Impact of obesity on the risk of venous thromboembolism in an inpatient pediatric population

Introduction: The incidence of venous thromboembolism in children has increased significantly over the past 20 years. Over the same period of time, there was an increase in the prevalence of obesity in the pediatric population. Obesity is a known risk factor for VTE in adults, but little information is available in children. Methods: This study evaluates the relation between obesity and VTE using a retrospective, case-control design, comparing the body mass index (BMI) of patients admitted with a diagnosis of VTE versus patients admitted with other diagnoses, at a single institution, between 2007 and 2011. Results: We studied 48 inpatients diagnosed with deep venous thrombosis or pulmonary embolism and a control group of 274 age and gender matched patients admitted with other diagnoses. We found obese patients (BMI > 95th percentile) to have significantly higher risk of VTE (odds ratio 2.1, with 95% CI 1.1-4.2) than patients of normal weight (BMI < 85th percentile). Overweight patients (BMI 85th-95th percentile) did not demonstrate a significant change in risk. Most of the VTE patients were adolescents and the majority of them had other identifiable risk factors for thrombosis. Conclusion: This study establishes a correlation between obesity and VTE in a group of hospitalized children, showing a risk for VTE in obese children similar to the one described in much larger adult cohorts.