Background and objectives: The metabolic syndrome, defined by abdominal obesity, elevation of blood pressure, fasting glucose and triglycerides and low levels of high-density lipoprotein cholesterol is associated with atherosclerotic disease. It induces a pro-inflammatory and prothrombotic state. Despite its high prevalence, data on the association with venous thromboembolism (VTE) are scarce. The aim of our study was to elucidate the association of the metabolic syndrome with the risk of VTE.
Design and methods: We conducted a case-control study to investigate the presence of the metabolic syndrome defined according to guidelines of the National Cholesterol Education Program, in high-risk patients with objectively confirmed recurrent VTE, who had had at least one unprovoked event of deep venous thrombosis or pulmonary embolism. Age and sex-matched healthy individuals served as controls.
Results: A total of 116 patients and 129 controls were enrolled. The prevalence of the metabolic syndrome was statistically significantly higher in patients (40/116, 35%) than in controls (26/129, 20%, p=0.012). The unadjusted odds ratio (OR) of the metabolic syndrome for VTE was 2.1 (95% CI [1.2-3.7], p=0.012) and remained statistically significant after adjustment for established thrombosis risk factors, sex and age (OR=2.2, 95% CI [1.1-4.3], p=0.020). Individuals with the metabolic syndrome (n=66) had significantly higher levels of high-sensitivity C-reactive protein (median, [interquartile range]: 0.312 mg/dL, [0.142-0.751] vs. 0.153 mg/dL, [0.073-0.330], p<0.001), fibrinogen (390 mg/dL, [342-432] vs. 343 mg/dL, [310-394], p<0.001) and factor VIII activity (182%, [157-216] vs. 159%, [133-199], p=0.005) compared to those without (n=179).
Interpretation and conclusions: The metabolic syndrome may contribute to the development of VTE and is associated with a two-fold increased risk of VTE.