title: In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: a cohort study.
abstract: OBJECTIVE
  Patients with diabetes mellitus form 23%-30% of published cohorts of critically ill patients. Conflicting published evidence links diabetes mellitus to both higher and lower mortality. Other cohort studies suggest that diabetes mellitus protects against acute lung injury. We hypothesized that diabetes mellitus is an independent risk factor for mortality. We further hypothesized that diabetes mellitus is a risk factor for cardiac overload and not for acute lung injury.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  The intensive care unit of a tertiary referral hospital.
  
  
  METHODS
  From November 1, 2004, to October 1, 2007, a cohort of patients admitted ≥48 hrs to the intensive care unit.
  
  
  METHODS
  None.
  
  
  RESULTS
  Of 2,013 patients, 317 had diabetes mellitus. Ninety-day mortality was higher in the diabetes mellitus patients compared to patients without diabetes mellitus (hazard ratio 1.53, 95% confidence interval 1.29-1.80). This association strengthened after adjusting for confounders and for medication (hazard ratio 1.53, 95% confidence interval 1.07-2.17).We found no association between diabetes mellitus and acute lung injury (relative risk ratio 1.01, 95% confidence interval 0.78-1.32; adjusted relative risk ratio 0.99, 95% confidence interval 0.75-1.31), but diabetes mellitus was a risk factor for cardiac overload (relative risk ratio 1.91, 95% confidence interval 1.30-2.81; adjusted relative risk ratio 1.45, 95% confidence interval 0.97-2.18). Statins were associated with both a reduced risk of mortality (hazard ratio 0.74, 95% confidence interval 0.63-0.87; adjusted hazard ratio 0.53, 95% confidence interval 0.44-0.64) and a decreased risk of developing acute lung injury (relative risk ratio 0.71, 95% confidence interval 0.56-0.89; adjusted relative risk ratio 0.61, 95% confidence interval 0.47-0.79).
  
  
  CONCLUSIONS
  Diabetes mellitus is an independent risk factor for mortality in critically ill patients and failure to adjust for statins underestimates the size of this association. Diabetes mellitus is not associated with acute lung injury but is associated with cardiac overload. A diagnosis of cardiac overload excludes a diagnosis of acute lung injury. Investigators who do not account for cardiac overload as a competing alternative outcome may therefore falsely conclude that diabetes mellitus protects from acute lung injury.
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands. gavin.koh@gmail.com
authors.forename: Gavin C K W
authors.initials: GC
authors.lastname: Koh
authors.forename: Alexander P J
authors.initials: AP
authors.lastname: Vlaar
authors.forename: Jorrit J
authors.initials: JJ
authors.lastname: Hofstra
authors.forename: H Katrien
authors.initials: HK
authors.lastname: de Jong
authors.forename: Samuel
authors.initials: S
authors.lastname: van Nierop
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Peacock
authors.forename: W Joost
authors.initials: WJ
authors.lastname: Wiersinga
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Schultz
authors.forename: Nicole P
authors.initials: NP
authors.lastname: Juffermans
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology; D000368:Aged; D002306:Cardiac Volume / Q000502:physiology; D016638:Critical Illness / Q000401:mortality*; D048909:Diabetes Complications / Q000401:mortality* / Q000503:physiopathology; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors