Background: To propose an ultrasound-based parameter for the diagnosis of muscle mass loss (MML) in cirrhosis.
Methods: This is an IRB-approved cross-sectional study (October 2013 to January 2017) with written informed consent including 357 subjects-234 cirrhosis and 123 controls. MML was diagnosed using the skeletal muscle index at the L3 level (L3-SMI) on computed tomography (CT). Transcutaneous ultrasound was used to demonstrate a cross section of the right iliopsoas muscle, and the iliopsoas muscle index (IP index) was defined by the iliopsoas muscle area/height2 (mm2/m2). Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic ability of IP index for MML.
Results: The iliopsoas muscle was detected in all subjects. The IP index was lower in cirrhosis than in controls: males (211.2 ± 73.8 vs. 295.5 ± 139.4, P < 0.0001) and females (200.2 ± 72.5 vs. 284.4 ± 112.4, P < 0.0001). L3-SMI and IP index showed correlations in males (r = 0.699, P < 0.0001) and in females (r = 0.707, P < 0.0001). Independent factors for MML by multivariate analysis were body mass index and IP index in both males and females. Sensitivity, specificity, and area under the ROC curve by IP index to detect MML were 79.5%, 73.1%, and 0.835, respectively, with the best cut-off value of 189.2 for males, and 84.6%, 78.8%, and 0.874, respectively, with the best cut-off value of 180.6 for females.
Conclusions: Using transcutaneous ultrasound, the IP index may be a valuable diagnostic parameter for MML in cirrhosis.
Keywords: Cirrhosis; Muscle mass loss; Non-invasive diagnosis; Ultrasound.