Serum lipid levels and the risk of venous thrombosis

Objective - Lipids, through effects on the coagulation and fibrinolytic systems, may contribute to the development of venous thrombosis. This association has been investigated in a few studies, with conflicting results. Methods and Results - We conducted a population-based, case-control study at a health maintenance organization in Washington State, to assess the association of serum lipid levels with the risk of venous thrombosis. Cases were 477 postmenopausal women with a first venous thrombosis during January 1995 through December 2001. Control subjects (1986) were a random sample of postmenopausal women. Medical records, computerized pharmacy databases, and a cancer registry served to collect data on lipid levels and risk factors for thrombosis. Total cholesterol levels were not associated with venous thrombosis. Only high HDL cholesterol levels were associated with a decreased risk of venous thrombosis after adjustment for hospitalization, malignancy, height and weight, postmenopausal hormone therapy, and vascular disease (for high-density lipoprotein [HDL] cholesterol levels >1.79 mmol/L versus those <1.79 mmol/L; odds ratio [OR], 0.71; 95% confidence interval [CI], 0.52 to 0.97). In contrast, elevated triglyceride levels were associated with an increased risk (OR, 2.13; 95% CI, 1.34 to 3.37) for women with triglyceride levels >1.05 mmol/L compared with women with lower levels. Conclusion - Elevated triglyceride levels were associated with a doubling of risk of venous thrombosis in postmenopausal women, whereas elevated HDL cholesterol levels were associated with a decreased risk.