Galley Proof 29/11/2018; 14:36 File: bmr–1-bmr181326.tex; BOKCTP/xjm p. 1 Journal of Back and Musculoskeletal Rehabilitation -1 (2018) 1–6 1 DOI 10.3233/BMR-181326 IOS Press Serum endothelin-1 levels, radiographic and ultrasonographic evaluations, and clinical parameters in patients with knee and/or hand osteoarthritis Merve Örücü Atar a,* , Levent Özçakar b , Zeynep Gençtürk c and Ye¸ sim Aytür d a Gaziler Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation, Training and Research Hospital, Ankara, Turkey b Department of Physical and Rehabilitation Medicine, Medical School, Hacettepe University, Ankara, Turkey c Department of Biostatistics, Faculty of Medicine, Ankara University, Ankara, Turkey d Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Ankara University, Ankara, Turkey Abstract. BACKGROUND: Endothelin-1 (ET-1) is one of the probable inflammatory factors stimulating cartilage degradation in os- teoarthritis (OA) pathogenesis. OBJECTIVE: To assess ET-1 level in OA and its correlation with radiographic findings, cartilage morphology and clinical pa- rameters. METHODS: One hundred and forty-six subjects (89 OA, 50 controls) were included in this cross-sectional study. Both knee and hand joints of the participants were examined using plain radiography and ultrasound imaging by which distal femoral cartilage thickness/grading and second metacarpophalangeal cartilage thickness were assessed. Subjects were evaluated for pain and func- tional status using visual analogue scale, Western Ontario and McMaster Universities Arthritis Index and Duruöz Hand Index. RESULTS: Serum ET-1 levels were higher in the OA group than the control group. Serum ET-1 levels were not correlated with cartilage thickness in patients with OA. Serum ET-1 levels were not correlated with either pain or other clinical parameters in the knee OA group and in the hand OA group. CONCLUSION: This is the first study evaluating the relationship between serum ET-1 levels and cartilage morphology and clinical parameters, which did not show any conclusive result. Future studies, overcoming the limitations of this study, might provide a better understanding of the role of ET-1 in the pathogenesis of OA. Keywords: Osteoarthritis, knee, hand, endothelin-1, ultrasound, cartilage 1. Introduction 1 Osteoarthritis (OA) is the most common disease af- 2 fecting joints. Despite the fact that OA affects all el- 3 * Corresponding author: Merve Örücü Atar, Gaziler Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation, Training and Research Hospital, Ankara, Turkey. Tel.: +90 312 291 1000; Fax: +90 0312 291 1009; E-mail: drmerve orucu@hotmail.com. ements of synovial joint such as cartilage, bone, syn- 4 ovial tissue, ligaments and capsule, primary changes 5 include loss of cartilage, remodeling of subchondral 6 bone and osteophyte formation [1]. The molecular 7 pathogenesis of OA is not fully understood; how- 8 ever, it is known that various genetic, environmental, 9 metabolic and biomechanical factors contribute to the 10 pathogenesis [2]. Previous literature supports the fact 11 that OA is not only a simple wear-and-tear arthritis, 12 but also an inflammatory disease [3]. Biochemical in- 13 ISSN 1053-8127/18/$35.00 c  2018 – IOS Press and the authors. All rights reserved uncorrected proof version