Phase Angle as a Comprehensive Tool for Nutritional Monitoring and Management in Patients with Crohn's Disease

Background and Aims: Crohn's disease (CD) is usually accompanied by malnutrition. CD-related malnutrition can increase morbidity, disability, mortality, and hospitalization costs. The purpose of this study was to find a reliable indicator for evaluating CD patients' nutritional status. Methods: All data were retrospectively collected from Xiangya Hospital, Central South University between May 2021 and February 2022. All patients were evaluated for nutritional status using the Global Leadership Initiative on Malnutrition (GLIM) criteria. Body composition, resistance, and reactance were recorded by a body analyser, and the phase angle (PhA) was calculated simultaneously. The Mann-Whitney U test, chi-square test, Fisher's exact test, and univariate and multivariate logistic regression analyses were used. A receiver operating characteristic (ROC) curve was built to evaluate the predictive value of differential variables for diagnosing malnutrition based on the GLIM criteria. Results: A total of 169 CD patients were enrolled, of which 74 (58.3%) males and 32 (76.2%) females were diagnosed with malnutrition; 34 (45.9%) males and 22 (68.8%) females were severely malnourished. Univariate analysis identified that as nutritional status deteriorated, body mass index, PhA, and levels of haemoglobin and albumin decreased, while platelet count, erythrocyte sedimentation rate, and levels of C-reactive protein and fibrinogen increased (p < 0.05). Logistic regression analysis revealed that the PhA was significantly independently associated with malnutrition (p < 0.05). The ROC curve analysis indicated that the optimal PhA cut-off levels of 6.11 degrees and 5.55 degrees could be used to predict malnutrition according to the GLIM criteria in males and females, respectively, with a PhA < 5.53 degrees and < 5.12 degrees indicating severe malnutrition in males and females, respectively. Conclusion: The PhA is a sensitive, noninvasive, portable, inexpensive tool that can be used to monitor and manage the nutritional status of CD patients.