Purpose: The aim of this study was to evaluate the association between blood glucose within 24 hours after intensive care unit (ICU) admission and prognosis.
Patients and Methods: A retrospective cohort study was conducted using data from a large critical care database. Patients who had a length of ICU stay ≥ 24 hours and at least two blood glucose records within 24 hours after ICU admission were included and hospital mortality was chosen as the primary outcome. The average, minimum, and maximum blood glucose within 24 hours after ICU admission were a priori selected as exposures and associations between each exposure and outcomes were assessed after adjusted for potential confounders.
Results: A total of  14,237 patients were included finally with an average age of 62.9± 17.7 years and a mean SAPS II on admission of 34 (26– 44). Among the study population, 20.2% (2872/14,237) had uncomplicated diabetes, and 6.7% (953/14,237) had complicated diabetes. Lowest hospital mortality rate was observed in the stratum with an average blood glucose ranged 110– 140 mg/dL, a minimum blood glucose ranged 80– 110 mg/dL, and a maximum blood glucose ranged 110– 140 mg/dL. After adjusted for confounders including age, sex, disease severity scores and comorbidities, an average blood glucose ranged  110– 140 mg/dL, a minimum blood glucose ranged 80– 110 mg/dL, and a maximum blood glucose ranged 110– 140 mg/dL were associated with the lowest risk of hospital mortality. Consistent results were found among patients without diabetes in the subgroup analyses stratified by diabetes.
Conclusion: A range of 110– 140 mg/dL for average and maximum blood glucose and a range of 80– 110 mg/dL for minimum blood glucose within 24 hours after ICU admission predicted better prognosis especially among patients without diabetes.
Keywords: blood glucose, critical care, mortality, retrospective studies