03 | Bedside ultrasound of the quadriceps femoris as a screening tool for sarcopenia in internal medicine patients: correlation with handgrip strength and clinical-functional impact

R. Piffero¹, F. Di Stefano² | ¹SOC Medicina Interna, Ospedale Castelli di Verbania, Dipartimento di Medicina Traslazionale (DiMeT), Università del Piemonte Orientale UPO, Novara; ²SOC Medicina Interna, Ospedale Castelli di Verbania.

Abstract

Introduction. Sarcopenia in hospitalized elderly causes disability, prolonged stay, and mortality. Bedside quadriceps ultrasound is emerging for muscle mass quantification, but its role as a handgrip strength surrogate remains undefined. We evaluated its accuracy in identifying reduced strength and explored associations with clinical-functional status.

Materials and Methods. Cross-sectional study at Castelli Hospital Internal Medicine, Verbania. We enrolled 100 patients (median age 80 years, interquartile range 71–87; 53 males, 47 females) admitted within 96 hours. Handgrip strength was measured via dynamometer (Southampton protocol) and quadriceps thickness by ultrasound. Assessments included Barthel Index, Clinical Frailty Scale, cognitive status, Charlson Comorbidity Index, and medications. We used receiver operating characteristic analysis, Spearman rho, and logistic regression.

Results. Low muscle strength prevalence (European Working Group on Sarcopenia in Older People 2 criteria) was 62% (p=0.57 between sexes). Quadriceps thickness correlated with handgrip strength overall (rho=0.655, p<0.001), in males (rho=0.587), and females (rho=0.660). Each millimeter added +0.63 kilograms of handgrip strength, independent of age and sex (p<0.001). Optimal thresholds: 24.8 millimeters in males (area under the curve=0.882; sensitivity 87.1%, specificity 77.3%) and 20.6 millimeters in females (area under the curve=0.837; sensitivity 83.9%, specificity 87.5%). Parameters correlated with Barthel Index (rho=0.638; rho=0.534), Clinical Frailty Scale (rho=-0.635; rho=-0.586), and cognitive status (p<0.001). The Charlson Comorbidity Index independently predicted poor discharge outcomes (p=0.021).

Conclusions. Bedside quadriceps ultrasound shows high diagnostic accuracy for probable sarcopenia, representing a valid complementary tool to handgrip strength in elderly medical patients. Morphological parameters correlate with functional performance and frailty.