Medicine (ACSM) in conjunction with the American Medical Association recognized that lifestyle interventions should be a component of the treatment of individuals and in 2007, launched the Exercise Is Medicine program (www.exerciseismedicine.org). This initiative, now international, calls upon health professionals to discuss physical activity during all patient and client interactions2,3 and to prescribe exercise to those reporting sedentary behaviors. Although the evidence supporting the association between physical inactivity and chronic diseases is strongest for type 2 diabetes and cardiovascular disease, the close relationship between those diseases and chronic kidney disease (CKD)4 highlights the potential for physical inactivity to contribute to both the development and progression of CKD, as well as the comorbid conditions associated with CKD.5 Recognizing this, the recent KDIGO (Kidney Disease: Improving Global Outcomes) CKD clinical practice guideline recommends that patients with CKD undertake regular exercise, compatible with cardiovascular health, aiming for at least 30 minutes 5 times per week.6 Consistent with the lack of conclusive data in this field, KDIGO acknowledges that the true effect of exercise on a range of clinical factors is not yet known. This may be a consequence of differing exercise prescriptions, including modality (aerobic, resistance, or combination), intensities, training durations, and strategies (eg, weight bearing and non–weight bearing). In addition, the current KDIGO guideline recommendations do not differentiate among CKD stages, instead suggesting a one-size-fits-all approach. This recommendation makes it easier for the physician to provide advice, but does not account for the variety of needs of patients or necessarily optimize the exercise regimen for individual patients. The KDIGO exercise recommendation simply provides a starting point; accordingly, patients’ needs may be served better through following the recommendations of a recent position statement on exercise in CKD.5 In this issue of AJKD, Heiwe and Jacobsen,7 in a systematic review and meta-analysis of randomized controlled trials investigating the efficacy of exercise in patients with CKD, determine the influence and effect Am J Kidney Dis. 2014;64(3):329-331
size of several modalities of exercise training on a range of clinical outcome measures, including blood pressure and cardiovascular function. The authors analyzed data from 41 randomized controlled trials involving 928 participants that compared one or more exercise modalities with sham or no exercise. Their results reinforce the recommendations made by KDIGO; specifically, across studies, exercise improves aerobic capacity, muscle strength, cardiovascular function, and healthrelated quality of life. Importantly, the authors also examined the benefits of exercise according to CKD stages, evaluating separately hemodialysis patients, transplant recipients, and individuals with non–dialysisdependent CKD stages 2-5. Although the overall results support the use of exercise as a treatment in all patients with CKD, insufficient data were available to assess the effectiveness of several exercise modalities to treat specific CKD subgroups. Specifically, further research is recommended to determine the efficacy of resistance and combination resistance and endurance training interventions on patients with non–dialysis-dependent CKD and transplant recipients. The positive findings of the meta-analysis conducted by Heiwe and Jacobsen7 provide further weight to recommendations that regular exercise be considered as “medicine” and included as a standard treatment for patients with CKD. However, despite the increasing breadth of evidence supporting the role of exercise, it appears to be poorly prescribed in nephrology practice.8 Many reasons may exist for this oversight, including lack of time for exercise counseling during clinic appointments, insufficient knowledge among nephrology providers about optimal exercise to prescribe to patients, or uncertainty about how to prescribe and adapt exercise interventions in response to changing patient needs. In addition, the importance of intrinsic limitations associated with any behavioral intervention, including generating and maintaining patient motivation to exercise, may challenge kidney professionals. Rather than prescribe a generic exercise program that may or may not suit individual patients’ needs and assume that patients will comply with this prescribed regimen, a potential alternative for the time-challenged clinician may be referral to an appropriate allied health professional, such as an ACSM-registered clinical Address correspondence to Andrew D. Williams, PhD, School of Health Sciences, University of Tasmania, Locked Bag 1320, Launceston, Tasmania 7250. E-mail: [email protected] Ó 2014 by the National Kidney Foundation, Inc. 0272-6386/$36.00 http://dx.doi.org/10.1053/j.ajkd.2014.06.004 329
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exercise physiologist, who has the necessary experience to incorporate disease-specific issues, comorbid conditions, the effects of medications, associated mental health issues, and potentially low patient motivation when individualizing a patient exercise program. The inclusion of exercise professionals in the treatment plan also may facilitate a supervised exercise intervention, which recently was shown to provide benefits beyond the prescription of unsupervised exercise in the CKD population,9 potentially as a result of greater adherence to the prescribed exercise. In many countries, the role of exercise as a treatment is not well recognized or supported within the existing health system despite the increasing evidence for the role of physical activity and exercise in the treatment of a range of chronic diseases. While physicians are encouraged within disease-specific guidelines to prescribe exercise, these recommendations often are general and often do not address the challenges faced by patients, many of whom have decades of sedentary behavior and comorbid conditions that make a generic approach to exercise prescription likely to fail. These challenges have been addressed partially in certain conditions, most notably through the successful inclusion of exercise, prescribed and supervised by appropriately qualified exercise professionals, into cardiac and pulmonary exercise programs in many countries. However, to date, there is no parallel in nephrology or other chronic conditions in which exercise also has been shown to be of benefit. In Australia, the importance of physical activity and recognition of the difficulties involved in achieving sustained lifestyle change also have been recognized through inclusion of exercise physiology services for individuals with chronic medical conditions into the rebatable health system.10 The Australian system uses the primary care physician as the gate keeper; this provider determines the appropriateness of exercise as a part of a patient’s treatment regimen and, assuming the patient is amenable, can refer to an accredited exercise physiologist for exercise prescription that meets the needs of the individual. For example, by accounting for comorbid conditions, the exercise physiologist may decide that the appropriate exercise prescription for a patient with stage 3 CKD with nonspecific lower back pain and osteoarthritis in both knees includes stationary cycling and pool-based exercises to reduce the impact on joints, with additional resistance training, avoiding exercises likely to exacerbate musculoskeletal problems. Through providing referral pathways and patient rebates for services delivered by the exercise physiologist, this approach acknowledges that general practitioners and specialists often lack both the time and skills necessary to prescribe appropriate exercises and directly assist patients at various stages of readiness to change their lifestyle behaviors. Although there 330
are a number of shortcomings in this system, including the inability of medical specialists to refer directly for rebatable services, the adoption of a similar approach in other health systems may further encourage the adoption of regular appropriate physical activity for individuals with or at risk of diseases influenced by poor lifestyle choices. Although all studies in the meta-analysis by Heiwe and Jacobsen7 were randomized controlled trials, many studies were of poor quality. For instance, several trials were excluded due to lack of a control group or failure to randomly assign participants to interventions. In addition, reporting of methodological and results information often was poor, with w80% of studies not reporting intention-to-treat analyses. It is likely that some outcome measures were not reported sufficiently, and potential publication bias, which favors positive outcomes, may further diminish reports of study results, particularly for smaller trials. In this regard, exercise treatment studies are not alone, with recent research indicating that almost two-thirds of trials in nephrology omit participants from analysis and approximately half include no intention-totreat analyses.11 In addition, patients who volunteer to participate in exercise studies likely constitute the most motivated and potentially the most active and fittest of the clinical population and accordingly are most likely to adhere to well-supervised exercise protocols. Further, with available data indicating that due to common exclusion criteria, w25% of patients are ineligible to participate in exercise and that a further 28% of those who are eligible choose not to participate,5 results may not be generalizable to the wider CKD population. Increasing evidence highlights the benefits of exercise on clinical risk factors in individuals with CKD, and as described in a recent review, the benefits of physical activity for these patients clearly outweigh the risks associated with remaining inactive.12 In addition to reinforcing the evidence for exercise as a treatment, the current meta-analysis by Heiwe and Jacobsen7 highlights that more work is required to determine the optimal exercise modality, frequency, and intensity to achieve the best outcomes for patients. Policymakers should consider how to implement the findings of studies that highlight the benefits of exercise in clinical populations into effective widespread clinical practice, with the Australian approach potentially providing a good starting point. Andrew D. Williams, PhD University of Tasmania Launceston, Australia Robert G. Fassett, PhD Jeff S. Coombes, PhD The University of Queensland St. Lucia, Australia Am J Kidney Dis. 2014;64(3):329-331
Editorial
ACKNOWLEDGEMENTS Support: None. Financial Disclosure: The authors declare that they have no relevant financial interests.
REFERENCES 1. Lee IM, Shiroma EJ, Lobelo F, Puska P, Blair SN, Katzmarzyk PT. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet. 2012;380(9838):219-229. 2. Sallis R. Developing healthcare systems to support exercise: exercise as the fifth vital sign. Br J Sports Med. 2011;45(6): 473-474. 3. Coombes JS, Law J, Lancashire B, Fassett RG. “Exercise Is Medicine”: curbing the burden of chronic disease and physical inactivity [published online ahead of print April 9, 2013]. Asia Pac J Public Health. http://dx.doi.org/10.1177/1010539513481492. 4. Gobal F, Deshmukh A, Shah S, Mehta JL. Triad of metabolic syndrome, chronic kidney disease, and coronary heart disease with a focus on microalbuminuria death by overeating. J Am Coll Cardiol. 2011;57(23):2303-2308. 5. Smart NA, Williams AD, Levinger I, et al. Exercise & Sports Science Australia (ESSA) position statement on exercise
Am J Kidney Dis. 2014;64(3):329-331
and chronic kidney disease. J Sci Med Sport. 2013;16(5): 406-411. 6. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int Suppl. 2013;3:1-150. 7. Heiwe S, Jacobson SH. Exercise training in adults with CKD: a systematic review and meta-analysis. Am J Kidney Dis. 2014;64(3):383-393. 8. Delgado C, Johansen KL. Deficient counseling on physical activity among nephrologists. Nephron Clin Pract. 2010;116(4): c330-c336. 9. Heiwe S, Jacobson SH. Exercise training for adults with chronic kidney disease. Cochrane Database Syst Rev. 2011;10: CD003236. 10. Department of Human Services. Chronic Disease Management Plan. 2014. http://www.humanservices.gov.au/customer/ services/medicare/chronic-disease-management-plan. Accessed April 28, 2014. 11. Deo A, Schmid CH, Earley A, Lau J, Uhlig K. Loss to analysis in randomized controlled trials in CKD. Am J Kidney Dis. 2011;58(3):349-355. 12. Johansen KL, Painter P. Exercise in individuals with CKD. Am J Kidney Dis. 2012;59(1):126-134.
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I
n addition to substantial epidemiologic evidence for the role of physical activity in the prevention and treatment of disease, inactivity is linked to a higher incidence of noncommunicable diseases and reduced life expectancy. 1 Consequently, the American College of Sports Medicine (ACSM) in conjunction with the American Medical Association recognized that lifestyle interventions should be a component of the treatment of individuals and in 2007, launched the Exercise Is Medicine program (www.exerciseismedicine.org). This initiative, now international, calls upon health professionals to discuss physical activity during all patient and client interactions2,3 and to prescribe exercise to those reporting sedentary behaviors. Although the evidence supporting the association between physical inactivity and chronic diseases is strongest for type 2 diabetes and cardiovascular disease, the close relationship between those diseases and chronic kidney disease (CKD)4 highlights the potential for physical inactivity to contribute to both the development and progression of CKD, as well as the comorbid conditions associated with CKD.5 Recognizing this, the recent KDIGO (Kidney Disease: Improving Global Outcomes) CKD clinical practice guideline recommends that patients with CKD undertake regular exercise, compatible with cardiovascular health, aiming for at least 30 minutes 5 times per week.6 Consistent with the lack of conclusive data in this field, KDIGO acknowledges that the true effect of exercise on a range of clinical factors is not yet known. This may be a consequence of differing exercise prescriptions, including modality (aerobic, resistance, or combination), intensities, training durations, and strategies (eg, weight bearing and non–weight bearing). In addition, the current KDIGO guideline recommendations do not differentiate among CKD stages, instead suggesting a one-size-fits-all approach. This recommendation makes it easier for the physician to provide advice, but does not account for the variety of needs of patients or necessarily optimize the exercise regimen for individual patients. The KDIGO exercise recommendation simply provides a starting point; accordingly, patients’ needs may be served better through following the recommendations of a recent position statement on exercise in CKD.5 In this issue of AJKD, Heiwe and Jacobsen,7 in a systematic review and meta-analysis of randomized controlled trials investigating the efficacy of exercise in patients with CKD, determine the influence and effect Am J Kidney Dis. 2014;64(3):329-331
size of several modalities of exercise training on a range of clinical outcome measures, including blood pressure and cardiovascular function. The authors analyzed data from 41 randomized controlled trials involving 928 participants that compared one or more exercise modalities with sham or no exercise. Their results reinforce the recommendations made by KDIGO; specifically, across studies, exercise improves aerobic capacity, muscle strength, cardiovascular function, and healthrelated quality of life. Importantly, the authors also examined the benefits of exercise according to CKD stages, evaluating separately hemodialysis patients, transplant recipients, and individuals with non–dialysisdependent CKD stages 2-5. Although the overall results support the use of exercise as a treatment in all patients with CKD, insufficient data were available to assess the effectiveness of several exercise modalities to treat specific CKD subgroups. Specifically, further research is recommended to determine the efficacy of resistance and combination resistance and endurance training interventions on patients with non–dialysis-dependent CKD and transplant recipients. The positive findings of the meta-analysis conducted by Heiwe and Jacobsen7 provide further weight to recommendations that regular exercise be considered as “medicine” and included as a standard treatment for patients with CKD. However, despite the increasing breadth of evidence supporting the role of exercise, it appears to be poorly prescribed in nephrology practice.8 Many reasons may exist for this oversight, including lack of time for exercise counseling during clinic appointments, insufficient knowledge among nephrology providers about optimal exercise to prescribe to patients, or uncertainty about how to prescribe and adapt exercise interventions in response to changing patient needs. In addition, the importance of intrinsic limitations associated with any behavioral intervention, including generating and maintaining patient motivation to exercise, may challenge kidney professionals. Rather than prescribe a generic exercise program that may or may not suit individual patients’ needs and assume that patients will comply with this prescribed regimen, a potential alternative for the time-challenged clinician may be referral to an appropriate allied health professional, such as an ACSM-registered clinical Address correspondence to Andrew D. Williams, PhD, School of Health Sciences, University of Tasmania, Locked Bag 1320, Launceston, Tasmania 7250. E-mail: [email protected] Ó 2014 by the National Kidney Foundation, Inc. 0272-6386/$36.00 http://dx.doi.org/10.1053/j.ajkd.2014.06.004 329
Williams, Fassett, and Coombes
exercise physiologist, who has the necessary experience to incorporate disease-specific issues, comorbid conditions, the effects of medications, associated mental health issues, and potentially low patient motivation when individualizing a patient exercise program. The inclusion of exercise professionals in the treatment plan also may facilitate a supervised exercise intervention, which recently was shown to provide benefits beyond the prescription of unsupervised exercise in the CKD population,9 potentially as a result of greater adherence to the prescribed exercise. In many countries, the role of exercise as a treatment is not well recognized or supported within the existing health system despite the increasing evidence for the role of physical activity and exercise in the treatment of a range of chronic diseases. While physicians are encouraged within disease-specific guidelines to prescribe exercise, these recommendations often are general and often do not address the challenges faced by patients, many of whom have decades of sedentary behavior and comorbid conditions that make a generic approach to exercise prescription likely to fail. These challenges have been addressed partially in certain conditions, most notably through the successful inclusion of exercise, prescribed and supervised by appropriately qualified exercise professionals, into cardiac and pulmonary exercise programs in many countries. However, to date, there is no parallel in nephrology or other chronic conditions in which exercise also has been shown to be of benefit. In Australia, the importance of physical activity and recognition of the difficulties involved in achieving sustained lifestyle change also have been recognized through inclusion of exercise physiology services for individuals with chronic medical conditions into the rebatable health system.10 The Australian system uses the primary care physician as the gate keeper; this provider determines the appropriateness of exercise as a part of a patient’s treatment regimen and, assuming the patient is amenable, can refer to an accredited exercise physiologist for exercise prescription that meets the needs of the individual. For example, by accounting for comorbid conditions, the exercise physiologist may decide that the appropriate exercise prescription for a patient with stage 3 CKD with nonspecific lower back pain and osteoarthritis in both knees includes stationary cycling and pool-based exercises to reduce the impact on joints, with additional resistance training, avoiding exercises likely to exacerbate musculoskeletal problems. Through providing referral pathways and patient rebates for services delivered by the exercise physiologist, this approach acknowledges that general practitioners and specialists often lack both the time and skills necessary to prescribe appropriate exercises and directly assist patients at various stages of readiness to change their lifestyle behaviors. Although there 330
are a number of shortcomings in this system, including the inability of medical specialists to refer directly for rebatable services, the adoption of a similar approach in other health systems may further encourage the adoption of regular appropriate physical activity for individuals with or at risk of diseases influenced by poor lifestyle choices. Although all studies in the meta-analysis by Heiwe and Jacobsen7 were randomized controlled trials, many studies were of poor quality. For instance, several trials were excluded due to lack of a control group or failure to randomly assign participants to interventions. In addition, reporting of methodological and results information often was poor, with w80% of studies not reporting intention-to-treat analyses. It is likely that some outcome measures were not reported sufficiently, and potential publication bias, which favors positive outcomes, may further diminish reports of study results, particularly for smaller trials. In this regard, exercise treatment studies are not alone, with recent research indicating that almost two-thirds of trials in nephrology omit participants from analysis and approximately half include no intention-totreat analyses.11 In addition, patients who volunteer to participate in exercise studies likely constitute the most motivated and potentially the most active and fittest of the clinical population and accordingly are most likely to adhere to well-supervised exercise protocols. Further, with available data indicating that due to common exclusion criteria, w25% of patients are ineligible to participate in exercise and that a further 28% of those who are eligible choose not to participate,5 results may not be generalizable to the wider CKD population. Increasing evidence highlights the benefits of exercise on clinical risk factors in individuals with CKD, and as described in a recent review, the benefits of physical activity for these patients clearly outweigh the risks associated with remaining inactive.12 In addition to reinforcing the evidence for exercise as a treatment, the current meta-analysis by Heiwe and Jacobsen7 highlights that more work is required to determine the optimal exercise modality, frequency, and intensity to achieve the best outcomes for patients. Policymakers should consider how to implement the findings of studies that highlight the benefits of exercise in clinical populations into effective widespread clinical practice, with the Australian approach potentially providing a good starting point. Andrew D. Williams, PhD University of Tasmania Launceston, Australia Robert G. Fassett, PhD Jeff S. Coombes, PhD The University of Queensland St. Lucia, Australia Am J Kidney Dis. 2014;64(3):329-331
Editorial
ACKNOWLEDGEMENTS Support: None. Financial Disclosure: The authors declare that they have no relevant financial interests.
REFERENCES 1. Lee IM, Shiroma EJ, Lobelo F, Puska P, Blair SN, Katzmarzyk PT. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet. 2012;380(9838):219-229. 2. Sallis R. Developing healthcare systems to support exercise: exercise as the fifth vital sign. Br J Sports Med. 2011;45(6): 473-474. 3. Coombes JS, Law J, Lancashire B, Fassett RG. “Exercise Is Medicine”: curbing the burden of chronic disease and physical inactivity [published online ahead of print April 9, 2013]. Asia Pac J Public Health. http://dx.doi.org/10.1177/1010539513481492. 4. Gobal F, Deshmukh A, Shah S, Mehta JL. Triad of metabolic syndrome, chronic kidney disease, and coronary heart disease with a focus on microalbuminuria death by overeating. J Am Coll Cardiol. 2011;57(23):2303-2308. 5. Smart NA, Williams AD, Levinger I, et al. Exercise & Sports Science Australia (ESSA) position statement on exercise
Am J Kidney Dis. 2014;64(3):329-331
and chronic kidney disease. J Sci Med Sport. 2013;16(5): 406-411. 6. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int Suppl. 2013;3:1-150. 7. Heiwe S, Jacobson SH. Exercise training in adults with CKD: a systematic review and meta-analysis. Am J Kidney Dis. 2014;64(3):383-393. 8. Delgado C, Johansen KL. Deficient counseling on physical activity among nephrologists. Nephron Clin Pract. 2010;116(4): c330-c336. 9. Heiwe S, Jacobson SH. Exercise training for adults with chronic kidney disease. Cochrane Database Syst Rev. 2011;10: CD003236. 10. Department of Human Services. Chronic Disease Management Plan. 2014. http://www.humanservices.gov.au/customer/ services/medicare/chronic-disease-management-plan. Accessed April 28, 2014. 11. Deo A, Schmid CH, Earley A, Lau J, Uhlig K. Loss to analysis in randomized controlled trials in CKD. Am J Kidney Dis. 2011;58(3):349-355. 12. Johansen KL, Painter P. Exercise in individuals with CKD. Am J Kidney Dis. 2012;59(1):126-134.
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