diazoxide has been found to be effective in treating patients with a form of hyperinsulinemic hypoglycemia known as nesidioblastosis (14). These findings suggest that diazoxide may also be useful for controlling and maintaining blood glucose and ensuring the quality of life (QOL) in patients with insulinoma indicative of a form of hyperinsulinemic hypoglycemia that is not indicated for surgery. In chronic renal failure patients, such as the present patient, reduced metabolic clearance is known to result in an elevated IRI level (15). Therefore, it is difficult to diagnose insulinoma based solely on the detection of an elevated IRI value under conditions of hypoglycemia. Moreover, diazoxide is excreted via the kidneys, and the administration of this drug in renal failure patients thus warrants careful consideration (16).
In the present study, an insulinoma was accurately diag- nosed using CT and EUS-guided fine-needle aspiration, and the effects of diazoxide therapy were confirmed with CGM. This is the first reported case in which diazoxide was used to treat insulinoma in a chronic renal failure patient on hemodialysis by carefully adjusting the dose of the drug.
Furthermore, it has been reported that, in diabetic pa- tients, the incidence of insulinoma is quite low compared to the general population (17), and there are few case reports in the medical literature on this subject (18). A retrospective study conducted at the Mayo Clinic reported only one case of insulinoma concomitant with diabetes among 313 cases recorded between 1927 and 1992 (19). Meanwhile, Ishii et al. reported only one diabetic patient among 443 cases of insulinoma (17, 20). Our current case is very rare in that, al- though the patient had diabetes mellitus with an HbA1c level of 15%, the subsequent onset of insulinoma-induced hypoglycemia may have been responsible for the dramatic improvement observed in the HbA1c value.
This report describes our experience in treating a mainte- nance dialysis patient with a history of diabetes mellitus who opted to undergo pharmacotherapy with diazoxide after developing insulinoma. In this case, we successfully adm