The SGLT-1/SGLT-2 dual inhibitor canagliflozin has positive effects on glucose trends, targets and variability in late dumping syndrome following gastrectomy: A case report

Background

Late dumping syndrome (LDS) refers to reactive hyperinsulinemic hypoglycemia episodes that occur one to 3 h following a high-carbohydrate meal in persons who have had gastric surgery. Dietary adjustments (such as regular composite meals containing lipids, protein, and carbohydrates with a low glycemic index) are effective in treating the majority of LDS patients; however, pharmaceutical interventions are required in some cases.

Case presentation

We describe the case of a 60-year-old woman with type 2 diabetes (T2DM) who developed late dumping syndrome symptoms following a gastric cancer gastrectomy. Both the 75-g oral glucose tolerance test (OGTT) and the mixed-meal tolerance test (MMTT) revealed reactive hyperinsulinemic hypoglycemia. We began therapy with canagliflozin, a sodium glucose-cotransporter (SGLT) inhibitor 300 mg before lunch after realizing that dietary changes were insufficient in reducing the occurrence of symptomatic hypoglycemic episodes. We repeated the OGTT after treatment, and the results showed still the presence of symptomatic hypoglycemia without significant differences in peak insulin values compared to the OGTT performed before treatment. Instead, the MMT showed a small, flattened insulin response without any hypoglycemic episodes. Furthermore, improvements were observed in glucose trends/targets as demonstrated by time in (TIR), above (TAR) and below (TBR) range and glucose variability (e.g. coefficient of variation) based on data collected from Flash Glucose Monitoring (FGM) before and during canagliflozin therapy.

Conclusion

The rapid transit of inadequately digested chyme from the stomach into the small intestine is one of the most important pathophysiological processes in LDS. Canagliflozin, unlike other molecules in the same family, inhibits intestine SGLT-1. By delaying glucose absorption at that level, it may reduce postprandial glucose and insulin rises. Our case report, however, demonstrates that the effect of canagliflozin on glucose homeostasis is determined by appropriate dietary habits, which seem to be critical for successfully reducing symptoms related to reactive hyperinsulinemic hypoglycemia following a gastric bypass surgery.