2005 HSR&D National Meeting Abstract
3041 — Hyperglycemia Predicts Mortality in Critically Ill Patients: Effect in Diabetes vs. No Diabetes
Falciglia M (Cincinnati VAMC, University of Cincinnati)
D'Alessio DA (Cincinnati VAMC, University of Cincinnati)
Freyberg RW (University of Cincinnati)
Deddens JA (University of Cincinnati)
Hofer TP (VA Ann Arbor HSR&D Center for Excellence)
Render ML (Cincinnati VAMC, University of Cincinnati)
Observational studies suggesting a relationship between plasma glucose and hospital morbidity/mortality are limited in that they have typically used only admission glucose as the glycemic measure, focused on specific subsets of patients, or were not uniformly risk-adjusted. We evaluated the independent effect of mean glucose on mortality risk in 28,608 intensive care unit (ICU) first admissions to 34 ICUs at 17 Veterans Affairs hospitals.
Mean glucose (MG) was the sum of all measured glucose values up to 48 hours prior to death or discharge, divided by the number of measurements. A predicted mortality risk for each case (INDEX) was calculated by applying a validated ICU logistic regression (LR) model that predicts hospital mortality using ICU admission diagnosis, co-morbid disease, laboratory variables, age, and transfer status. The effect of MG (categorized as 111-145, 146-199, 200-300, and >300 mg/dl) was then analyzed with individual INDEX in a second LR model for all cases and for subsets by admission diagnosis, and absence/presence of diabetes.
In the second LR model (AUROC 0.898), MG independently predicted mortality for the entire cohort (p-value < 0.0001) and for patients without diabetes (p-value < 0.0001), but not for patients with diabetes (p-value = 0.07). Mortality increased with worsening hyperglycemia. For MG groups, 111-145, 146-199, 200-300, and >300 mg/dl, adjusted odds ratios (95% confidence intervals) were respectively: 1.1 (1.0-1.3), 1.3 (1.1-1.5), 1.4 (1.2-1.6), 1.7 (1.3-2.1) for the entire cohort; and 1.1 (1.0-1.3), 1.4 (1.2-1.6), 2.1 (1.7-2.6), 2.8 (1.9-4.3) for patients without diabetes. MG increased the risk of mortality for patients admitted with acute myocardial infarction, arrhythmia, coronary artery bypass graft surgery, and stroke.
Hyperglycemia, even mild, significantly and independently increases mortality risk in a large heterogeneous cohort of ICU patients after extensive risk adjustment. This effect is greater in patients without a co-morbid diagnosis of diabetes.
These findings suggest that glucose control may be an intervention that alone could improve ICU outcomes. The difference in the predictive effect of hyperglycemia on mortality in patients with and without the diagnosis of diabetes may be the result of treatment differences.