Dumping Syndrome and Postbariatric Hypoglycemia: Supporting Evidence for a Common Etiology

Surg Obes Relat Dis. 2021 Nov;17(11):1912-1918. doi: 10.1016/j.soard.2021.05.020. Epub 2021 May 19.


Background: Dumping syndrome (DS) and postbariatric hypoglycemia (PBH) are frequent complications of bariatric surgery. Previously known as "early and late dumping," these complications have been separated due to differences in their onset and behaviors.

Objectives: To investigate a potentially common etiology of DS and PBH using an analysis of a mixed meal test (MMT) study.

Setting: A large teaching hospital in the Netherlands.

Methods: From all patients who underwent bariatric surgery in 2008-2011, a random selection completed an MMT (n = 47). Patients scored complaints related to DS and PBH with a standardized questionnaire at several time intervals. The groups were divided into patients with (DS+; n = 22) and without (DS-; n = 25) an increase in DS symptoms after the start of the MMT. Glucose and gut hormone levels were compared. Hypoglycemia was defined as a blood glucose level below 3.3 mmol/L.

Results: The DS+ group had lower blood glucose values compared to the DS- group, which reached significance at 90 and 120 minutes (P < .05). For the DS+ group, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and satiety were higher at various time intervals (P < .05) compared to the DS- group. No differences were found for insulin and hunger score. GLP-1 and PYY were correlated with symptoms of DS.

Conclusion: Patients with DS complaints had lower postprandial glucose values. GLP-1 and PYY values were elevated in the DS+ group early and late during the test. These hormones also correlated with DS. These findings support the hypothesis of a common etiology of DS and PBH and a role of GLP-1 and PYY in both complications.

Keywords: Bariatric surgery; Dumping syndrome; GLP-1; Gastric bypass; PYY; Postbariatric hypoglycemia.

MeSH terms

  • Bariatric Surgery* / adverse effects
  • Blood Glucose
  • Dumping Syndrome / etiology
  • Gastric Bypass*
  • Humans
  • Hypoglycemia* / etiology
  • Obesity, Morbid* / surgery
  • Peptide YY


  • Blood Glucose
  • Peptide YY