283-LB: The Differential Effect of Gastric Bypass vs. Sleeve Gastrectomy on Prandial Symptoms of Hypoglycemia and Dumping Syndrome

Gastric bypass surgery (GB), and to lesser degree sleeve gastrectomy (SG), predispose to prandial hypoglycemia. Diagnosis is challenging since hypoglycemic symptoms overlap with those of dumping syndrome. Here, we sought to determine whether symptoms distribution after meal challenge differ among GB vs. SG or non-operated controls (CN), and between GB with and without documented hypoglycemia syndrome as per Whipple's triad. Plasma glucose and prandial symptoms were obtained every 15 min during a 3-h mixed-meal test in matched, non-diabetic groups of 11 hypoglycemic-GB (HGB), 18 asymptomatic-GB (AGB), 24 SG and 5 CN. Symptoms were stratified into autonomic (breathlessness, fatigue, sleepiness, palpitation, restlessness, dizziness, shaking, sweating, feeling warm) and neuroglycopenic (fainting or syncope, impaired cognition, irritability, seizure), and gastrointestinal (GI) symptoms. Peak-to-nadir glycemic excursion was higher in GB vs. SG vs. CN (137±8.0 vs. 86.6±6.0 vs. 48.6±9.1 mg/dl, respectively, P < 0.001). GI symptoms were experienced mainly within first 60 minutes of meal study in all 4 groups (P < 0.001 for time factor), and their average score was higher in GB compared with SG (by 2-fold) and CN subjects (by 14-fold, P < 0.01 for group factor). Likewise, autonomic symptoms were most prevalent during the early phase of the meal (P < 0.05), and their average score tended to be higher in GB compared with SG (by 2-fold) and CN subjects (by 5-fold, P = 0.06 for group factor). Neither GI nor autonomic symptom scores differed among HGB and AGB. Given the low rate of chemical hypoglycemia, neuroglycopenic symptoms were rare and not different among the groups. We conclude that the majority of autonomic symptoms, often mistaken for hypoglycemia, occur in early prandial phase and are not different among GB with and without documented hypoglycemia syndrome. Thus, presence of neuroglycopenia is critical in diagnosis of clinical hypoglycemia in this population.