Background: Shorter time spent in specific blood glucose ranges is associated with mortality benefit in critically ill patients. However, various time in range values are reported, each based on a specific blood glucose range. Objective: To evaluate relationship between percentage of time spent at various blood glucose ranges (TIR) and mortality in critically ill patients. Methods: Single-center, retrospective, cohort study that included adult patients admitted to ICU for at least one day. We evaluated the relationship between TIR at prespecified blood glucose ranges and hospital mortality in diabetic and non-diabetic patients Results: Of the 5287 patients included, 3705 (70.0%) were non-diabetic and 1582 were diabetic (29.9%). Diabetic patients had higher in-hospital mortality rate (15.8%) compared to non-diabetic patients (11.3%), p < 0.0001, and with higher incidence of hyperglycemia (77.8% vs. 39.4%) and hypoglycemia (14.3% vs. 10%) compared to non-diabetic patients, p < 0.0001. The highest median TIR for both diabetic [76% (49.1 - 97.8%)] and non-diabetic patients [100% (92.3--100%)] was at blood glucose range of 70-180 mg/dL. In non-diabetic cohort, the only optimal TIR of 40% at blood glucose range of 70-120 mg/dL was identified. Non-diabetic patients stratified into TIR 70-120 mg/dL > 40% reported significantly lower mortality (7.0%) rate compared to patients with TIR 70-120 mg/dL < 40% (15.7%), OR 0.52, 95% CI 0.27-0.97, adjusted-p = 0.03. In diabetic patients, no relationship was detected between TIR at all predefined glucose ranges and hospital mortality. Conclusion: Critically ill non-diabetic patients who spent at least 40% of time in blood glucose range of 70-120 mg/dL had improved survival. This association was not observed in diabetic patients.
Keywords: critically ill patients; diabetes; dysglycemia; glucose; glycemic variability; intensive insulin therapy.