Ingestion of an exogenous ketone monoester improves the glycemic response during oral glucose tolerance test in individuals with impaired glucose tolerance: A cross-over randomized trial

In a randomized cross-over trial, nine Japanese adults aged 48 to 62 with impaired glucose tolerance had a 180 minute, 75 g oral glucose tolerance test with and without ketone monoester ingestion. The area under the curve (AUC) of D-beta-hydroxybutyrate was 5995.3 mmol/L·h with the monoester versus 116.1 without. The improved glucose excursion was associated with a higher insulin AUC during the first 90 minutes, while the C-peptide AUC was unchanged in that period. Over the full 180 minutes, the AUCs of insulin, C-peptide, glucagon, and free fatty acids were similar in both conditions.