Hypoglycemic loss of consciousness due to postprandial reactive hypoglycemia in a severely obese woman with prediabetes: a case report

UNLABELLED: Despite the increasing number of patients diagnosed with postprandial reactive hypoglycemia (PRH), standardized diagnostic criteria and evaluation methods have not been established. Since PRH is generally defined as "hypoglycemia occurring due to elevated endogenous insulin levels following a high-carbohydrate meal in people without diabetes mellitus", prediabetes is considered one of the obvious pathologies of PRH. However, it has recently been reported that early diabetes can enter a state of "remission"; therefore, it is difficult to distinguish between prediabetes and early diabetes. We present a case of PRH in an obese woman with prediabetes, identified through oral glucose tolerance testing and continuous glucose monitoring. She experienced severe hypoglycemia, which sometimes resulted in loss of consciousness. However, her PRH symptoms were effectively treated with an α-glucosidase inhibitor. We believe it would be beneficial for clinicians to study this case, as it clearly demonstrates a pathology of PRH in a patient with prediabetes and/or early diabetes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at https://doi.org/10.1007/s13340-026-00927-0.