The obesity paradox in community-acquired bacterial pneumonia

Background: The impact of obesity on the outcome of pneumonia is uncertain. Methods: We retrospectively identified 266 hospitalized patients with proven pneumococcal or Haemophilus community-acquired pneumonia who had at least one body mass index (BMI, kg/m(2)) value documented in the 3 months before admission. Patients were classified as underweight (BMI < 18.5), normal weight (BMI 18.5 to <25), overweight (BMI 25 to <30), or obese (BMI >= 30). The association of absolute BMI values and BMI categories with the mortality at 30 days after admission for pneumonia was investigated. Results: Increasing BMI values were associated with reduced 30-day mortality, even after adjustment for significant covariates (odds ratio 0.88, confidence interval 0.81-0.96; p < 0.01). There was a significant trend towards lower mortality in the overweight and obese (non-parametric trend, p = 0.02). Conclusions: Our data suggest that obesity may exert a protective effect against 30-day mortality from community-acquired bacterial pneumonia. (C) 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.