Cholecystectomy increases the risk of dumping syndrome and postbariatric hypoglycemia after bariatric surgery

The Impact of Cholecystectomy in Patients with Post-Bariatric Surgery Hypoglycemia

BACKGROUND

Metabolic surgery is the foremost treatment for obesity and its associated medical conditions. Nonetheless, post-bariatric hypoglycemia (PBH) emerges as a prevalent complication. PBH pathophysiology implicates heightened insulin and glucagon-like peptide 1 (GLP-1) levels, with bile acids (BA) contributing to GLP-1 release. A plausible association exists between cholecystectomy and PBH, which is attributed to alterations in BA metabolism and ensuing hormonal responses. The objective of this retrospective cohort study was to evaluate the impact of cholecystectomy on PBH pharmacological treatment, diagnostic timelines and metabolic parameters.

MATERIALS AND METHODS

Patients diagnosed with PBH after bariatric surgery were evaluated based on their history of cholecystectomy. Demographic, anthropometric and clinical data were collected. Mixed meal tolerance tests (MMTT) results were compiled to assess metabolic responses.

RESULTS

Of the 131 patients with PBH included in the study, 29 had prior cholecystectomy. The time to PBH diagnosis was similar across groups. Patients with prior cholecystectomy required higher doses of acarbose (p = 0.046), compared to those without prior cholecystectomy. Additionally, MMTT revealed higher insulin (t = 60 min: p = 0.010 and t = 90 min: p = 0.034) and c-peptide levels (t = 60 min: p = 0.008) and greater glycemic variability in patients with prior cholecystectomy (p = 0.049), highlighting the impact of cholecystectomy on glucose metabolism.

CONCLUSION

Our study offers novel insights into PBH pharmacotherapy, indicating that PBH patients with a history of cholecystectomy require elevated doses of acarbose for symptom control than PBH patients without such surgical history. Furthermore, our findings underscore the pivotal role of hyperinsulinism in PBH aetiology, emphasizing the significance of the BA-GLP-1-insulin axis.

Postbariatric surgery hypoglycemia: Nutritional, pharmacological and surgical perspectives

Post-bariatric hypoglycaemia (PBH) is a metabolic complication of bariatric surgery (BS), consisting of low post-prandial glucose levels in patients having undergone bariatric procedures. While BS is currently the most effective and relatively safe treatment for obesity and its complications, the development of PBH can significantly impact patients' quality of life and mental health. The diagnosis of PBH is still challenging, considering the lack of definitive and reliable diagnostic tools, and the fact that this condition is frequently asymptomatic. However, PBH's prevalence is alarming, involving up to 88% of the post-bariatric population, depending on the diagnostic tool, and this may be underestimated. Given the prevalence of obesity soaring, and an increasing number of bariatric procedures being performed, it is crucial that physicians are skilled to diagnose PBH and promptly treat patients suffering from it. While the milestone of managing this condition is nutritional therapy, growing evidence suggests that old and new pharmacological approaches may be adopted as adjunct therapies for managing this complex condition.

Diagnosis and management of post-bariatric surgery hypoglycemia

INTRODUCTION

While bariatric surgery remains the most effective treatment for obesity that allows substantial weight loss with improvement and possibly remission of obesity-associated comorbidities, some postoperative complications may occur. Managing physicians need to be familiar with the common problems to ensure timely and effective management. Of these complications, postoperative hypoglycemia is an increasingly recognized complication of bariatric surgery that remains underreported and underdiagnosed.

AREA COVERED

This article highlights the importance of identifying hypoglycemia in patients with a history of bariatric surgery, reviews pathophysiology and addresses available nutritional, pharmacological and surgical management options. Systemic evaluation including careful history taking, confirmation of hypoglycemia and biochemical assessment is essential to establish accurate diagnosis. Understanding the weight-dependent and weight-independent mechanisms of improved postoperative glycemic control can provide better insight into the causes of the exaggerated responses that lead to postoperative hypoglycemia.

EXPERT OPINION

Management of post-operative hypoglycemia can be challenging and requires a multidisciplinary approach. While dietary modification is the mainstay of treatment for most patients, some patients may benefit from pharmacotherapy (e.g. GLP-1 receptor antagonist); Surgery (e.g. reversal of gastric bypass) is reserved for unresponsive severe cases. Additional research is needed to understand the underlying pathophysiology with a primary aim in optimizing diagnostics and treatment options.

Continuous glucose monitoring in patients with post-bariatric hypoglycaemia reduces hypoglycaemia and glycaemic variability

AIM

To determine whether continuous glucose monitoring (CGM) can reduce hypoglycaemia in patients with post-bariatric hypoglycaemia (PBH).

MATERIALS AND METHODS

In an open-label, nonrandomized, pre-post design with sequential assignment, CGM data were collected in 22 individuals with PBH in two sequential phases: (i) masked (no access to sensor glucose or alarms); and (ii) unmasked (access to sensor glucose and alarms for low or rapidly declining sensor glucose). Twelve participants wore the Dexcom G4 device for a total of 28 days, while 10 wore the Dexcom G6 device for a total of 20 days.

RESULTS

Participants with PBH spent a lower percentage of time in hypoglycaemia over 24 hours with unmasked versus masked CGM (<3.3 mM/L, or <60 mg/dL: median [median absolute deviation {MAD}] 0.7 [0.8]% vs. 1.4 [1.7]%, P = 0.03; <3.9 mM/L, or <70 mg/dL: median [MAD] 2.9 [2.5]% vs. 4.7 [4.8]%; P = 0.04), with similar trends overnight. Sensor glucose data from the unmasked phase showed a greater percentage of time spent between 3.9 and 10 mM/L (70-180 mg/dL) (median [MAD] 94.8 [3.9]% vs. 90.8 [5.2]%; P = 0.004) and lower glycaemic variability over 24 hours (median [MAD] mean amplitude of glycaemic excursion 4.1 [0.98] vs. 4.4 [0.99] mM/L; P = 0.04). During the day, participants also spent a greater percentage of time in normoglycaemia with unmasked CGM (median [MAD] 94.2 [4.8]% vs. 90.9 [6.2]%; P = 0.005), largely due to a reduction in hyperglycaemia (>10 mM/L, or 180 mg/dL: median [MAD] 1.9 [2.2]% vs. 3.9 [3.6]%; P = 0.02).

CONCLUSIONS

Real-time CGM data and alarms are associated with reductions in low sensor glucose, elevated sensor glucose, and glycaemic variability. This suggests CGM allows patients to detect hyperglycaemic peaks and imminent hypoglycaemia, allowing dietary modification and self-treatment to reduce hypoglycaemia. The use of CGM devices may improve safety in PBH, particularly for patients with hypoglycaemia unawareness.

Late dumping syndrome preceded by Coxsackievirus B4 infection and cholecystectomy

A 44-year-old female patient presented with weight loss, diarrhea and intermittent episodes of left upper quadrant (LUQ) pain lasting for 3 years, accompanied by acute episodes of focal LUQ pain, dizziness, tachycardia, borborygmi and bloating, occurring approximately 60 min after meals. The patient developed chronic acalculous cholecystitis and transient exocrine pancreatic insufficiency after infection with Coxsackievirus B4 (CVB4), which resolved following laparoscopic cholecystectomy 2 years before the current presentation. Although imaging and functional investigation studies were unremarkable, a gastric transit study revealed rapid clearance of radiolabeled food, and the patient's symptomatology and gastrointestinal studies supported the diagnosis of late dumping syndrome. The patient's symptoms significantly improved with adherence to recommended dietary changes, including an increase in protein intake, abstinence from simple carbohydrates and avoidance of simultaneous consumption of beverages with food, following consultation with a dietitian.

Medical and surgical treatment of postbariatric hypoglycaemia: Retrospective data from daily practice

AIM

To evaluate medical and surgical treatment of postbariatric hypoglycaemia (PBH) in daily practice.

MATERIALS AND METHODS

Retrospective data were extracted from medical records from four hospitals. PBH was defined by neuroglycopenic symptoms together with a documented glucose <3.0 mmol/L in the postprandial setting after previous bariatric surgery. Data were scored semiquantitatively on efficacy and side effects by two reviewers independently. Duration of efficacy and of use were calculated.

RESULTS

In total, 120 patients were included with a median follow-up of 27 months with a mean baseline age of 41 years, total weight loss of 33% and glucose nadir 2.3 mmol/L. Pharmacotherapy consisted of acarbose, diazoxide, short- and long-acting octreotide and glucagon-like peptide-1 receptor agonist analogues (liraglutide and semaglutide) with an overall efficacy in 45%-75% of patients. Combination therapy with two drugs was used by 30 (25%) patients. The addition of a second drug was successful in over half of the patients. Long-acting octreotide and the glucagon-like peptide-1 receptor agonist analogues scored best in terms of efficacy and side effects with a median duration of use of 35 months for octreotide. Finally, 23 (19%) patients were referred for surgical intervention. Efficacy of the surgical procedures, pouch banding, G-tube placement in remnant stomach and Roux-en-Y gastric bypass reversal, pooled together, was 79% with a median duration of initial effect of 13 months.

CONCLUSIONS

In daily practice, pharmacotherapy for PBH was successful in half to three quarters of patients. Combination therapy was often of value. One in five patients finally needed a surgical procedure, with overall good results.

Glucose metabolism after bariatric surgery: implications for T2DM remission and hypoglycaemia

Although promising therapeutics are in the pipeline, bariatric surgery (also known as metabolic surgery) remains our most effective strategy for the treatment of obesity and type 2 diabetes mellitus (T2DM). Of the many available options, Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are currently the most widely used procedures. RYGB and VSG have very different anatomical restructuring but both surgeries are effective, to varying degrees, at inducing weight loss and T2DM remission. Both weight loss-dependent and weight loss-independent alterations in multiple tissues (such as the intestine, liver, pancreas, adipose tissue and skeletal muscle) yield net improvements in insulin resistance, insulin secretion and insulin-independent glucose metabolism. In a subset of patients, post-bariatric hypoglycaemia can develop months to years after surgery, potentially reflecting the extreme effects of potent glucose reduction after surgery. This Review addresses the effects of bariatric surgery on glucose regulation and the potential mechanisms responsible for both the resolution of T2DM and the induction of hypoglycaemia.

Medical Nutrition Therapy and Other Approaches to Management of Post-bariatric Hypoglycemia: A Team-Based Approach

PURPOSE OF REVIEW

This manuscript provides a review of post-bariatric hypoglycemia (PBH) with a special focus on the role of the registered dietitian-nutritionist (RDN) and medical nutrition therapy (MNT) recommendations as foundational for management.

RECENT FINDINGS

As the number of bariatric surgeries rises yearly, with 256,000 performed in 2019, PBH is an increasingly encountered late complication. Following Roux-en-Y (RYGB) or vertical sleeve gastrectomy (VSG), about 1/3 of patients report symptoms suggestive of at least mild postprandial hypoglycemia, with severe and/or medically confirmed hypoglycemia in 1-10%. Anatomical alterations, changes in GLP1 and other intestinally derived hormones, excessive insulin response, reduced insulin clearance, impaired counterregulatory hormone response to hypoglycemia, and other factors contribute to PBH. MNT is the cornerstone of multidisciplinary treatment, with utilization of personal continuous glucose monitoring to improve safety when possible. While many individuals require pharmacotherapy, there are no currently approved medications for PBH. Increasing awareness and identification of individuals at risk for or with PBH is critical given the potential impact on safety, nutrition, and quality of life. A team-based approach involving the individual, the RDN, and other clinicians is essential in providing ongoing assessment and individualization of MNT in the long-term management of PBH.

Pramlintide for post-bariatric hypoglycaemia

AIMS

The aim of this study was to examine the hypothesis that pramlintide would reduce hypoglycaemia by slowing gastric emptying and reducing postprandial glucagon secretion, thus limiting postprandial glycaemic excursions and insulin secretion, and thus to determine the efficacy of pramlintide on frequency and severity of hypoglycaemia in post-bariatric hypoglycaemia (PBH).

MATERIALS AND METHODS

Participants with PBH following gastric bypass were recruited from outpatient clinics at the Joslin Diabetes Center, Boston, Massachusetts for an open-label study of pramlintide efficacy over 8 weeks. Twenty-three participants were assessed for eligibility, 20 participants had at least one pramlintide dose, and 14 completed the study. A mixed-meal tolerance test (MMTT) was performed at baseline and after 8 weeks of subcutaneous pramlintide with a sequential dose increase to a maximum of 120 micrograms (mean 69 ± 32 mcg) three times daily. The primary endpoint was change in glucose excursions during the MMTT. Secondary measures included MMTT insulin response, satiety and dumping score, percentage time with sensor glucose (SG) <3.9 mM, and number of days with minimum SG <3 mM, during masked continuous glucose monitoring.

RESULTS

There were no differences in MMTT glucose, glucagon or insulin between baseline and post treatment. We observed no significant change in satiety or dumping scores. The overall frequency of low SG values did not change, although there was substantial inter-individual variability.

CONCLUSIONS

In PBH, pramlintide does not modulate glycaemic or insulin responses, satiety, or dumping scores during an MMTT and does not impact glycaemic excursions or decrease low SG levels in the outpatient setting.

Postbariatric hypoglycemia: symptom patterns and associated risk factors in the Longitudinal Assessment of Bariatric Surgery study

BACKGROUND

Postbariatric hypoglycemia (PBH) can be a devastating complication for which current therapies are often incompletely effective. More information is needed regarding frequency, incidence, and risk factors for PBH.

OBJECTIVES

To examine hypoglycemia symptoms following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB) and baseline and in-study risk factors.

SETTING

Multicenter, at 10 US hospitals in 6 geographically diverse clinical centers.

METHODS

A prospective, longitudinal cohort study of adults undergoing RYGB or LAGB as part of clinical care between 2006 and 2009 were recruited and followed until January 31, 2015, with baseline and annual postoperative research assessments. We analyzed baseline prevalence and post-operative incidence and frequency of self-reported hypoglycemia symptoms as well as potential preoperative risk factors.

RESULTS

In all groups, postoperative prevalence of hypoglycemia symptoms was 38.5%. Symptom prevalence increased postoperatively from 2.8%-36.4% after RYGB in patients without preoperative diabetes (T2D), with similar patterns in prediabetes (4.9%-29.1%). Individuals with T2D had higher baseline hypoglycemia symptoms (28.9%), increasing after RYGB (57.9%). Hypoglycemia symptoms were lower after LAGB, with 39.1% reported hypoglycemia symptoms at only 1 postoperative visit with few (4.0%) having persistent symptoms at 6 or more annual visits. Timing of symptoms was not restricted to the postprandial state. Symptoms of severe hypoglycemia were reported in 2.6-3.6% after RYGB. The dominant risk factor for postoperative symptoms was preoperative symptoms; additionally, baseline selective serotonin (SSRI) and serotonin-norepinephrine (SNRI) reuptake inhibitor use was also associated with increased risk in multivariable analysis. Weight loss and regain were not related to hypoglycemia symptom reporting.

CONCLUSION

Hypoglycemia symptoms increase over time after RYGB, particularly in patients without diabetes. In a small percentage, symptoms can be persistent or severe and require hospitalization. Preoperative hypoglycemia symptoms and SSRI/SNRI use in RYGB patients without diabetes is associated with increased risk of symptoms.

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

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.

Altered bile acid kinetics contribute to postprandial hypoglycaemia after Roux-en-Y gastric bypass surgery

BACKGROUND/OBJECTIVES

Bile acids (BA) act as detergents in intestinal fat absorption and as modulators of metabolic processes via activation of receptors such as FXR and TGR5. Elevated plasma BA as well as increased intestinal BA signalling to promote GLP-1 release have been implicated in beneficial health effects of Roux-en-Y gastric bypass surgery (RYGB). Whether BA also contribute to the postprandial hypoglycaemia that is frequently observed post-RYGB is unknown.

METHODS

Plasma BA, fibroblast growth factor 19 (FGF19), 7α-hydroxy-4-cholesten-3-one (C4), GLP-1, insulin and glucose levels were determined during 3.5 h mixed-meal tolerance tests (MMTT) in subjects after RYGB, either with (RYGB, n = 11) or without a functioning gallbladder due to cholecystectomy (RYGB-CC, n = 11). Basal values were compared to those of age, BMI and sex-matched obese controls without RYGB (n = 22).

RESULTS

Fasting BA as well as FGF19 levels were elevated in RYGB and RYGB-CC subjects compared to non-bariatric controls, without significant differences between RYGB and RYGB-CC. Postprandial hypoglycaemia was observed in 8/11 RYGB-CC and only in 3/11 RYGB. Subjects who developed hypoglycaemia showed higher postprandial BA levels coinciding with augmented GLP-1 and insulin responses during the MMTT. The nadir of plasma glucose concentrations after meals showed a negative relationship with postprandial BA peaks. Plasma C4 was lower during MMTT in subjects experiencing hypoglycaemia, indicating lower hepatic BA synthesis. Computer simulations revealed that altered intestinal transit underlies the occurrence of exaggerated postprandial BA responses in hypoglycaemic subjects.

CONCLUSION

Altered BA kinetics upon ingestion of a meal, as frequently observed in RYGB-CC subjects, appear to contribute to postprandial hypoglycaemia by stimulating intestinal GLP-1 release.

Hypoglycemia After Upper Gastrointestinal Surgery: Clinical Approach to Assessment, Diagnosis, and Treatment

CONTEXT

Post-bariatric hypoglycemia (PBH) is an increasingly encountered complication of upper gastrointestinal surgery; the prevalence of this condition is anticipated to rise given yearly increases in bariatric surgical procedures. While PBH is incompletely understood, there is a growing body of research describing the associated factors, mechanisms, and treatment approaches for this condition.

EVIDENCE ACQUISITION

Data are integrated and summarized from studies of individuals affected by PBH and hypoglycemia following upper gastrointestinal surgery obtained from PubMed searches (1990-2020).

EVIDENCE SYNTHESIS

Information addressing etiology, incidence/prevalence, clinical characteristics, assessment, and treatment were reviewed and synthesized for the practicing physician. Literature reports were supplemented by clinical experience as indicated, when published data were not available.

CONCLUSION

PBH can be life-altering and severe for a subset of individuals. Given the chronic nature of this condition, and sequelae of both acute and recurrent episodes, increasing provider awareness of both the condition and associated risk factors is critical for assessment, prompt diagnosis, treatment, and preoperative identification of individuals at risk.