“Over the age span from 20 years 80 years of age, there is approximately a 30% reduction in muscle mass and a decline in cross-sectional area of about 20%.”

In 2009, the International Working Group on sarcopenia reached a consensus definition:

“Sarcopenia is the age-associated loss of skeletal muscle mass and function. Sarcopenia is a complex syndrome that is associated with muscle mass loss alone or in conjunction with increased fat mass. The causes of sarcopenia are multifactorial and can include disuse, changing endocrine function, chronic diseases, inflammation, insulin resistance, and nutritional deficiencies. While cachexia may be a component of sarcopenia, the two conditions are not the same.”

Sarcopenia and fragility fractures

The skeletal and muscular systems are inextricably linked because the strongest mechanical forces applied to bones result from contractions of muscles. Those forces impact on bone density and bone strength. As such, concurrent sarcopenia and osteoporosis has been characterised as a ‘hazardous duet’. The two conditions may share common pathogenic pathways, including:

  • Sensitivity to reduced anabolic hormone secretion
  • Increased inflammatory cytokine activity
  • Reduced physical activity

Identification of individuals with sarcopenia can be readily undertaken by assessment of lower extremity function and, more recently, by DXA-based measures of body composition. A broad range of approaches to the treatment of sarcopenia are under investigation including:

  • Exercise and physical therapy
  • Nutritional therapies
  • Androgen therapy
  • Novel anti-sarcopenic agents

The following publications provide further information:

  • The Official Positions of the International Society for Clinical Densitometry: body composition analysis reporting. J Clin Densitom. 2013 Oct-Dec;16(4):508-519. PubMed ID 24183640
  • Sarcopenia and fragility fractures. Eur J Phys Rehabil Med. 2013 Feb;49(1):111-117. PubMed ID 23575205
  • Sarcopenia: An Undiagnosed Condition in Older Adults. Current Consensus Definition: Prevalence, Etiology, and Consequences. J Am Med Dir Assoc. 2011 May ; 12(4): 249–256. PubMed ID 21527165

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