N04 Impact of phase angle on nutritional assessment and disease activity in patients with Ulcerative Colitis

Abstract Background An increase in the prevalence of Ulcerative Colitis (UC) has been reported, especially in Latin America, malnutrition occurs in up to 70% of patients with active disease. The complete assessment of nutritional status is the best method to make an adequate diagnosis since it considers 4 parameters, anthropometry, biochemistry, clinical, and dietary, however, it is very extensive and there are other methods such as bioelectrical impedance (BIA), which is a non-invasive way to estimate the percentage and amount of fat, muscle, water and phase angle (PhA). Moreover, PhA has been proposed as a marker of cell integrity which may be a substitute for complete nutritional assessment. Therefore, the study aimed to evaluate the effectiveness of PhA in the nutritional diagnosis of patients with UC. Methods A cross-sectional study was carried out in patients with UC and healthy controls. Body composition was measured in both groups to obtain the PhA. U Mann-Whitney test was used to compare the data. Patients were classified according to their PhA, considering a normal value of >6.1° and a low value of >6.1°. Results The study included 60 UC and 120 controls, 65% were women, and 35% men, the PhA was lower in UC compared to the controls, in addition to the fact that patients with active disease had a lower PhA compared to patients with remission (5.6±0.9 vs 6.06±0.8, p<0.05). In our study, patients with a low PhA had a lower amount of weight (Active: 60.5±13.6 vs 70.3±.8, p=0.018, Remission: 57.1±11.4 vs 69.4±8.7, p=0.006), dry lean mass (Active: 13.8±3.6 vs 18.2±.6, p=0.009; Remission: 13.1±2 vs 19.7±5.3, p<0.001), total body water (Active: 27.4±6.2 vs 32.9±4.6, p=0.028; Remission: 25.3±3.8 vs 34.4±9.2, p=0.003), and intracellular water (Active: 51.9±3.2 vs 55.1±3.3, p=0.042; Remission: 49.3±10.7 vs 55.8±3.6, p=0.025 ) regardless of disease activity. In this population, we can observe that the inflammation markers (ESR, CRP) were increased in accordance with the activity of the disease associated with PhA, which is consistent with what has been reported in the literature. Conclusion The PhA is modified in patients with UC compared to healthy patients, even more so when they have active disease. Women with active UC are those at risk of malnutrition and cardiovascular risk measured by PhA and CCI. PhA is effective in diagnosing malnutrition in patients with UC regardless of conventional parameters for evaluating nutritional status (Figure 1).