Table 1.

Possible model populations of accelerated aging (with related weaknesses and strengths) on which targeting sarcopenia interventions.

Population	Weaknesses	Strengths
Healthy volunteers restrained from physical activities	-Ethical concerns, especially for longer term studies -Difficult recruitment of older persons	-Possible easy recruitment -Few clinical and biological confounders potentially affecting the study findings
Progeroid patients	-Ethical concerns -Limited number of patients -Not exactly mimicking normal aging	-Multisystemic accelerated aging
Bed-ridden subjects due to acute illness (e.g., influenza, hip fractures, elective surgery)	-Possible interference of the acute condition on the skeletal muscle decline -Possible influence of treatment-related factors	-Possible easy recruitment -Possible evaluation of specific (primary condition-based) stimuli on the determination of the muscle loss
Patients with specific conditions characterized by chronic elevation of inflammatory status (e.g., acquired immune deficiency syndrome [AIDS], rheumatoid arthritis)	-Limited number of (older) patients for some specific diseases -Possible interference of the primary condition on the skeletal muscle decline -Specifically focused on inflammation as determinant of muscle decline	-Multisystemic accelerated aging
Older subjects with initial muscle impairment	-Disabling process already started (thus, limited use for real preventive studies) -Presence of (age-related) comorbidities	-Easy recruitment -Specifically focused on older persons