Postprandial Symptoms in a Mixed-Meal-Test after Bariatric Surgery: Clinical Experience and a Critical Review of Dumping Syndrome Definition and Management.

Introduction: Despite recent attempts to reach a consensus on the diagnostic criteria and treatment of dumping syndrome (DS) after bariatric surgery, many questions about the clinical applicability and significance of standardized provocation tests remain unanswered. The objective of this study was to retrospectively evaluate a mixed-meal-test (MMT) based on general nutritional recommendations after bariatric surgery and its clinical value in diagnosing DS.

Methods: The MMT contained 15.5 g of protein, 10 g of fat, 20.7 g of carbohydrates, and 3.1 g of dietary fiber, totaling 241 kcal. Symptoms based on the Sigstad Score, along with blood sugar, hematocrit, pulse rate, and blood pressure, were collected as primary readouts. The analysis included 58 MMTs from 56 patients who reported postprandial symptoms indicative of DS and were referred to the clinic by surgeons or general practitioners.

Results: Although all individuals reported significant symptoms at home, the MMT showed a positive symptom score (Sigstad Score ≥7) in only 16 cases (28%). Neither a heart rate increase >10 BPM nor the 3% hematocrit increase suggested as cut-offs for early DS by the consensus paper were associated with the Sigstad Score or individually reported symptoms. None of the participants had a postprandial glucose decrease below 50 mg/dL; one fell below 60 mg/dL and 14 fell below 70 mg/dL. A blood glucose decrease below 70 mg/dL was not associated with symptoms.

Conclusion: The MMT showed that only a minority of patients reported classical DS symptoms under controlled conditions. Changes in hematocrit, heart rate, and blood sugar decrease below 70 mg/dL did not help to predict symptoms in the individuals studied. The data, in the context of existing evidence, suggest that provocation tests have little value in clinical practice and that DS as a clinical entity after bariatric surgery should be reevaluated.