- Email: [email protected]
The Authors Respond
Letters to the Editor
The Authors Respond We thank Drs Nightingale and Bilzon for their comments and reflections on our recent article.1 We agree that achieving negative energy balance will contribute to a beneficial effect on body composition and possibly reduce cardiovascular disease (CVD) risk in adults with spinal cord injury (SCI). Investigating energy balance requires assessing both energy intake and energy expenditure (EE) (thermal effect of food þ resting metabolic rate [RMR] þ physical activity). To obtain neutral or negative energy balance, EE must exceed energy intake. The RMR accounts for approximately 65%, physical activity accounts for 25% to 30%, and thermal effect of food accounts for approximately 10% of total daily EE.2 EE decreases after SCI because of a reduction in all 3 components: lower RMR,3 decreased physical activity,4 and a possible lower thermic effect of food.5 The RMR is the most quantitatively important component of daily EE; because of the reduction in metabolically active skeletal muscle and altered sympathetic nervous system postinjury, the RMR is 14% to 27% lower in SCI compared with able-bodied individuals.2 Therefore, to prevent weight gain after SCI, total caloric intake should be reduced or physical activity should be increased accordingly. As our article1 indicates, voluntary upper-body exercise alone may not be enough to evoke changes in body composition or CVD risk factors after SCI. However, our findings do suggest that the physical activity guidelines prescription may prevent negative changes in body composition.1 Modifications to the physical activity guidelines and/or an associated dietary intervention may be required to induce CVD risk profile improvements. Although there are specific diet recommendations for individuals with SCI6 (ie, adequate fiber and fluids to prevent constipation, adequate protein to prevent pressure ulcers, adequate calcium and vitamin D to prevent sublesional osteoporosis, lower total caloric intake to prevent obesity), food intake does not always change in a beneficial way postinjury. A study assessing calorie and macronutrient intake using a food frequency questionnaire among 162 persons with chronic SCI showed a shift toward intake of fat and simple carbohydrates at the expense of complex carbohydrates and high levels of polyunsaturated and monounsaturated fatty acids.7 Improving diet and focusing on caloric restriction will aid in controlling overweight and obesity and may alleviate the compensatory energy intake that has been observed among able-bodied persons when participating in a prescribed exercise program.8 Although evidence exists that caloric restriction alone can provide improvements in traditional CVD risk factors (ie, abdominal obesity, elevated triglycerides, low high-density lipoprotein, high blood pressure, elevated fasting glucose),9 over the last decade, assessment of these factors has failed to predict cardiovascular events in almost half of the cases in able-bodied persons and does not fully explain CVD risk after SCI.10,11 There is evidence that exercise exerts direct effects on blood vessels that result in measurable reductions in CVD risk.12 Antiatherogenic hormones (eg, nitric oxide) are released from the endothelium in response to exercise; increased nitric oxide may decrease free radical production and/or increase the expression of antioxidant enzymes, subsequently affecting CVD risk.13 Strong evidence exists that exercise training is
www.archives-pmr.org
1039 associated with improvement of both vascular structure14 and function.13 Further, exercise training is associated with enhanced heart rate variability,15 a predictor of cardiovascular mortality.16 Although we agree that assessing or manipulating either component of this energy balance equation alone (energy intake vs EE) may not be enough to result in measurable changes in CVD risk, we do continue to recommend exercise as an indispensable component in improving CVD risk because the positive effects are far reaching in terms of changes in traditional and novel risk factors. In summary, few studies have been conducted assessing energy balance in individuals with SCI, and none have been conducted that manipulate both energy intake and EE to provide health benefits. Future studies examining these questions should assess both energy intake via food logs and EE via the RMR, physical activity questionnaires that incorporate both activities of daily living and leisure time physical activity (ie, physical activity recall assessment for adults with SCI17), and accelerometery (ie, multisensory armband18). Julia Totosy de Zepetnek, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Chelsea Pelletier, PhD Department of Health Sciences University of Northern British Columbia Prince George, BC, Canada Audrey Hicks, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Maureen MacDonald, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Disclosures: none.
References 1. Totosy de Zepetnek JO, Pelletier CA, Hicks AL, MacDonald MJ. Following the physical activity guidelines for adults with spinal cord injury for 16 weeks does not improve vascular health: a randomized controlled trial. Arch Phys Med Rehabil 2015;96: 1566-75. 2. Buchholz AC, McGillivray CF, Pencharz PB. Differences in resting metabolic rate between paraplegic and able-bodied subjects are explained by differences in body composition. Am J Clin Nutr 2003; 77:371-8. 3. Buchholz AC, Pencharz PB. Energy expenditure in chronic spinal cord injury. Curr Opin Clin Nutr Metab Care 2004;7:635-9. 4. Buchholz AC, McGillivray CF, Pencharz PB. Physical activity levels are low in free-living adults with chronic paraplegia. Obes Res 2003; 11:563-70. 5. Monroe MB, Tataranni PA, Pratley R, Manore MM, Skinner JS, Ravussin E. Lower daily energy expenditure as measured by a respiratory chamber in subjects with spinal cord injury compared with control subjects. Am J Clin Nutr 1998;68:1223-7. 6. Khalil RE, Gorgey AS, Janisko M, Dolbow DR, Moore JR, Gater DR. The role of nutrition in health status after spinal cord injury. Aging Dis 2013;4:14-22.
1040
Letters to the Editor
7. Sabour H, Javidan AN, Vafa MR, et al. Calorie and macronutrients intake in people with spinal cord injuries: an analysis by sex and injury-related variables. Nutrition 2012;28:143-7. 8. Turner JE, Markovitch D, Betts JA, Thompson D. Nonprescribed physical activity energy expenditure is maintained with structured exercise and implicates a compensatory increase in energy intake. Am J Clin Nutr 2010;92:1009-16. 9. Fontana L, Villareal DT, Weiss EP, et al. Calorie restriction or exercise: effects on coronary heart disease risk factors. A randomized, controlled trial. Am J Physiol Endocrinol Metab 2007; 293:E197-202. 10. Naghavi M, Libby P, Falk E, et al. From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I. Circulation 2003;108:1664-72. 11. Mora S, Cook N, Buring JE, Ridker PM, Lee IM. Physical activity and reduced risk of cardiovascular events: potential mediating mechanisms. Circulation 2007;116:2110-8. 12. Green DJ, O’Driscoll G, Joyner MJ, Cable NT. Exercise and cardiovascular risk reduction: time to update the rationale for exercise? J Appl Physiol 2008;105:766-8.
13. Green DJ, Maiorana A, O’Driscoll G, Taylor RR. Topical review: effects of exercise training on vascular endothelial nitric oxide function in humans. J Physiol 2004;561:1-25. 14. Dinenno FA, Tanaka H, Monahan KD, et al. Regular endurance exercise induces expansive arterial remodelling in the trained limbs of healthy men. J Physiol 2001;534:287-95. 15. Levy WC, Cerqueira MD, Harp GD, et al. Effect of endurance exercise training on heart rate variability at rest in healthy young and older men. Am J Cardiol 1998;82:1236-41. 16. Tsuji H, Venditti Jr FJ, Manders ES, et al. Reduced heart rate variability and mortality risk in an elderly cohort. The Framingham Heart Study. Circulation 1994;90:878-83. 17. Latimer AE, Ginis KA, Craven BC, Hicks AL. The physical activity recall assessment for people with spinal cord injury: validity. Med Sci Sports Exerc 2006;38:208-16. 18. Dwyer TJ, Alison JA, McKeough ZJ, Elkins MR, Bye PT. Evaluation of the SenseWear activity monitor during exercise in cystic fibrosis and in health. Respir Med 2009;103:1511-7. http://dx.doi.org/10.1016/j.apmr.2016.02.021
Corrections In the article “Exercise Recommendations and Considerations for Persons With Spinal Cord Injury” (Evans et al, Arch Phys Med Rehabil 2015;96:1749-50), these cardiovascular and muscular strength/endurance recommendations are a modified version of the Physical Activity Guidelines for Adults with Spinal Cord Injury developed and published by Martin Ginis KA, Hicks AL, Latimer AE, et al. The development of evidence-informed physical activity guidelines for adults with spinal cord injury. Spinal Cord 2011;49:1088-96.
0003-9993/16 http://dx.doi.org/10.1016/j.apmr.2016.03.005
In the article “Timed 360 Turn Test for Assessing People With Chronic Stroke” (Shiu et al, Arch Phys Med Rehabil 2016;97:536-44), the sentence in the abstract that reads Participants: Individuals with chronic stroke (nZ72) and healthy individuals (nZ35) of similar age (NZ107). Should read: Participants: Individuals with chronic stroke (nZ37) and healthy individuals (nZ35) of similar age (NZ72).
0003-9993/16 http://dx.doi.org/10.1016/j.apmr.2016.04.003
www.archives-pmr.org
The Authors Respond We thank Drs Nightingale and Bilzon for their comments and reflections on our recent article.1 We agree that achieving negative energy balance will contribute to a beneficial effect on body composition and possibly reduce cardiovascular disease (CVD) risk in adults with spinal cord injury (SCI). Investigating energy balance requires assessing both energy intake and energy expenditure (EE) (thermal effect of food þ resting metabolic rate [RMR] þ physical activity). To obtain neutral or negative energy balance, EE must exceed energy intake. The RMR accounts for approximately 65%, physical activity accounts for 25% to 30%, and thermal effect of food accounts for approximately 10% of total daily EE.2 EE decreases after SCI because of a reduction in all 3 components: lower RMR,3 decreased physical activity,4 and a possible lower thermic effect of food.5 The RMR is the most quantitatively important component of daily EE; because of the reduction in metabolically active skeletal muscle and altered sympathetic nervous system postinjury, the RMR is 14% to 27% lower in SCI compared with able-bodied individuals.2 Therefore, to prevent weight gain after SCI, total caloric intake should be reduced or physical activity should be increased accordingly. As our article1 indicates, voluntary upper-body exercise alone may not be enough to evoke changes in body composition or CVD risk factors after SCI. However, our findings do suggest that the physical activity guidelines prescription may prevent negative changes in body composition.1 Modifications to the physical activity guidelines and/or an associated dietary intervention may be required to induce CVD risk profile improvements. Although there are specific diet recommendations for individuals with SCI6 (ie, adequate fiber and fluids to prevent constipation, adequate protein to prevent pressure ulcers, adequate calcium and vitamin D to prevent sublesional osteoporosis, lower total caloric intake to prevent obesity), food intake does not always change in a beneficial way postinjury. A study assessing calorie and macronutrient intake using a food frequency questionnaire among 162 persons with chronic SCI showed a shift toward intake of fat and simple carbohydrates at the expense of complex carbohydrates and high levels of polyunsaturated and monounsaturated fatty acids.7 Improving diet and focusing on caloric restriction will aid in controlling overweight and obesity and may alleviate the compensatory energy intake that has been observed among able-bodied persons when participating in a prescribed exercise program.8 Although evidence exists that caloric restriction alone can provide improvements in traditional CVD risk factors (ie, abdominal obesity, elevated triglycerides, low high-density lipoprotein, high blood pressure, elevated fasting glucose),9 over the last decade, assessment of these factors has failed to predict cardiovascular events in almost half of the cases in able-bodied persons and does not fully explain CVD risk after SCI.10,11 There is evidence that exercise exerts direct effects on blood vessels that result in measurable reductions in CVD risk.12 Antiatherogenic hormones (eg, nitric oxide) are released from the endothelium in response to exercise; increased nitric oxide may decrease free radical production and/or increase the expression of antioxidant enzymes, subsequently affecting CVD risk.13 Strong evidence exists that exercise training is
www.archives-pmr.org
1039 associated with improvement of both vascular structure14 and function.13 Further, exercise training is associated with enhanced heart rate variability,15 a predictor of cardiovascular mortality.16 Although we agree that assessing or manipulating either component of this energy balance equation alone (energy intake vs EE) may not be enough to result in measurable changes in CVD risk, we do continue to recommend exercise as an indispensable component in improving CVD risk because the positive effects are far reaching in terms of changes in traditional and novel risk factors. In summary, few studies have been conducted assessing energy balance in individuals with SCI, and none have been conducted that manipulate both energy intake and EE to provide health benefits. Future studies examining these questions should assess both energy intake via food logs and EE via the RMR, physical activity questionnaires that incorporate both activities of daily living and leisure time physical activity (ie, physical activity recall assessment for adults with SCI17), and accelerometery (ie, multisensory armband18). Julia Totosy de Zepetnek, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Chelsea Pelletier, PhD Department of Health Sciences University of Northern British Columbia Prince George, BC, Canada Audrey Hicks, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Maureen MacDonald, PhD Department of Kinesiology, McMaster University Hamilton, ON, Canada Disclosures: none.
References 1. Totosy de Zepetnek JO, Pelletier CA, Hicks AL, MacDonald MJ. Following the physical activity guidelines for adults with spinal cord injury for 16 weeks does not improve vascular health: a randomized controlled trial. Arch Phys Med Rehabil 2015;96: 1566-75. 2. Buchholz AC, McGillivray CF, Pencharz PB. Differences in resting metabolic rate between paraplegic and able-bodied subjects are explained by differences in body composition. Am J Clin Nutr 2003; 77:371-8. 3. Buchholz AC, Pencharz PB. Energy expenditure in chronic spinal cord injury. Curr Opin Clin Nutr Metab Care 2004;7:635-9. 4. Buchholz AC, McGillivray CF, Pencharz PB. Physical activity levels are low in free-living adults with chronic paraplegia. Obes Res 2003; 11:563-70. 5. Monroe MB, Tataranni PA, Pratley R, Manore MM, Skinner JS, Ravussin E. Lower daily energy expenditure as measured by a respiratory chamber in subjects with spinal cord injury compared with control subjects. Am J Clin Nutr 1998;68:1223-7. 6. Khalil RE, Gorgey AS, Janisko M, Dolbow DR, Moore JR, Gater DR. The role of nutrition in health status after spinal cord injury. Aging Dis 2013;4:14-22.
1040
Letters to the Editor
7. Sabour H, Javidan AN, Vafa MR, et al. Calorie and macronutrients intake in people with spinal cord injuries: an analysis by sex and injury-related variables. Nutrition 2012;28:143-7. 8. Turner JE, Markovitch D, Betts JA, Thompson D. Nonprescribed physical activity energy expenditure is maintained with structured exercise and implicates a compensatory increase in energy intake. Am J Clin Nutr 2010;92:1009-16. 9. Fontana L, Villareal DT, Weiss EP, et al. Calorie restriction or exercise: effects on coronary heart disease risk factors. A randomized, controlled trial. Am J Physiol Endocrinol Metab 2007; 293:E197-202. 10. Naghavi M, Libby P, Falk E, et al. From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I. Circulation 2003;108:1664-72. 11. Mora S, Cook N, Buring JE, Ridker PM, Lee IM. Physical activity and reduced risk of cardiovascular events: potential mediating mechanisms. Circulation 2007;116:2110-8. 12. Green DJ, O’Driscoll G, Joyner MJ, Cable NT. Exercise and cardiovascular risk reduction: time to update the rationale for exercise? J Appl Physiol 2008;105:766-8.
13. Green DJ, Maiorana A, O’Driscoll G, Taylor RR. Topical review: effects of exercise training on vascular endothelial nitric oxide function in humans. J Physiol 2004;561:1-25. 14. Dinenno FA, Tanaka H, Monahan KD, et al. Regular endurance exercise induces expansive arterial remodelling in the trained limbs of healthy men. J Physiol 2001;534:287-95. 15. Levy WC, Cerqueira MD, Harp GD, et al. Effect of endurance exercise training on heart rate variability at rest in healthy young and older men. Am J Cardiol 1998;82:1236-41. 16. Tsuji H, Venditti Jr FJ, Manders ES, et al. Reduced heart rate variability and mortality risk in an elderly cohort. The Framingham Heart Study. Circulation 1994;90:878-83. 17. Latimer AE, Ginis KA, Craven BC, Hicks AL. The physical activity recall assessment for people with spinal cord injury: validity. Med Sci Sports Exerc 2006;38:208-16. 18. Dwyer TJ, Alison JA, McKeough ZJ, Elkins MR, Bye PT. Evaluation of the SenseWear activity monitor during exercise in cystic fibrosis and in health. Respir Med 2009;103:1511-7. http://dx.doi.org/10.1016/j.apmr.2016.02.021
Corrections In the article “Exercise Recommendations and Considerations for Persons With Spinal Cord Injury” (Evans et al, Arch Phys Med Rehabil 2015;96:1749-50), these cardiovascular and muscular strength/endurance recommendations are a modified version of the Physical Activity Guidelines for Adults with Spinal Cord Injury developed and published by Martin Ginis KA, Hicks AL, Latimer AE, et al. The development of evidence-informed physical activity guidelines for adults with spinal cord injury. Spinal Cord 2011;49:1088-96.
0003-9993/16 http://dx.doi.org/10.1016/j.apmr.2016.03.005
In the article “Timed 360 Turn Test for Assessing People With Chronic Stroke” (Shiu et al, Arch Phys Med Rehabil 2016;97:536-44), the sentence in the abstract that reads Participants: Individuals with chronic stroke (nZ72) and healthy individuals (nZ35) of similar age (NZ107). Should read: Participants: Individuals with chronic stroke (nZ37) and healthy individuals (nZ35) of similar age (NZ72).
0003-9993/16 http://dx.doi.org/10.1016/j.apmr.2016.04.003
www.archives-pmr.org