Serial measurements of body composition using bioelectrical impedance and clinical usefulness of phase angle in colorectal cancer

Background: Although body composition (BC) can be measured easily using bioelectrical impedance analysis (BIA), there are few studies of serial BC measurements in colorectal cancer (CRC). The purpose of the present study was to observe the serial change of BC in patients with CRC surgery from the initiation to the end of chemotherapy and to evaluate its clinical usefulness. Methods: From July 2018 to November 2019, patients undergoing elective CRC surgery were enrolled. All clinical data were reviewed retrospectively. BIA data were collected prospectively at four time points (initial, discharge day, first chemotherapy, and 6 months later). BC was measured using a commercial BIA device. Results: A total of 160 patients were enrolled, and 110 (68.8%) patients were followed. Most BC measurements, such as weight, body mass index, skeletal muscle mass, skeletal muscle index, and fat mass index, were lowest at the first chemotherapy and rebounded after 6 months. Phase angle (PhA) and the ratio of extracellular water to total body water (ECW/TBW) were “V” shaped and inverted “V” shaped, respectively, and the peaks were on discharge days. This pattern of BC showed significant difference according to sarcopenia, old age (>70 years), and advanced stage (III or IV). The change of PhA and ECW/TBW sensitively pattern differences according to clinical aspect. Conclusions: Using BIA, serial BC measurements were taken to establish a pattern based on clinical characteristics. PhA showed the most sensitive change according to the patient's clinical aspect.