Glycemic Effects of a Low-Carbohydrate Enteral Formula Compared With an Enteral Formula of Standard Composition in Critically Ill Patients: An Open-Label Randomized Controlled Clinical Trial

Background: Enteral low-carbohydrate formulas (LCFs) could serve as a noninsulin alternative for the treatment of stress hyperglycemia in critically ill patients. We compared the glycemic effects of an LCF with a standard formula. Methods: We conducted an open-label randomized trial in patients admitted to our intensive care unit between September 2015 and June 2016. Adult patients with an indication for enteral nutrition were randomized to an LCF (Glucerna 1.5 kcal) or a standard enteral formula (Fresubin Energy Fibre, with additional protein supplement). Primary outcome was glucose variability defined as mean absolute glucose (MAG) change (mmol/L/h). Secondary outcomes were mean glucose, time in target, hypoglycemic and hyperglycemic events, and insulin requirements. We assessed glycemic outcomes per blinded continuous glucose monitoring (CGM) system and compared outcomes with glucose measurements per blood gas analysis and point-of-care device. Results: We randomized 107 patients (LCF: n = 53; standard: n = 54). Six patients had no CGM data, leaving 101 patients (n = 52; n = 49) for the intention-to-treat analysis. MAG change and time in target range were not different between groups. LCF gave a lower mean glucose measured per point-of-care device (7.8 ± 1.0 vs 8.4 ± 1.1 mmol/L, P =.007). LCF patients required significantly less insulin on the second study day (46.8 vs 68.0 IU, P =.036). Conclusion: LCF showed a trend toward a modestly reduced mean glucose and significantly lower insulin requirements as compared with standard feeding but had no effect on glucose variability or time in target range.