Hyperthyroidism is associated with shortened APTT and increased fibrinogen values in a general population of unselected outpatients.
Although clinical evidence supports a plausible association between thyroid disorders and venous thrombosis, reliable evidence is so far lacking on the potential biological mechanisms and neither temporary nor permanent thromboembolic risk factors were constantly identified. We performed a 2-years retrospective analysis to retrieve combined results of activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, and thyroid stimulating hormone (TSH), performed on outpatients over 15 years of age and referred by general practitioners for routine blood testing. Cumulative results were retrieved for 1,329 such outpatients. Patients with hyperthyroidism had shortened APTT (28.4 vs. 29.4 s; P = 0.043) and higher fibrinogen (4.1 vs. 3.8 g/l; P = 0.028) values when compared with euthyroid patients, whereas no significant differences were observed between euthyroid patients and those with hypothyroidism. Hyperthyroid patients had also an increased prevalence of shortened APTTs (<25.5 s) and higher values of fibrinogen (>4.0 g/l) than those with normal thyroid function. This study confirms that hyperthyroidism might be associated with hypercoagulability due to shortened APTT and increased fibrinogen values. Should these findings be confirmed, consideration should be given to prevent thrombotic complications in patients with hyperthyroidism.
Lippi
Giuseppe
G
Sezione di Chimica Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università degli Studi di Verona, Ospedale Policlinico GB Rossi, Piazzale Scuro, Verona, Italy. ulippi@tin.it
Franchini
Massimo
M
Targher
Giovanni
G
Montagnana
Martina
M
Salvagno
Gian Luca
GL
Guidi
Gian Cesare
GC
Favaloro
Emmanuel J
EJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005340:Fibrinogen / Q000032:analysis*; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D010314:Partial Thromboplastin Time; D012189:Retrospective Studies; D019851:Thrombophilia / Q000209:etiology
D005340:Fibrinogen
Thyroid. 2003 Jan;13(1):3-126
12625976
Blood Coagul Fibrinolysis. 2007 Dec;18(8):801-3
17982323
J Clin Endocrinol Metab. 1993 Mar;76(3):609-14
7680353
Med Sci Monit. 2008 Jan;14(1):CR42-46
18160944
Thromb Haemost. 2007 May;97(5):803-6
17479191
Endocr J. 2007 Aug;54(4):593-9
17690487
Hematology. 2006 Jun;11(3):203-8
17325963
J Clin Endocrinol Metab. 2007 Jul;92(7):2415-20
17440013
J Endocrinol Invest. 2002 Apr;25(4):345-50
12030606
Cancer. 1994 Feb 1;73(3):702-5
8299093
J Endocrinol Invest. 1988 Nov;11(10):723-5
2466071
Clin Endocrinol (Oxf). 2006 Oct;65(4):530-5
16984248
J Stroke Cerebrovasc Dis. 2000 Mar-Apr;9(2):89-90
17895204
J Clin Endocrinol Metab. 2006 Feb;91(2):530-4
16303831
Clin Chem. 2004 Dec;50(12):2338-44
15472032
Semin Thromb Hemost. 1991;17 Suppl 3:250-3
1754882
J Thromb Haemost. 2006 Apr;4(4):750-1
16634741
Blood. 2004 Dec 1;104(12):3631-4
15297315
Clin Endocrinol (Oxf). 2006 Mar;64(3):323-9
16487444
Ann Intern Med. 1982 Nov;97(5):713-6
6814317
Br J Haematol. 2006 Jul;134(2):227-32
16846482
J Thromb Haemost. 2006 Apr;4(4):752-6
16634742
Wien Klin Wochenschr. 2006 Feb;118(1-2):16-20
16489520
Curr Opin Hematol. 2007 May;14(3):236-41
17414213
Eur J Intern Med. 2008 Jul;19(5):386-7
18549950
J Neurol. 2008 Jul;255(7):962-6
18560795