Obesity is not associated with recurrent venous thromboembolism in elderly patients: Results from the prospective SWITCO65+ cohort study

BACKGROUND Whether obesity is associated with recurrent venous thromboembolism (VTE) in elderly patients is unknown. OBJECTIVES To examine the association between two obesity measures, the body mass index (BMI) and the waist circumference (WC), and recurrent VTE in elderly patients. PATIENTS/METHODS We studied 986 patients aged ≥65 years with an acute VTE from a prospective multicenter cohort study (09/2009-12/2013). The BMI was determined and categorized as <25, 25 to <30, or ≥30 kg/m2. The WC was categorized as <80 cm in women (w)/<94 cm in men (m), 80 to <88 cm (w)/94 to <102 cm (m), or ≥88 cm (w)/≥102 cm (m). We examined the association between the BMI and the WC and the time to a first symptomatic recurrent VTE using competing risk regression, adjusting for known risk factors of VTE recurrence and periods of anticoagulation. RESULTS The mean follow-up was 28 months. The 3-year cumulative incidence of recurrent VTE did not vary by BMI and was 17.6% for a BMI <25 kg/m2, 11.5% for a BMI 25 to <30 kg/m2, and 16.9% for a BMI ≥30 kg/m2 (P = 0.09). The 3-year cumulative incidence of recurrent VTE did not vary by WC. After adjustment, neither the BMI (sub-hazard ratio [SHR] 1.02, 95% confidence interval [CI 0.98-1.05]) nor the WC (SHR 1.01, 95% CI 0.99-1.02) was associated with recurrent VTE. CONCLUSIONS Measures of body weight were not associated with recurrent VTE in our cohort. Obesity does not appear to be a predictor of recurrent VTE in the elderly.