Importance of Hyperhomocysteinemia as a Risk Factor for Venous Thromboembolism in a Taiwanese Population. A Case-Control Study

Abstract

Objective: To determine the current status of hyperhomocysteinemia, which is a known risk for venous thrombosis (DVT), in Taiwan. Subjects: 101 unselected patients with a minimum of one episode of deep leg DVT, either initial inpatients or current compliant outpatients in a teaching hospital. Methods: Various thrombophilic risks, gene polymorphism and clinical predisposition were evaluated. Results and conclusions: Patients presented higher fast total plasma homocysteine (hcy) levels than age- and sex-matched controls did (14.1 vs. 9.94 μM). Based on the 95th percentile of control values, hyperhomocysteinemia had a four- to nine-fold risk for DVT, irrespective of clinical predisposition, as well as other thrombophilic risks surveyed. Polymorphism of a metabolizing enzyme, methylenetetrahydrofolate reductase (MTHFR), was not associated with DVT, although homozygous thermolabile mutation tended to have higher plasma hcy levels. Factor V Leiden was absent in analysis of 80 patients. In complete evaluation (hcy, antithrombin (AT), protein S (PS), protein C (PC), lupus anticoagulant (LA), anticardiolipin antibody) of a subset of 83 patients hyperhomocysteinemia was the most prevalent risk (33.7%), with PC or PS deficiencies following (22.9%). Thus, hyperhomocysteinemia is a prominent risk for DVT in Taiwan.