Multifrequency Bioelectrical Impedance Analysis Compared With Computed Tomography for Assessment of Skeletal Muscle Mass in Primary Colorectal Malignancy: A Predictor of Short-Term Outcome After Surgery

Background: Herein, we evaluate the accuracy and reliability of multifrequency bioelectrical impedance analysis (BIA) to assess skeletal muscle mass (SMM) in the colorectal cancer patient compared with computed tomography (CT) scan and also analyze the association between SMM of BIA and postoperative outcomes. Methods: From March to May 2017, the body composition of patients scheduled for elective surgery due to primary colorectal cancer in our institution was analyzed at the time of admission using BIA (InBody S20, Biospace Co Ltd, Seoul, South Korea). The relationship between the single cross-sectional area of skeletal muscle at the lumbar region using preoperative CT scan and the SMM determined via BIA were assessed. Postoperative outcomes were compared according to different status of SMM on BIA categorized into 3 groups (low, medium, or high). Results: Fifty patients were analyzed, and the length of hospital stay was shorter and the initiation of oral diet was significantly earlier in the group with high SMM than in other groups (P = 0.001 and 0.038, respectively). The SMM on BIA showed a very significant correlation with skeletal muscle index using CT scan (0.705 of correlation coefficients, P < 0.001) and also strongly correlated with skeletal muscle index after adjusting for age, weight, and BMI on multivariate analysis (β = 0.391 ± 0.057, P < 0.001). Conclusion: SMM determined by BIA is strongly correlated with SMM estimated by CT scan. Authors suppose that BIA could be an alternative to CT scan for the assessment of SMM in colorectal cancer patients.