BIOELECTRICAL IMPEDANCE PHASE ANGLE IN UNDERWEIGHT PATIENTS

The aim of this analysis is to evaluate the results from Bioimpedance Vector Analysis (BIVA) performed in underweight patients and possible correlations between sex or subgroup (constitutionally lean – CL – or anorexia nervosa – AN). Underweight (BMI < 18,5) patients (CL or AN), from May 2017 to July 2018 were included in the results. Weight was measured to the nearest 0.1 kg and height to the nearest 0.5 cm. BIVA was performed with a single-frequency bioimpedance analyzer (BIA 101 RJL, Akern Bioresearch, Italy). Results are presented as mean and standard deviation. From May 2017 to July 2018, n. 65 BIVA were performed in both AN or CL underweight patients. Results are presented in Table 1. Median phase angle is 6,1±1,6 (5,9±1,0 in men, 6,1±1,0 in women). Results by age group are presented in Table 2. Result by subgroup (AN or CL) are presented in Table 3. Median phase angle is 6,4±2,0 in AN, 5,7±0,9 in CL. In our sample there are no significant differences in BMI and phase angle neither between underweight men and women nor between anorectic and constitutionally lean patients. Though, phase angle could be a reliable marker of changes in body composition throughout nutritional treatment. Marra M, Caldara A, Montagnese C, De Filippo E, Pasanisi F, Contaldo F, Scalfi L. Bioelectrical impedance phase angle in constitutionally lean females, ballet dancers and patients with anorexia nervosa. Eur J Clin Nutr. 2009 Jul;63(7):905-8