Sarcopenia and frailty: An in-depth analysis of the pathophysiology and effect on liver transplant candidates

Table 1 Assessment methods for sarcopenia

Method	Measurement	Description	Advantages	Disadvantages
HGS	Muscle strength (kg)	Uses a dynamometer to measure hand grip force, indicating overall muscle strength	Simple, non-invasive, and cost-effective; strong correlation with overall muscle function	Affected by motivation, hand injuries, and neurological conditions
Gait speed	Walking speed (meter/second)	Measures the time taken to walk a set distance (e.g., 4-6 meters), assessing mobility	Quick and easy to perform; predictive of disability and mortality	Influenced by joint pain, neurological conditions, and cardiovascular fitness
SPPB	Composite score (0-12)	Includes balance, gait speed, and chair stand tests to assess lower limb function	Comprehensive evaluation; predicts adverse outcomes	Requires trained personnel and space for testing
Chair stand test	Time to complete 5 sit-to-stand repetitions (second)	Evaluates lower limb strength by timing how long a person takes to rise from a chair without arm support	Functional test; easy to administer	Affected by arthritis, balance disorders, and pain
DXA	ALM in kg/m²	Measures muscle mass through low-dose X-ray imaging, considered a gold standard	Accurate, reliable, and widely used in research	Expensive; limited availability in clinical settings
BIA	SMI	Uses electrical currents to estimate body composition, including muscle mass	Portable, affordable, and non-invasive	Less accurate in patients with fluid imbalances
CT/MRI	Cross-sectional muscle area and density	Directly visualizes muscle tissue and fat infiltration in specific body regions	Highly precise and can assess muscle quality	Expensive; CT involves radiation exposure

HGS: Handgrip strength; SPPB: Short physical performance battery; DXA: Dual-energy X-ray absorptiometry; BIA: Bioelectrical impedance analysis; CT: Computed tomography; MRI: Magnetic resonance imaging; ALM: Appendicular lean mass; SMI: Skeletal muscle mass index.