SAT0311 BIOELECTRICAL IMPEDANCE VECTOR ANALYSIS FOR NUTRITIONAL STATUS ASSESSMENT IN SYSTEMIC SCLEROSIS AND ASSOCIATION WITH DISEASE CHARACTERISTICS
Authors: M. DI Battista, S. Barsotti, A. Monaco, A. Rossi, A. Della Rossa, M. Mosca
Journal: Annals of the Rheumatic Diseases (2020)

Background: Bioelectrical impedance vector analysis (BIVA) is a common non-invasive method for estimating body composition which ultimately allows to obtain information on subject’s nutritional status. So far no data about the use of BIVA in patients with systemic sclerosis (SSc) have been published. Objectives: We used BIVA in a cohort of SSc patients in order to assess their nutritional status and any correlation with the various clinical characteristics of the disease, also evaluating the differences with the general population. Methods: We collected data from consecutive patients diagnosed with SSc according to EULAR/ACR criteria and from healthy controls (HC) matched for age and sex. Patients underwent BIVA for the assessment of fat mass (FM), free fat mass (FFM), total body water (TBW), extracellular water (ECW), body cellular mass (BCM), basal metabolic rate (BMR) and ECM/BCM ratio, an early index of protein catabolism. Data included anthropometric and clinical features, Body Mass Index (BMI) and specific organ involvement with particular attention to gastrointestinal symptoms. Laboratory parameters, including haemoglobin and albumin levels, were also collected. Additionally, patients completed the UCLA GIT 2.0 questionnaire. Results: Data from 50 SSc patients (92% female; mean age 61.1±12.5 years; mean disease duration 13.4±10.2 years) and from 50 HC were compared. BIVA revealed that SSc patients presented a significant reduction in BMR, BCM and ECW values compared to HC (p&lt;0.001 for all). The former also exhibited a higher ECM/BCM ratio (p&lt;0.001). No significant differences regarding FM, FFM, TBW and BMI were found between the two groups. Among the cohort of SSc patients, a direct correlation was found between age and ECW (p=0.001; ρ=0.473) and between disease duration and FM (p=0.023; ρ=0.325), whereas age inversely correlated with BMR (p=0.012; ρ=-0.357). Patients with anaemia and/or hypoalbuminemia had significantly reduced BMR, BCM and TBW values; those with hypoalbuminemia also had elevated ECW levels (p=0.001). No other significant associations with BIVA values were found among the laboratory findings and among the gastrointestinal complaints. Results showed relevant interrelations between BIVA parameters and the SSc-related involvement of different organs, e.g. digital ulcers, interstitial lung disease and pulmonary arterial hypertension (See Table 1). In addition, a higher skin involvement inversely correlated with FM (p=0.038; ρ=-0.387). The only correlation that emerged from the UCLA GIT 2.0 questionnaire was the inverse relationship between TBW and GIT-reflux (p=0.017; ρ=-0.385). Four patients died during the study: they had significantly lower BMR and BCM, with an increased ECW. Table 1. Ongoing digital ulcers History of digital ulcers Interstitial lung disease Pulmonary arterial hypertension Heart involvement FM p=0.006 ns p=0.042 ns ns FFM p=0.019 p=0.046 ns ns ns TBW p&lt;0,001 ns p=0.007 ns ns ECW ns ns p=0.015 p=0.004 p=0.02 BCM p=0.01 p=0.047 p=0.016 p=0.013 p=0.03 BMR p=0.002 p=0.036 p=0.004 p=0.015 ns ECM/BCM ns ns p=0.034 ns ns Conclusion: BIVA has shown that SSc patients have a worse nutritional status than HC. The parameters obtained with BIVA in SSc patients correlate with serological malnutrition markers (haemoglobin and albumin), with various organ-specific SSc manifestations (cardiopulmonary involvement and digital ulcers) and with mortality. BIVA could therefore play a role in the prognostic stratification of SSc patients. Disclosure of Interests: None declared