REVIEW Sarcopenia: a predictor of mortality and the need for early diagnosis and intervention Lidiane Isabel Filippin • Vivian Nunes de Oliveira Teixeira • Magali Pilz Monteiro da Silva • Fernanda Miraglia • Fabiano Silva da Silva Received: 18 June 2014 / Accepted: 23 October 2014 Ó Springer International Publishing Switzerland 2014 Abstract The term sarcopenia refers to the loss of muscle mass that occurs with aging. Sarcopenia is defined by the European Working Group on Sarcopenia in Older People (EWGSOP) as low muscle mass and low muscle function (strength and performance). Its prevalence varies depend- ing on the definition used for it, but estimates propose a loss of approximately 8 % per decade until the age of 70 years; afterwards, the loss increases and ranges from 13 to 24 % per decade. Irrespective of how sarcopenia is defined, both low muscle mass and poor muscle strength are highly prevalent and important risk factors for dis- ability and increased mortality in individuals as they age. In this review, we address age-related muscle loss and the risk factors of mortality, emphasizing the need for early diagnosis and intervention. Keywords Sarcopenia Á Mortality Á Disability Á Aging Introduction Sarcopenia is a condition that is characterized by pro- gressive and generalized loss of muscle mass and strength with a high risk of adverse outcomes, such as decreased physical performance, poor quality of life and death [1–4]. From a histological point of view, sarcopenia is charac- terized by a decrease in the number and size of the muscle fibers [5]. The term ‘‘sarcopenia’’, coined by [6], originates from the Greek words sarx (flesh) and penia (loss) [7]. Nevertheless, clinicians and researchers are largely una- ware of the term ‘‘sarcopenia’’. Often, this term is mis- takenly confused with other definitions, such as cachexia (loss of skeletal muscle mass due to disease) or atrophy (loss of skeletal muscle mass due to inactivity) [8]. The term ‘sarcopenia’ was originally defined as a decrease in muscle mass related to aging [9]. However, it has since become a general term to define loss of muscle mass and muscle strength related to aging [10]. Recently, studies have shown that decreased muscle strength is more pro- nounced than the reduction in muscle mass among the elderly [3, 11–14], and muscle strength is a better predictor of disability [15]. Newman et al. [3] demonstrated that low muscle mass did not explain the strong association of strength with mortality, demonstrating that muscle strength is more important than quantity as a marker of muscle quality in estimating mortality risk. For this reason, the European Working Group on Sarcopenia in Older People (EWGSOP) developed an algorithm to diagnose sarcopenia based on three criteria: decrease of muscle strength, reduced muscle mass and impaired physical performance [16]. The causes of sarcopenia are multifactorial and can include many factors, such as physical inactivity, decreased mobility, slow gait, and poor physical endurance. These factors are linked with motor unit loss, declines in mito- chondrial biogenesis and chronic inflammatory processes [1, 17, 18], and they are thought to perpetuate the loss of muscle throughout the aging process through mechanisms that are not fully understood [18, 19]. Furthermore, aging L. I. Filippin (&) Mestrado em Sau ´de e Desenvolvimento Humano, Centro Universita ´rio La Salle, Canoas, RS, Brazil e-mail: lidiane.filippin@unilasalle.edu.br L. I. Filippin Á M. P. M. da Silva Á F. Miraglia Á F. S. da Silva Centro Universita ´rio La Salle, Canoas, RS, Brazil V. N. O. Teixeira Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil 123 Aging Clin Exp Res DOI 10.1007/s40520-014-0281-4