LETTERS TO THE EDITOR
ACKNOWLEDGMENTS Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the author and has determined that the author has no financial or any other kind of personal conflicts with this paper. Author Contributions: LPSP is the sole author of this paper. Sponsor’s Role: None.
REFERENCES 1. Bahat G. Risk of proton pump inhibitor–induced mild hyponatremia in older adults. J Am Geriatr Soc 2014;62:1206–1207. 2. Buon M, Gaillard C, Martin J et al. Risk of proton pump inhibitor– induced mild hyponatremia in older adults. J Am Geriatr Soc 2013;61:2052–2054.
COMMENT ON “SARCOPENIC OBESITY AND RISK OF CARDIOVASCULAR DISEASE AND MORTALITY: A POPULATION-BASED COHORT STUDY OF OLDER MEN” To the Editor: We read with interest the article by Atkins and colleagues,1 who reported an association between sarcopenia, central obesity, and all-cause and cardiovascular mortality in elderly men. They also found that the greatest risk of all-cause mortality occurred in obese individuals with sarcopenia. The results are particularly important because the prevalence of sarcopenia was reported to be up to 84% in different elderly male cohorts.2 Nevertheless, some methodological concerns need to be acknowledged. First, the method of diagnosing sarcopenia relied on an equation involving midarm muscle circumference (MAMC; mid-upper arm circumference (cm)–0.3142 9 triceps skinfold thickness (mm)), which had previously been found to be strongly correlated with dual-energy X-ray absorptiometry (DEXA),3 although that study was conducted in individuals undergoing hemodialysis and not in healthy individuals. Moreover, an earlier study reported a weaker correlation (correlation coefficients=0. 24–0.36) for MAMC and DEXA based on lean tissue masses in healthy postmenopausal women.4 Second, the study by Atkins and colleagues defined subjects with sarcopenia as those in the lowest two-fifths of the MAMC distribution. This statistical approach may not be consistent with earlier studies in which sarcopenia was defined as the lowest two quintiles the of entire population.5,6 Third, MAMC relies on anthropometric measurements, but the European Working Group on Sarcopenia in Older People clearly recommended against routine use of anthropometric measurements in the diagnosis of sarcopenia.7 Therefore, although the sample size seems to be satisfactory even for skewed parameters, a more-accurate diagnosis of sarcopenia might have led to more-robust results in this study. Umut Safer, MD Department of Geriatrics, Gulhane School of Medicine, Ankara, Turkey
JUNE 2014–VOL. 62, NO. 6
Ilker Tasci, MD Department of Internal Medicine, Gulhane School of Medicine, Ankara, Turkey Vildan Binay Safer, MD Department of Physical Medicine and Rehabilitation, Ankara Physical Medicine and Rehabilitation Research and Training 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: All authors discussed and prepared the manuscript. Sponsor’s Role: None.
REFERENCES 1. Atkins JL, Whincup PH, Morris RW et al. Sarcopenic obesity and risk of cardiovascular disease and mortality: A population-based cohort study of older men. J Am Geriatr Soc 2014;62:253–260. 2. Batsis JA, Barre LK, Mackenzie TA et al. Variation in the prevalence of sarcopenia and sarcopenic obesity in older adults associated with different research definitions: Dual-energy X-ray absorptiometry data from the National Health and Nutrition Examination Survey 1999–2004. J Am Geriatr Soc 2013;61:974–980. 3. Noori N, Kopple JD, Kovesdy CP et al. Mid-arm muscle circumference and quality of life and survival in maintenance hemodialysis patients. Clin J Am Soc Nephrol 2010;5:2258–2268. 4. Zoico E, Di Francesco V, Guralnik JM et al. Physical disability and muscular strength in relation to obesity and different body composition indexes in a sample of healthy elderly women. Int J Obes Relat Metab Disord 2004;28:234–241. 5. Davison KK, Ford ES, Cogswell ME et al. Percentage of body fat and body mass index are associated with mobility limitations in people aged 70 and older from NHANES III. J Am Geriatr Soc 2002;50:1802–1809. 6. Kim TN, Yang SJ, Yoo HJ et al. Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study. Int J Obes 2009;33:885–892. 7. Cruz-Jentoft AJ, Baeyens JP, Bauer JM et al. Sarcopenia: European consensus on definition and diagnosis. Age Ageing 2010;39:412–442.
RESPONSE TO SAFER ET AL. To the Editor: We thank Dr. Safer and colleagues for their interest in our recent report on sarcopenic obesity.1 Safer and colleagues note that the European Working Group on Sarcopenia in Older People does not recommend assessment of midarm muscle circumference (MAMC) for the diagnosis of sarcopenia.2 Our report was based on MAMC because, in this population-based study in widely dispersed primary care settings, it was not possible to use a criterion standard measure of muscle mass, such as dual-energy X-ray absorptiometry (DXA), computed tomography or magnetic resonance imaging. Moreover, the American Heart Association recognizes the validity of upper-arm anthropometric measures for the assessment of muscle mass.3 Although the study by Noori, reporting an association between MAMC and lean mass from DXA,4 was based in a very specific