Developing consensus criteria for sarcopenia: an update.

Sarcopenia, the age-related loss of muscle mass and strength, is a major cause of impaired physical function, which contributes to mobility disability, falls and hospitalizations in older adults. Lower muscle mass and strength are also associated with lower bone mineral density and greater risk for osteoporotic fractures. Thus, identification of sarcopenia could be important for fracture prevention as it may help improve fracture risk assessment, and muscle mass and strength can be improved with exercise, even among the frailest older adults. Unfortunately, there are no consensus diagnostic criteria for sarcopenia. Consequently there is no guidance to help clinicians identify older adults with clinically meaningful low muscle mass or weakness. Further, development of novel sarcopenia therapies is hindered not only due to the difficulty in identifying participants for clinical trials, and but also because there are no validated, clinically appropriate endpoints for assessment of treatment efficacy. There is currently a major push to establish a consensus definition of sarcopenia, and recent work holds promise that this goal may be within reach. This article discusses the evolution of the definition of sarcopenia, and focuses on the latest recommended diagnostic criteria proposed by the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project. While these empirically-based cut-points for clinically important low muscle mass and weakness are a significant step forward for the sarcopenia field, important questions remain to be answered before consensus diagnostic criteria can be definitively established. Ongoing work to refine sarcopenia criteria will further advance the field and bring this important contributor to falls, fractures and disability into the mainstream of clinical care and ultimately lead to better quality of life with aging.