L I T E R AT U R E R E V I E W
Sarcopenia in older people Solomon Yu FRACP, MBBS, 1,2 Kandiah Umapathysivam PhD 3 and Renuka Visvanathan PhD, FANZSGM, FRACP, MBBS 1,2 1 Adelaide Geriatrics Training and Research with Aged Care (G-TRAC) Center, School of Medicine, University of Adelaide, 2Aged and Extended Care Services, Queen Elizabeth Hospital, Central Adelaide Local Health Network, and 3The Joanna Briggs Institute, School of Translational Health Science, Faculty of Health Sciences, University of Adelaide, Adelaide, South Australia, Australia
ABSTRACT Sarcopenia is the age-related loss of muscle mass and strength. It has been receiving international attention because of its increased prevalence in western societies, such as Australia, which have large and growing older populations. Adverse health consequences of sarcopenia are falls and loss of independence, increased health costs and reduced quality of life. Recently, there have been international attempts to come to a consensus with regards to a definition of the condition, and, increasingly, clinicians are being encouraged to screen and assess for sarcopenia. Screening pathways are being investigated and some are discussed in this review. There is an emphasis on early screening, as it is believed that early detection will allow early intervention. As with most conditions in older age, there are many environmental and medical factors that can contribute to the development and worsening of sarcopenia, and it is important that, when possible, these contributing factors be addressed. Pharmaceutical treatment strategies are under development with some early promise and there is the possibility of clinical trials in the near future. Currently, nutritional supplementation and physical therapy are the strategies advocated for the management of sarcopenia once it is diagnosed. Key words: aging, body composition, muscle mass, nutrition, sarcopenia Int J Evid Based Healthc 2014; 12:227–243.
Over the past decade, refining the definition of sarcopenia has led to significant variation in the meaning.9 Initially, researchers focused on the loss of muscle mass or muscle strength or physical function individually rather than in combination. Furthermore, various measurements of muscle mass were referred to in the literature, including the use of terms such as ‘lean body mass’ (LBM) and ‘appendicular skeletal muscle mass’ (ASM). However, in recent years, there have been attempts to standardize the definition of sarcopenia internationally. In keeping with this, since 2009, there have been six international efforts at reaching consensus (detailed in Table 1). Whilst there remains great variability as to how best to assess muscle mass and what cut-offs should be used to define low muscle mass, there appears to be a general consensus that gait speed is likely to be the most practical method by which to assess muscle performance in clinical practice. However, there remains some ambiguity on the best cut-off for gait speed, with
ith normal ageing, physiological changes in the body composition are observed. In general, body weight increases and peaks at the age of 65 years in women and 54 years in men.1,2 The weight gain is predominantly as a result of gain in fat mass,3 which tends to be distributed viscerally in both sexes.4 There is also a decrease in the adipose tissue thickness in the arms and legs.5 The decline of muscle mass is approximately 8% per decade from the age of 50 years until the age of 70 years.6 After 70 years, weight loss with concomitant muscle mass loss is more common, reaching rates of 15% per decade.2,6 Irwin Rosenberg proposed the term ‘sarcopenia’ in 1989, to describe the age-related loss of muscle mass observed with ageing.7,8 Taken from Greek, sarcopenia means ‘poverty of flesh’.7,8
Correspondence: Solomon Yu, FRACP, MBBS, Queen Elizabeth Hospital, Adelaide, Australia. E-mail: [email protected]
International Journal of Evidence-Based Healthcare ß 2014 University of Adelaide, Joanna Briggs Institute
©2014 University of Adelaide, Joanna Briggs Institute. Unauthorized reproduction of this article is prohibited.
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Table 1. The various consensus diagnostic criteria for sarcopenia Study group
ESPEN special interest group10
Loss of muscle mass and strength
Criteria 1: Low muscle mass >2 SD below mean of the younger adults Criteria 2: Low gait speed 2 SD below mean of the younger adults12: Men