BackgroundHashimoto’s disease is an autoimmune disease characterised by autoantibody positivity in the blood and diffuse lympocyte infiltration in the thyroid. Thyroxine is an important hormone in collagen and matrix metabolism. Low levels of thyroid hormones or antibodies positivity may lead to tendon pathologies and subsequent shoulder pain in patients with Hashimoto’s disease.Objectives1)To investigate tendon thickness and pathologies in patients with Hashimoto’s disease. 2) To investigate if shoulder pain in Hashimoto’s disease is associated with ultrasonographic tendon pathologies.MethodsAssuming a 0.5 mm mean difference and 0.7 mm SD of thickness at rotator cuff tendons with 80% power and 5% significance 119 female subjects (40 patients euthyroid Hashimoto’s disease, 28 subclinical hypothyroid Hashimoto’s disease and 51 healthy subjects) were recruited.1 Participants were divided into three groups: Group 1: patients with subclinical hypothyroid Hashimoto’s disease, Group 2: patients with euthyroid Hashimoto’s disease, Group 3: healthy controls. A rheumatologist experienced in musculoskeletal ultrasonography and blind to clinical data of the patients evaluated the thickness of biceps, subscapularis, supraspinatus, infraspinatus tendons at both shoulders according to standard protocol.2 The presence of subacromial bursitis, effusion, tendon rupture or tendinosis were recorded. The participants of TSH (thyroid stimulated hormone), free T3 (triiodothyronine), free T4 (thyroxine), anti TPO (thyroid peroxidase) and anti TG (thyroglobulin) antibodies levels were measerud. In addition the presence and duration of shoulder pain of the participants were recorded.ResultsHeight, weight, BMI (body mass index), free T3 and free T4 levels were similar between three groups (p=0.830, p=0.205, p=0.374, p=0.430 and p=0.497, respectively). Tendon thicknesses in patient groups are presented in table 1. Biceps brachii, subscapularis, supraspinatus and infraspinatus tendon thicknesses were increased significantly in both euthyroid Hashimoto’s disease and subclinical hypothyroid Hashimoto’s disease groups at dominant and non- dominant arms compared to healthy controls. However there was no such difference between euthyroid Hashimoto’s disease and subclinical hypothyroid Hashimoto’s disease groups. There was no correlation between levels of TSH, anti TPO, anti TG and tendon thickness. Two participants in three groups had shoulder pain for 1–3 months. These participants had no ultrasonographic shoulder tendon pathology.Abstract FRI0564 – Table 1Differences between euthyroid Hashimoto’s disease, subclinical hypothyroid Hashimoto’s disease and health controls in dominant and non-dominant arms.ConclusionsPresence of autoimmun thyroid disease may lead to increased shoulder tendon thickness. However increase in tendon thickness is not seemed to be associated with shoulder pain.References[1] Kim K, et al. Ultrasound Dimensions of the Rotator Cuff and Other Associated Structures in Korean Healthy Adults. Journal of Korean medical science201...