Clinical features of symptomatic hypoglycemia observed after bariatric surgery

Ketotic Hypoglycaemia Following Sleeve Gastrectomy

Post-bariatric surgery hypoglycaemia is typically mediated by hyperinsulinaemia, although the exact mechanisms are incompletely understood. Two cases of non-insulin mediated, ketotic hypoglycaemia following sleeve gastrectomy are presented. After fasting for 40 and 65 h, respectively, both patients developed symptomatic hypoglycaemia, with corresponding low insulin, low c-peptide and elevated beta-hydroxybutyrate levels. Morning cortisol and IGF1 levels were normal. Potential mechanisms for ketotic hypoglycaemia following bariatric surgery include reduction in hepatic, renal and intestinal gluconeogenesis, or alternatively an underlying inborn error of metabolism such as a glycogen storage disorder unmasked by bariatric surgery. Most glycogen storage disorders present in childhood, but there have been rare case reports of glycogen storage disorders types I, III and IX diagnosed in adulthood. Neither of the above cases had other features of a glycogen storage disorder such as elevated lactate, hyperuricaemia, hypertriglyceridaemia, hepatomegaly, myopathy or an indicative family history. Both patients trialled first-line dietary management, which was inadequate in managing hypoglycaemia. Treatment with the glucagon-like peptide-1 receptor agonist semaglutide resulted in the resolution of hypoglycaemic episodes in one patient, and a significant reduction in hypoglycaemic episodes in the other patient.

Postprandial hypoglycemia as a complication of bariatric and metabolic surgery: a comprehensive review of literature

Postprandial hypoglycemia (PPH) is a challenging and significant complication that can occur following bariatric and metabolic surgery. Symptoms of PPH are typical of hypoglycemia, such as sweating, weakness, disorientation, palpitation, etc. The complex nature of PPH is essential to achieve accurate diagnosis and effective management. This review aims to give extensive coverage of the intricate nature of PPH common with bariatric and metabolic surgery, outlining its pathogenesis, risk factors, clinical presentation, diagnostic strategies, and treatment options. The study explores various clinical forms and pathogenic mechanisms behind PPH while discussing diagnostic tools like continuous glucose monitoring or mixed meal tolerance tests. Furthermore, it considers possible interventions, including dietary changes, pharmaceutical therapies, and surgeries, to relieve symptoms and improve patient's quality of life. It aims to comprehensively understand how healthcare professionals can effectively manage this disorder for patients undergoing bariatric and metabolic surgery.

An Imbalance of Pathophysiologic Factors in Late Postprandial Hypoglycemia Post Bariatric Surgery: A Narrative Review

With a rise in obesity and more patients opting for bariatric surgery, it becomes crucial to understand associated complications like postprandial hypoglycemia (PPH). After bariatric surgery, significant changes are seen in insulin sensitivity, beta cell function, glucagon-like peptide 1 (GLP-1) levels, the gut microbiome, and bile acid metabolism. And in a small subset of patients, exaggerated imbalances in these functional and metabolic processes lead to insulin-glucose mismatch and hypoglycemia. The main treatment for PPH involves dietary modifications. For those that do not respond, medications or surgical interventions are considered to reverse some of the imbalances. We present a few case reports of patients that safely tolerated GLP-1 agonists. However, larger randomized control trials are needed to further characterize PPH and understand its treatment.

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.

Effects of a new 75 g glucose- and high fat-containing cookie meal test on postprandial glucose and triglyceride excursions in morbidly obese patients

A new meal tolerance test (MTT) using a 75 g glucose- and high fat-containing meal was applied to classify glucose intolerance in morbidly obese patients. According to the MTT data, the concordance rate of diagnosis was 82.5% compared to the 75 g oral glucose tolerance test (OGTT) in patients with normal glucose tolerance (NGT, n = 40). In the NGT patients, the insulinogenic index (r = 0.833), Matsuda index (r = 0.752), and disposition index (r = 0.845) calculated from the MTT data were each significantly (p < 0.001) correlated with those derived from the OGTT data. However, in patients with impaired glucose tolerance (IGT, n = 23) or diabetes mellitus (DM, n = 17), the postprandial glucose levels post-MTT were significantly lower than those post-OGTT, without increases in the postprandial insulin levels post-MTT. Thus, the severity of glucose intolerance measured by the MTT was milder than that indicated by the OGTT. Plasma levels of both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were increased at the postprandial state, but only the GIP levels post-MTT were significantly higher than those post-OGTT. The enhancement of glucose disposal rates in patients with NGT or IGT after the MTT was associated with increased GIP levels. The postprandial hypertriglyceridemia induced by the MTT was associated with insulin resistance, but it was not associated with the impaired insulinogenic index or the disposition index. These results indicate that the new MTT is clinically useful to evaluate both abnormal glucose and triglyceride excursions caused by abnormal insulin sensitivity and secretions of insulin and gut hormones in morbidly obese patients.

Evaluation and Management of Patients Referred for Post-Bariatric Surgery Hypoglycemia at a Tertiary Care Center

PURPOSE

Following bariatric surgery, patients can develop non-specific symptoms self-described as hypoglycemia. However, confirming hypoglycemia can be technically challenging, and therefore, these individuals are frequently treated empirically. This study aimed to describe what diagnostic evaluation and therapeutic interventions patients referred for post-bariatric surgery hypoglycemia undergo.

METHODS

Retrospective observational cohort study of patients with a history of bariatric surgery was evaluated for post-bariatric surgery hypoglycemia in a tertiary referral center from 2008 to 2017. We collected demographic and bariatric surgery information, clinical presentation of symptoms referred to as hypoglycemia, laboratory and imaging studies performed to evaluate these symptoms, and symptom management and outcomes.

RESULTS

A total of 60/2450 (2.4%) patients who underwent bariatric surgery were evaluated in the Department of Endocrinology for hypoglycemia-related symptoms. The majority were middle-aged women without type 2 diabetes who had undergone Roux-en-Y gastric bypass. Thirty-nine patients (65%) completed a biochemical assessment for hypoglycemia episodes. Six (10%) had confirmed hypoglycemia by Whipple's triad, and four (6.7%) met the criteria for post-bariatric surgery hypoglycemia based on clinical and biochemical criteria. All patients were recommended dietary modification as the initial line of treatment, and this intervention resulted in most patients reporting at least some improvement in their symptoms. Eight patients (13%) were prescribed pharmacotherapy, and two patients required additional interventions for symptom control.

CONCLUSIONS

In our experience, evaluation for hypoglycemia-related symptoms after bariatric surgery was rare. Hypoglycemia was confirmed in the minority of patients. Even without establishing a diagnosis of hypoglycemia, dietary changes were a helpful strategy for symptom management for most patients.

Symptomatic Hypoglycemia After Gastric Bypass: Incidence and Predictive Factors in a Cohort of 1,138 Consecutive Patients

OBJECTIVE

After Roux-en-Y gastric bypass (RYGB), postprandial hyperinsulinemic hypoglycemia (PPHH) is particularly critical because of the risk of trauma. The aim of this study was to assess the incidence and identify risk factors for symptomatic PPHH.

METHODS

Patients with RYGB were classified into moderate PPHH (MH) or severe hypoglycemia (SH), which is defined as patients with neuroglycopenic symptoms. Logistic multivariate linear regressions were performed to identify predictive factors for symptomatic PPHH and more specifically for SH with neuroglycopenic symptoms. Patients with diabetes and those with a follow-up shorter than 2 years were excluded.

RESULTS

Among the 1,138 patients, 44.2% had at least one episode of hypoglycemia with a mean delay of 25.5 (21.3) months, 32.6% had MH, and 11.6% had SH. The annual incidence rate of SH was 2.5% the first year, 3.7% the second year, and 1.5% the third year. Independent predictive factors for higher risk of SH were: younger age (odds ratio [OR] = 1.01; 95% CI: 1.05-16.69; P = 0.0007), lower BMI after RYGB (OR = 1.61; 95% CI: 1.17-2.22; P = 0.0035), and maximal weight loss (OR = 1.04; 95% CI = 1.39-1.23; P = 0.0106), whereas higher preoperative BMI was protective (OR = 0.78; 95% CI: 0.64-0.95; P = 0.0112).

CONCLUSIONS

This observational cohort study showed that the incidence of severe PPHH with neuroglycopenic symptoms after RYGB was higher than expected.

Insights from the Impact of Meal Composition on Glucose Profile Towards Post-bariatric Hypoglycemia Management

BACKGROUND/AIM

The need to improve post-bariatric hypoglycemia (PBH) diagnosis and clinical management is well recognized. Our aim was to evaluate the influence of meal nutritional composition on interstitial fluid glucose (IFG) profiles and symptom profile after Roux-en-Y gastric bypass (RYGB).

METHODS

Seventeen subjects previously submitted to RYGB were allocated into two groups of symptomatic (n = 9) or control individuals (n = 8), according to spontaneous report of symptoms suggestive of hypoglycemia. Subjects were provided with a food and symptom diary (FSD) to record dietary intake and symptoms experienced, while using a flash glucose monitoring (FGM) system for 14 days.

RESULTS

Postprandial symptom reports occurred in 70.5% of subjects (88.9% vs 50.0%, p = 0.0790, symptomatic vs control), although symptoms with concurrent IFG < 54 mg/dL and within 54 to 69 mg/dL were only observed in 31.9% and 4.8% of the events in the symptomatic vs control group, respectively (p = 0.0110). Daily glucose profiles, total energy, and macronutrients intake were not significantly different between the groups. However, nutritional composition of meals preceding reported symptoms had lower protein (3.2 g ± 1.0 g vs 7.7 g ± 0.5 g, p = 0.0286) or higher sugar (11.6 g ± 2.4 g vs 4.3 g ± 0.9 g, p = 0.0333) content.

CONCLUSIONS

Postprandial symptoms are often in patients after RYGB. Concurrent hypoglycemia only occurs in up to a third of the symptomatic episodes being more frequent in patients that spontaneously reported complaints. Hypoglycemia is more likely to be triggered by meals with a low protein or high sugar content. These findings highlight the putative role of meal composition in eliciting PBH and reinforce the need to refine nutritional intervention.