Shear-wave elastography for muscle assessment in geriatric outpatients at increased risk of falling

Sarcopenia, defined by the loss of muscle strength, quantity, and quality, increases the risk of functional decline and adverse outcomes. Shear-wave elastography (SWE), a non-invasive ultrasound-based technique, quantifies muscle stiffness. However, its diagnostic value in sarcopenia remains unclear. This study investigated the relationship between rectus femoris (RF) stiffness and physical performance in geriatric outpatients with and without sarcopenia.

This cross-sectional study, conducted in a geriatric outpatient clinic, included consecutive patients aged ≥ 65 years. Muscle stiffness was assessed using SWE, and muscle thickness was measured to estimate appendicular lean mass (ALM). Sarcopenia was diagnosed per EWGSOP2 criteria. Analyses included group comparisons, multivariable regression, and evaluating diagnostic accuracy using previously suggested SWE thresholds.

In total, 114 patients were included (mean age 80 ± 9.9 years; 65.8% female). The prevalence of sarcopenia was 20.1%. No significant difference in SWE was found between sarcopenic and non-sarcopenic participants (p = 0.78), nor was SWE associated with age (ρ = - 0.03, p = 0.72). Lower SWE was associated with poor physical performance (short physical performance battery ≤ 7; β = - 1.30, p = 0.025). At Q1 (4.062 kPa), the relative risk (RR) of sarcopenia was 0.83 (95% CI: 0.36-1.90); sensitivity 74%, specificity 22%. At Q3 (8.249 kPa), RR 2.33 (95% CI: 1.09-4.96); sensitivity 26%, specificity 90%. At Youden's (8.226 kPa), RR 2.68 (95% CI: 1.31-5.47); sensitivity 30.4%, specificity 90.1%.

Lower SWE is associated with poor physical performance. SWE is not a reliable standalone marker for sarcopenia in geriatric outpatients. Until stronger evidence emerges, assessing ALM remains preferable.