Postbariatric hypoglycemia (PBH) is a complication of bariatric surgery, mainly Roux-en-Y bypass (GB) . Surgery-induced changes in the gastrointestinal anatomy affect nutrient passage, absorption kinetics and may contribute to PBH. Here we aim to explore early postprandial glucose turnover in GB subjects with confirmed PBH vs. unaffected operated and non-operated controls. A total of 32 subjects (age = 48 [32,53] y, BMI = 29 [25,32] kg/m2; median [IQR]) , belonging to 4 matched (age/BMI/sex) groups (GB with PBH [GB-PBH] and unaffected [GB], sleeve gastrectomy [SG] and non-operated controls [C]) , ingested 15g of labeled [U-13C]-glucose (t=0 min) , 100 min after initiation of a primed constant infusion (30 μg/kg/min) of [6,6-2H2]-glucose. Plasma glucose and enrichments were measured, allowing the calculation of postprandial glucose fluxes, i.e. rates of meal glucose appearance (Rameal) , endogenous glucose production (EGP) and glucose disappearance (Rd) , together with insulin concentration. iAUC (0-20 min) of plasma glucose was significantly higher in both GB groups than C (GB-PBH: 36 [29,38], GB: 38 [31,40], C: 9 [17,19] mmol/L*min; p<0.01) . This was also the case for Rameal normalized to glucose dose (GB-PBH: 39 [34,42], GB: 42 [35,44], C: 20 [16,27] %; p<0.03) and Rd normalized to basal (GB-PBH: 56 [19,83], GB: 65 [54,76], C: -8 [-20,21] %; p<0.03) but not EGP, which was similarly suppressed in all groups. Finally, iAUC (0-20 min) of plasma insulin was significantly higher in GB and SG than C (GB: 657 [534,826], SG: 563 [351,822], C: 265 [192,310] μU/mL*min; p<0.03) while GB-PBH failed to reach significance (477 [384,631] μU/mL; p=0.06) . After a small dose (15g) of oral glucose, early postprandial glucose exposure, Rameal and Rd were faster in GB subjects than C, while insulin exposure was higher in almost all operated groups vs. C. However, no difference between GB groups was observed, underscoring the multifactorial etiology of PBH.


M.Schiavon: None. A.Tripyla: None. D.Herzig: None. A.Thomas: None. L.Bally: None. C.Dalla man: Research Support; Becton, Dickinson and Company, Sanofi-Aventis Deutschland GmbH.


MIUR (Italian Minister for Education) under the initiative "Departments of Excellence" (Law 232/2016) and Swiss National Science Foundation (SNSF) PCEGP3_186978

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