Thyroid-stimulating hormone concentration as an independent risk factor of venous thromboembolism regardless of thyroid function.

Abstract

Thyroid dysfunction has been recognised as playing a role in the coagulation cascade, but the clinical implications of this phenomenon are unclear. The aim of our study was to assess the predictive power of TSH measurement on the presence or absence of venous thromboembolism (VTE). From January 2009 to August 2012, all consecutive patients hospitalised for suspected VTE were included in the study. VTE was confirmed either by pulmonary angiography or compressive ultrasound. We investigated the predictive power of TSH concentration on the risk of VTE in univariate and multivariate analysis including the existing risk factors (age, D-dimer). A total of 232 patients were eligible for final analysis, with a median age of 70 years (IQR 58-80) and male-to-female ratio of 124:108. VTE was confirmed in 124 patients (53.4%). TSH concentration was significantly higher in cases with VTE (median 2.17 vs. 1.76 mIU/L, p = 0.0104), but free T4 concentrations were not found to be significantly different. Receiver operating curve analysis identified the cut-off of TSH > 2.686 mIU/L as a predictor of VTE with the prevalence of VTE 47.1 vs. 66.7% below and above this cut-off, p = 0.011. Multivariate logistic regression identified five independent predictors of VTE: male gender (odds ratio, OR = 2.22), D-dimer > 0.5 mg/L OR = 16.42), CRP > 5 g/L (OR = 9.178), TSH > 2.686 mIU/L (OR = 2.269), and age (OR = 0.9767/year). Among patients with suspected venous thromboembolism TSH concentration was found to be an independent predictor of VTE in addition to gender, D-dimer, C-reactive protein (CRP), and age.