Glucagon treatment for post-gastric bypass hypoglycemia

Hyperinsulinemic hypoglycemia is a recently described complication of Roux-en-Y gastric bypass (RYGB). We hypothesized that glucagon administration would help maintain normal postprandial plasma glucose concentrations by stimulating hepatic glucose output, and if so, represent a new therapeutic option for postbypass hypoglycemia. In this study, we compared the insulin and glycemic response to a mixed meal with and without concomitant glucagon infusion in a patient with severe recurrent hypoglycemia after RYGB. Although effective in transiently raising postprandial plasma glucose values, glucagon infusion was also associated with higher insulin concentrations, and failed to prevent symptomatic hypoglycemia. This case demonstrates that glucagon may have limited clinical utility in the treatment of post-RYGB hyperinsulinemic hypoglycemia.