Assessing the ability of SARC-F to reflect elastography-based muscle quality in older adults

Sarcopenia is a geriatric syndrome characterized by progressive loss of skeletal muscle mass, strength, and function associated with aging. Studies evaluating the relationship between sarcopenia screening tools and elastography-based muscle quality measurements are quite limited. The main objective of this study was to evaluate the relationship between the SARC-F score and muscle elasticity in older adults.

This cross-sectional study included 140 adults aged ≥60 years attending geriatric or internal medicine outpatient clinics at a tertiary academic center. Sociodemographic characteristics, comorbidities, BMI, nutritional status (MNA-SF), frailty (Clinical Frailty Scale, FRAIL), and SARC-F scores were recorded. Rectus femoris thickness and elasticity were assessed using shear-wave elastography.

The median age was 65 (60-91), and 62.9% (n = 88) were female. Positive SARC-F screen (SARC-F ≥ 4) was observed in 29.3% (n = 41). Participants at risk for sarcopenia were older (70 vs. 64 years, p < 0.001), more frail (CFS 5 vs. 3, p < 0.001), more malnourished (MNA-SF 10 vs. 13, p < 0.001), and had lower RF thickness (8.4 vs. 9.8 mm, p = 0.013) and lower muscle elasticity (10.9 vs. 14.6 kPa, p = 0.002). A weak negative correlation was found between SARC-F and RF elasticity (ρ = -0.315, p < 0.001). In the age- and sex-adjusted model, this association was no longer significant (p = 0.116). In multivariable stepwise regression, RF elasticity was not independently associated with SARC-F. .

SARC-F is a practical screening tool for sarcopenia risk but may not adequately reflect muscle quality. These findings suggest that incorporating muscle quality assessments (e.g. shear-wave elastography) into sarcopenia screening may improve diagnostic accuracy and clinical management.