POS0509 PREVALENCE OF RHEUMATOID CACHEXIA AND ITS ASSOCIATION WITH SERUM FETUIN-A LEVELS IN CAUCASIAN PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract
Background: Rheumatoid cachexia is an under-recognized pathological condition, which is characterized by a loss of muscle strength and can be presented as a low fat-free mass and normal or high BMI in patients with rheumatoid arthritis determined by dual-energy X-ray absorptiometry (DEXA) [1]. Though fetuin-A is one of a major noncollagen proteins in bone tissue it is of interest to clarify its association with rheumatoid cachexia. Objectives: To define the prevalence of rheumatoid cachexia in Caucasian patients with rheumatoid arthritis determined by DEXA method and to study the association of serum fetuin-A levels with body composition and rheumatoid cachexia in this group. Methods: 110 Caucasian patients with rheumatoid arthritis undergone DEXA with «Total Body» program. All patients fulfilled the 2010 ACR/EULAR classification criteria for rheumatoid arthritis. The diagnosis of rheumatoid cachexia was based on Engvall I.L. criteria: fat-free mass index less than 10th percentile with fat mass index above 25th percentile [1]. We used values for these indexes from the study performed in 2008 by Coin A. et al. on Italian population due to a lack of standard values [2]. Fetuin-A in serum was determined by enzyme-linked immunosorbent assay. 72 patients have been taking glucocorticoids for more than 3 months in dose equivalent or higher than 5 mg of prednisolone daily. Statistical analysis was performed using a software package “Statistica 12.0”. Parametric data is presented as M±St.dev, and nonparametric as Me [Q1-Q3]. Results: Rheumatoid cachexia was diagnosed in 25 patients (22,7%) with mean age of 52,2±8,14 years. The prevalence of cachexia was the same in groups of patients who took glucocorticoids (n=16, 22,2%) and who didn’t (n=9, 23,7%; p = 0,465). Median cumulative dose of oral glucocorticoids in patients with rheumatoid cachexia was higher but fell just short of statistical significance (8,0 [2,9-13,5] g vs 5,4 [0,2-11,6] g; Z=-1,42; p = 0,156). Median serum fetuin-A levels were only slightly significantly lower in patients with rheumatoid cachexia (757,7 [700,5-932,0] µg/ml vs 769,3 [660,3-843,4] µg/ml; Z=-1,35; p=0,175). Positive statistically significant correlations were observed between serum fetuin-A levels and bone mass in right (r=0,222, p = 0,027) and left (r=0,263, p = 0,008) lower limbs, trunk (r=0,268, p = 0,007), gynoid region (r=0,293, p = 0,003), both lower limbs (r=0,246, p = 0,014) and whole-body (r=0,235, p = 0,019). Conclusion: Rheumatoid cachexia was diagnosed in 22,7% of patients with rheumatoid arthritis. No association was observed between glucocorticoids intake and rheumatoid cachexia, despite the expected influence of them on muscle mass. We may suggest that occurrence and pathogenesis of this condition is complex and should be studied more precisely. It is well-known that patients with such condition have a higher risk for metabolic syndrome, arterial hypertension and mortality. We observed positive correlations between serum fetuin-A levels and bone mass in lower limbs, trunk, gynoid region and whole-body. Considering that fetuin-A is also associated with bone mineral density [3], it may be regarded as a marker of bone remodeling. References: [1]Engvall I.L., Elkan A.C., Tengstrand B., Cederholm T., Brismar K., Hafstrom I. Cachexia in rheumatoid arthritis is associated with inflammatory activity, physical disability, and low bioavailable insulin-like growth factor. Scand J Rheumatol. 2008; 37 (5): 321–328. [2]Coin A., Sergi G., Minicuci N., Giannini S., Barbiero E., Manzato E., Pedrazzoni M., Minisola S., Rossini M., Del Puente A., Zamboni M., Inelmen E.M., Enzi G. Fat-free mass and fat mass reference values by dual-energy X-ray absorptiometry (DEXA) in a 20-80 year-old Italian population. Clinical Nutrition. 2008; 27 (1): 87-94. [3]Sari, A., & Uslu, T. The relationship between fetuin-a and bone mineral density in postmenopausal osteoporosis. Turkish Journal of Rheumatology. 2013; 28 (3): 195-201. Disclosure of Interests: None declared