Defining and Characterizing Postprandial Reactive Hypoglycemia

<i>Objective:</i> Individuals with reactive hypoglycemia (RH) may be more likely to develop obesity and type 2 diabetes, but the ability to identify RH has been hampered by the lack of clear criteria. This study used calculus-based curve parameters from a mixed macronutrient liquid meal test (MMTT) to define RH in men and women with obesity. <i>Methods:</i> A total of 69 non-diabetic adults aged 35 ± 8.3 years with obesity (BMI 32.3 ± 4.2 kg/m²) underwent a 4 h MMTT to define RH, and an intravenous glucose tolerance test (IVGTT) to characterize RH (via insulin sensitivity, the acute insulin response to glucose (AIRg), insulin clearance, and the disposition index). Perceived hunger and fullness were assessed by visual analog scale. <i>Results:</i> RH was defined using curve properties of the MMTT. A total of 19 of the 69 participants had a reactive hypoglycemic response to the MMTT. Glucose AUC and nadir were lower, timing of glucose nadir was earlier, and insulin sensitivity was higher in RH compared to non-RH. Sex (female) and race (AA) were significant predictors of RH presence. <i>Conclusions:</i> Among individuals with obesity, RH is characterized by greater sensitivity to insulin and greater disposition index. We introduce a novel and reproducible method to define RH using curve-based criteria from a mixed meal test integrated with gold-standard IVGTT-derived outcomes.