Type 2 diabetes and 1-year mortality in intensive care unit patients

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. Design We conducted this population-based cohort study in Northern Denmark during 20052011. We included all ICU patients aged 40years 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 KaplanMeier method and hazard ratios of death (HRs) during follow-up using Cox regression, controlling for confounding factors and stratified by relevant subgroups. Results Among 45018 ICU patients, 7219 (16 center dot 0%) had type 2 diabetes. Overall, 1-year mortality was 36 center dot 0% in ICU patients with type 2 diabetes, rising to 54 center dot 6% in patients with pre-existing heart and kidney diseases, compared with 29 center dot 1% in nondiabetic patients. Comparing diabetic with nondiabetic patients, the adjusted 0- to 30-day HR was 1 center dot 20 (95% confidence interval (CI): 1 center dot 131 center dot 26) and 1 center dot 19 (95% CI: 1 center dot 101 center dot 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.