Sonographic Features of Rectus Femoris Muscle in Patients with Metabolic Dysfunction-Associated Fatty Liver Disease and Their Correlation with Body Composition Parameters and Muscle Strength: Results of a Single-Center Cross-Sectional Study

This study aimed to describe sonographic features of rectus femoris muscle (RFM) in patients with metabolic dysfunction-associated fatty liver disease (MASLD) and their correlation with body composition parameters and muscle strength. A total of 67 patients with MASLD underwent dual-energy X-ray absorptiometry (DEXA), bioimpedance analysis (BIA), muscle strength measurement (grip strength [GS] and chair stand test [CST]), and ultrasound (US) investigation of the RFM in the dominant thigh using a 4 to 18 MHz linear probe. MASLD patients exhibited increased RFM echogenicity, possibly due to fatty infiltration. We confirmed that the greater the subcutaneous fat thickness, the smaller was the muscle mass (p < 0.001), and the lower was the muscle strength (p < 0.001 for GS and p = 0.002 for CST). On the contrary, the greater the anteroposterior diameter (APD) of RFM, the higher was the muscle mass (p < 0.001), and the greater was the muscle strength (p < 0.001 for GS and p = 0.007 for CST). In addition, APD of the RFM and stiffness of RFM exhibited direct correlation with bone mineral density values of the lumbar spine (p = 0.005 for both GS and CST). We concluded that US investigation of the RFM in the dominant thigh can be helpful in identifying MASLD patients at a high risk of musculoskeletal disorders given repeated point-of-care clinical evaluations.