Pancreatic exocrine insufficiency after bariatric surgery

Long-term systemic effects of metabolic bariatric surgery: A multidisciplinary perspective

Background

Obesity is a global health crisis with profound implications on various body systems, contributing to a series of comorbidities. Metabolic Bariatric Surgery (MBS) has emerged as an effective treatment option for severe obesity, with significant weight reduction and potential systemic physiological alterations.

Objectives

This narrative review aims to provide a comprehensive analysis of the long-term effects of MBS on a wide array of body systems, including the heart, liver, kidneys, reproductive system, skin, lungs, digestive tract, pancreas, and blood, as well as related cancers of these organs.

Methods

A systematic search was conducted in academic databases (PubMed, ISI Web of Science, and Scopus) for observational studies and reviews published between July 2000 and December 2023, investigating the association between MBS and the subsequent function of different organ systems. High-quality studies were prioritized to ensure reliable evidence synthesis.

Results

MBS has demonstrated favorable outcomes in reducing cardiovascular disease risk, improving cardiac function, and alleviating heart failure symptoms. It has also been associated with improved respiratory function, remission of obstructive sleep apnea, and reduced cancer incidence and mortality. Additionally, MBS has shown benefits in managing gastrointestinal disorders, enhancing glycemic control, and promoting pancreatic beta-cell regeneration in type 2 diabetes mellitus. However, some methods of MBS are associated with a higher risk of cholelithiasis, GERD, and pancreatic exocrine insufficiency.

Conclusion

MBS has far-reaching systemic effects beyond weight loss, offering potential long-term benefits for various organ systems and comorbidities associated with obesity. For many patients with severe obesity, the potential benefits of Metabolic and Bariatric Surgery (MBS) can outweigh the associated risks. However, careful evaluation by a qualified healthcare professional is crucial to determine candidacy and ensure a successful outcome. Further research is needed to fully elucidate the long-term impacts and tailor personalized treatment approaches.

Pancreatic exocrine insufficiency after non-pancreatic upper gastrointestinal surgery: meta-analysis

BACKGROUND

Untreated pancreatic exocrine insufficiency (PEI) results in substantial patient harm. Upper gastrointestinal surgery (bariatric metabolic surgery and oesophagogastric resection) affects the delicate physiology of pancreatic exocrine function and may result in PEI. The aim of this study was to assimilate the literature on incidence, diagnosis, and management of PEI after bariatric metabolic surgery and oesophagogastric resection.

METHODS

A systematic review of PubMed, MEDLINE, and Embase databases identified studies investigating PEI after non-pancreatic upper gastrointestinal surgery. Meta-analyses were undertaken for incidence of PEI and benefit of pancreatic enzyme replacement therapy.

RESULTS

Among 1620 patients from 24 studies included in quantitative synthesis, 36.0% developed PEI. The incidence of PEI was 23.0 and 50.4% after bariatric metabolic surgery and oesophagogastric resection respectively. Notably, the incidence of PEI was 44% after biliopancreatic diversion with duodenal switch and 66.2% after total gastrectomy. The most common diagnostic test used was faecal elastase 1 (15 of 31 studies), with less than 200 µg/g being diagnostic of PEI. A total of 11 studies considered the management of pancreatic exocrine insufficiency, with 78.6% of patients responding positively to pancreatic enzyme replacement when it was prescribed.

CONCLUSION

PEI is common after non-pancreatic upper gastrointestinal surgery and patients may benefit from enzyme replacement therapy.

AGA Clinical Practice Update on the Epidemiology, Evaluation, and Management of Exocrine Pancreatic Insufficiency: Expert Review

DESCRIPTION

Exocrine pancreatic insufficiency (EPI) is a disorder caused by the failure of the pancreas to deliver a minimum/threshold level of specific pancreatic digestive enzymes to the intestine, leading to the maldigestion of nutrients and macronutrients, resulting in their variable deficiencies. EPI is frequently underdiagnosed and, as a result, patients are often not treated appropriately. There is an urgent need to increase awareness of and treatment for this condition. The aim of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review was to provide Best Practice Advice on the epidemiology, evaluation, and management of EPI.

METHODS

This Expert Review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. These Best Practice Advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these Best Practice Advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: EPI should be suspected in patients with high-risk clinical conditions, such as chronic pancreatitis, relapsing acute pancreatitis, pancreatic ductal adenocarcinoma, cystic fibrosis, and previous pancreatic surgery. BEST PRACTICE ADVICE 2: EPI should be considered in patients with moderate-risk clinical conditions, such as duodenal diseases, including celiac and Crohn's disease; previous intestinal surgery; longstanding diabetes mellitus; and hypersecretory states (eg, Zollinger-Ellison syndrome). BEST PRACTICE ADVICE 3: Clinical features of EPI include steatorrhea with or without diarrhea, weight loss, bloating, excessive flatulence, fat-soluble vitamin deficiencies, and protein-calorie malnutrition. BEST PRACTICE ADVICE 4: Fecal elastase test is the most appropriate initial test and must be performed on a semi-solid or solid stool specimen. A fecal elastase level <100 μg/g of stool provides good evidence of EPI, and levels of 100-200 μg/g are indeterminate for EPI. BEST PRACTICE ADVICE 5: Fecal elastase testing can be performed while on pancreatic enzyme replacement therapy. BEST PRACTICE ADVICE 6: Fecal fat testing is rarely needed and must be performed when on a high-fat diet. Quantitative testing is generally not practical for routine clinical use. BEST PRACTICE ADVICE 7: Response to a therapeutic trial of pancreatic enzymes is unreliable for EPI diagnosis. BEST PRACTICE ADVICE 8: Cross-sectional imaging methods (computed tomography scan, magnetic resonance imaging, and endoscopic ultrasound) cannot identify EPI, although they play an important role in the diagnosis of benign and malignant pancreatic disease. BEST PRACTICE ADVICE 9: Breath tests and direct pancreatic function tests hold promise, but are not widely available in the United States. BEST PRACTICE ADVICE 10: Once EPI is diagnosed, treatment with pancreatic enzyme replacement therapy (PERT) is required. If EPI is left untreated, it will result in complications related to fat malabsorption and malnutrition, having a negative impact on quality of life. BEST PRACTICE ADVICE 11: PERT formulations are all derived from porcine sources and are equally effective at equivalent doses. There is a need for H2 or proton pump inhibitor therapy with non-enteric-coated preparations. BEST PRACTICE ADVICE 12: PERT should be taken during the meal, with the initial treatment of at least 40,000 USP units of lipase during each meal in adults and one-half of that with snacks. The subsequent dosage can be adjusted based on the meal size and fat content. BEST PRACTICE ADVICE 13: Routine supplementation and monitoring of fat-soluble vitamin levels are appropriate. Dietary modifications include a low-moderate fat diet with frequent smaller meals and avoiding very-low-fat diets. BEST PRACTICE ADVICE 14: Measures of successful treatment with PERT include reduction in steatorrhea and associated gastrointestinal symptoms; a gain of weight, muscle mass, and muscle function; and improvement in fat-soluble vitamin levels. BEST PRACTICE ADVICE 15: EPI should be monitored and baseline measurements of nutritional status should be obtained (body mass index, quality-of-life measure, and fat-soluble vitamin levels). A baseline dual-energy x-ray absorptiometry scan should be obtained and repeated every 1-2 years.

Assessment of Exocrine Pancreatic Function Following Bariatric/Metabolic Surgery: a Prospective Cohort Study

BACKGROUND

Exocrine pancreatic insufficiency (EPI) can be seen after bariatric/metabolic surgery. Fecal elastase level is a simple test in diagnosing and grading EPI. Quality of life changes in patients with bariatric/metabolic surgery related to gastrointestinal complaints is debated.

AIM

This study aimed to investigate rates and grades of EPI via fecal elastase levels and association between EPI and quality of life in bariatric surgery patients.

METHODS

A prospective study was performed for patients with bariatric/metabolic surgery at their second-year follow-up. Fecal elastase levels were used to diagnose and grade EPI as severe or moderate. Patient's gastrointestinal quality of life index (GIQLI) was calculated. Patients were grouped as sleeve gastrectomy (SG), one-anastomosis gastric bypass (OAGB), single-anastomosis sleeve ileal bypass (SASI), and transit bipartition (TB). Rates of severe or moderate EPI were primary outcome. Secondary outcome was an association between fecal elastase and GIQLI.

RESULTS

There were 17, 29, 21, and 15 patients in OAGB, SG, TB, and SASI groups. There was no significant difference between groups in GIQLI scores and fecal elastase levels (p = 0.152 and p = 0.361). Rates of patients with moderate EPI in the groups OAGB, SG, TB, and SASI were 23.5%, 17.2%, 14.3%, and 20.0%. GIQLI scores were not significantly correlated with age, postoperative morphometric data, and fecal elastase values (p > 0.05).

CONCLUSION

Rates of patients with moderate EPI ranged from 14.3 to 23.5% at second-year follow-up. There was no patient with severe EPI. GIQLI scores were not significantly correlated with fecal elastase levels and different types of bariatric/metabolic surgery.

Abbreviated 13C-mixed triglyceride breath test for detection of pancreatic exocrine insufficiency performs equally as standard 5-hour test in patients after gastrectomy performed for gastric cancer

BACKGROUND

¹³C-mixed triglyceride breath test (¹³C-MTGT) is a non-invasive test for the detection of moderate and severe pancreatic exocrine insufficiency (PEI), but it requires prolonged breath sampling. The aim of this study was to determine the diagnostic power of abbreviated ¹³C-MTGT in detecting PEI in patients after subtotal and total gastrectomy performed due to gastric cancer.

SUBJECTS AND METHODS

This cross-sectional observational study included 3 groups of subjects; healthy controls, patients with subtotal and patients with total gastrectomy. Demographic and clinical data of patients were collected. Stool samples to determine faecal elastase (Fe-1) and chymotrypsin were collected and measured by ELISA. All subjects performed 5-hour ¹³C-MTGT breath test. The concentration and relative content of ¹³C in exhaled air was measured by isotope ratio mass spectrometer (IRMS). PEI was confirmed as values of ¹³C-exhalation < 26.8% after 5 hours.

RESULTS

Overall, 65 participants were included into analysis, 22 having PEI (n = 11 after subtotal and n = 11 after total gastrectomy, both performed for gastric cancer). ¹³C-MTGT breath test showed difference in percent of exhaled ¹³C between PEI and non-PEI patients already after 60 minutes (p = 0.034). Receiver operating characteristic (ROC) curve analysis showed that cut-off value of 13.74% after 150 minutes is showing equivalent diagnostic power to the longer test with sensitivity and specificity both above 90% for the exclusion of PEI in patients after subtotal and/or total gastrectomy.

CONCLUSIONS

In this study abbreviated ¹³C-MTGT test could be shortened from 5 to 2.5 hours without decrease in its diagnostic accuracy for detection of PEI in patients with subtotal or total gastrectomy performed for gastric cancer. This allows significant time savings in the diagnostics of PEI in this subgroup of patients.

The influence of gastric bypass surgery on the concentration of high mobility group box 1, nuclear factor erythroid 2-related factor 2 and the genes expression of high mobility group box 1, nuclear factor erythroid2-related factor 2, interleukin 6, and tumor necrosis factor-alpha in the peripheral blood mononuclear cells of patients with morbid obesity

BACKGROUND AND OBJECTIVES

Obesity is known as a disease with a chronic low-grade state of inflammation and high levels of oxidative stress. Given the challenges and consequences caused by obesity, obesity therapy is an essential subject to address. For sustainable weight loss, gastric bypass surgery is the most successful and essential option.

METHODS

This prospective cohort study was performed on 35 patients aged (18-54) with morbid obesity (BMI: 42.06 kg/m²). Volunteers blood was taken, and peripheral blood mononuclear cells (PBMCs) were isolated, high mobility group box 1(HMGB1), nuclear factor erythroid2-related factor 2(Nrf2), Interleukin 6(IL-6), tumor necrosis factor-alpha (TNF-α), and biochemical factors were determined one day before and 4 months after surgery.

RESULTS

Four months following surgery, the BMI, hip and waist circumferences, and waist-to-hip ratio (WHR) all decreased significantly. The lipid profile and antioxidant power were dramatically enhanced after surgery. IL-6 and TNF-α expression in PBMC patients showed a significant decrease after surgery. HMGB1 and Nrf2 expression in PBMC of postoperative patients decreased compared to before surgery, and HMGB1, and Nrf2 protein levels also decreased after surgery.

CONCLUSION

Weight loss indicated the significant function of adipose tissue in the induction of oxidative stress and inflammatory factors. Gastric bypass reduced the inflammation conditions and improved the metabolic status and living situations in the patients with morbid obesity.