Risk Factors for Venous Thromboembolism

BACKGROUND: Studies have suggested a link between risk factors for atherosclerotic disease and venous thromboembolism (VTE), but results are heterogeneous. We sought to identify risk factors for VTE with a focus on risk factors for atherosclerotic disease. METHODS AND RESULTS: Data were taken from the Copenhagen City Heart Study, a prospective cohort study of a random, age-stratified sample of people living in a defined area in Copenhagen, Denmark, started in 1976 with follow-up until 2007. First VTE (deep vein thrombosis and pulmonary embolism) diagnosis was retrieved from electronic national registries from study baseline to 2007. Of 18 954 subjects (median follow-up, 19.5 years) representing 360 399 person-years of follow-up, 969 subjects experienced at least 1 VTE, corresponding to a crude incidence rate of 2.69 (95% confidence interval CI, 2.52 to 2.86) per 1000 person-years. The variables found to be significantly associated with VTE in a multivariable model adjusted for age and calendar time were as follows: body mass index (hazard ratio HR for >or=35 versus or=25 g tobacco per day versus never smoker=1.52 95% CI, 1.15 to 2.01); gender (HR for men versus women=1.24 95% CI, 1.08 to 1.42); household income (HR for medium versus low=0.82 95% CI, 0.70 to 0.95); and diastolic blood pressure (HR for >100 versus <80 mm Hg=1.34 95% CI, 1.08 to 1.66). Other cardiovascular risk factors including total/high-density lipoprotein/low-density lipoprotein cholesterol levels, triglyceride levels, and diabetes mellitus were not associated with VTE. CONCLUSIONS: Obesity and smoking were both found to be important risk factors for VTE whereas total/high-density lipoprotein/low-density lipoprotein cholesterol levels, triglyceride levels, and diabetes mellitus were not.