Obesity and Risk of Sepsis: A Population-Based Cohort Study

OBJECTIVE: Sepsis, the syndrome of microbial infection complicated by systemic inflammation, is associated with significant morbidity and mortality. We sought to determine if obesity increases risk of sepsis events. DESIGN AND METHODS: We used data from the 30,239 subject population-based longitudinal cohort study REasons for Geographic and Racial Differences in Stroke (REGARDS). Using measurements at the start of the study, we defined obesity using body mass index (BMI; <18.5 kg/m(2)=underweight, 18.5–24.9 =normal, 25.0–29.9=overweight, 30.0–39.9=obese, ≥40=morbidly obese) and waist circumference (WC; [male≤102 cm or female≤88 cm]= normal, [male>102 cm or female>88 cm]=obese). Over an 8-year observation period, we evaluated the association between obesity and subsequent sepsis events, adjusting for sociodemographic factors, health behaviors, chronic medical conditions, statin use and high-sensitivity C-reactive protein. RESULTS: There were 975 incident sepsis events. Compared to those with a BMI of 18.5–24.9, sepsis risk was higher only for BMI ≥40 (HR 1.57, (1.16–2.14)). Risk of sepsis was associated with increased WC (HR 1.34 (1.14–1.56)). In a model with both BMI and WC, sepsis risk was associated with increased WC (HR 1.47 (1.20–1.79)) but not BMI. CONCLUSIONS: Obesity is independently associated with future sepsis events. WC is a better predictor of future sepsis risk than BMI.