Plasma Coagulation Factors in Thyrotoxicosis

Abstract

A coagulation factor analysis was performed in 50 thyrotoxic and 22 control patients. The results showed a distinct fall in 4 different coagulation factors, viz., prothrombin and factors VII, IX and X in the thyrotoxic group. No changes were observed in the other coagulation factors and no correlation was found between the coagulation disturbances and the severity or duration of the disease.

Coagulation and Fibrinolysis in Thyroid Disease

“…Although precise statistics are not available it has been a clinical im pression that thromboembolic disorders are uncommon in patients with hyperthyroidism [3,14,17], This is of interest in view of the reduction in plasma fibrinolytic activity and increase in two of the plasma protease in hibitors with antiplasmin activity, but the hyperdynamic circulation [3] may counterbalance these potential hypercoagulable changes. While ar terial disease is prevalent in untreated hypothyroidism there is no known evidence for an increased incidence of clinical thromboembolism.…”

“…The effect of thyroid hormones on haemostasis has attracted relatively little attention although alterations in components of both the fibrinolytic enzyme system and the coagulation mechanism have been reported in patients with thyroid dysfunction. Hy perthyroidism has been shown to be associated with decreased fibrinolytic activity [4,16], decreased plasminogen concentration [4], increased fac tor VIII levels [11, 14, 31J, and a decreased level of the vitamin K-dependent factors [3,17]. In contrast, hypothyroidism is associated with in creased fibrinolytic activity [16,18] and a number of patients have a de crease in the levels of factors VIII, IX and XI [12,31].…”

Metabolism of the Coagulation Factors of the Prothrombin Complex in Hypothyroidism in Man

“…The reports on abnormal levels of coagulation factors in thyroid disease in the literature suggest that the katabolic and anabolic rates are not in balance. Ikkala et al (1962) reported a moderate but significant reduction in the activity levels of prothrombin and of factors VII, IX and X in thyrotoxicosis, and Simone et al (1965) found low levels of factors VIII, IX and XI in hypothyroidism.…”