Endocrine Abstracts (2018) 56 P576 | DOI: 10.1530/endoabs.56.P576

Prevalence and pathophysiology of early dumping in patients after primary Roux-en-Y gastric bypass during a mixed meal tolerance test

Ragnild Wijma1, Marloes Emous1, Erik Totté1, Merel van den Broek2, Albert Wolthuis3, Anke Laskewitz3, Anneke Muller-Kobold4, Bruce Wolffenbuttel5 & André van Beek5


1Department of Bariatric and Metabolic Surgery, Heelkunde Friesland Groep, Medical Center Leeuwarden, Leeuwarden, Netherlands; 2Department of Endocrinology, Medical Center Leeuwarden, Leeuwarden, Netherlands; 3Certe Laboratories, Medical Center Leeuwarden, Leeuwarden, Netherlands; 4Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, Netherlands; 5Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands.


Introduction: The endocrinologist is confronted with an increasingly large population of postbariatric patients who present with endocrine problems. One of these is early dumping, a complication that may be the result of increased entero-endocrine activity. To address the prevalence of early dumping and to gain further insight into its pathophysiology, we performed a Mixed Meal Tolerance Test (MMTT) in a random sample of patients after Roux-en-Y gastric bypass (RYGB).

Methods: A random sample of 140 patients who underwent primary RYGB surgery between 2008 and 2011 were invited to participate. In total, 46 patients completed the MMTT with a standardized liquid supplement. The Dumping Severity Score (DSS) for early dumping was assessed every 30 minutes. Blood samples were collected at baseline, every 10 min during the first half hour and at 60 min after the start. The samples were assessed for hematocrit and glucagon-like-peptide-1 (GLP-1), Peptide YY (PYY), and vasoactive intestinal peptide (VIP).

Results: The prevalence of a high suspicion of early dumping based on the DSS was 26%. There was no difference in blood pressure and heart rate between patients with high or low suspicion of early dumping. The percentual change in hematocrit was slightly higher in patients with high suspicion of early dumping. No differences were seen for inactive GLP-1 and VIP between patients with high or low suspicion of early dumping. Patients with high suspicion of early dumping had higher levels of active GLP-1 and PYY.

Conclusion: The prevalence of complaints suggestive of early dumping in a random population of patients at mid-term post-RYGB is 26 percent in response to a mixed meal. Postprandial increases in both GLP-1 and PYY are associated with complaints of early dumping, suggesting gut L-cell overactivity in this syndrome.