Hypothyroidism main cause of coagulation alterations

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Eur

J Endocrinol. 2011 Jan 21. [Epub ahead of print]

Evaluation

of the respective influence of thyroid hormones and thyrotropin on blood

coagulation parameters in patients with hypothyroidism.

Yango

J, opoulou

O, Eeckhoudt

S, Hermans

C, Daumerie

C.

J Yango, endocrinology,

cliniques universitaires saint-luc, brussels, 1200, Belgium.

Abstract

Background: Alterations

of coagulation parameters are common in patients with hypothyroidism. Although

thyroid hormone deficiency is considered to be responsible for these changes,

the underlying mechanisms have not yet been established. Objective: To evaluate

the influence of peripheral thyroid hormones (FT4) and thyrotropin (TSH) on

blood clotting by assessing coagulation parameters in patients with a history

of total thyroidectomy for thyroid cancer, under three different conditions:

induced hypothyroidism, euthyroid state, and following recombinant human

thyrotropin (rhTSH) administration. Methods: Coagulation parameters (platelet

count, fibrinogen, international normalized ratio [iNR], prothrombin time,

thrombin time, activated partial thromboplastin time [APTT], factor VIII

activity[(FVIII: C], as well as von Willebrand factor antigen [VWF: Ag] and

activity [VWF: CBA]) were measured in patients with severe hypothyroidism

following withdrawal of thyroid hormone replacement therapy, and in the same

patients with euthyroidism after restoring replacement treatment (group A), and

before and after administering rhTSH (group . Results: FVIII:C, VWF:Ag, and

VWF:CBA were significantly decreased (p <0.001), whereas APTT was

significantly increased (p <0.001) in patients with severe hypothyroidism

compared to the euthyroid state. No changes in clotting parameters were

observed in patients who received rhTSH therapy. Conclusion: This prospective

study shows that severe short-term hypothyroidism is associated with

significantly lower levels of VWF: Ag, VWF: CBA, and FVIII: C. Administration

of exogenous TSH has no effect on coagulation parameters. These findings suggest

that thyroid hormone deficiency is likely to be the main cause of coagulation

alterations in patients with hypothyroidism.

PMID: 21257724

[PubMed - as supplied by publisher]