590
LETTERS TO THE EDITOR
MARCH 2014–VOL. 62, NO. 3
The study was designed to measure fat mass using Quad Scan 4000 (Bodystat, Isle of Man, UK), which relies on bioelectrical impedance analysis (BIA). BIA is more practical and feasible than the other criterion standard modalities for body composition analysis, so it has emerged as an attractive tool to measure body composition in routine and research purposes, but limited validity of BIA systems on body composition assessment raises some concerns regarding the accuracy of the results obtained. A recent study indicated this limitation by comparing BIA with dual-energy X-ray absorptiometry, a more-sensitive but still not the criterion standard technique in the assessment of body composition.3 Moreover, BIA measurement is based on total body water, which requires a premeasurement preparation to perform reliable measurement.4 Finally, the study by Sousa and colleagues lacks some critical information on any standardization protocol (whether all measurements were taken at the same time period of resistance training program). Vildan Binay Safer, MD Department of Physical Medicine and Rehabilitation Ankara Physical Medicine and Rehabilitation Research and Training Hospital, Ankara, Turkey Umut Safer, MD Department of Geriatrics, Gulhane School of Medicine Ankara, Turkey
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Vildan Binay Safer and Umut Safer discussed and prepared the manuscript. Sponsor’s Role: None.
REFERENCES 1. Sousa N, Mendes R, Abrantes C, et al. Is once-weekly resistance training enough to prevent sarcopenia? J Am Geriatr Soc 2013;61:1423–1424. 2. Koster A, Patel KV, Visser M, et al. Joint effects of adiposity and physical activity on incident mobility limitation in older adults. J Am Geriatr Soc 2008;56:636–643. 3. Sillanp€ a€ a E, Cheng S, H€akkinen K et al. Body composition in 18 to 88year-old adults—comparison of multifrequency bioimpedance and
JAGS
dual-energy X-ray absorptiometry. Obesity (Silver Spring) 2013. doi:10. 1002/oby.20583 4. Thibault R, Genton L, Pichard C. Body composition: Why, when and for who? Clin Nutr 2012;31:435–447.
RESPONSE TO DRS. SAFER AND SAFER To the Editor: We are grateful to Safer and Safer1 for commenting on the methodology used to measure body fat percentage in our recent study.2 The validity of bioelectrical impedance analysis (BIA) for assessing body composition in older adults is important. Despite not being the criterion standard method, BIA is an easily performed, noninvasive way to measure body composition. Moreover, it has been shown to evaluate body composition reliably in older adults.3,4 To provide a more-accurate assessment of intracellular and extracellular water, a frequency of 50 kHz was selected. The same technicians performed all measurements in the morning after an overnight fast in a quiet room with ambient temperature of 22°C. Each participant reported at 7 a.m. on five separate occasions (before training, and after 8, 16, 24, and 32 weeks). Participants did not perform physical exercise and abstained from alcohol and caffeine consumption for at least 24 hours before testing; they were not feverish or dehydrated. In a recent study,5 BIA provided systematically different body composition estimates throughout the adult age span, with considerable intraindividual variation, but in our study,2 the same BIA equipment was used in all participants, in five repeated measurements, so no inclusion bias was present. Analyzing the results as a whole, body fat percentage was not the only variable that changed in the experimental group. Body weight decreased slightly after 32 weeks of training ( 1 kg), whereas dry lean mass remained constant throughout the study. Thus, the results identified in the body fat percentage are consistent with the values identified in the remaining variables (Table 1). Finally, we conclude with two key points: the use of BIA is an easy and functional method to obtain important information for diagnosing and prevent sarcopenia, and the increase in muscular fitness through exercise training may result from significant loss of body fat, with no change in muscle mass.
Table 1. Body Weight, Body Fat, and Dry Lean Mass Measurements over 32 Weeks in the Experimental Group (n = 16) Baseline
Week 8
a
Week 24
Week 32
72.6 10.8 27.4 3.0 10.7 3.6
72.2 11.7 26.4 2.4a 10.5 3.8
Mean SD
Measurement
Body weight, kg Body fat, % Dry lean mass, kg
Week 16
73.2 11.2 28.7 1.9 10.9 3.7
Significant difference from Week 8, P < .05.
73.2 11.7 29.3 3.2 10.9 3.7
73.1 11.1 28.3 2.1 10.8 3.6
JAGS
MARCH 2014–VOL. 62, NO. 3
Nelson Sousa, PhD Romeu Mendes, MD Research Center in Sport Sciences, Health Sciences and Human Development, University of Tra´s-os-Montes e Alto Douro, Vila Real, Portugal Jose´ Oliveira, PhD Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Sousa and Mendes discussed and prepared the manuscript. Oliveira supervised. Sponsor’s Role: None.
REFERENCES 1. Safer U, Safer VB. Comment on: “Is Once-weekly resistance training enough to prevent sarcopenia?”. J Am Geriatr Soc 2013;62:589–590. 2. Sousa N, Mendes R, Abrantes C et al. Is once-weekly resistance training enough to prevent sarcopenia? J Am Geriatr Soc 2013;61:1423–1424. 3. Haapala I, Hirvonen A, Niskanen L et al. Anthropometry, bioelectrical impedance and dual-energy X-ray absorptiometry in the assessment of body composition in elderly Finnish women. Clin Physiol Funct Imaging 2002;22:383–391. 4. Roubenoff R, Baumgartner RN, Harris TB et al. Application of bioelectrical impedance analysis to elderly populations. J Gerontol A Biol Sci Med Sci 1997;52A:M129–M136. 5. Sillanp€ a€ a E, Cheng S, H€akkinen K et al. Body composition in 18- to 88year-old adults—comparison of multifrequency bioimpedance and dualenergy X-ray absorptiometry. Obesity (Silver Spring) 2013 [Epub ahead of print].
RE: EFFECTS OF RESISTANCE VERSUS MULTICOMPONENT TRAINING ON BODY COMPOSITION AND FUNCTIONAL FITNESS IN INSTITUTIONALIZED ELDERLY WOMEN To the Editor: We read with great interest the study by Sousa and Mendes,1 who reported that 12 weeks of training protocol was not enough to induce changes in the body composition of institutionalized elderly women. The results of that study are particularly important because body composition changes with aging even in weight-stable elderly men and women.2 Beyond these, we would like to comment on some points. Body composition measurement in the study was made using bioelectrical impedance analysis (BIA). For body composition analysis in elderly adults, accuracy of BIA is under discussion.3 The theory of BIA measurement relies on the capacity of hydrated tissues to conduct electrical energy, which allows estimation of total body water (TBW). Calculation of lipid and fat-free mass with BIA was made using equations on TBW,4 so changes in TBW may easily affect BIA results, and pretest preparation is mandatory to minimize the effect of
LETTERS TO THE EDITOR
591
the confounders. The pretest protocol was not reported. Moreover, a recent study showed that a 12-week training program had a significant effect on changes in body fat, total lean mass, and total fat mass in an elderly population.5 In Sousa and Mendes’s study, body composition was measured using dual-energy X-ray absorptiometry, which is the recommended alternative to criterion standard methods. We believe that these problems may have affected the results. Umut Safer, MD Department of Geriatrics, Gulhane School of Medicine, Ankara, Turkey Vildan Binay Safer, MD Department of Physical Medicine and Rehabilitation, Ankara Physical Medicine and Rehabilitation Training and Research Hospital, Ankara, Turkey
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Umut Safer and Vildan Binay Safer discussed and prepared the manuscript. Sponsor’s Role: None.
REFERENCES 1. Sousa N, Mendes R. Effects of resistance versus multicomponent training on body composition and functional fitness in institutionalized elderly women. J Am Geriatr Soc 2013;61:1815–1817. 2. Zamboni M, Zoico E, Scartezzini T et al. Body composition changes in stable-weight elderly subjects: The effect of sex. Aging Clin Exp Res 2003;15:321–327. 3. Safer U, Tasci I, Binay Safer V et al. Is segmental bioelectrical impedance analysis a valid tool to assess muscle mass in the elderly? Geriatr Gerontol Int 2013;13:1085–1086. 4. Thibault R, Genton L, Pichard C. Body composition: Why, when and for who? Clin Nutr 2012;31:435–447. 5. Romero-Arenas S, Blazevich AJ, Martinez-Pascual M et al. Effects of high-resistance circuit training in an elderly population. Exp Gerontol 2013;48:334–340.
RESPONSE TO DRS. SAFER AND SAFER To the Editor: We are grateful to Safer and Safer1 for commenting on the methodology used to measure body composition in our recent study.2 The validity of bioelectrical impedance analysis for assessing body composition is an important question, particularly when institutionalized elderly adults, whose daily life is spent almost exclusively within the institution, are being evaluated. Institutionalized elderly adults have particular characteristics that must be taken into account in this type of study. It has been reported that 65% of institutionalized elderly adults spend their time doing little or nothing, 12% of their time in social activities, and the majority of their time in their rooms, sitting and alone.3 Another study reported that most institutionalized elderly adults
LETTERS TO THE EDITOR
MARCH 2014–VOL. 62, NO. 3
The study was designed to measure fat mass using Quad Scan 4000 (Bodystat, Isle of Man, UK), which relies on bioelectrical impedance analysis (BIA). BIA is more practical and feasible than the other criterion standard modalities for body composition analysis, so it has emerged as an attractive tool to measure body composition in routine and research purposes, but limited validity of BIA systems on body composition assessment raises some concerns regarding the accuracy of the results obtained. A recent study indicated this limitation by comparing BIA with dual-energy X-ray absorptiometry, a more-sensitive but still not the criterion standard technique in the assessment of body composition.3 Moreover, BIA measurement is based on total body water, which requires a premeasurement preparation to perform reliable measurement.4 Finally, the study by Sousa and colleagues lacks some critical information on any standardization protocol (whether all measurements were taken at the same time period of resistance training program). Vildan Binay Safer, MD Department of Physical Medicine and Rehabilitation Ankara Physical Medicine and Rehabilitation Research and Training Hospital, Ankara, Turkey Umut Safer, MD Department of Geriatrics, Gulhane School of Medicine Ankara, Turkey
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Vildan Binay Safer and Umut Safer discussed and prepared the manuscript. Sponsor’s Role: None.
REFERENCES 1. Sousa N, Mendes R, Abrantes C, et al. Is once-weekly resistance training enough to prevent sarcopenia? J Am Geriatr Soc 2013;61:1423–1424. 2. Koster A, Patel KV, Visser M, et al. Joint effects of adiposity and physical activity on incident mobility limitation in older adults. J Am Geriatr Soc 2008;56:636–643. 3. Sillanp€ a€ a E, Cheng S, H€akkinen K et al. Body composition in 18 to 88year-old adults—comparison of multifrequency bioimpedance and
JAGS
dual-energy X-ray absorptiometry. Obesity (Silver Spring) 2013. doi:10. 1002/oby.20583 4. Thibault R, Genton L, Pichard C. Body composition: Why, when and for who? Clin Nutr 2012;31:435–447.
RESPONSE TO DRS. SAFER AND SAFER To the Editor: We are grateful to Safer and Safer1 for commenting on the methodology used to measure body fat percentage in our recent study.2 The validity of bioelectrical impedance analysis (BIA) for assessing body composition in older adults is important. Despite not being the criterion standard method, BIA is an easily performed, noninvasive way to measure body composition. Moreover, it has been shown to evaluate body composition reliably in older adults.3,4 To provide a more-accurate assessment of intracellular and extracellular water, a frequency of 50 kHz was selected. The same technicians performed all measurements in the morning after an overnight fast in a quiet room with ambient temperature of 22°C. Each participant reported at 7 a.m. on five separate occasions (before training, and after 8, 16, 24, and 32 weeks). Participants did not perform physical exercise and abstained from alcohol and caffeine consumption for at least 24 hours before testing; they were not feverish or dehydrated. In a recent study,5 BIA provided systematically different body composition estimates throughout the adult age span, with considerable intraindividual variation, but in our study,2 the same BIA equipment was used in all participants, in five repeated measurements, so no inclusion bias was present. Analyzing the results as a whole, body fat percentage was not the only variable that changed in the experimental group. Body weight decreased slightly after 32 weeks of training ( 1 kg), whereas dry lean mass remained constant throughout the study. Thus, the results identified in the body fat percentage are consistent with the values identified in the remaining variables (Table 1). Finally, we conclude with two key points: the use of BIA is an easy and functional method to obtain important information for diagnosing and prevent sarcopenia, and the increase in muscular fitness through exercise training may result from significant loss of body fat, with no change in muscle mass.
Table 1. Body Weight, Body Fat, and Dry Lean Mass Measurements over 32 Weeks in the Experimental Group (n = 16) Baseline
Week 8
a
Week 24
Week 32
72.6 10.8 27.4 3.0 10.7 3.6
72.2 11.7 26.4 2.4a 10.5 3.8
Mean SD
Measurement
Body weight, kg Body fat, % Dry lean mass, kg
Week 16
73.2 11.2 28.7 1.9 10.9 3.7
Significant difference from Week 8, P < .05.
73.2 11.7 29.3 3.2 10.9 3.7
73.1 11.1 28.3 2.1 10.8 3.6
JAGS
MARCH 2014–VOL. 62, NO. 3
Nelson Sousa, PhD Romeu Mendes, MD Research Center in Sport Sciences, Health Sciences and Human Development, University of Tra´s-os-Montes e Alto Douro, Vila Real, Portugal Jose´ Oliveira, PhD Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Sousa and Mendes discussed and prepared the manuscript. Oliveira supervised. Sponsor’s Role: None.
REFERENCES 1. Safer U, Safer VB. Comment on: “Is Once-weekly resistance training enough to prevent sarcopenia?”. J Am Geriatr Soc 2013;62:589–590. 2. Sousa N, Mendes R, Abrantes C et al. Is once-weekly resistance training enough to prevent sarcopenia? J Am Geriatr Soc 2013;61:1423–1424. 3. Haapala I, Hirvonen A, Niskanen L et al. Anthropometry, bioelectrical impedance and dual-energy X-ray absorptiometry in the assessment of body composition in elderly Finnish women. Clin Physiol Funct Imaging 2002;22:383–391. 4. Roubenoff R, Baumgartner RN, Harris TB et al. Application of bioelectrical impedance analysis to elderly populations. J Gerontol A Biol Sci Med Sci 1997;52A:M129–M136. 5. Sillanp€ a€ a E, Cheng S, H€akkinen K et al. Body composition in 18- to 88year-old adults—comparison of multifrequency bioimpedance and dualenergy X-ray absorptiometry. Obesity (Silver Spring) 2013 [Epub ahead of print].
RE: EFFECTS OF RESISTANCE VERSUS MULTICOMPONENT TRAINING ON BODY COMPOSITION AND FUNCTIONAL FITNESS IN INSTITUTIONALIZED ELDERLY WOMEN To the Editor: We read with great interest the study by Sousa and Mendes,1 who reported that 12 weeks of training protocol was not enough to induce changes in the body composition of institutionalized elderly women. The results of that study are particularly important because body composition changes with aging even in weight-stable elderly men and women.2 Beyond these, we would like to comment on some points. Body composition measurement in the study was made using bioelectrical impedance analysis (BIA). For body composition analysis in elderly adults, accuracy of BIA is under discussion.3 The theory of BIA measurement relies on the capacity of hydrated tissues to conduct electrical energy, which allows estimation of total body water (TBW). Calculation of lipid and fat-free mass with BIA was made using equations on TBW,4 so changes in TBW may easily affect BIA results, and pretest preparation is mandatory to minimize the effect of
LETTERS TO THE EDITOR
591
the confounders. The pretest protocol was not reported. Moreover, a recent study showed that a 12-week training program had a significant effect on changes in body fat, total lean mass, and total fat mass in an elderly population.5 In Sousa and Mendes’s study, body composition was measured using dual-energy X-ray absorptiometry, which is the recommended alternative to criterion standard methods. We believe that these problems may have affected the results. Umut Safer, MD Department of Geriatrics, Gulhane School of Medicine, Ankara, Turkey Vildan Binay Safer, MD Department of Physical Medicine and Rehabilitation, Ankara Physical Medicine and Rehabilitation Training and Research Hospital, Ankara, Turkey
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Umut Safer and Vildan Binay Safer discussed and prepared the manuscript. Sponsor’s Role: None.
REFERENCES 1. Sousa N, Mendes R. Effects of resistance versus multicomponent training on body composition and functional fitness in institutionalized elderly women. J Am Geriatr Soc 2013;61:1815–1817. 2. Zamboni M, Zoico E, Scartezzini T et al. Body composition changes in stable-weight elderly subjects: The effect of sex. Aging Clin Exp Res 2003;15:321–327. 3. Safer U, Tasci I, Binay Safer V et al. Is segmental bioelectrical impedance analysis a valid tool to assess muscle mass in the elderly? Geriatr Gerontol Int 2013;13:1085–1086. 4. Thibault R, Genton L, Pichard C. Body composition: Why, when and for who? Clin Nutr 2012;31:435–447. 5. Romero-Arenas S, Blazevich AJ, Martinez-Pascual M et al. Effects of high-resistance circuit training in an elderly population. Exp Gerontol 2013;48:334–340.
RESPONSE TO DRS. SAFER AND SAFER To the Editor: We are grateful to Safer and Safer1 for commenting on the methodology used to measure body composition in our recent study.2 The validity of bioelectrical impedance analysis for assessing body composition is an important question, particularly when institutionalized elderly adults, whose daily life is spent almost exclusively within the institution, are being evaluated. Institutionalized elderly adults have particular characteristics that must be taken into account in this type of study. It has been reported that 65% of institutionalized elderly adults spend their time doing little or nothing, 12% of their time in social activities, and the majority of their time in their rooms, sitting and alone.3 Another study reported that most institutionalized elderly adults
