title: Type 2 diabetes and 1-year mortality in intensive care unit patients.
abstract: BACKGROUND
  Data on the prognostic impact of diabetes and diabetic complications in intensive care unit (ICU) patients are limited and inconsistent. We, therefore, examined mortality in ICU patients with type 2 diabetes with and without pre-existing heart and kidney diseases compared with nondiabetic patients.
  
  
  METHODS
  We conducted this population-based cohort study in Northern Denmark during 2005-2011. We included all ICU patients aged 40 years or older from the 17 ICUs in the area and identified type 2 diabetes by either a filled prescription for an antidiabetic drug, a previous diagnosis of diabetes, or an elevated glycosylated haemoglobin level. Diabetic patients were disaggregated according to pre-existing diagnoses of heart disease (myocardial infarction or heart failure) and kidney disease. We estimated 1-year mortality by the Kaplan-Meier method and hazard ratios of death (HRs) during follow-up using Cox regression, controlling for confounding factors and stratified by relevant subgroups.
  
  
  RESULTS
  Among 45 018 ICU patients, 7219 (16·0%) had type 2 diabetes. Overall, 1-year mortality was 36·0% in ICU patients with type 2 diabetes, rising to 54·6% in patients with pre-existing heart and kidney diseases, compared with 29·1% in nondiabetic patients. Comparing diabetic with nondiabetic patients, the adjusted 0- to 30-day HR was 1·20 (95% confidence interval (CI): 1·13-1·26) and 1·19 (95% CI: 1·10-1·28) during the 31- to 365-day follow-up period. Pre-existing kidney disease further increased the impact of diabetes, while heart disease alone had no such effect.
  
  
  CONCLUSIONS
  ICU patients with type 2 diabetes had higher 1-year mortality compared with nondiabetic ICU patients, particularly those with pre-existing kidney disease.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark. cc@dce.au.dk
authors.forename: Christian F
authors.initials: CF
authors.lastname: Christiansen
authors.forename: Martin B
authors.initials: MB
authors.lastname: Johansen
authors.forename: Steffen
authors.initials: S
authors.lastname: Christensen
authors.forename: James M
authors.initials: JM
authors.lastname: O'Brien
authors.forename: Else
authors.initials: E
authors.lastname: Tønnesen
authors.forename: Henrik T
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D015331:Cohort Studies; D003422:Critical Care / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality*; D058065:Diabetic Cardiomyopathies / Q000401:mortality*; D003928:Diabetic Nephropathies / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality