THU0237 MUSCLE ARCHITECTURE IN PATIENTS WITH SJÖGREN’S SYNDROME
Authors: Duygu Tecer, Dilek Büyükşireci, Jale Meray, Feride Nur Göğüş
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Although fatigue and skeletal muscle involvement is not rare in Sjögren's Syndrome (SS) patients, there is not much data about the macroscopic structure of the skeletal muscle. <h3>Objectives</h3> 1) To investigate if ultrasonographic muscle architecture and muscle strength differed in SS patients 2) To investigate if these changes correlated with disease activity, fatigue, anxiety and depression. <h3>Methods</h3> Assuming 2.40 mm mean difference and 2.5 mm SD of thickness at vastus lateralis muscle with 80% power and 5% significance 19 SS patients and 19 healthy controls (HCs) were recruited (1). Disease activity was measured by EULAR Sjögren Disease Activity Index (ESSDAI), anxiety and depression were assessed with the Hospital Anxiety and Depression Scale (HADS), fatigue with Multidimensional Assessment of Fatigue scale (MAF), quality of life with Health Assessment Questionnaire (HAQ). A single rheumatologist, blind to the participants' group assignment, performed the ultrasonographic evaluation using a multi-frequency linear probe. Thickness of bilateral quadriceps femoris, gastrocnemius and soleus muscles, pennation angle and fascicle length was measured. Isokinetic knee and ankle muscle strength tests were performed at 60- 180°/s and 30- 120°/s respectively by a calibrated isokinetic testing machine. <h3>Results</h3> Patients with SS scored higher than HCs for depression, anxiety, quality of life and fatigue (p&lt;0.0001). At dominant leg, pennation angle of vastus medialis muscle was significantly lower in SS group than HCs (10.263.63 SD deg vs 14.156.36 SD deg, p=0.049). At non-dominant leg, pennation angle of gastrocnemius medialis muscle was significantly higher in SS group than HCs (22.894.82 SD vs 19.154.68 SD deg, p=0.006). In addition, fascicle length of gastrocnemius medialis muscle was significantly shorter in SS group than HCs (42.2610.33 SD mm vs 49.258.27 SD mm, p= 0.036). Peak torque/body weight of knee and ankle muscles in SS group did not differ from that of HCs. However, in SS group, at dominant leg, ESSDAI was negatively correlated with knee extension strength at velocities 60°/s and 180°/s (r=-0.572, p=0.010; r=-0.617, p=0.05 respectively), knee flexion strength at 60°/s velocity (r= -0.492, p=0.033), ankle plantar flexion strength at 30°/s velocity (r=-0.730, p=0.001). Similarly at non-dominant leg, ESSDAI was negatively correlated with knee extension strength at velocities 60°/s and 180°/s (r=-0.575, p=0.010, r=-0.508, p=0.026 respectively) and ankle plantar flexion strength at 30°/s velocity (r=-0.506, p=0.027). Fatigue was negatively correlated with ankle plantar flexion strength at 120°/s velocity (r=-0.484, p=0.036) at dominant leg, knee extension strength at 180°/s velocity (r=-0.521, p=0.022) knee flexion at 60°/s velocity (r=-0.585, p=0.011) at non-dominant leg. There was no correlation between anxiety, depression and muscle strength. <h3>Conclusion</h3> Patients with SS have some minor structural changes on ultrasonographic evaluation. Although there was no difference in isokinetic muscle strength measurements between groups, knee strength and endurance had a moderate negative correlation with disease activity in SS patients. <h3>Reference</h3> [1] Kaya A, et al. Ultrasonographic evaluation of the muscle architecture in patients with systemic lupus erythematosus. Clin Rheumatol2013; 32: 1155-1160. <h3>Disclosure of Interests</h3> None declared