title: The obesity paradox in community-acquired bacterial pneumonia.
abstract: 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/m²) 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.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Ottawa, The Ottawa Hospital, 1053 Carling Ave, CPC 470, Ottawa, Ontario, K1Y 4E9, Canada. vcorrales@uottawa.ca
authors.forename: Vicente F
authors.initials: VF
authors.lastname: Corrales-Medina
authors.forename: Josemon
authors.initials: J
authors.lastname: Valayam
authors.forename: Jose A
authors.initials: JA
authors.lastname: Serpa
authors.forename: Adriana M
authors.initials: AM
authors.lastname: Rueda
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Musher
mesh_terms: D000368:Aged; D015992:Body Mass Index; D017714:Community-Acquired Infections / Q000453:epidemiology; D015897:Comorbidity; D006192:Haemophilus Infections / Q000453:epidemiology*; D006801:Humans; D008875:Middle Aged; D009026:Mortality; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology*; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology*; D012189:Retrospective Studies; D013851:Thinness / Q000453:epidemiology*