Glycemic Control and Insulin Requirement According to Enteral Formula Type in Critically Ill Patients with Type 2 Diabetes: A Retrospective Comparative Study

Background/Objectives: This study evaluated whether a low-carbohydrate diabetes-specific enteral formula improves glycemic control and insulin requirement compared with a standard enteral formula in critically ill patients with type 2 diabetes mellitus (T2DM) under pandemic-related product accessibility constraints. Methods: This retrospective observational study included adult ICU patients with T2DM receiving enteral nutrition between August 2021 and August 2023. Patients were grouped according to enteral formula type as standard enteral formula or diabetes-specific enteral formula. All patients received continuous nasogastric enteral feeding according to routine ICU practice. Glycemic control was managed using intravenous insulin infusion protocols. One hundred eligible patients were analyzed. Results: Fifty patients were included in each group. Baseline characteristics were broadly comparable, although differences in BMI and feeding rate were observed. Mean glucose level, daily insulin requirement, hypoglycemia, hyperglycemia, and glycemic variability were similar between groups (all p > 0.05). However, the number and percentage of days within the target glycemic range were higher in the diabetes-specific formula group (both p = 0.021). Clinical outcomes were comparable between groups. In multivariable analysis, mean glucose level independently predicted insulin requirement and glycemic variability, whereas formula type did not. Product-related costs were lower in the diabetes-specific formula group (all p < 0.001). Conclusions: Diabetes-specific enteral formula did not improve mean glucose level or insulin requirement in critically ill patients with T2DM, although it was associated with better maintenance of the target glycemic range and lower product-related costs. Enteral formula choice should therefore be individualized rather than routinely determined by diabetes status alone.