A Multivariable Model Based on Ultrasound Imaging Features of Gastrocnemius Muscle to Identify Patients With Sarcopenia

Abstract

ObjectivesLow skeletal muscle mass, strength, or somatic function are used to diagnose sarcopenia; however, effective assessment methods are still lacking. Therefore, we evaluated the effectiveness of ultrasound in identifying patients with sarcopenia.MethodsThis study included 167 patients, 78 with sarcopenia and 89 healthy participants, from two hospitals. We evaluated clinical factors and five ultrasound imaging features, of which three ultrasound imaging features were used to create the model. In both the training and validation datasets, the sarcopenia detection performances of chosen ultrasonic characteristics and the constructed model were evaluated using receiver operating characteristic (ROC) curves. The predictive performance was evaluated by area under the ROC (AUROC), calibration, and decision curves.ResultsThere were statistically significant differences in muscle thickness (MT) of gastrocnemius medialis muscle (GM), flaky myosteatosis echo (FE), pennation angle (PA), average shear wave velocity (SWV) in the relaxed state (RASWV), and average SWV in the passive stretched state (PASWV) between sarcopenic and normal subjects. PA, RASWV, and PASWV were effective predictors of sarcopenia. The AUROC (95% confidence interval) for these three parameters were 0.930 (0.882–0.978), 0.865 (0.791–0.940), and 0.849 (0.770–0.928), respectively, in the training set, and 0.873 (0.777–0.969), 0.936 (0.878–0.993), and 0.826 (0.716–0.935), respectively, in the validation set. The combined model had better detection power. Finally, the calibration curve showed that the combined model had good prediction accuracy.ConclusionOur model can be used to identify sarcopenia in primary medical institutions, which is valuable for the early recognition and management of sarcopenia patients.

Ultrasound Assessment of the Gastrocnemius Muscle as a Potential Tool for Identifying Sarcopenia in Patients with Type 2 Diabetes

“…21 Previous studies demonstrated that ultrasound measurement of gastrocnemius muscle could identify sarcopenia in hospitalized patients older than 60 years. 33 Considering that the gastrocnemius muscle was more readily available than the quadriceps, we chose gastrocnemius muscle as the measured muscle. Similarly, we found that type 2 diabetic patients with sarcopenia had lower CSA, MT and SWE values than patients without sarcopenia, and we also developed a diagnostic model for sarcopenia using age, CSA and SWE.…”

“…It may be due to a decrease in the number of muscle fibers and an increase in the amount of connective tissue such as adipose and extracellular matrix in patients with sarcopenia, resulting in a more significant decrease in muscle stiffness in patients with sarcopenia. 33,38 SWE, which spatially represents soft tissue stiffness and measures muscle quality, appears to be a reliable technique for assessing muscle fibrosis in sarcopenia. Cr is an endogenous product released by muscle, and its blood concentration depends on muscle mass.…”