The Changes in Coagulation Test Results in Subjects with Varying Levels of Thyroid Stimulating Hormone.

Background: The aim is to investigate the changes in coagulation test results in subjects with varying serum levels of thyroid stimulating hormone.

Methods: We performed a one-year retrospective analysis to retrieve combined results of activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fib), D-dimer, free thyroxine (fT4), tri-iodothyronine (fT3), and thyroid stimulating hormone (TSH) from inpatients who were referred by general practitioners for routine blood testing. Cumulative results were retrieved for 2,794 such inpatients.

Results: Patients with a TSH level < 0.34 µIU/mL had higher PT values (10.43 ± 1.02 vs. 10.27 ± 0.91) and Fib values (3.00 ± 0.92 vs. 2.7 ± 0.56) compared with patients with 0.34 µIU/mL < TSH < 5.6 µIU/mL. Conversely, the PT values (10.01 ± 0.95 vs. 10.27 ± 0.91) were lower and APTT (33.70 ± 4.17 vs. 32.56 ± 4.12) values higher in patients with TSH > 5.6 µIU/mL compared to patients with 0.34 µIU/mL < TSH < 5.6 µIU/mL.

Conclusions: There are changes in coagulation test results in subjects with varying levels of thyroid stimulating hormone.