Thyroid Dysfunction in Patients with and Without Venous Thromboembolism: a Case Control Study

Recent studies report an association between thyroid dysfunction and venous thromboembolism (VTE). Considering the high prevalence of thyroid diseases in India, identification of thyroid dysfunction as a risk factor for VTE will have implications in management. The aim of study was to determine if thyroid dysfunction could be considered as risk factor for unprovoked VTE. The study was conducted on 102 patients with unprovoked VTE and 102 age and gender matched controls in a tertiary care centre. Clinical profile and thyroid function tests (Free T3, Free T4, TSH) including antibody profile (Anti TPO and Anti TG) were compared between two groups. Thyroid disease was identified in 34 cases and 14 controls (33.1% vs. 13.7%, P = 0.001) Out of 34 cases with thyroid dysfunction, 17 had subclinical hypothyroidism (SCH) while 6 out of 14 controls had SCH. Both thyroid dysfunction and SCH were found to be associated with unprovoked VTE, as compared with controls; [Odds ratio (OR) = 3.14, 95% CI 1.56-6.33, P = 0.001] and (OR = 3.71; 95% CI 1.4-9.9; P = 0.01) respectively. Thyroid dysfunction was significantly higher among patients with unprovoked VTE. Thyroid dysfunction, SCH were associated with unprovoked VTE.