AB0057 Decreased irisin level as risk factor of pathological fractures in rheumatoid arthritis patients

Abstract

BackgroundRecent studies have been suggested that adipokines and myokines may be implicated in bone metabolism and pathogenesis of osteoporosis (OP).1 Previous studies have revealed inverse correlation between irisin levels and vertebral fragility fractures, but no significant correlation was found between irisin and bone mineral density (BMD) as well as with lean weight. There is no previously published data about irisin levels in rheumatoid arthritis (RA) patients.2–4 ObjectivesTo investigate serum irisin levels in patients with RA.MethodsWe studied 170 people: 110 RA patients (mean age 53.58±12.32; hereinafter M±SD) and 60 healthy controls. All patients with RA were examined using dual-energy X-ray absorptiometry using LUNAR DPX-Pro densitometer. Osteoporotic fractures were confirmed by X-ray examination and/or by anamnesis data. All patients were passed through extensive clinical and laboratory examination, including N-terminal propeptide of procollagen type I, C-telopeptide of type I collagen, 25(OH)-vitamin D concentration. Serum irisin levels were measured by ELISA (BioVender test system, Cat №RAG018R).ResultsThe mean concentration of irisin in RA group was 14.48±7.07 mg/ml, which was significantly lower than of healthy donors – 20.49±4.82 mg/ml (p<0,001). We subsequently divided all of RA patients into two groups: the first one (n=44) included patients with reduced serum irisin levels (below 10.85 mg/mL), and the second one (n=66) with normal irisin levels (above 10.85 mg/ml). The first group had significantly higher activity (DAS28), increased frequency of extra-articular manifestations, disease duration more than 5 years, class III of functional joints disability and lower levels of 25(OH)-vitamin D. We also observed higher incidence of pathological bone fractures in this group (p=0,047). There wasn’t any significant correlation between serum irisin level and BMD at any localization, lean, or fat weight. We did not reveal any difference of bone turnover markers (serum C-terminal telopeptide of type I collagen, serum N-terminal propeptide of type I procollagen (P1NP)) between these groups.ConclusionsWe have therefore revealed relationships between decreased serum irisin levels, 25(OH)-vitamin D concentration and higher incidence of pathological bone fractures in RA patients. We found no connexion between serum irisin levels and BMD at any site and body composition. We could consequently suppose, that irisin levels may reflect bone quality or increased fall risk.References[1] Palermo A, Strollo R, Maddaloni E, et al. Irisin is associated with osteoporotic fractures independently of bone mineral density, body composition or daily physical activity. Clin Endocrinol (Oxf)2015;82(4):615–9.[2] Boström P, Wu J, Jedrychowski MP, et al. A PGC1-α-dependent myokine that drives brown-fat-like development of white fat and thermogenesis. Nature2012;481(7382):463–8.[3] Colaianni G, Cuscito C, Mongelli T, et al. Irisin enhances osteoblast differentiation in vitro. Int J Endocrinol2014;2014:902186.[4] Sivordova LE, Zavodo...

Serum irisin concentrations and osteoporotic vertebral fractures in women with rheumatoid arthritis

“…[9,8] There are some studies that identify low irisin levels in RA compared with controls. [17,26] Our results are concordant with these studies showing lower serum levels of irisin in RA group with respect to our group of women without rheumatic disease.…”

“…Lavrova et al observed in their RA patients that low irisin concentrations were related with osteoporotic fractures in general. [17] In the best of our knowledge this study is the first to assess the relation between irisin levels and osteoporotic VFs in RA patients. We identified that low irisin concentrations increased the risk of osteoporotic VFs in RA patients.…”

“…[14][15][16] In RA patients, Lavrova et al observed an association of lower concentrations of Irisin with the presence of low-grade fractures, higher degree of inflammatory activity, disease duration, and presence of extraarticular manifestations. [17] The aim of this study is to evaluate the association of serum levels of irisin with the presence of VFs in women with RA. New studies are needed to determine if irisin would be a useful diagnostic marker and a therapeutic target for clinical use.…”

“…In postmenopausal women some reports have associated low levels of irisin with osteoporotic fractures [14–16] . In RA patients, Lavrova et al observed an association of lower concentrations of Irisin with the presence of low-grade fractures, higher degree of inflammatory activity, disease duration, and presence of extra-articular manifestations [17] …”

Irisin as a Novel Biomarker of Subclinical Atherosclerosis, Cardiovascular Risk and Severe Disease in Axial Spondyloarthritis

“…In such study, the authors found that patients with more severe disease symptoms exhibited lower serum levels of irisin, which is in accordance with our results (45). Also in this line, previous studies performed in other rheumatic diseases reported an inverse association between irisin serum levels and disease activity (22,(46)(47)(48). In addition, patients treated with conventional DMARDs and NSAIDs exhibited lower serum irisin levels.…”