Sarcopenia related mobility dysfunction was a preventable presentation in transitional variation of frailty. However, the definition, associated risk factors, clinical course and outcome of sarcopenia in Taiwanese older adults are still under-clarified and need for further study.

Inclusion Criteria:

• functional decline in recent one year
• cognitive impairment
• depressive symptom
• mobility impairment
• fall in recent one year
• eating or feeding problems
• weight loss
• co-morbid conditions≧5
• tracking by different physician ≧3 in recent half year
• poly-pharmacy≧8 in recent 3 months
• hospitalization ≧1 in recent one year
• emergency visits≧2 in recent one year
• aged ≧ 80.

Exclusion Criteria:

• non-ambulatory (bed-ridden) patients
• long-term residents at nursing homes
• patients with a life expectancy shorter than six months
• impairment in vision, hearing, or communicative ability, making convenience of clinical evaluation during the study period impossible.

Healthy subjects One thousand Taiwanese subjects aged 20-40 will be recruited equally divided in both genders. Exclusion criteria includes (1) morbid obesity (BMI over 35) ; (2) long term use of body composition modified medications, like steroid, medications for endocrine diseases (hyperthyroidism, diabetes) and autoimmune diseases; (3) energy consumption diseases, such as cancer, organ failure; (4) pregnant women.

Patient enrollment The research subjects will be culled from outpatients aged over 65 at NTUH.