Liver Function in Patients With Nonalcoholic Fatty Liver Disease Randomized to Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy: A Secondary Analysis of a Randomized Clinical Trial

New insights on mesenchymal stem cells therapy from the perspective of the pathogenesis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) manifests as chronic hepatic steatosis, occurring variably across people due to racial and genetic diversity. It represents a stage in the development of chronic liver disease, marked by fat accumulation, inflammatory responses, oxidative stress in the endoplasmic reticulum, and fibrosis as primary concerns. Understanding its underlying mechanisms remains a challenging and pivotal area of study. In the past, acute liver injury-related diseases were commonly treated with methods such as liver transplantation. However, the emergence of artificial liver has shifted focus to stem cell therapies. Unlike conventional drugs, stem cell therapies are continuously evolving. Despite being classified as drugs, stem cells demonstrated significant efficacy after multiple injections. Mesenchymal stem cells, unlike other types of stem cells, do not have the risk of tumor formation and low immunogenicity, reducing the hypersensitivity reactions associated with liver transplantation. Increasingly, studies suggest that mesenchymal stem cells hold promise in the treatment of chronic liver injury diseases. This review focuses on investigating the role of mesenchymal stem cells in chronic metabolic liver diseases, such as non-alcoholic fatty liver disease, and delves into their specific functions.

Metabolic-Associated Fatty Liver Disease and Weight Loss After Bariatric Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and Metabolic Dysfunction-Associated Steatohepatitis (MASH) are increasingly prevalent in patients undergoing bariatric surgery (BS). Understanding their impact on weight loss outcomes after surgery and highlighting the results of surgical techniques such as Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG) in relation to the presence of MASH are essential for improving patient management and predicting long-term success.

METHODS

A systematic review and meta-analysis were conducted. We searched the PubMed database; inclusion criteria were BS patients with liver impairment data at surgery and weight loss data at follow-up of 6 months or longer. Meta-analyses were conducted using R's meta package, assessing heterogeneity with the I2 statistic and employing subgroup analyses where necessary.

RESULTS

Out of 1126 eligible studies, 22 were included in the final systematic review. For the MASLD vs. Normal Liver (NL) comparison, no significant difference in BMI change was found at 12 months, but subgroup analysis indicated a possible publication bias (published data vs data collected). In the MASH vs. non-MASH comparison, high heterogeneity was noted at 12 months, and further stratification by surgical technique revealed that SG patients with MASH experienced lower weight loss, approaching statistical significance.

CONCLUSIONS

MASLD does not significantly affect short-term weight loss outcomes post-BS, but long-term results show variability. Standardized reporting practices and complete data dissemination are essential for future research to enhance meta-analysis reliability and generalizability.

Laparoscopic Roux-en-Y Versus Mini-Gastric Bypass on Liver Function at 6 Months in Morbid Obesity Patients: A Cross-Sectional Study

Background: Various weight loss surgeries exist, with no absolute superiority; each has pros and cons. Due to rising bariatric surgeries globally, it's vital to investigate comparisons between two-mini gastric bypass and Roux-en-Y gastric bypass (RYGB), especially regarding their impact on liver function. Objectives: The purpose of this study was to "draw comparisons between the effects of mini gastric bypass and laparoscopic Roux-en-Y gastric bypass on liver function at 6 months among patients with morbid obesity." Methods: This cross-sectional study included 90 bariatric surgery candidates (Body Mass Index (BMI) 35 - 50) from 2018 - 2021. Forty-five had laparoscopic mini gastric bypass surgery, while 45 had Roux-en-Y gastric bypass. Demographic, anthropometric, lab, and sonographic tests were conducted at baseline, 3-, and 6-months post-surgery. Data was analyzed using SPSS. Results: In a study of 90 patients (75.6% female, mean age 38.6 ± 10.4 years), both surgeries (Mini gastric bypass (MGB) and RYGB) effectively reduced body weight, BMI, and waist circumference at 3- and 6-months post-surgery. However, MGB showed significantly higher BMI and weight loss compared to RYGB (P = 0.003). In 90 patients, both surgeries reduced weight and BMI. However, MGB showed better BMI/weight loss. LFTs (ALT, AST, ALP) remained stable after MGB but worsened at 3 months after RYGB before recovering by 6 months. Mini gastric bypass also showed better GGT improvement. Both procedures improved fatty liver grading, FBS, and HbA1C levels equally. No significant differences were observed in blood pressure, platelet count, hemoglobin, or MCV. Ferritin levels increased in both groups but were higher in RYGB. CRP was higher in RYGB at 3 months. Conclusions: Roux-en-Y gastric bypass temporarily exacerbated liver enzymes and inflammation, but MGB resulted with more weight reduction. In comparison to RYGB, MGB improved LFTs more consistently.

Randomized controlled trials comparing gastric bypass, gastric band, and sleeve gastrectomy: A systematic review examining validity and applicability to wider clinical practice

Consideration of how applicable the results of surgical trials are to clinical practice is important to inform decision-making. Randomized controlled trials comparing at least two surgical interventions (of gastric bypass, gastric band, and sleeve gastrectomy) for severe and complex obesity were examined using the PRagmatic Explanatory Continuum Indicator Summary-2 tool, to consider how applicable the trial results are to clinical practice, and the Risk of Bias 2 tool, to examine validity. MEDLINE, Embase, and CENTRAL databases were searched for studies published between November 2013 and June 2021, and 15 were identified. Using the PRagmatic Explanatory Continuum Indicator Summary-2 tool, three were classified as pragmatic, with good applicability to clinical practice. Ten had more explanatory domains but did include some pragmatic characteristics, and two were predominantly explanatory. This was due to some trial design features that would not be considered applicable to the wider clinical setting, including being single-centered, having prescribed intervention delivery methods, and intensive follow-up regimens. Only two trials had low risk of bias, of which one was considered pragmatic. Three had high risk of bias. Overall, few trials in bariatric surgery are pragmatic with low risk of bias. Well-designed pragmatic trials are needed to inform practice and reduce research waste.

Safety and Efficacy of LSG Versus LRYGB on Patients with Obesity: a Systematic Review and Meta-analysis from RCTs

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are the two most frequently performed techniques in treating obesity and its related comorbidities. We aimed to compare the clinical efficacy and safety of LSG with LRYGB in terms of short- and mid-term outcomes of weight loss, obesity-related comorbidities, and post-operative complications via a meta-analysis of RCTs.

METHODS

Clinical comparative RCTs on LSG and LRYGB were searched through PubMed, MEDLINE, and Web of Science databases from inception to August 2022. Pooled outcomes from the selected studies were discussed by the random-effect meta-analysis method. Quality assessment and risk of bias for selected RCTs were implemented, and all the statistical analyses were performed.

RESULTS

Twenty studies, including 1270 patients, were enrolled. Meta-analysis results indicated the great superior efficacy of LRYGB to LSG in BMI loss at 6 (MD -1.35 kg/m2, 95% CI: -2.07 to -0.62, p = 0.0003), 12 months (MD -1.09 kg/m2, 95% CI: -1.86 to -0.33, p = 0.005), and 36 months (MD -1.47 kg/m2, 95% CI: -2.77 to -0.16, p = 0.03) as well as %EWL gaining at 36 months. Significantly higher remission rates of T2DM and dyslipidemia were achieved by LRYGB at 12 months. Besides, better improvements for T2DM-related and lipid biochemical parameters were found favoring LRYGB. However, LSG resulted in a lower post-operative complication rate and shorter operating time.

CONCLUSIONS

Present meta-analysis results suggested that LRYGB was superior to LSG concerning short- and mid-term weight loss, short-term T2DM remission efficacy, and related biochemical parameters. LSG is favored for obviously fewer complications and shorter operating time.

2024 UPDATE: the Brazilian Diabetes Society position on the management of metabolic dysfunction-associated steatotic liver disease (MASLD) in people with prediabetes or type 2 diabetes

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common liver disease affecting 30% of the world's population and is often associated with metabolic disorders such as metabolic syndrome, type 2 diabetes (T2D), and cardiovascular disease. This review is an update of the Brazilian Diabetes Society (Sociedade Brasileira de Diabetes [SBD]) evidence-based guideline for the management of MASLD in clinical practice.

METHODS

The methodology was published previously and was defined by the internal institutional steering committee. The SBD Metabolic Syndrome and Prediabetes Department drafted the manuscript, selecting key clinical questions for a narrative review using MEDLINE via PubMed with the MeSH terms [diabetes] and [fatty liver]. The best available evidence was reviewed, including randomized clinical trials (RCTs), meta-analyses, and high-quality observational studies related to MASLD.

RESULTS AND CONCLUSIONS

The SBD Metabolic Syndrome and Prediabetes Department formulated 9 recommendations for the management of MASLD in people with prediabetes or T2D. Screening for the risk of advanced fibrosis associated with MASLD is recommended in all adults with prediabetes or T2D. Lifestyle modification (LSM) focusing on a reduction in body weight of at least 5% is recommended as the first choice for these patients. In situations where LSMs are insufficient to achieve weight loss, the use of anti-obesity medications is recommended for those with a body mass index (BMI) ≥ 27 kg/m2. Pioglitazone and glucagon-like peptide-1 receptor agonists (GLP-1RA) monotherapy are the first-line pharmacological treatments for steatohepatitis in people with T2D, and sodium-glucose cotransporter-2 (SGLT2) inhibitors may be considered in this context. The combination of these agents may be considered in the treatment of steatohepatitis and/or fibrosis, and bariatric surgery should be considered in patients with a BMI ≥ 35 kg/m2, in which the combination of LSM and pharmacotherapy has not been shown to be effective in improving MASLD.

Digeda-4 decoction and its disassembled prescriptions improve dyslipidemia and apoptosis by regulating AMPK/SIRT1 pathway on tyloxapol-induced nonalcoholic fatty liver disease in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Nonalcoholic fatty liver disease (NAFLD) is a manifestation of metabolic syndrome in the liver and the leading cause of chronic liver disease worldwide. Digeda-4 decoction (DGD-4) is a commonly prescribed Mongolian herbal drug for treating acute and chronic liver injury and fatty liver. However, the mechanisms underlying the improvement of dislipidemia and liver injury via treatment with DGD-4 remain unclear. Disassembling a prescription is an effective approach to studying the effects and mechanisms underlying Mongolian medicine prescriptions. By disassembling a prescription, it is feasible to discover effective combinations of individual herbs to optimize a given prescription. Accordingly, we disassembled DGD-4 into two groups: the single Lomatogonium rotatum (L.) Fries ex Nym (LR) (DGD-1) and non-LR (DGD-3).

AIM OF THIS STUDY

To study whether DGD-4 and its disassembled prescriptions have protective effects against tyloxapol (TY)-induced NAFLD and to explore the underlying mechanisms of action and compatibility of prescriptions.

MATERIAL AND METHODS

NAFLD mice were developed by TY induction. Biochemical horizontal analyses, enzyme-linked immunosorbent assay, and liver histological staining were performed to explore the protective effects of DGD-4 and its disassembled prescriptions DGD-3 and DGD-1. Furthermore, we performed immunohistochemical analyses and Western blotting to further explore the expression of target proteins.

RESULTS

DGD-4 and its disassembled prescriptions could inhibit TY-induced dislipidemia and liver injury. In addition, DGD-4 and its disassembled prescriptions increased the levels of p-AMPKα and p-ACC, but decreased the levels of SREBP1c, SCD-1, SREBP-2, and HMGCS1 proteins. The activation of lipid metabolic pathways SIRT1, PGC-1α, and PPARα improved lipid accumulation in the liver. Moreover, DGD-4 could inhibit hepatocyte apoptosis and treat TY-induced liver injury by upregulating the Bcl-2 expression, downregulating the expression of Bax, caspase-3, caspase-8, and the ratio of Bax/Bcl-2, and positively regulating the imbalance of oxidative stress (OxS) markers (such as superoxide dismutase [SOD], catalase [CAT], malondialdehyde [MDA], and myeloperoxidase [MPO]). DGD-1 was superior to DGD-3 in regulating lipid synthesis-related proteins such as SREBP1c, SCD-1, SREBP-2, and HMGCS1. DGD-3 significantly affected the expression of lipid metabolic proteins SIRT1, PGC-1α, PPARα, apoptotic proteins Bcl-2, Bax, caspase-3, caspase-8, and the regulation of Bax/Bcl-2 ratio. However, DGD-1 showed no regulatory effects on Bax and Bcl-2 proteins.

CONCLUSION

This study demonstrates the protective effects of DGD-4 in the TY-induced NAFLD mice through a mechanism involving improvement of dyslipidemia and apoptosis by regulating the AMPK/SIRT1 pathway. Although the Monarch drug DGD-1 reduces lipid accumulation and DGD-3 inhibits apoptosis and protects the liver from injury, DGD-4 can be more effective overall as a therapy when compared to DGD-1 and DGD-3.

Prevalence of elevated alkaline phosphatase levels among post-bariatric surgery patients

INTRODUCTION

Little is known about the prevalence of elevated alkaline phosphatase in post-bariatric surgery patients due to under-utilization of this test after surgery. Elevated alkaline phosphatase levels are caused by hepatobiliary disease or bone resorption, which can lead to gallstones and osteoporosis. Early, post-operative measurement of alkaline phosphatase can prevent complications, thus reducing morbidity and overall healthcare costs. The purpose of this study was to determine the prevalence of elevated alkaline phosphatase levels among post-operative bariatric surgery patients.

METHODS

This was a retrospective study of patients 18 years or older, who underwent laparoscopic sleeve gastrectomy (LSG) at a Midwestern Weight Management Clinic between January 1, 2002 and December 31, 2020. Alkaline phosphatase levels, weight, body mass index (BMI), gamma-glutamyl transferase (GGT), parathyroid hormone (PTH), calcitriol, and calcitonin, vitamin D and multivitamin supplementation were measured at baseline, 3, 6, and 12 months post-surgery.

RESULTS

Two hundred thirty patients with mean age of 47 years and BMI of 44.6 were included with 80.9% (n = 186) female. Alkaline phosphatase was elevated relative to baseline for 36.1% of patients (n = 52) at 3 months post-surgery, 42.4% of patients (n = 56) at 6 months, and 43.3% of patients (n = 45) at 12 months (p < 0.001). There were six cases of documented cholelithiasis post-surgery.

CONCLUSION

A significant proportion of participants experienced elevations in alkaline phosphatase following surgery, indicating that the prevalence of gallbladder pathology and bone resorption may be higher than previously thought. This merits additional investigation into these complications post-operatively to determine prevalence and avoid excess morbidity.

Practical guideline on obesity care in patients with gastrointestinal and liver diseases - Joint ESPEN/UEG guideline

BACKGROUND

Patients with chronic gastrointestinal disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean gastrointestinal patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The present practical guideline is intended for clinicians and practitioners in general medicine, gastroenterology, surgery and other obesity management, including dietitians and focuses on obesity care in patients with chronic gastrointestinal diseases.

METHODS

The present practical guideline is the shortened version of a previously published scientific guideline developed according to the standard operating procedure for ESPEN guidelines. The content has been re-structured and transformed into flow-charts that allow a quick navigation through the text.

RESULTS

In 100 recommendations (3× A, 33× B, 24 × 0, 40× GPP, all with a consensus grade of 90% or more) care of gastrointestinal patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially metabolic associated liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present practical guideline offers in a condensed way evidence-based advice how to care for patients with chronic gastrointestinal diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

NAFLD as the metabolic hallmark of obesity

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide, associated with a high risk of progression to NASH, liver cirrhosis and hepatocarcinoma. Its prevalence is closely related to obesity (understood as adipose-based disease and insulin resistance), which makes that at present NAFLD can be considered a metabolic dysfunction hallmark, regardless of the body mass index. Despite being such a prevalent condition, with such severe consequences, at present there are no reliable biomarkers for its diagnosis or specific treatment. Significant and sustained weight loss, as well as some antidiabetic treatments, has shown promising results for NAFLD but data needs confirmation in larger clinical trials and longer follow-up. Efforts should be made for a better and more accurate baseline diagnosis (including large-scale genetics), identification of patients at higher risk for progression to NASH as well as adequate treatment, to allow us to offer a personalized approach in NAFLD in the context of precision medicine.

Combined non-alcoholic fatty liver disease and type 2 diabetes in severely obese patients-medium term effects of sleeve gastrectomy versus Roux-en-Y-gastric bypass on disease markers

Background

We aimed to evaluate the medium-term efficacy of sleeve gastrectomy (SG) vs. Roux-en-Y gastric bypass (RYGB) on remission of non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

Methods

We identified severely obese patients [body mass index (BMI) >35 kg/m2] with NAFLD (as defined by the Longitudinal Assessment of Bariatric Surgery Study) and T2DM (as defined by the American Association of Clinical Endocrinologists and the American College of Endocrinology) who underwent SG or RYGB in a single university surgical centre. The cohorts were match-paired and data were analysed after at least 3 years of follow up. The key outcomes measured were: (I) the improvement of liver function tests and NAFLD markers; (II) glycemic control and insulin resistance.

Results

Ninety-six patients were investigated; 44 (45.8%) were women. The mean pre-operative BMI was 45.2 kg/m2 in the SG and 42.0 kg/m2 in the RYGB group. SG and RYGB both significantly reduced serum liver enzyme concentrations. NAFLD markers resolved 2 years after SG in all patients. In contrast, only 78% and 80% of patients achieved remission of NAFLD 2 and 3 years after RYBG respectively. Both procedures resulted in comparable rates of remission of T2DM.

Conclusions

Bariatric surgery with SG may be preferable to RYGB for obese patients with NAFLD and T2DM based on the rates of remission of markers of these co-morbidities. However, our results need to be confirmed in prospective trials. Understanding the metabolic effects of specific bariatric surgical procedures may facilitate the development of a personalised approach to weight-loss surgery.

Bariatric surgery for diabetic comorbidities: A focus on hepatic, cardiac and renal fibrosis

Continuously rising trends in diabetes render this disease spectrum an epidemic proportion worldwide. As the disease progresses, the pathological effects of diabetes may impair the normal function of several vital organs, eventually leading to increase the risk of other diabetic comorbidities with advanced fibrosis such as non-alcoholic fatty liver disease, diabetic cardiomyopathy, and diabetic kidney disease. Currently, lifestyle changes and drug therapies of hypoglycemic and lipid-lowering are effective in improving multi-organ function, but therapeutic efficacy is difficult to maintain due to poor compliance and drug reactions. Bariatric surgery, including sleeve gastrectomy and Roux-en-Y gastric bypass surgery, has shown better results in terms of prognosis for diabetes through long-term follow-up. Moreover, bariatric surgery has significant long-term benefits on the function of the heart, liver, kidneys, and other organs through mechanisms associated with reversal of tissue fibrosis. The aim of this review is to describe the impact of type 2 diabetes mellitus on hepatic, cardiac and renal fibrosis and to summarize the potential mechanisms by which bariatric surgery improves multiple organ function, particularly reversal of fibrosis.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint ESPEN/UEG guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for ESPEN guidelines, following the Scottish Intercollegiate Guidelines Network (SIGN) grading system (A, B, 0, and good practice point (GPP)). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

European guideline on obesity care in patients with gastrointestinal and liver diseases - Joint European Society for Clinical Nutrition and Metabolism / United European Gastroenterology guideline

BACKGROUND

Patients with chronic gastrointestinal (GI) disease such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), celiac disease, gastroesophageal reflux disease (GERD), pancreatitis, and chronic liver disease (CLD) often suffer from obesity because of coincidence (IBD, IBS, celiac disease) or related pathophysiology (GERD, pancreatitis and CLD). It is unclear if such patients need a particular diagnostic and treatment that differs from the needs of lean GI patients. The present guideline addresses this question according to current knowledge and evidence.

OBJECTIVE

The objective of the guideline is to give advice to all professionals working in the field of gastroenterology care including physicians, surgeons, dietitians and others how to handle patients with GI disease and obesity.

METHODS

The present guideline was developed according to the standard operating procedure for European Society for Clinical Nutrition and Metabolism guidelines, following the Scottish Intercollegiate Guidelines Network grading system (A, B, 0, and good practice point [GPP]). The procedure included an online voting (Delphi) and a final consensus conference.

RESULTS

In 100 recommendations (3x A, 33x B, 24x 0, 40x GPP, all with a consensus grade of 90% or more) care of GI patients with obesity - including sarcopenic obesity - is addressed in a multidisciplinary way. A particular emphasis is on CLD, especially fatty liver disease, since such diseases are closely related to obesity, whereas liver cirrhosis is rather associated with sarcopenic obesity. A special chapter is dedicated to obesity care in patients undergoing bariatric surgery. The guideline focuses on adults, not on children, for whom data are scarce. Whether some of the recommendations apply to children must be left to the judgment of the experienced pediatrician.

CONCLUSION

The present guideline offers for the first time evidence-based advice how to care for patients with chronic GI diseases and concomitant obesity, an increasingly frequent constellation in clinical practice.

Obesity Management in the Primary Prevention of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary hepatic malignancy and a leading cause of cancer-related death globally. HCC is associated with an indolent clinical presentation, resulting in frequent advanced stage diagnoses where surgical resection or transplant therapies are not an option and medical therapies are largely ineffective at improving survival. As such, there is a critical need to identify and enhance primary prevention strategies to mitigate HCC-related morbidity and mortality. Obesity is an independent risk factor for the onset and progression of HCC. Furthermore, obesity is a leading cause of nonalcoholic steatohepatitis (NASH), the fasting growing etiological factor of HCC. Herein, we review evolving clinical and mechanistic associations between obesity and hepatocarcinogenesis with an emphasis on the therapeutic efficacy of prevailing lifestyle/behavioral, medical, and surgical treatment strategies for weight reduction and NASH reversal.

When Sugar Reaches the Liver: Phenotypes of Patients with Diabetes and NAFLD

Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD) have been traditionally linked to one another. Recent studies suggest that NAFLD may be increasingly common in other types of diabetes such as type 1 diabetes (T1DM) and less frequently ketone-prone and Maturity-onset Diabetes of the Young (MODY) diabetes. In this review, we address the relationship between hyperglycemia and insulin resistance and the onset and progression of NAFLD. In addition, despite the high rate of patients with T2DM and other diabetes phenotypes that can alter liver metabolism and consequently develop steatosis, fibrosis, and cirrhosis, NALFD screening is not still implemented in the daily care routine. Incorporating a clinical algorithm created around a simple, non-invasive, cost-effective model would identify high-risk patients. The principle behind managing these patients is to improve insulin resistance and hyperglycemia states with lifestyle changes, weight loss, and new drug therapies.

Liver Injury and Acute Liver Failure After Bariatric Surgery: An Overview of Potential Injury Mechanisms

The obesity epidemic has caused a surge in the use of bariatric surgery. Although surgery-induced weight loss is an effective treatment of nonalcoholic fatty liver disease, it may precipitate severe hepatic complications under certain circumstances. Acute liver injury (ALI) and acute liver failure (ALF) following bariatric surgery have been reported in several case series. Although rare, ALI and ALF tend to emerge several months after bariatric surgery. If so, it can result in prolonged hospitalization, may necessitate liver transplantation, and in some cases prove fatal. However, little is known about the risk factors for developing ALI or ALF after bariatric surgery and the mechanisms of liver damage in this context are poorly defined. This review provides an account of the available data on ALI and ALF caused by bariatric surgery, with emphasis on potential injury mechanisms and the outcomes of liver transplantation for ALF after bariatric surgery.

The Concept of Indeterminable NASH Inducted by Preoperative Diet and Metabolic Surgery: Analyses of Histopathological and Clinical Features

Practitioners routinely perform intraoperative liver biopsies during laparoscopic sleeve gastrectomy (LSG) to evaluate nonalcoholic fatty liver disease (NAFLD). In some patients, hepatocyte ballooning, inflammation, and fibrosis without steatosis are observed, even in the absence of other etiologies. We call this finding indeterminable nonalcoholic steatohepatitis (Ind-NASH). In this study, we clarified the prevalence, as well as histopathological and clinical features, of Ind-NASH through intraoperative liver biopsy in Japanese patients presenting with severe obesity. We enrolled 63 patients who had undergone LSG and intraoperative liver biopsy. In patients diagnosed with histopathological NASH, we performed protocol liver biopsies at 6 and 12 months after LSG. We statistically analyzed these histopathological findings and clinical parameters and found the prevalence rate of Ind-NASH discovered through intraoperative biopsy to be 15.9%. Protocol liver biopsy also revealed that Ind-NASH was an intermediate condition between NASH and normal liver. The clinical features of patients with Ind-NASH are a higher body weight compared to NASH (134.9 kg vs. 114.7 kg; p = 0.0245), stronger insulin resistance compared to nonalcoholic fatty liver (homeostasis model assessment–insulin resistance: 7.1 vs. 4.9; p = 0.0188), and mild liver dysfunction compared to NASH. Patients with Ind-NASH observed positive weight-loss effects from a preoperative diet compared to the postoperative course (percentage total weight loss: 32.0% vs. 26.7%; p < 0.0001). Patients with Ind-NASH may also be good candidates for metabolic surgery owing to their good treatment response; therefore, efforts should be made by specialists in the near future to deeply discuss and define Ind-NASH.

Preoperative circulating peroxiredoxin 1 levels as a predictor of non-alcoholic fatty liver disease remission after laparoscopic bariatric surgery

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with obesity and insulin resistance and can be improved after bariatric surgery. Circulating Peroxiredoxin 1 (Prdx1) protein was reported to regulate energy metabolism and inflammation. This study aimed to investigate the roles of serum prdx1 in NAFLD patients with obesity undergoing LSG and to develop a prognostic model to predict the remission of severe NAFLD.

METHODS

The data of 93 participants from a tertiary hospital were assessed. Before laparoscopic sleeve gastrectomy (LSG) and three months after LSG, anthropometric parameters, laboratory biochemical data, and abdominal B-ultrasound results were collected, and their hepatic steatosis index (HSI) and triglyceride-glucose index (TyG) were calculated. A NAFLD improvement (NAFLD-I) nomogram prediction model was constructed using the least absolute shrinkage and selection operator (LASSO) regression and multiple regression, and its predictive ability was verified in a validation cohort.

RESULTS

The baseline Prdx1 (OR: 0.887, 95% CI: 0.816-0.963, p=0.004), preoperative TyG (OR: 8.207, 95% CI: 1.903-35.394, p=0.005) and HSI (OR: 0.861, 95% CI: 0.765-0.969, p=0.013) levels were independently associated with NAFLD-I at three months after LSG in NAFLD patients with obesity. In the primary and validation cohorts, the area under the receiver operating characteristic (AUC) of the developed nomogram model was 0.891 and 0.878, respectively. The preoperative circulating Prdx1 levels of NAFLD patients with obesity were significantly reduced after LSG (25.32 [18.99-30.88] vs. 23.34 [15.86-26.42], p=0.001). Prdx1 was related to obesity and hepatic steatosis based on correlation analysis.

CONCLUSION

The nomogram based on preoperative serum prdx1, HSI and TyG could be an effective tool for predicting remission of severe NAFLD after LSG.

Gastric Bypass Versus Sleeve Gastrectomy in Type 2 Diabetes: Effects on Hepatic Steatosis and Fibrosis : A Randomized Controlled Trial

BACKGROUND

Weight loss improves fatty liver disease. No randomized trial has compared the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on liver fat content and fibrosis.

OBJECTIVE

To compare the 1-year effects of SG and RYGB on hepatic steatosis and fibrosis.

DESIGN

Single-center, randomized, controlled trial (Oseberg [ObesitySurgery in Tønsberg]). (ClinicalTrials.gov: NCT01778738).

SETTING

Tertiary care obesity center in Norway.

PARTICIPANTS

100 patients (65% female; mean age, 47.5 years; mean body mass index, 42 kg/m²) with type 2 diabetes mellitus (T2DM).

INTERVENTION

From January 2013 to February 2018, patients were randomly assigned (1:1 ratio) to SG or RYGB.

MEASUREMENTS

The primary outcome was remission of T2DM (previously published). Predefined secondary outcomes in the present study were hepatic steatosis and fibrosis assessed by magnetic resonance imaging (liver fat fraction), enhanced liver fibrosis (ELF) test, noninvasive indices, and liver enzymes.

RESULTS

Liver fat fraction declined similarly after SG (-19.7% [95% CI, -22.5% to -16.9%]) and RYGB (-21.5% [CI, -24.3% to -18.6%]) from surgery to 1-year follow-up, and almost all patients (SG, 94%; RYGB, 100%) had no or low-grade steatosis at 1 year. The ELF score category remained stable in 77% of patients, but 18% experienced worsening of fibrosis at 1 year, with no substantial between-group difference.

LIMITATIONS

Single-center study, short follow-up time, and lack of power for secondary outcomes.

CONCLUSION

With an almost complete clearance of liver fat 1 year after surgery, RYGB and SG were both highly effective in reducing hepatic steatosis. Bariatric surgery had less influence on degree of fibrosis in the short term, but assessment of long-term progression is warranted.

PRIMARY FUNDING SOURCE

Vestfold Hospital Trust and the South-Eastern Norway Regional Health Authority.

Risks and Rewards of Bariatric Surgery in Advanced Chronic Liver Diseases

The burden of obesity and metabolic syndrome has determined a sharp increase in bariatric surgery (BS) procedures, which lead to marked weight loss, improved metabolic syndrome, reduced cardiovascular risk, and even improvement in nonalcoholic steatohepatitis (NASH). Despite these promising results, BS in patients with chronic liver disease can rarely lead to worsening of liver function, progression to cirrhosis and its complications, and even liver transplantation. On the other hand, since obesity in patients with cirrhosis is a major cofactor for progression to a decompensated stage of the disease and a risk factor for hepatocellular carcinoma, BS has been used to achieve weight loss in this population. In this review, we critically analyze the existing data on outcomes of BS in patients with cirrhosis and the possible mechanisms leading to fibrosis progression and worsening liver function in patients undergoing BS. Finally, we propose a set of measures that could be taken to improve the multidisciplinary management of liver disease in patients undergoing BS, including early recognition of malnutrition and alcohol misuse.

Efficacy and Safety of Endoscopic Balloon Placement for Weight Loss in Patients With Cirrhosis Awaiting Liver Transplantation

The efficacy and safety of a fluid-filled intragastric balloon (IGB) for weight loss in patients with cirrhosis on the liver transplantation (LT) waiting list is unknown. We enrolled stable compensated patients with body mass index >35 kg/m² and on the waiting list for IGB placement endoscopically for a maximum of 6 months. A total of 8 patients (7 men) aged mean ± SD, 56 ± 4.6 years with Model for End-Stage Liver Disease-sodium (MELD-Na) scores 14.1 ± 3.4 experienced weight reduction (146 ± 22.2 kg versus 127 ± 21.6 kg [P = 0.005] with IGB in place and 130 ± 24.6 kg [P = 0.014] at 6 months), with a total body weight loss of 12.2% ± 8.8% with IGBs in place and 10.9% ± 8.9% at 6 months. Body fat decreased from 48.6% ± 5.8% to 40.6% ± 6.4% (P = 0.001) and lean mass increased from 51.3% ± 6% to 59.4% ± 6.4% (P = 0.001). No change in MELD-Na scores occurred (P = 0.770). Early balloon retrieval was attributed to accommodative symptoms (n = 2) and liver decompensation (n = 1). Mallory Weiss tears (n = 3), but no portal hypertensive bleeding, occurred. Liver decompensation and/or hepatocellular carcinoma (HCC) developed in 3 patients. A total of 4 patients with LT ± sleeve gastrectomy maintained overall weight loss. Of 4 patients who did not receive transplants, 2 experienced weight regain. IGB results in short-term weight loss in patients with cirrhosis awaiting LT, with body fat loss without lean mass loss. Adverse effects were common. Decompensation and HCC did occur, with uncertainty of the relation to weight loss, and thus careful patient selection and close follow-up are required.

Current Options and Future Directions for NAFLD and NASH Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with a broad spectrum ranging from simple steatosis to advanced stage of nonalcoholic steatohepatitis (NASH). Although there are many undergoing clinical trials for NAFLD treatment, there is no currently approved treatment. NAFLD accounts as a major causing factor for the development of hepatocellular carcinoma (HCC), and its incidence rises accompanying the prevalence of obesity and diabetes. Reprogramming of antidiabetic and anti-obesity medicine is a major treatment option for NAFLD and NASH. Liver inflammation and cellular death, with or without fibrosis account for the progression of NAFLD to NASH. Therefore, molecules and signaling pathways involved in hepatic inflammation, fibrosis, and cell death are critically important targets for the therapy of NAFLD and NASH. In addition, the avoidance of aberrant infiltration of inflammatory cytokines by treating with CCR antagonists also provides a therapeutic option. Currently, there is an increasing number of pre-clinical and clinical trials undergoing to evaluate the effects of antidiabetic and anti-obesity drugs, antibiotics, pan-caspase inhibitors, CCR2/5 antagonists, and others on NAFLD, NASH, and liver fibrosis. Non-invasive serum diagnostic markers are developed for fulfilling the need of diagnostic testing in a large amount of NAFLD cases. Overall, a better understanding of the underlying mechanism of the pathogenesis of NAFLD is helpful to choose an optimized treatment.

Bariatric surgery for non-alcoholic fatty liver disease in individuals with obesity (Base-NAFLD): protocol of a prospective multicenter observational follow-up study

BACKGROUND

Bariatric surgery may be indicated in patients with nonalcoholic fatty liver disease (NAFLD) to achieve and maintain the degree of weight loss required to ensure therapeutic effects. However, bariatric surgery is still underrecognized in the treatment of NAFLD, including its inflammatory subtype, nonalcoholic steatohepatitis (NASH). Moreover, there is a lack of follow-up outcome data on different types of bariatric surgery in patients with NAFLD. This study aims to adequately assess the effect of bariatric surgery on NAFLD remission in obese patients.

METHODS

This prospective multicentre observational follow-up study will include 142 obese patients with NAFLD scheduled to undergo one of the following surgical procedures: sleeve gastrostomy, Roux-en-Y gastric bypass, and one anastomosis gastric bypass. The primary outcome is the complete remission rate of NAFLD one year postoperatively, which is defined by liver fat fraction < 5% on magnetic resonance imaging; the secondary outcomes includes (i) changes in NASH and liver fibrosis biopsy findings, (ii) changes in body weight and abdominal adipose weight, (iii) resolution of obesity-related comorbidities, and (iv) incidence of adverse events. A long-term follow-up related to this study will also be conducted.

DISCUSSION

This study will provide a necessary and preliminary foundation for the early identification and targeted treatment of patients with NAFLD who can be referred for bariatric surgery, as indicated for management of obesity and metabolic disease.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04366999. Registered 21 April 2020. ( https://clinicaltrials.gov/ct2/show/NCT04366999 ).

Pregnancy and lactation after Roux-en-Y gastric bypass worsen nonalcoholic fatty liver disease in obese rats and lead to differential programming of hepatic de novo lipogenesis in offspring

Maternal obesity increases the risk of nonalcoholic fatty liver disease (NAFLD) in offspring. The Roux-en-Y gastric bypass (RYBG) is effective for achieving weight loss and ameliorates NAFLD. To determine whether these benefits are maintained after pregnancy and/or lactation, and whether they modulate hepatic morphofunction in the next generation, we evaluated hepatic lipid metabolism in Western diet (WD)-obese female rats that underwent RYGB and in their F1 offspring at adulthood. Female Wistar rats consumed a WD from 21 to 130 days of age, before being submitted to RYGB (WD-RYGB-F0) or SHAM (WD-SHAM-F0) operations. After 5 weeks, these females were mated with control male breeders, and the male and female F1 offspring were identified as WD-RYGB-F1 and WD-SHAM-F1. WD-RYGB-F0 dams exhibited lower serum lipids levels, but severe hepatic steatosis and pathological features of advanced liver injury. The hepatic proteins involved in lipogenesis were reduced in WD-RYGB-F0, as were the genes related to β-oxidation and bile acids (BAs). Although the female and male WD-RYGB-F1 groups did not exhibit hepatic steatosis, the livers of female WD-RYGB-F1 demonstrated higher amounts of lipogenic genes and proteins, while male WD-RYGB-F1 presented a similar downregulation of lipogenic factors to that seen in WD-RYGB-F0 dams. In contrast, maternal and offspring groups of both sexes displayed reductions in the expressions of genes involved in BAs physiology and gluconeogenesis. As such, RYGB aggravates NAFLD after pregnancy and lactation and induces a gender-dependent differential expression of the hepatic lipogenesis pathway in offspring, indicating that female WD-RYGB-F1 may be an increased risk of developing NAFLD.

Hepatic Function and Fibrosis Assessment Via 2D-Shear Wave Elastography and Related Biochemical Markers Pre- and Post-Gastric Bypass Surgery

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) exhibits a worldwide distribution and encompasses a wider range of hepatic abnormalities that can culminate in serious clinical outcomes. The growing incidence of NAFLD necessitates more efficient management strategies particularly in clinically severe obese patients. Weight reduction is the cornerstone of NAFLD treatment; therefore, bariatric surgery could be a therapeutic approach in selected obese patients afflicted with NAFLD and other cardiometabolic comorbidities.

OBJECTIVE

The present study focused on the potential role of bariatric surgery on hepatic function and NAFLD-related histopathological features measured through a noninvasive method.

METHOD

Ninety patients entered to this study and underwent initial preoperative assessments including demographic profile, anthropometric measurements, standard laboratory tests, and hepatic biopsy. Liver stiffness was also evaluated via two-dimensional shear wave elastography (2D-SWE). All assessments were repeated over the subsequent 6 months following surgery except for liver biopsy.

RESULTS

Postoperative hepatic elasticity was lessened after 6 months (p = 0/002).The levels of alanine aminotransferase, gamma-glutamyl transferase, total protein, lipid indices, glucose, and platelet count were also improved following surgery (p < 0/001). Further progression of fibrosis was observed in 25% of patients after surgery.

CONCLUSION

Bariatric surgery was associated with a favorable impact on anthropometric and hepatic elasticity indices as well as metabolic parameters. The ideal target population for bariatric surgery should be thoroughly addressed, and the underlying risk factors for fibrosis progression need to be controlled before surgery. However, expanded research designed as comprehensive randomized controlled trials are recommended to confirm these findings.

Gastric Bypass Compared with Sleeve Gastrectomy for Nonalcoholic Fatty Liver Disease: a Systematic Review and Meta-analysis

The effects of bariatric procedures on nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) remain unclear. A systematic review and meta-analysis was performed to compare the impact of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on NAFLD/NASH. Patients submitted to RYGB presented significant reduction of steatohepatitis (RD: 0.53; 95% CI 0.33 to 0.74) and fibrosis (RD: 0.26; 95% CI 0.14 to 0.37). SG caused a significant reduction of steatohepatitis (RD: 0.42; 95% CI 0.27 to 0.57), but not of fibrosis (RD: 0.20; 95% CI -0.00 to 0.39). The NAFLD Activity Score was significantly improved after both procedures, as well as biochemical tests. No difference was found between RYGB and SG regarding the histopathological outcomes. SG and RYGB are equivalently effective for treating NAFLD/NASH.

Comparison of Liver Recovery After Sleeve Gastrectomy and Roux-en-Y-Gastric Bypass

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common condition in patients with obesity. Bariatric surgery has often been proposed as a viable treatment option, but the ideal surgical procedure remains unclear. Inconsistently, reports on postoperative deterioration of liver function put further doubt on which technique to apply. Aim of this study was to assess the impact of Roux-en-Y-gastric bypass (RYGB) and sleeve gastrectomy (SG) on the postoperative recovery of liver function.

METHODS

A total of 175 patients with obesity that underwent bariatric surgery in our institution were included in this prospective cohort study. BMI, laboratory values, and liver function capacity (using LiMAx) were assessed preoperatively and at 6 and 12 months postoperatively. Generalized linear model (GLM) was performed to determine variables influencing liver function capacity after the operation.

RESULTS

Prior to operations, 64% of patients presented with a diminished liver function capacity, as measured by LiMAx test. Liver function capacity significantly recovered after 12 months in the SG group (300 μg/kg/h preop vs. 367 μg/kg/h postop) but not in the RYGB group (306 μg/kg/h preop vs. 349 μg/kg/h). Preoperative factors impeding liver function recovery included type 2 diabetes mellitus (T2DM), weight, male sex, AST/thrombocyte ratio (APRI), and gamma-glutamyltransferase (GGT).

CONCLUSION

Bariatric surgery, especially sleeve gastrectomy, leads to an improvement of liver function. However, in some patients with T2DM, higher preoperative weight and male sex postoperative deterioration of liver function capacity may occur.

Sleeve Gastrectomy Is Associated with a Greater Reduction in Plasma Liver Enzymes Than Bypass Surgeries-A Registry-Based Two-Year Follow-Up Analysis

Bariatric surgeries may lead to an improvement in metabolic fatty liver disease, and a reduction in the levels of the hepatic enzyme Alanine Aminotransferase (ALT). We compared the effects of Sleeve Gastrectomy (SG), Roux en Y Gastric Bypass (RYGB) and One Anastomosis Gastric Bypass (OAGB) on the levels of ALT by analysis of two-year follow-up data from 4980 patients in the Israeli Bariatric Registry that included laboratory tests and demographic information. Pre-operative characteristics of patients, and particularly levels of liver enzymes, were similar across surgery types. Regression modeling and retrospective matching showed that SG was superior to RYGB and OAGB in reducing ALT levels, and in reducing the fraction of patients with abnormally high ALT levels. Two-year post-surgery, an increase in ALT levels from normal to abnormal levels was observed in 5% of SG patients, and in 18% and 23% of RYGB and OAGB patients. In conclusion, SG leads to a greater reduction in ALT levels compared with bypass surgeries and a lower incidence of post-surgical elevation of ALT levels. Further studies are required to identify the cause for the rise in liver enzymes, and to determine whether ALT levels correlate with liver pathology especially following bariatric surgery.

Visual Analysis of Biomarkers Reveals Differences in Lipid Profiles and Liver Enzymes before and after Gastric Sleeve and Bypass

INTRODUCTION

Bariatric surgery results in both intentional and unintentional metabolic changes. In a high-volume bariatric center, extensive laboratory panels are used to monitor these changes pre- and postoperatively. Consecutive measurements of relevant biochemical markers allow exploration of the health state of bariatric patients and comparison of different patient groups.

OBJECTIVE

The objective of this study is to compare biomarker distributions over time between 2 common bariatric procedures, i.e., sleeve gastrectomy (SG) and gastric bypass (RYGB), using visual analytics.

METHODS

Both pre- and postsurgical (6, 12, and 24 months) data of all patients who underwent primary bariatric surgery were collected retrospectively. The distribution and evolution of different biochemical markers were compared before and after surgery using asymmetric beanplots in order to evaluate the effect of primary SG and RYGB. A beanplot is an alternative to the boxplot that allows an easy and thorough visual comparison of univariate data.

RESULTS

In total, 1,237 patients (659 SG and 578 RYGB) were included. The sleeve and bypass groups were comparable in terms of age and the prevalence of comorbidities. The mean presurgical BMI and the percentage of males were higher in the sleeve group. The effect of surgery on lowering of glycated hemoglobin was similar for both surgery types. After RYGB surgery, the decrease in the cholesterol concentration was larger than after SG. The enzymatic activity of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate in sleeve patients was higher presurgically but lower postsurgically compared to bypass values.

CONCLUSIONS

Beanplots allow intuitive visualization of population distributions. Analysis of this large population-based data set using beanplots suggests comparable efficacies of both types of surgery in reducing diabetes. RYGB surgery reduced dyslipidemia more effectively than SG. The trend toward a larger decrease in liver enzyme activities following SG is a subject for further investigation.

First Case Report of Fulminant Hepatitis After Laparoscopic Sleeve Gastrectomy Associated with Concomitant Maximal Therapeutic Dose of Acetaminophen Use, Protein Calorie Malnutrition, and Vitamins A and D, Selenium, and Glutathione Deficiencies

Nonalcoholic fatty liver disease (NAFLD) is increasingly being linked to obesity. Although laparoscopic sleeve gastrectomy (LSG) is effective for weight loss that can ultimately resolve NAFLD, an initial transient deterioration of liver functions could be observed during the first few months post-operatively, after which a subsequent improvement of the liver functions might occur. Rapid weight loss, nutritional deficiencies, and protein malnutrition can all contribute to hepatic dysfunction and can affect the metabolism of medications such as acetaminophen leading to more insult to a compromised liver. We report acute liver failure after LSG associated with protein calorie malnutrition, multiple nutritional deficiencies in addition to concomitant use of therapeutic doses of acetaminophen. Treatment with N-acetylcysteine, and replacement of deficient multivitamins and trace elements resulted in significant improvement in liver functions.

Duodenal-jejunal bypass improves nonalcoholic fatty liver disease independently of weight loss in rodents with diet-induced obesity

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver-related mortality. NAFLD is associated with obesity, hepatic fat accumulation, and insulin resistance, all of which contribute to its pathophysiology. Weight-loss is the main therapy for NAFLD, and metabolic surgery is the most effective treatment for morbid obesity and its metabolic comorbidities. Although has been reported that Roux-en-Y gastric bypass can reverse NAFLD, it is unclear whether such effects result from reduced weight, from a lower calorie-intake, or from the direct influence of surgery on mechanisms contributing to NAFLD. We aimed to investigate whether gastrointestinal (GI) bypass surgery could induce direct effects on hepatic fat accumulation and insulin resistance, independently of weight reduction. Twenty Wistar rats on a high-fat diet underwent duodenal-jejunal-bypass (DJB) or sham operation and were pair fed (PF) for 15 wk after surgery to obtain a matched weight. Outcome measures include ectopic fat deposition, expression of genes and proteins involved in fat metabolism, insulin-signaling, and gluconeogenesis in liver and muscle. Despite no differences in body weight and calorie intake, DJB showed lower ectopic fat accumulation, improved peripheral and hepatic insulin sensitivity, and enhanced lipid droplet degradation. In both tissues, DJB increased insulin signaling, whereas hepatic key enzymes involved in gluconeogenesis and de novo lipogenesis were decreased. These findings suggest that DJB can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of NAFLD that share a mutual pathway, in which perilipin-2 (PLIN2) seems to be the main player, supporting further investigation into strategies that target the gut to treat metabolic liver diseases.NEW & NOTEWORTHY Our findings suggest that duodenal-jejunal bypass can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of nonalcoholic fatty liver disease that share a mutual pathway, in which perilipin-2 seems to be the main player. Our study supports further investigation into the role of proximal small intestine exclusion in the pathophysiology of nonalcoholic fatty liver disease to uncover less invasive treatments that mimic the effects of metabolic surgery and aims to prevent and treat metabolic liver disease.

Modifications of IGF2 and EGFR plasma protein concentrations in NAFLD patients after bariatric surgery

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is strictly associated with the epidemic of obesity and is becoming the most prevalent liver disease worldwide. In severe obesity, bariatric surgery (BS) is the most effective treatment not only for obesity but also for the associated metabolic co-morbidities, NAFLD, among others. To date, noninvasive diagnostic/prognostic methods cannot evaluate hepatic improvements following surgery.

OBJECTIVES

We aimed to measure plasma level of insulin-growth factor-2 protein (IGF2) and epithermal growth factor receptor (EGFR), and to assess their relationship with clinical and biochemical parameters during the 12 months follow-up.

METHODS

Demographic, clinical-biochemical data, and plasma IGF2 and EGFR were measured in 69 patients preoperatively (T0) and 6 and 12 months (T6M and T12M, respectively) after BS. Liver biopsy was performed at T0. Relationships between IGF2, EGFR, and several biochemical parameters were performed using Pearson or Spearman correlation analysis.

RESULTS

IGF2 plasma level increases during follow-up, passing from 2.5 (1.8-15.5) at baseline to 13.3 (8.6-19.1) at T12M, p < 0.001. Conversely, EGFR showed a not significant reduction. At T12M, the plasma level of both markers was comparable to those of lean subjects. The clinical-biochemical parameters (BMI, glycated hemoglobin, HOMA-IR) also return to the normal range at T12M. Correlation analysis demonstrated that IGF2 was significantly associated with total bilirubin, direct bilirubin, and albumin at T0 while with blood glucose, ALT, GGT, and AST/ALT ratio at T6M and T12M.

CONCLUSIONS

IGF2 plasma levels increase after bariatric surgery, and these changes are associated with the modification of hepatic biochemical parameters, even if other clinic or metabolic improvements cannot be excluded.

Mechanisms of nonalcoholic fatty liver disease and implications for surgery

Background

Nonalcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in both adults and children worldwide. Understanding the pathogenic mechanisms behind NAFLD provides the basis for identifying risk factors, such as metabolic syndrome, pancreatoduodenectomy, and host genetics, that lead to the onset and progression of the disease. The progression from steatosis to more severe forms, such as steatohepatitis, fibrosis, and cirrhosis, leads to an increased number of liver and non-liver complications.

Purpose

NAFLD-associated end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC) often require surgery as the only curative treatment. In particular, the presence of NAFLD together with the coexisting metabolic comorbidities that usually occur in these patients requires careful preoperative diagnosis and peri-/postoperative management. Bariatric surgery, liver resection, and liver transplantation (LT) have shown favorable results for weight loss, HCC, and ESLD in patients with NAFLD. The LT demand and the increasing spread of NAFLD in the donor pool reinforce the already existing lack of donor organs.

Conclusion

In this review, we will discuss the diverse mechanisms underlying NAFLD, its implications for surgery, and the challenges for patient management.

Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures - 2019 Update: Cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPGs) was commissioned by the American Association of Clinical Endocrinologists (AACE), The Obesity Society (TOS), American Society for Metabolic and Bariatric Surgery (ASMBS), Obesity Medicine Association (OMA), and American Society of Anesthesiologists (ASA) Boards of Directors in adherence with the AACE 2017 protocol for standardized production of CPGs, algorithms, and checklists.

METHODS

Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts.

RESULTS

New or updated topics in this CPG include: contextualization in an adiposity-based chronic disease complications-centric model, nuance-based and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current health care arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest).

CONCLUSIONS

Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence based within the context of a chronic disease. A team approach to perioperative care is mandatory, with special attention to nutritional and metabolic issues.

A Pilot Study of Serum Sphingomyelin Dynamics in Subjects with Severe Obesity and Non-alcoholic Steatohepatitis after Sleeve Gastrectomy

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is present in a high percentage of obese patients undergoing bariatric surgery. A significant proportion of patients still present NASH even after considerable weight loss and metabolic improvements after surgery.

OBJECTIVE

To determine whether the changes in the serum lipidome after sleeve gastrectomy could be used to discriminate obese patients with NASH patients to those with non-alcoholic fatty liver (NAFL).

METHODS

This study involved 24 patients with grade 3 obesity diagnosed with either NAFL (n = 8) or NASH (n = 16) using the non-invasive OWLiver assay. All patients suffering from NASH were re-evaluated 6 months after bariatric surgery using the OWLiver test to confirm NASH resolution. Serum lipid extracts were assessed at baseline and 6 months post surgery and were analyzed in an ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC-TOF-MS)-based platform.

RESULTS

Lipidomic analysis revealed a differential sphingomyelin profile in patients with NASH resolution after sleeve gastrectomy. Certain serum sphingomyelin species were significantly higher at baseline in NASH patients in comparison to those with NAFL. Sphingomyelin profile of subjects with NASH resolution was similar to that for obese subjects with NAFL before bariatric surgery.

CONCLUSION

Our study indicates that the serum sphingomyelin levels could be related to the status of non-alcoholic fatty liver disease and that certain sphingomyelin species may be used for the follow-up of obese patients with NASH after sleeve gastrectomy.

Longitudinal Comparison of the Effect of Gastric Bypass to Sleeve Gastrectomy on Liver Function in a Bariatric Cohort: Tehran Obesity Treatment Study (TOTS)

BACKGROUND

Patients with morbid obesity commonly have fatty liver disease and elevated liver enzymes. While surgery effectively induces weight loss, bariatric techniques may differ regarding liver function improvement.

OBJECTIVES

To evaluate and compare the trends of liver function recovery after gastric bypass surgery (GB) with sleeve gastrectomy (SG).

SETTING

University hospitals, Iran.

METHODS

Adult bariatric candidates without a history of alcohol consumption or other etiologies of liver disease who underwent SG (n = 682) or GB (n = 355) were included. Trends of weight loss parameters and alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) at 0, 6 (in 90.4%), 12 (in 83.5%), and 24 months (in 67.1%) were compared using generalized estimating equations method.

RESULTS

Overall, 1037 patients with mean age of 38.4 ± 11.2 and mean body mass index of 44.9 ± 6.2 kg/m² were analyzed. Seventy-eight percent of patients had fatty liver by ultrasound. Both GB and SG patients lost significant weight, with GB patients having a higher percentage of excess weight loss at 24 months (80.1% vs. 75.9%, P_{between-group} = .008). SG patients showed more favorable trends in liver chemistries with significantly lower ALT at 12 months and AST and ALP levels at 6 and 12 months. However, the two groups were comparable at 24 months. Significantly more GB patients developed high ALT at 6 and high AST at 6 and 12 months. Undergoing GB was associated with smaller 0-12-month changes in ALT, AST, and ALP.

CONCLUSIONS

Bariatric surgery resulted in improvement in liver function parameters, with SG showing advantages over GB in the first postoperative year.

NAFLD as a continuum: from obesity to metabolic syndrome and diabetes

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) has been increasing rapidly. It is nowadays recognized as the most frequent liver disease, affecting a quarter of global population and regularly coexisting with metabolic disorders such as type 2 diabetes, hypertension, obesity, and cardiovascular disease. In a more simplistic view, NAFLD could be defined as an increase in liver fat content, in the absence of secondary cause of steatosis. In fact, the clinical onset of the disease is a much more complex process, closely related to insulin resistance, limited expandability and dysfunctionality of adipose tissue. A fatty liver is a main driver for a new recognized liver-pancreatic α-cell axis and increased glucagon, contributing to diabetes pathophysiology.

MAIN TEXT

This review will focus on the clinical and pathophysiological connections between NAFLD, insulin resistance and type 2 diabetes. We reviewed non-invasive methods and several scoring systems for estimative of steatosis and fibrosis, proposing a multistep process for NAFLD evaluation. We will also discuss treatment options with a more comprehensive view, focusing on the current available therapies for obesity and/or type 2 diabetes that impact each stage of NAFLD.

CONCLUSION

The proper understanding of NAFLD spectrum-as a continuum from obesity to metabolic syndrome and diabetes-may contribute to the early identification and for establishment of targeted treatment.

WEIGHT LOSS COMPARISON AFTER SLEEVE AND ROUX-EN-Y GASTRIC BYPASS: SYSTEMATIC REVIEW

INTRODUCTION

Bariatric surgery is currently the gold standard treatment for obesity. The two most accomplished surgeries are the Roux-en-Y gastric bypass and the sleeve gastrectomy, and controversies exist in which is better.

OBJECTIVE

To compare the two techniques in relation to weight loss with at least five years of follow-up.

METHODS

Search in Medline, PubMed, Embase, SciElo, Lilacs, Cochrane databases from 2001 (beginning of vertical gastrectomy) until 2018, using the following headings: "sleeve" or "sleeve gastrectomy" combined with "gastric bypass" or "Roux-en-Y gastric bypass", "weight loss" and "clinical trial". Criteria for inclusion of articles were patients aged between 18 and 65 years; clinical trial; comparison between the two techniques; minimum five-year follow-up; outcome with weight loss assessment.

RESULTS

The initial search identified 1940 articles, of which 185 publications were identified as clinical trials. One hundred and forty-one were excluded, 67 because they did not compare the two techniques, 57 not addressed weight loss and 17 were repeated articles. Thirty-four studies were retrieved for a more detailed analysis; 36 studies were excluded due to a follow-up of less than five years, and another compared the mini-gastric bypass. In total, seven studies were included in the systematic review, but there was no significant difference in three of them.

CONCLUSION

The gastric bypass had a greater weight loss than the vertical gastrectomy in all the evaluated studies.

Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures - 2019 update: cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic & Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPG) was commissioned by the American Association of Clinical Endocrinologists, The Obesity Society, the American Society of Metabolic and Bariatric Surgery, the Obesity Medicine Association, and the American Society of Anesthesiologists boards of directors in adherence to the American Association of Clinical Endocrinologists 2017 protocol for standardized production of CPG, algorithms, and checklists.

METHODS

Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts.

RESULTS

New or updated topics in this CPG include contextualization in an adiposity-based, chronic disease complications-centric model, nuance-based, and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current healthcare arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest).

CONCLUSIONS

Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence-based within the context of a chronic disease. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.