Assessment of Muscle Quality and Quantity for the Diagnosis of Sarcopenia Using Mid-Thigh Computed Tomography : A Cohort Study

Abstract

BackgroundPreviously, sarcopenia was diagnosed based on walking speed, grip strength, and muscle mass. However, recent consensus has proposed a concern regarding the use of muscle mass measurement for sarcopenia diagnosis due to lack of accuracy; therefore, new assessment methods in clinical practice are required. We compared computed tomography (CT) with various motor function tests to determine the validity of CT as a potential diagnostic method for sarcopenia.MethodsIn total, 214 patients who were examined at our center during the study period (2016–2017) were included in the study. Single-slice CT scan of the mid-thigh region was performed, from which cross-sectional area (CSA) and CT attenuation value (CTV) of quadriceps femoris were evaluated for each subject. Other assessments included skeletal mass index, muscle strength and physical performance. Furthermore, subjects were classified into four groups: normal, low muscle mass (low mass), poor muscle function/strength (poor function), and sarcopenia.ResultsCSA and muscle strength exhibited the strongest correlation. Some physical performance tests showed the strongest correlation with CTV. CSA was significantly reduced both in men and women with low mass and sarcopenia group (p < 0.01), whereas CTV was significantly lower in men with sarcopenia group and in women with poor function and sarcopenia group (p < 0.01).ConclusionsCSA mostly reflects muscle strength, whereas CTV mostly reflects physical performance. CT with measurements of CSA and CTV enables the evaluation of muscle mass and quality simultaneously. Thus, CT is thought to be useful for the assessment of motor function and diagnosis of sarcopenia.