The association of overweight and ankle injuries in children.

OBJECTIVES: Overweight children are at increased risk for many medical problems. Trauma is the leading etiology of childhood morbidity and mortality. No previous study has evaluated the association between overweight and acute ankle injuries in children. We hypothesized that being overweight is associated with an increased risk of ankle injury in children. METHODS: We conducted a case-control study in an urban pediatric emergency department. Subjects aged 5 to 19 years were recruited from June 2005 through July 2006. Children with acute ankle trauma were enrolled as cases. A convenience sample of children with a chief complaint of fever, headache, or sore throat was enrolled as controls. Demographic information and anthropometric measurements were obtained. Age- and gender-specific body mass index percentiles (BMI-Ps) were calculated using pediatric norms. Multivariate unconditional logistic regression was used to assess the relationship between overweight and ankle injury, adjusting for demographic variables. Through medical records, we obtained demographic information and weight, but not height, of all cases that were not enrolled. This allowed us to conduct a sensitivity analysis in which we combined the enrolled and nonenrolled cases into a single case group and made increasingly more unlikely assumptions about the height percentiles of the nonenrolled cases. RESULTS: One hundred eighty cases and 180 controls were enrolled in the study. We observed a significant association between overweight and ankle injury (multivariate-adjusted odds ratio 3.26, 95% confidence interval, 1.86-5.72; P value for trend <.0001). Although this result may be an overestimate of the magnitude of the association due to a possible bias in the selection of cases, sensitivity analysis demonstrated the robustness of the statistical significance of the finding. CONCLUSIONS: Overweight children may be at increased risk of ankle injury.