Impact of the Time-Weighted Average Glucose Concentration and Diabetes on In-Hospital Mortality in Critically Ill Patients Older Than 75 Years: A Retrospective Cohort Study

Abstract

ObjectiveTo evaluate the effects of diabetes and hyperglycemia on in-hospital mortality in critically ill patients older than 75 years. MethodsThis was a single-center retrospective cohort study of patients older than 75 years in the first intensive care unit stay. The patients were divided into the following 4 groups: time-weighted average glucose (TWAG) <140 mg/dL without diabetes (group 1), TWAG ≥140 mg/dL without diabetes (group 2), TWAG <180 mg/dL with diabetes (group 3), and TWAG ≥180 mg/dL with diabetes (group 4). Clinical and laboratory data were analyzed. ResultsA total of 6760 patients over 75 years of age were included, including 2089 patients previously diagnosed with diabetes. The patients in group 2 had the highest in-hospital mortality (27.4%). In the fully adjusted regression model, the risk of in-hospital mortality increased by 76% (odds ratio = 1.76, 95% CI: 1.49-2.08) in group 2 as compared with group 1. Those from groups 3 and 4 exhibited risks equivalent to the risks of those in group 1; similar results were observed in the subgroup analysis. A J-shaped curve relationship and threshold effect were observed in patients without diabetes. For those with diabetes, a flatter curve pattern with a small slope was observed. ConclusionStress hyperglycemia was more detrimental to short-term prognosis than diabetes status in these patients. Looser glucose control may be suitable for patients older than 75 years with diabetes but unnecessary for those without diabetes. Patients with diabetes may be more resistant to the detrimental effects of glucose variations.