AB0676 BODY COMPOSITION IN MYOSITIS PATIENTS AND THE ASSOCIATION WITH DISEASE SPECIFIC FEATURES, PHYSICAL ACTIVITY AND PLASMA LEVELS OF INFLAMMATORY CYTOKINES
Authors: Sabina Oreska, Maja Špiritović, Petr Česák, Ondrej Marecek, Hana Štorkánová, Hana Smucrova, Barbora Heřmánková, Kateřina Kubinova, Martin Klein, Lucia Vernerová, Olga Růžičková, Karel Pavelka, Ladislav Šenolt, Heřman Mann, Jiří Vencovský, Michal Tomčík
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Skeletal muscle, pulmonary, and articular involvement in idiopathic inflammatory myopathies (IIM) limit the mobility/self-sufficiency of patients, and can have a negative impact on body composition. <h3>Objectives:</h3> To assess body composition and physical activity of IIM patients and healthy controls (HC) and the association with selected inflammatory cytokines in IIM. <h3>Methods:</h3> 54 patients with IIM (45 females; mean age 57.7; disease duration 5.8 years; PM, (22)/DM, (25)/IMNM, (7)) and 54 age-/sex-matched HC (45 females, mean age 57.7) without rheumatic/tumor diseases were included. PM/DM patients fulfilled Bohan/Peter criteria for PM/DM. We assessed body composition (densitometry: iDXA Lunar, bioelectric impedance: BIA2000-M), physical activity (Human activity Profile, HAP questionnaire), disease activity (MITAX and MYOACT activity score), muscle involvement (manual muscle test, MMT-8 and functional index, FI2) and plasma levels of 27 cytokines (commercial multiplex ELISA kit, Bio-Rad Laboratories). Data are presented as mean±SD. <h3>Results:</h3> Compared to HC, patients with IIM had a trend towards significantly increased body fat% (BF%) as assessed by iDXA (39.9±7.1 vs. 42.4±7.1 %, p=0.077), but significantly decreased lean body mass (LBM) as assessed both by iDXA (45.6±8.1 vs. 40.6±7.2 kg, p=0.001) and BIA (52.6±8.8 vs. 48.7±9.0 kg, p=0.023), and increased extracellular mass/body cell mass (ECM/BCM) ratio (1.06±0.15 vs. 1.44±0.42, p&lt;0.001), reflecting deteriorated nutritional status and worse muscle predispositions for physical activity. Compared to HC, IIM patients had significantly lower bone mineral density (BMD: 1.2±0.1 vs. 1.1±0.1 g/cm<sup>2</sup>, p&lt;0.001). Disease duration negatively correlated with BMD (r=-0.392, p=0.004) and LBM-BIA (r=-0.272, p=0.047). Disease activity assessed by both MITAX and MYOACT positively correlated with LBM-BIA (MITAX: r=0.294, p=0.031; MYOACT: r=0.335, p=0.013) and LBM-DXA (MITAX: r=0.341, p=0.012; MYOACT: r=0.368, p=0.007), similarly as with basal metabolic rate (BMR; MITAX: r=0.336, p=0.014; MYOACT: r=0.351, p=0.010), and fat free mass (FFM; MITAX: r=0.338, p=0.014; MYOACT: r=0.356, p=0.009). CRP was positively associated with BF% assessed both by DEXA (r=0.276, p=0.035) and BIA (r=0.306, p=0.025). Higher BF%-DEXA was associated with worse physical endurance (FI2: r=-0.311, p=0.026) and worse ability to perform physical activity (HAP: r=-0.292, p=0.032). MMT-8 score negatively correlated with ECM/BCM ratio (r=-0.385, p=0.006). Plasma levels of IL-1ra positively correlated with body mass index (BMI, r=0.359, p=0.009), BF% (r=0.363, p=0.009), and visceral fat (VF, r=0.409, p=0.003). Plasma levels of MCP-1 positively correlated with ECM/BCM ratio (r=0.387, p=0.005). Increased plasma levels of IL-10 were associated with decreased LBM (r=-0.473, p=0.014). <h3>Conclusion:</h3> Compared to healthy age-/sex-matched individuals we found significant negative changes in body composition of our IIM patients, which are associated with their disease activity and duration, inflammatory status, skeletal muscle involvement, and physical activity. Plasma levels of several inflammatory cytokines were associated with alterations of body composition in IIM patients and highlight the potential role of inflammatory status on impaired body composition during the course of IIM. <h3>Acknowledgement:</h3> Supported byAZV NV18-01-00161A, MHCR 023728 and GAUK 312218 <h3>Disclosure of interests:</h3> Sabina Oreska: None declared, Maja Špiritović: None declared, Petr Česák: None declared, ondrej Marecek: None declared, Hana Štorkánová: None declared, Hana Smucrova: None declared, Barbora Heřmánková: None declared, Kateřina Kubinova: None declared, Martin Klein: None declared, Lucia Vernerová: None declared, Olga Růžičková: None declared, Karel Pavelka: None declared, Ladislav Šenolt Grant/research support from: abbVie, Consultant for: abbVie, Bristol-Myers Squibb, Celgene Corporation, Merck Sharp and Dohme, Novartis, Pfizer, Roche, UCB, amgen, Takeda, Speakers bureau: abbVie, amgen, Bristol-Myers Squibb, Celgene Corporation, Eli Lilly, Merck Sharp and Dohme, Novartis, Pfizer, Roche, UCB, Heřman Mann Consultant for: Pfizer, Eli Lilly, Sanofi, Speakers bureau: abbVie, Roche, Pfizer, MSD, Eli Lilly, Sanofi, Jiří Vencovský Consultant for: Samsung, Speakers bureau: abbVie, Novartis, Pfizer, Sanofi, Eli Lilly, Biogen, UCB, MSD, Werfen, Roche, Michal Tomčík: None declared