Effectiveness of sitagliptin in a patient with late dumping syndrome after total gastrectomy

An 83-year-old man developed hypoglycemia after undergoing total gastrectomy for gastric cancer in 200X-4. The patient was admitted to our hospital in May 200X and placed on continuous glucose monitoring (CGM). Glycemic excursions were examined while on 3-meal/day (1700 kcal) and 6-meal/day (1800 kcal) diets. Oxyhyperglycemia followed about 2 h later by a sudden drop in glucose levels was seen with both regimens. These findings were consistent with late dumping syndrome. CGM was continued, oral miglitol at 150 mg/day or sitagliptin at 50 mg/day was started, and glycemic excursions were compared. Results were similar for both drugs, with reductions in postprandial glucose elevations. Meal tolerance testing 3 months after oral sitagliptin, compared to before starting treatment, showed reductions in both early postprandial hyperglycemia and insulin hypersecretion. These findings suggest that DPP-4 inhibitors such as sitagliptin may be effective for treating post-gastrectomy late dumping syndrome.