Late dumping K91.1

In 1913, Hertz first described the relationship between postprandial symptoms and rapid gastric emptying after gastric surgery. The term "dumping" was coined by Wyllys et al. in 1920 for patients with typical symptoms after gastrectomy (Mala 2015).

In late dumping, symptoms of hypoglycemia occur approximately 1 ½ - 3 h after eating (Herold 2022) in patients undergoing gastric or esophageal surgery (Scarpellini 2020).

At the 2020 Delphi consensus process with international multidisciplinary experts, an international consensus on the diagnosis and treatment of dumping syndrome was established for the first time (Scarpellini 2020).

Dumping syndrome (DS [Rindel 2018]) is divided into early and late dumping. Both can occur together or individually (Scarpellini 2020).

After gastric surgery, dumping syndrome is one of the most common complaints (Mala 20150). Late dumping occurs significantly less frequently than early dumping (Herold 2022).

It occurs preferentially after bariatric surgery such as Roux- en- Y- gastric bypass (RYGB) and sleeve gastrectomy at 34.2% (Scarpellini 2020).

After bariatric surgery, the oral glucose tolerance test showed a prevalence of late dumping of 72%; after a liquid mixed-meal test, this was 29%. Inpatient treatment for hypoglycemia was required in only 0.2% of bariatric surgery patients (Smajis 2018).

Five years after gastric resection, Mala (2015) found late dumping in 38% of patients.

Late dumping is caused by reactive hypoglycemia (Herold 2022).

Symptoms of late dumping are related to neuroglycopenia and autonomic and/or adrenergic response. The key mediator of late dumping is an exaggerated response of incretins such as GLP1 (Scarpelli 2020).

After ingestion of carbohydrates, there is a rapid shift of glucose concentration to the ileum with hyperinsulinemic response and subsequent reactive hypoglycemia (Scarpellini 2020). However, the complete pathophysiology has not yet been fully elucidated (van de Felde 2021).

Up to 10-fold increased p. p. concentrations of GIP and GLP- 1 have been found in bariatric surgery patients. It is assumed that the highly elevated insulin levels in these patients result from the greatly increased secretion of incretin. Hyperinsulinemia is not observed after i. v. glucose administration (Smajis 2018).

Symptoms of reactive hypoglycemia usually do not occur until 3 - 12 months after bariatric surgery. The reason for this is thought to be the increase in insulin sensitivity with increasing weight loss (Scarpellini 2020).

If the pylorus remains intact during surgery, dumping syndrome does not occur, as the ingested food then continues to be released into the small intestine in small quantities (Felsenreich 2021).

After bariatric surgery, it usually takes between 3 - 12 months for symptoms of late dumping to appear for the first time, although the threshold for symptomatology in hypoglycemia is individual (Mala 2015).

There may be p. p. following symptoms in reactive hypoglycemia such as:

- Sweating

- ravenous hunger

- restlessness

- Feeling of weakness (Herold 2022)

- diaphoresis

- palpitations

- tachycardias

- Syncope (Kasper 2015)

- tremor (Mala 20150)

The diagnosis is made on the basis of:

- Detailed medical history

- Oral glucose tolerance test (oGTT)

Nowadays, the modified oral glucose tolerance test is the preferred method for diagnosis. It typically results in a hypoglycemic- nadir value < 50 mg/dl (< 2.8 mmol / l) 1 ½ to 3 h p. p. (Herold 2022).

- Mixed Meal Tolerance Test (MMTT).

This is a liquid test in which proteins and lipids are fed in addition to glucose (Smajis 2018).

Smajis (2018) attributes a higher diagnostic value to the Mixed- Meal- Test, because in the oral glucose tolerance test even healthy individuals show blood glucose values of < 55 mg / dl in about 10%. This may also explain the high difference in prevalence of 72 %: 29 % between the two tests. Smajis therefore considers the oral glucose tolerance test inappropriate in V. a. a postbariatric hypoglycemia. However, no standardized and accepted meal test exists to date.

To improve symptoms,:

- fast absorbing carbohydrates should be eliminated from the diet (Scarpellini 2020)

- the diet should be high in protein and low in carbohydrates

- consist of frequent small meals (Herold 2022)

- the food should be chewed slowly and well (Scarpellini 2020)

The patient should consume a smaller amount of carbohydrate approximately 3 h after a meal has taken place (Herold 2022).

A double-blind crossover study by Craig (2016) demonstrated that i.v. infusion of the GLP-1 receptor antagonist exendin-4 can prevent 100% of reactive hypoglycemia and normalize beta-cell function (Craig 2016).

- Acarbose:

- inhibits glucose absorption

- reduces gastrointestinal hormone release

- reduces the occurrence of hypoglycemia

Dosage recommendation: 50 - 100 mg 3 x / d with meals (Scarpellini 2020).

- Diazoxide:

Diazoxide inhibits insulin secretion by opening ATP-sensitive potassium channels in beta cells, thus preventing reactive hypoglycemia.

However, only quantitatively small multicenter, retrospective, systematic case series exist to date showing symptomatic improvement with diazoxide (Scarpellini 2020).

Dosage recommendation: 150 mg 3 x / d (Patti 2005).

- Dasiglucagon:

Dasiglucagon is a potentially new therapeutic agent. The randomized, double-blind, placebo-controlled crossover study by Nielsen et al., published only in 2022, shows that single-dose treatment with 80 µg or 200 µg effectively attenuates late dumping in patients with e.g. RYGB surgery.

Dosage Recommendation:

- Single dose dasiglucagon 80 µg achieves a significant 70- min reduction in hypoglycemia < 3.9 mmol / l.

- Single dose dasiglucagon 200 µg achieves a significant 70- minute reduction in hypoglycemia < 3.9 mmol / l and complete prevention of hypoglycemia < 3.9 mmol / l without subsequent hyperglycemia (Nielsen 2022).

Patients in whom bariatric surgery is required and whose occupation does not allow dumping syndrome in any case, especially hypoglycemia such as professional drivers, should receive a surgical procedure in which the pylorus is preserved. Only if the pylorus is preserved can the ingested food continue to be delivered in small quantities into the small intestine (Felsenreich 2021).

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