Diabetes and Glucose Dysregulation and Transition to Delirium in ICU Patients.

OBJECTIVES: To investigate whether diabetes and glucose dysregulation (hyperglycemia and/or hypoglycemia) are associated with ICU delirium.

DESIGN: Prospective cohort study.

SETTING: Thirty-two-bed mixed intensive care in a tertiary care center.

PATIENTS: Critically ill patients admitted to the ICU with transitions of mental status from awake and nondelirious to delirious or remaining awake and nondelirious on the next day. Patients admitted because of a neurologic illness were excluded.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: The study population consisted of 2,745 patients with 1,720 transitions from awake and nondelirious to delirious and 11,421 nontransitions remaining awake and nondelirious. Generalized mixed effects models with logit link function were performed to study the association between diabetes mellitus, glucose dysregulation, and delirium, adjusting for potential confounders. Diabetes was not associated with delirium (odds ratio adjusted, 0.93; 95% CI, 0.73-1.18). In all patients, the occurrence of hyperglycemia (odds ratio adjusted, 1.35; 95% CI, 1.15-1.59) and the occurrence of both hyperglycemia and hypoglycemia on the same day (odds ratio adjusted, 1.65; 95% CI, 1.12-2.28) compared with normoglycemia were associated with transition to delirium. Hypoglycemia was not associated with transition to delirium (odds ratio adjusted, 1.86; 95% CI, 0.73-3.71). In patients without diabetes, the occurrence of hyperglycemia (odds ratio adjusted, 1.41; 95% CI, 1.16-1.68) and the occurrence of both hyperglycemia and hypoglycemia on the same day (odds ratio adjusted, 1.87; 95% CI, 1.07-2.89) were associated with transition to delirium. In patients with diabetes, glucose dysregulation was not associated with ICU delirium.

CONCLUSIONS: Diabetes mellitus was not associated with the development of ICU delirium. For hypoglycemia, only a nonsignificant odds ratio for ICU delirium could be noted. Hyperglycemia and the occurrence of hyperglycemia and hypoglycemia on the same day were associated with ICU delirium but only in patients without diabetes. Our study supports the institution of measures to prevent glucose dysregulation in nondiabetic ICU patients and contributes to the understanding of the determinants of delirium.