Sarcopenia: describing rather than defining a condition

Abstract

BackgroundTraditional definitions of sarcopenia have described an aging-associated disorder roughly defined as muscle mass two standard deviations below the young adult demographic. In an effort to clear the ambiguity pertaining to such descriptions, two international bodies have put forth working definitions of sarcopenia, namely The Society of Sarcopenia, Cachexia and Wasting Disorders in 2011, and The European Working Group on Sarcopenia in Older People in 2009.ReviewThis paper will look at the current zeitgeist of sarcopenia through a range of studies and will argue that what we have is an amalgamated and often conflicted description, rather than a definition, of the sarcopenic condition. Herein, we will consider whether such descriptions of sarcopenia should center on the consideration of the neuromuscular junction (NMJ) rather than describing the condition more in terms of muscular pathology.ConclusionConsideration was given to studies of the NMJ to advance the idea that present notions of the sarcopenic condition are incomplete and that at its’ core, sarcopenia is an age-related disorder of the NMJ.

Muscle wasting in ageing and chronic illness

“…14 Furthermore, the term 'skeletal muscle function deficit' helps to integrate functional deficits distinct from ageing such as diabetic polyneuropathy or secondary malnutrition and impairments in muscle strength or power that are independent of muscle mass. 11 Cachexia In contrast to age-related muscle wasting, the term cachexia describes the wasting in patients with weight loss and chronic diseases such as CHF, cancer, chronic kidney disease, chronic obstructive pulmonary disease, neuromuscular disease, chronic infection, and metabolic disease-associated disease processes. 2,15 However, a current review article on sarcopenia argues '…that what we have…' would be '…an amalgamated and often conflicted description, rather than a definition, of the sarcopenic condition…'.…”

Evaluation of C-terminal Agrin Fragment as a marker of muscle wasting in patients after acute stroke during early rehabilitation

“…are discussed in the multifactorial aetiology of sarcopenia 15, 16, 17, 18. In aging loss of motoneurons has been proposed as pathogenic and contributing to the developing of sarcopenia 19, 20…”

The role of muscle mass and body fat on disability among older adults: A cross-national analysis

“…Moreover, the maintenance of SMM in older adults has been reported to be one of the most important factors for independent living (Cesari et al, 2009;Newman et al, 2006). Sarcopenia, which previously referred only to this muscle mass decline associated with aging, has more recently been redefined to integrate the concept of muscle strength (power) and physical performance (Alchin, 2014;Stenholm et al, 2008).…”