Chronology of age-related disease definitions: Osteoporosis and sarcopenia

► Sarcopenia is a term used to describe deficiency of muscle mass at older age. ► There is no universal consensus on the definition of sarcopenia. ► It took over 50 years to reach a World Health Organization definition for osteoporosis. ► Comparable steps in the process of reaching a definition for sarcopenia and osteoporosis have been identified. ► Critical steps needed to define sarcopenia are available medication, pharmaceutical interest and public awareness.