Abdominal obesity and the risk of venous thromboembolism among women: a potential role of interleukin-6.

Abdominal obesity increases the risk of venous thromboembolism (VTE). It remains unclear to what extent inflammation contributes to the risk of VTE from abdominal obesity. Our objectives were to investigate the association between abdominal obesity and VTE and the effect of inflammation on this association in a case-control study comprised of women. We included 84 patients with VTE (18-60 years of age) and 100 controls. Waist circumference (WC), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hsCRP) levels were determined at least 7 months after the thrombotic event. A total of 51 patients (61%) and 43 (43%) controls had abdominal obesity (WC ≥88 cm). The odds ratios (OR) adjusted for age were 2.40 [95% confidence interval (CI) 1.06-5.41; P=0.035] for a WC ≥88 cm compared to a WC <80 cm; the association was attenuated after adjusting for IL-6 (OR 1.86, 95% CI 0.80-4.33; P=0.149). For every 10-cm increment in WC, the risk of VTE adjusted for age increased by 1.38 (95% CI 1.08-1.77; P=0.010). The effect of an increased WC on the risk of VTE was again attenuated when IL-6 was entered in the regression model (OR 1.24, 95% CI 0.95-1.61; P=0.109). Risk estimates did not substantially change with adjustment for hsCRP. Our data indicate that the association between VTE and an increased WC was attenuated after adjustment for IL-6, suggesting a potential role of this interleukin in mediating the link between abdominal obesity and VTE.