• Cohort study;
  • diabetes mellitus type 2;
  • heart disease;
  • intensive care;
  • kidney disease;
  • mortality



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.


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.


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.


ICU patients with type 2 diabetes had higher 1-year mortality compared with nondiabetic ICU patients, particularly those with pre-existing kidney disease.