Identifying sarcopenia.
OBJECTIVE
The present review describes and discusses the currently available definitions for sarcopenia from consensus studies.


RESULTS
Different sarcopenia definitions have been proposed in these last years. Six main approaches to an operative definition of sarcopenia have been identified. Although the first definitions were solely based on the assessment of the amount of muscle mass, current definitions seem to consistently recognize a bi-dimensional nature of sarcopenia. So, these approaches imply the need of simultaneously assessing both age-related quantitative (i.e. amount of muscle mass) and qualitative (i.e. muscle strength and function) declines of skeletal muscle.


CONCLUSIONS
Although current consensus exists about a bi-dimensional nature, the proposed approaches to measure sarcopenia are characterized by methodological differences. The majority of the operative definitions proposes to assess muscle mass as an index of appendicular muscle mass divided by squared height (evaluated by dual energy X-ray absorptiometry), assess strength using hand-held dynamometers, and assess function by evaluating gait speed at habitual pace over a short distance. Nevertheless, the clinically relevant thresholds and how to combine the three aspects in an operative definition in order to identify sarcopenia are heterogeneous. A main drawback is that supportive empirical data are missing for these conceptual definitions regarding the risk-assessment of different clinically significant adverse outcomes.
Gérontopôle de Toulouse, Department of Geriatric Medicine, Toulouse University Hospital bINSERM Unit 1027, University Toulouse-III, Toulouse, France. abellan.g@chu-toulouse.fr
Gabor
G
Abellan van Kan
Mathieu
M
Houles
Bruno
B
Vellas
D005684:Gait / Q000502:physiology*; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000473:pathology*; D009929:Organ Size; D055948:Sarcopenia / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology