Does the Tendency to Thrombosis Increase in Autoimmune Thyroid Dysfunction? Rotational Thromboelastometric Analysis

Abstract The tendency for thrombosis is a well-known issue in hyperthyroidism, and the tendency for both bleeding and thrombosis has been shown in hypothyroidism. In the study, we aimed to establish the tendency to thrombosis by evaluating the coagulation system in thyroid diseases using thromboelastography (TEG). Thirty patients with new-onset autoimmune-based hypothyroidism, 30 with hyperthyroidism and 30 healthy volunteer subjects were enrolled in this study. Complete blood count, prothrombin time, activated partial thromboplastin time, fibrinogen levels and rotational thromboelastography (ROTEM) were studied. In the ROTEM/TEG analysis, coagulation time (CT), coagulation formation time (CFT) and maximum clot firmness (MCF) were measured. Short CT and/or CFT and/or long MCF were presumed as the tendency to hypercoagulability. The mean age of subjects with hyperthyroidism and hypothyroidism was 46±15.9 years and 44.8±13 years, respectively. The thrombocyte count in the hypothyroid group and both thrombocyte counts and fibrinogen levels in the hyperthyroid group was significantly higher than in the healthy group (p=0.004, p=0.001, p<0.001, respectively). According to ROTEM/TEG results, higher mean MCF figures were noted in both the hypo- and hyperthyroid groups compared with the healthy group (p=0.014 (hypothyroid vs. healthy groups), p=0.020 (hyperthyroid vs. healthy groups)). We showed a tendency for thrombosis using ROTEM in patients with both hyper- and hypothyroidism without thrombosis. The correlation between ROTEM/TEG parameters and the main components of thrombosis formation (thrombocyte count and fibrinogen level) indicate that the main factor might be inflammation (autoimmunity), apart from thyroid hormone levels.