A Common Pathogenetic Link between Venous Thrombosis and Atherosclerosis: Increased Prevalence of Small, Dense LDL

Abstract number: P0588

Simioni¹ P, Zambon² A, Bertocco² S, Tormene¹ D, Polentarutti² V, Fadin¹ M, Perlati¹ M, Prandoni¹ P, Pagnan¹ A

¹¹Dept of Medical and Surgical Sciences, 2^nd Chair of Internal Medicine, University of Padua, Padua, Italy ¹¹Dept of Medical and Surgical Sciences, 2^nd Chair of Internal Medicine, University of Padua, Padua, Italy ²²Dept of Clinical and Experimental Medicine, University of Padua, Padua, Italy

Background:  Small, dense and highly low-density lipoproteins (sdLDL) are highly atherogenic and associated with endothelial dysfunction due to their increased susceptibility to oxidation. No information is available on the role of sdLDL in the pathogenesis of VTE.

Patients and methods:  Fifty consecutive patients, aged 60 ± 15 years, with a first episode of objectively documented VTE, with no previous history of symptomatic atherosclerosis were evaluated. Patients were classified as having secondary (cancer, estrogen use, trauma etc.) or spontaneous VTE. Patients with inherited thrombophilia, antiphospholipid antibodies, diabetes and those under lipid-lowering medications were excluded. Seventy healthy controls were also evaluated. Lipoprotein subclasses were isolated using density gradient ultracentrifugation and lipid measurements were performed by standardized enzymatic kits.

Results:  Twenty-one and 29 patients had secondary and spontaneous VTE, respectively. VTE patients had similar total, LDL, VLDL, IDL, HDL cholesterol and triglycerides as compared to controls. No significant differences in these parameters were found between spontaneous and secondary VTE patients. Despite similar LDL-C, patients with VTE had significantly higher cholesterol in the densest LDL subfractions (P > 0.01) than controls. Interestingly, these subfractions carry only about 10–15% of the overall LDL-C. The increased cholesterol in the densest LDL subfractions was entirely due to the group with spontaneous VTE (P < 0.01 vs. both controls and secondary VTE), while patients with secondary VTE had similar cholesterol distribution across the all lipoprotein density range.

Conclusions:  Patients with spontaneous VTE have significant increased cholesterol in the densest LDL, while no differences were found in the other lipoprotein subclasses. The increased susceptibility to oxidation and the pro-inflammatory potential of these denser LDL particles may contribute to the pathogenesis of VTE.