Venous thromboembolism in association with features of the metabolic syndrome. 
Central obesity, diabetes mellitus, dyslipidaemia and chronic hypertension--features of the metabolic syndrome--have been individually associated with venous thromboembolism (VTE).  However, whether each of these factors additively increases the risk of VTE is uncertain.  To determine whether features of the metabolic syndrome independently increase the risk of VTE.  Prospective cohort study derived from the Heart Outcomes Prevention Evaluation 2 (HOPE-2) randomized clinical trial.  One hundred and forty-five clinical centres in 13 countries.  We studied 5522 adults aged > or =55 years with cardiovascular disease or diabetes mellitus.  At enrollment, 35% had 0-1 features of the metabolic syndrome, 30% had two, 24% had three and 11% had four.  We defined symptomatic VTE as an objectively confirmed new episode of deep-vein thrombosis or pulmonary embolism.  VTE occurred in 88 individuals during a median 5.0 years of follow-up.  The incidence rate of VTE (per 100 person-years) was 0.30 with 0-1 features, 0.36 with two features, 0.38 with three features and 0.40 with four features of the metabolic syndrome (trend p = 0.43).  Relative to the presence of 0-1 features of the metabolic syndrome, the adjusted hazard ratio (95%CI) for VTE was 1.22 (0.71-2.08) with two features, 1.25 (0.70-2.24) with three features, and 1.26 (0.59-2.69) with four features.  The number of features of the metabolic syndrome present was not a clinically important risk factor for VTE in older adults with vascular arterial disease.