Changes of coagulation function and platelet parameters in patients with Graves' hyperthyroidism before and after ¹³¹I treatment

Objective: To explore the changes of coagulation function and platelet parameters before and after treatment of Graves disease (GD) with radioactive iodine-131. Methods: 35 patients with Graves' disease and hyperthyroidism admitted to our hospital from January, 2015 to January, 2019 were selected and defined as the hyperthyroidism group, in which all patients received ¹³¹I treatment, while 35 healthy patients admitted during the same period were selected as the control group. The changes of thyroid function, coagulation function and platelet parameters in the hyperthyroidism group before and after treatment and the control group were then measured. Results: Before treatment, compared with the control group, thyroid stimulating hormone (TSH) was significantly decreased in the hyperthyroidism group, while FT₃ and FT₄ were significantly increased (P < 0.05). After treatment, FT₃ and FT₄ in the hyperthyroidism group were significantly reduced, compared with the ratio before treatment (P < 0.05), but there was no statistical difference when compared with the control group. TSH was significantly increased after treatment, with a significant difference when compared with the control group and before treatment (P < 0.05). Compared with control group, the hyperthyroidism group showed significant differences in the large platelet ratio (P-LCR), platelet count (PLT), mean platelet volume (MPV) and platelet volume distribution width (PDW), activated partial blood coagulation live enzymes time (APTT), thrombin time, thrombin time, TT), prothrombin time (PT) and fibrinogen (FIB), and plasma D-dimer (D-D) before treatment (P < 0.05). After treatment, DW, APTT, PT and p-lcr in the hyperthyroidism group were not significantly different from those in the control group (all P > 0.05). There were significant differences in APTT, TT, PT, FIB and D-D in the hyperthyroidism group between before and after treatment (all P < 0.05), while there were no statistically significant differences in P-LCR, PLT, MPV and PDW in the hyperthyroidism group between before and after treatment. Correlation analysis showed that PT and FIB were positively correlated with FT₃ and FT₄ , while PLT was negatively correlated with FT₃ (all P < 0.05). Conclusion: Compared with normal healthy people, patients with hyperthyroidism are generally in a state of hypercoagulability, with the phenomenon of coagulation dysfunction. After ¹³¹I treatment, the coagulation indexes and platelet parameters change with the level of thyroid hormone. Clinically, monitoring the coagulation function and platelet parameters has a certain clinical significance for the assessment of potential thrombotic risk. (authors)