Roux-en-Y gastric bypass improves liver histology in patients with non-alcoholic fatty liver disease

Associations between metabolic dysfunction-associated fatty liver disease and atherosclerotic cardiovascular disease

Non-alcoholic fatty liver disease (NAFLD) is closely related to metabolic syndrome and remains a major global health burden. The increased prevalence of obesity and type 2 diabetes mellitus (T2DM) worldwide has contributed to the rising incidence of NAFLD. It is widely believed that atherosclerotic cardiovascular disease (ASCVD) is associated with NAFLD. In the past decade, the clinical implications of NAFLD have gone beyond liver-related morbidity and mortality, with a majority of patient deaths attributed to malignancy, coronary heart disease (CHD), and other cardiovascular (CVD) complications. To better define fatty liver disease associated with metabolic disorders, experts proposed a new term in 2020 - metabolic dysfunction associated with fatty liver disease (MAFLD). Along with this new designation, updated diagnostic criteria were introduced, resulting in some differentiation between NAFLD and MAFLD patient populations, although there is overlap. The aim of this review is to explore the relationship between MAFLD and ASCVD based on the new definitions and diagnostic criteria, while briefly discussing potential mechanisms underlying cardiovascular disease in patients with MAFLD.

Initial outcomes of a dedicated multidisciplinary non-alcoholic fatty liver disease clinic: a retrospective cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a major healthcare burden. Real-world outcomes in dedicated tertiary care settings in Australia remain unknown.

AIM

To evaluate the initial outcomes of patients referred to a dedicated multidisciplinary tertiary care NAFLD clinic.

METHODS

Retrospective review of all adult patients with NAFLD who attended a dedicated tertiary care NAFLD clinic between January 2018 and February 2020 and who had two clinic visits and FibroScans at least 12 months apart. Demographic and health-related clinical and laboratory data were extracted from electronic medical records. Key outcome measures were serum liver chemistries, liver stiffness measurement (LSM) and weight control at 12 months.

RESULTS

A total of 137 patients with NAFLD were included. Median (interquartile range (IQR)) follow-up time was 392 days (343-497 days). One hundred and eleven patients (81%) achieved weight control (i.e. weight loss or stability). Markers of liver disease activity were significantly improved, including median (IQR) serum alanine aminotransferase (48 (33-76) vs 41 (26-60) U/L, P = 0.009) and aspartate aminotransferase (35 (26-54) vs 32 (25-53) U/L, P = 0.020). Median (IQR) LSM across the whole cohort was significantly improved (8.4 (5.3-11.8) vs 7.0 (4.9-10.1) kPa, P = 0.001). No significant reduction was observed in mean body weight or the frequency of metabolic risk factors.

CONCLUSIONS

This study highlights a new model of care for patients with NAFLD and demonstrates promising initial outcomes in relation to significant reductions in markers of liver disease severity. Although most patients achieved weight control, further refinements are needed to achieve significant weight reduction including more frequent and structured dietetic and/or pharmacotherapeutic interventions.

Bariatric-metabolic surgery versus lifestyle intervention plus best medical care in non-alcoholic steatohepatitis (BRAVES): a multicentre, open-label, randomised trial

BACKGROUND

Observational studies suggest that bariatric-metabolic surgery might greatly improve non-alcoholic steatohepatitis (NASH). However, the efficacy of surgery on NASH has not yet been compared with the effects of lifestyle interventions and medical therapy in a randomised trial.

METHODS

We did a multicentre, open-label, randomised trial at three major hospitals in Rome, Italy. We included participants aged 25-70 years with obesity (BMI 30-55 kg/m2), with or without type 2 diabetes, with histologically confirmed NASH. We randomly assigned (1:1:1) participants to lifestyle modification plus best medical care, Roux-en-Y gastric bypass, or sleeve gastrectomy. The primary endpoint of the study was histological resolution of NASH without worsening of fibrosis at 1-year follow-up. This study is registered at ClinicalTrials.gov, NCT03524365.

FINDINGS

Between April 15, 2019, and June 21, 2021, we biopsy screened 431 participants; of these, 103 (24%) did not have histological NASH and 40 (9%) declined to participate. We randomly assigned 288 (67%) participants with biopsy-proven NASH to lifestyle modification plus best medical care (n=96 [33%]), Roux-en-Y gastric bypass (n=96 [33%]), or sleeve gastrectomy (n=96 [33%]). In the intention-to-treat analysis, the percentage of participants who met the primary endpoint was significantly higher in the Roux-en-Y gastric bypass group (54 [56%]) and sleeve gastrectomy group (55 [57%]) compared with lifestyle modification (15 [16%]; p<0·0001). The calculated probability of NASH resolution was 3·60 times greater (95% CI 2·19-5·92; p<0·0001) in the Roux-en-Y gastric bypass group and 3·67 times greater (2·23-6·02; p<0·0001) in the sleeve gastrectomy group compared with in the lifestyle modification group. In the per protocol analysis (236 [82%] participants who completed the trial), the primary endpoint was met in 54 (70%) of 77 participants in the Roux-en-Y gastric bypass group and 55 (70%) of 79 participants in the sleeve gastrectomy group, compared with 15 (19%) of 80 in the lifestyle modification group (p<0·0001). No deaths or life-threatening complications were reported in this study. Severe adverse events occurred in ten (6%) participants who had bariatric-metabolic surgery, but these participants did not require re-operations and severe adverse events were resolved with medical or endoscopic management.

INTERPRETATION

Bariatric-metabolic surgery is more effective than lifestyle interventions and optimised medical therapy in the treatment of NASH.

FUNDING

Fondazione Policlinico Universitario A Gemelli, Policlinico Universitario Umberto I and S Camillo Hospital, Rome, Italy.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Mechanisms linking bariatric surgery to adipose tissue, glucose metabolism, fatty liver disease and gut microbiota

PURPOSE

In the last 20 years, bariatric surgery has achieved an important role in translational and clinical research because of obesity comorbidities. Initially, a tool to lose weight, bariatric surgery now has been shown to be involved in several metabolic pathways.

METHODS

We conducted a narrative review discussing the underlying mechanisms that could explain the impact of bariatric surgery and the relationship between obesity and adipose tissue, T2D, gut microbiota, and NAFLD.

RESULTS

Bariatric surgery has an impact in the relation between obesity and type 2 diabetes, but in addition  it induces the white-to-brown adipocyte trans-differentiation, by enhancing thermogenesis. Another issue is the connection of bariatric surgery with the gut microbiota and its role in the complex mechanism underlying weight gain.

CONCLUSION

Bariatric surgery modifies gut microbiota, and these modifications influence lipid metabolism, leading to improvement of non-alcoholic fatty liver disease.

Diet-induced gut dysbiosis and inflammation: Key drivers of obesity-driven NASH

Sucrose, the primary circulating sugar in plants, contains equal amounts of fructose and glucose. The latter is the predominant circulating sugar in animals and thus the primary fuel source for various tissue and cell types in the body. Chronic excessive energy intake has, however, emerged as a major driver of obesity and associated pathologies including nonalcoholic fatty liver diseases (NAFLD) and the more severe nonalcoholic steatohepatitis (NASH). Consumption of a high-caloric, western-style diet induces gut dysbiosis and inflammation resulting in leaky gut. Translocation of gut-derived bacterial content promotes hepatic inflammation and ER stress, and when either or both of these are combined with steatosis, it can cause NASH. Here, we review the metabolic links between diet-induced changes in the gut and NASH. Furthermore, therapeutic interventions for the treatment of obesity and liver metabolic diseases are also discussed with a focus on restoring the gut-liver axis.

Pre-operative cardiopulmonary, metabolic, abdominal, and somatic variations by race in men with obesity resolve after Laparoscopic Roux-en-Y gastric bypass (LRYGB): Dyslipidemia and psychologicals by race persist

BACKGROUND

Whether/how LRYGB men vary by race in clinical characteristics/post-operative outcomes is unknown.

OBJECTIVE

Identify male pre-/post LRYGB clinical/outcomes variations by race.

METHODS

Data from 17,734 LYRGB BOLD database men were analyzed in five groups: African American (AA, n = 1310), Caucasian (C, n = 14,168), Asian (A, n = 53), Hispanic (H, n = 1519), and Other (O, Pacific Islander, Native American, or more than one race, n = 684).

DATA

demographics, BMI, and 28 weight-related conditions.

RESULTS

Pre-LRYGB age, health insurance, unemployment, BMI, and 24/28 obesity related comorbidities varied by race (p < 0.01). Highest pre-LRYGB: AA 4, C 14, A 5, H none, O 1 comorbidity. 12 month BMI and 14 comorbidities varied by race (p < 0.05). 24 months only dyslipidemia, depression, and psychological impairment varied by race (p < 0.05).

CONCLUSION

Demographics, BMI and 24 obesity comorbidities vary by race in LRYGB men, but only 3 at 24 months. Caucasians have the greatest cardiopulmonary related comorbidities. This advanced knowledge may facilitate peri-operative management.

Bariatric Surgery Improves Nonalcoholic Fatty Liver Disease: Systematic Review and Meta-Analysis

PURPOSE

Bariatric surgery has been uncovered to relieve nonalcoholic fatty liver disease (NAFLD) in patients with obesity, while current studies have neutral or opposite results. This systematic review and meta-analysis aimed to evaluate the effects of bariatric surgery on NAFLD in patients with obesity.

MATERIALS AND METHODS

PubMed, Embase, Cochrane Central, and Web of Science databases were performed to obtain publications containing comparison results of liver biopsy before and after bariatric surgery in obesity. Primary outcomes were biopsy-confirmed remission of NAFLD and NAFLD activity scores. Secondary outcomes were liver function. This study was registered with PROSPERO, CRD42021240346.

RESULTS

Thirty-seven studies were included. After bariatric surgery, a biopsy-confirmed resolution of steatosis was improved in 56% of patients, ballooning degeneration in 49%, inflammation in 45%, and fibrosis in 25%. Bariatric surgery significantly decreased mean NAFLD activity scores. RYGB achieved the most obviously improvements in steatosis, and SG attained the most notably ameliorations in fibrosis. The percentage of patients with improved steatosis and hepatic fibrosis in Asian countries was higher than non-Asian countries. The reduction of ALT and AST was 11.95U/L and 6.44 U/L after surgery.

CONCLUSION

Our study has revealed that bariatric surgery brought out significantly resolution of NAFLD in individuals with obesity. RYGB and SG have been proved to be of benefit to many hepatic parameters, and the improvement of liver steatosis and fibrosis, particularly in Asian countries. It is strongly suggested that bariatric surgery should be considered as a novel treatment for NAFLD.

Hepatic steatosis changes after early gastric cancer surgery

Background: Nonalcoholic fatty liver disease dramatically improves after bariatric surgery, primarily due to improvements in hepatic insulin sensitivity. Since the procedure for gastric cancer surgery is very similar to that for bariatric surgery, we investigated changes in fatty liver following gastrectomy for gastric cancer according to the type of surgery.Methods: We evaluated hepatic steatosis in 212 early gastric cancer patients using Hounsfield units (HUs) on non-contrast computed tomography preoperatively and 6, 12, and 24 months after surgery. We compared the preoperative and postoperative liver-to-spleen HU ratio according to the type of surgery: Billroth I, Billroth II, and total gastrectomy with Roux-en-Y reconstruction. Results: The initial results (liver/spleen HUs and the liver-to-spleen HU ratio) did not significantly differ according to surgical group. After surgery, only patients who underwent total gastrectomy with Roux-en-Y exhibited significant changes in the liver-to-spleen HU ratio at 6 months. In 26 patients who had higher initial HU levels of the spleen than the liver, the liver-to-spleen HU ratio significantly increased from 0.836 to 1.115 at 6 months, 1.109 at 12 months, and 1.102 at 24 months (P<0.01). Conclusion: Significant changes in hepatic steatosis were found in even normal patients (with higher liver than spleen HU values) who underwent total gastrectomy with Roux-en-Y. Patients who initially had fatty liver also showed a significant increase in the liver-to-spleen HU ratio. These results suggest that total gastrectomy with Roux-en-Y reconstruction can have a positive effect on the improvement of hepatic steatosis.

Fit mothers for a healthy future: Breaking the intergenerational cycle of non-alcoholic fatty liver disease with maternal exercise

SPECIAL ISSUE: 'FOIEGRAS-Bioenergetic Remodelling in the Pathophysiology and Treatment of Non-Alcoholic Fatty Liver Disease'.

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) emerges as significant health burden worldwide. Lifestyle changes, unhealthy dietary habits and physical inactivity, can trigger NAFLD development. Persisting on these habits during pregnancy affects in utero environment and prompts a specific metabolic response in foetus resulting in offspring metabolic maladjustments potentially critical for developing NAFLD later in life. The increasing prevalence of NAFLD, particularly in children, has shifted the research focus towards preventive and therapeutic strategies. Yet, designing effective approaches that can break the NAFLD intergenerational cycle becomes even more complicated. Regular physical exercise (PE) is a powerful non-pharmacological strategy known to counteract deleterious metabolic outcomes. In this narrative review, we aimed to briefly describe NAFLD pathogenesis focusing on maternal nutritional challenge and foetal programming, and to provide potential mechanisms behind the putative intergenerational effect of PE against metabolic diseases, including liver diseases.

METHODS

Following detailed electronic database search, recent existing evidence about NAFLD development, intergenerational programming and gestational exercise effects was critically analysed and discussed.

RESULTS

PE during pregnancy could have a great potential to counteract intergenerational transmission of metabolic burden. The interplay between different PE roles-metabolic, endocrine and epigenetic-could offer a more stable in utero environment to the foetus, thus rescuing offspring vulnerability to metabolic disturbances.

CONCLUSIONS

The better understanding of maternal PE beneficial consequences on offspring metabolism could reinforce the importance of PE during pregnancy as an indispensable strategy in improving offspring health.

Non-Alcoholic Fatty Liver Disease (NAFLD) and Bariatric/Metabolic Surgery as Its Treatment Option: A Review

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) has considerably increased over the last years. NAFLD is currently the most common cause of chronic liver disease in the developing world. The diagnosis of NAFLD/NASH is often incidental, as the early-stage of disease is frequently free of symptoms. Most patients recognized with NAFLD have severe obesity and other obesity-related disease such as type 2 diabetes mellitus (T2DM), insulin-resistance, dyslipidemia and hypertension. The only proven method for NAFLD improvement and resolution is weight loss. Bariatric surgery leads to significant and long-term weight loss as well as improvement of coexisting diseases. There is a lot of evidence suggesting that metabolic/bariatric surgery is an effective method of NAFLD treatment that leads to reduction in steatosis, hepatic inflammation and fibrosis. However, there is still a need to perform long-term studies in order to determine the role of bariatric surgery as a treatment option for NAFLD and NASH. This review discusses current evidence about epidemiology, pathogenesis and treatment options for NAFLD including bariatric/metabolic surgery and its effect on improvement and resolution of NAFLD.

Efficacy and safety of endoscopic sleeve gastroplasty versus laparoscopic sleeve gastrectomy in obese subjects with Non-Alcoholic SteatoHepatitis (NASH): study protocol for a randomized controlled trial (TESLA-NASH study)

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is frequently associated with obesity, and its standard treatment is weight loss with diet and exercise; a dy% weight reduction has been associated with improvement in liver histological and analytical abnormalities. However, less than 25% of subjects achieve this goal. Laparoscopic sleeve gastrectomy (LSG) represents the most common procedure of bariatric surgery, providing effective weight loss and improvement in comorbidities such as NASH, but it is associated with several postoperative complications. Endoscopic bariatric techniques are currently on the rise as a new tool in the fight against obesity, offering patients an alternative to more invasive surgery. However, their efficacy and safety compared with LSG is unclear.

METHODS

The TESLA-NASH study is a randomized, controlled, open-label, unicentric clinical trial with a medical device. The aim of this study is to evaluate and compare the efficacy and safety of endoscopic sleeve gastroplasty (ESG) versus laparoscopic sleeve gastrectomy (LSG) in liver histology improvement of patients with obesity +/- metabolic syndrome and NASH. A total of 30 patients will be randomized 1:1 to the experimental or control group.

DISCUSSION

LSG is an effective treatment for weight reduction and for the remission of hepatic alterations. However, LSG is associated with acute and chronic postoperative complications. Bariatric endoscopic techniques promise less invasive and more cost-effective approaches to the treatment of obesity and metabolic comorbidities. ESG represents one of the most promising novel endoscopic interventions and it is mainly proposed for patients with mild-to-moderate obesity, but there are still no guidelines that specify its applicability criteria. This clinical trial will help us apply different tactics to the treatment of obesity and NASH.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04060368. Registered on Nov 15, 2019.

New targets for NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease worldwide. It is characterised by steatosis, liver inflammation, hepatocellular injury and progressive fibrosis. Several preclinical models (dietary and genetic animal models) of NAFLD have deepened our understanding of its aetiology and pathophysiology. Despite the progress made, there are currently no effective treatments for NAFLD. In this review, we will provide an update on the known molecular pathways involved in the pathophysiology of NAFLD and on ongoing studies of new therapeutic targets.

Bariatric Surgery and Liver Disease: General Considerations and Role of the Gut-Liver Axis

Weight loss is a therapeutic solution for many metabolic disorders, such as obesity and its complications. Bariatric surgery aims to achieve lasting weight loss in all patients who have failed after multiple dietary attempts. Among its many benefits, it has been associated with the regression of non-alcoholic fatty liver disease (NAFLD), which is often associated with obesity, with evidence of substantial improvement in tissue inflammation and fibrosis. These benefits are mediated not only by weight loss, but also by favorable changes in systemic inflammation and in the composition of the gut microbiota. Changes in microbial metabolites such as short-chain fatty acids (SCFAs), capable of acting as endocrine mediators, and bile acids (BAs) as well as modifications of the gut-brain axis, are among the involved mechanisms. However, not all bariatric surgeries show beneficial effects on the liver; those leading to malabsorption can cause liver failure or a marked worsening of fibrosis and the development of cirrhosis. Nevertheless, there are still many unclear aspects, including the extent of the benefits and the magnitude of the risks of bariatric surgery in cirrhotic patients. In addition, the usefulness and the safety of these procedures in patients who are candidates to or who have undergone liver transplant need solid supporting evidence. This paper aims to review literature data on the use of bariatric surgery in the setting of chronic liver disease.

The Effect of Laparoscopic Sleeve Gastrectomy and Gastric Bypass Surgery on Non-Alcoholic Steatohepatitis in Iranian Patients with Obesity

BACKGROUND Non-alcoholic steatohepatitis (NASH) is a serious comorbidity in patients with obesity and because of the high risk of cirrhosis and the extreme mortality rate of NASH, approaching effective treatment methods, and improvements are crucial. Following few studies comparing the impact of laparoscopic gastric bypass (LGB) and laparoscopic sleeve gastrectomy (LSG) surgery on NASH, our study was conducted to assess the effect of these two surgical methods separately in patients with NASH through ultrasonography, and concurrently, on other factors such as lipid profiles and blood pressure to reduce the complications of complex obesity surgeries on patients and also provide a solution to prevent NASH-related cirrhosis. METHODS This study was performed at Imam Khomeini Hospital Complex; Vali-e-Asr Hospital affiliated to Tehran University of Medical Sciences.All patients with obesity who had undergone bariatric surgery at Vali-e-Asr Hospital during 2017 and 2018 were included in this prospective cohort study. Weight, body mass index (BMI), blood pressure, Alanine transaminase(ALT), Aspartate transaminase(AST),lipid profile and Fasting blood sugar(FBS)were evaluated before and one year after surgery. The patients underwent an ultrasound examination before surgery to determine the fatty liver grade. The type of operation (sleeve or bypass) was governed by the patient him/herself after receiving thorough clarifications about the available methods, their complications, and expected outcomes. In addition, by the separation of fatty liver grading with ultrasound modality, the correlation between ultrasound grading, laboratory results, and the rate of weight loss in patients who undergone both sleeve and bypass surgeries were evaluated and compared during a one-year follow-up. RESULTS In this study, 44 patients were included. 22 patients underwent laparoscopic sleeve gastrectomy (LSG), and 22 patients underwent laparoscopic gastric bypass (LGB) surgery. The mean age of the patients was 40.45 ± 12.01 years. 35 patients (79.5%) were women, and 9 patients (20.5%) were men. Most patients (81.8%) had grade I and II in terms of preoperative liver ultrasonography results. Bariatric surgery (LSG and LGB) greatly enhanced NASH's hepatic status in liver ultrasonography. Since the liver status of patients with preoperative ultrasonography was not significantly different between the two groups, there was no substantial distinction among the two groups in this regard, postoperatively. Weight and BMI, lipid profile, liver enzymes, FBS, and mean arterial blood pressure (MAP) were significantly reduced individually in both groups and all patients one year after surgery. None of the postoperative variables and their modifications had a prominent difference between the two groups except for High-density lipoprotein(HDL)level after surgery. The postoperative HDL was considerably higher in the LGB group (p = 0.014). However, the changes in HDL were not statistically different between both groups. The levels of AST, ALT, total cholesterol, LDL, and FBS were associated with the NASH grade. CONCLUSION Both types of LSG and LGB bariatric surgeries have been shown to significantly reduce BMI and improve lipid profiles, liver enzymes, and blood glucose levels in patients one year after surgery. The NASH status was also ameliorated considerably. The two types of surgery were not remarkably different in these modifications. Besides, there was a significant correlation between AST, ALT, total cholesterol, LDL, and FBS levels with the NASH grade.

Nonalcoholic Fatty Liver Disease (NAFLD). Mitochondria as Players and Targets of Therapies?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and represents the hepatic expression of several metabolic abnormalities of high epidemiologic relevance. Fat accumulation in the hepatocytes results in cellular fragility and risk of progression toward necroinflammation, i.e., nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Several pathways contribute to fat accumulation and damage in the liver and can also involve the mitochondria, whose functional integrity is essential to maintain liver bioenergetics. In NAFLD/NASH, both structural and functional mitochondrial abnormalities occur and can involve mitochondrial electron transport chain, decreased mitochondrial β-oxidation of free fatty acids, excessive generation of reactive oxygen species, and lipid peroxidation. NASH is a major target of therapy, but there is no established single or combined treatment so far. Notably, translational and clinical studies point to mitochondria as future therapeutic targets in NAFLD since the prevention of mitochondrial damage could improve liver bioenergetics.

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.

BYPASS VS. SLEEVE AND ITS EFFECTS IN NON-ALCOHOLIC FATTY LIVER DISEASE: WHAT IS THE BEST TECHNIQUE?

BACKGROUND

Strongly associated with obesity, non-alcoholic fatty liver disease is considered the hepatic manifestation of the metabolic syndrome. It presents as simple steatosis and steatohepatitis, which can progress to cirrhosis and its complications. Among the therapeutic alternatives is bariatric surgery.

AIM

To compare the effect of the two most frequent bariatric procedures (sleeve and bypass) on liver disease regarding to epidemiological, demographic, clinical and laboratory parameters.

METHODS

The results of intraoperative and 12 months after surgery liver biopsies were used. The NAFLD activity score (NAS) was used to assess and compare the stages of liver disease.

RESULTS

Sixteen (66.7%) patients underwent Bypass procedure and eight (33.3%) Sleeve. It was observed that the variation in the NAFLD activity score was significantly greater in the Bypass group than in Sleeve (p=0.028) and there was a trend regarding the variation in fibrosis (p=0.054).

CONCLUSION

Both surgical techniques were effective in improving the hepatic histology of most operated patients. When comparing sleeve and bypass groups, bypass showed better results, according to the NAS score.

Protocols for Mitochondria as the Target of Pharmacological Therapy in the Context of Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent metabolic chronic liver diseases in developed countries and puts the populations at risk of progression to liver necro-inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma. Mitochondrial dysfunction is involved in the onset of NAFLD and contributes to the progression from NAFLD to nonalcoholic steatohepatitis (NASH). Thus, liver mitochondria could become the target for treatments for improving liver function in NAFLD patients. This chapter describes the most important steps used for potential therapeutic interventions in NAFLD patients, discusses current options gathered from both experimental and clinical evidence, and presents some novel options for potentially improving mitochondrial function in NAFLD.

Therapeutic approaches for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) have been reported as a novel worldwide epidemic, very often associated with obesity, metabolic syndrome, and type 2 diabetes. Both conditions have also been shown to be associated with a number of endocrine pathologies. Despite the epidemic, the complex pathophysiology and major complications, ranging from metabolic disturbances (diabetes and more) to cardiovascular disease, people with NASH are left with very few management options. The best and most approved therapeutic option is lifestyle intervention. Although pharmacotherapies based on pathophysiological background are in development, response rates appear modest, mainly for fibrosis treatment, which is the reason for lack of approved drug therapy. Previous drugs analyzed, such as pioglitazone and vitamin E, show weak efficacy. From different phase II trials, antidiabetic (injectable) drugs seem to be promising, both in mono- or bitherapy. Also, derivatives of peroxisome proliferator-activated receptors may have an interesting future, as well. For that reason, more focus should be given on prevention of this novel disease entity. In view of this booming epidemic, with a background of obesity and type 2 diabetes, and the important medical consequences, early recognition, prevention and intervention of NAFLD/NASH seems appropriate. In this review, we will focus on the different current and future therapeutic intervention options, taking into consideration the complex pathophysiology of this disease.

Phase angle and non-alcoholic fatty liver disease before and after bariatric surgery

BACKGROUND

Obesity is a global health problem that is continuing to increase in the young population. In Brazil, the frequency of obesity in 2018 was 19.8%. Several comorbidities are directly associated with obesity, such as non-alcoholic fatty liver disease (NAFLD), which is considered the most common liver disorder in Western countries and affects up to 46% of adults. Bariatric surgery is effective in treating obesity and can improve NAFLD; however, the effect of bariatric surgery on body composition, phase angle (PA), and improving NAFLD needs to be further studied.

AIM

To analyze the PA in the postoperative period of bariatric surgery and to correlate it with changes in body composition and liver disease.

METHODS

This study is a retrospective cohort study of the analysis of the medical records of patients undergoing bariatric surgery in a reference center of a teaching hospital in Porto Alegre over a 2-year period. Patients older than 18 years whose record contained all information relevant to the study were included. The data analyzed were body composition and PA through electrical bioimpedance and NAFLD through liver biopsy in the pre- and postoperative period. The level of significance adopted for the statistical analyses was 5%.

RESULTS

We evaluated 379 patients with preoperative data. Regarding PA, 169 patients were analyzed, and 33 patients had liver biopsy pre- and postoperatively with NAFLD information. In total, 79.4% were female, with a mean age of 39.1 ± 10.6 years. The average body mass index (BMI) was 45.9 ± 7.5 kg/m². The PA showed a mean of 5.8 ± 0.62° in the preoperative period and a significant reduction in the postoperative period. A postoperative reduction in body composition data (skeletal muscle mass, fat percentage, fat mass, body cell mass, BMI and visceral fat area) was shown as well. Regarding liver disease, all patients presented a reduction in the degrees and stages of liver disease in the postoperative period, and some had no degree of liver disease at all.

CONCLUSION

PA decreased after bariatric surgery, with a direct correlation with weight loss and changes in body composition. The decrease in PA was not correlated with the improvement in NAFLD.

Predictors of Alcohol Use after Bariatric Surgery

Patients undergoing bariatric surgery are at risk for devloping an alcohol use disorder (AUD). The purpose of this study was to investigate pre-surgical psychosocial risk factors for post-surgical alcohol consumption and hazardous drinking. Participants (N = 567) who underwent bariatric surgery between 2014 and 2017 reported their post-surgical alcohol use. Information was collected from the pre-surgical evaluation including history of alcohol use, psychiatric symptoms, and maladaptive eating behaviors (i.e., binge eating, purging, and emotional eating). Younger age and pre-surgical alcohol use predicted post-surgical alcohol use and hazardous drinking. In addition, higher levels of depressive symptoms and maladaptive eating patterns predicted post-surgical binge drinking. Clinicians conducting pre-surgical psychosocial evaluations should be aware of the multiple risk factors related to post-surgical problematic alcohol use. Future research should evaluate whether preventive interventions for high-risk patients decrease risk for post-surgical alcohol misuse.

Bariatric Surgery is Associated With Decreased Progression of Nonalcoholic Fatty Liver Disease to Cirrhosis: A Retrospective Cohort Analysis

OBJECTIVE

This study sought to compare trends in the development of cirrhosis between patients with NAFLD who underwent bariatric surgery and a well-matched group of nonsurgical controls.

SUMMARY OF BACKGROUND DATA

Patients with NAFLD who undergo bariatric surgery generally have improvements in liver histology. However, the long-term effect of bariatric surgery on clinically relevant liver outcomes has not been investigated.

METHODS

From a large insurance database, patients with a new NAFLD diagnosis and at least 2 years of continuous enrollment before and after diagnosis were identified. Patients with traditional contraindications to bariatric surgery were excluded. Patients who underwent bariatric surgery were identified and matched 1:2 with patients who did not undergo bariatric surgery based on age, sex, and comorbid conditions. Kaplan-Meier analysis and Cox proportional hazards modeling were used to evaluate differences in progression from NAFLD to cirrhosis.

RESULTS

A total of 2942 NAFLD patients who underwent bariatric surgery were identified and matched with 5884 NAFLD patients who did not undergo surgery. Cox proportional hazards modeling found that bariatric surgery was independently associated with a decreased risk of developing cirrhosis (hazard ratio 0.31, 95% confidence interval 0.19-0.52). Male gender was associated with an increased risk of cirrhosis (hazard ratio 2.07, 95% confidence interval 1.31-3.27).

CONCLUSIONS

Patients with NAFLD who undergo bariatric surgery are at a decreased risk for progression to cirrhosis compared to well-matched controls. Bariatric surgery should be considered as a treatment strategy for otherwise eligible patients with NAFLD. Future bariatric surgery guidelines should include NAFLD as a comorbid indication when determining eligibility.

Clinical Characteristics and Outcome of Morbidly Obese Bariatric Patients with Concurrent Hepatitis C Viral Infection

BACKGROUND

Hepatitis C virus (HCV) is an important cause of liver cirrhosis and its complications. The safety and efficacy of bariatric surgery in patients with HCV infection is not clear.

METHODS

Charts were reviewed to identify patients with HCV infection before bariatric surgery. Bariatric surgical patients with non-alcoholic steatohepatitis (NASH) and without NASH (non-NASH) were recruited as comparative groups. Demographic variables, perioperative data, follow-up, and HCV-related parameters were extracted and compared.

RESULTS

Forty-seven bariatric patients between 2000 and 2016 that suffered from HCV infection were identified. The mean age and body mass index (BMI) at baseline were 34.5 ± 9.9 years and 40.4 ± 7.7 kg/m², respectively. The HCV(+) group was associated with female sex, older age, lower BMI, and waist circumference than both NASH and non-NASH groups. Both HCV(+) and NASH groups had higher liver function tests and incidence of metabolic syndrome than non-NASH group. The HCV(+) group had lower uric acid and albumin level than the NASH group. Early major postoperative complication occurred in 1 (2.1%) patient of the HCV(+) group. At follow-up, the mean BMI decreased to 29.1 ± 7.1 kg/m² and total weight loss was 25% for the HCV(+) group at 5 years after surgery. The weight loss curves were similar between the HCV(+) group and NASH group. During follow-up, no patients died but one patient with HCV(+) developed flare up of hepatitis after gastric bypass. The mean liver transaminase level remained in normal range for the HCV(+) group.

CONCLUSION

Co-existence of HCV infection does not influence the outcome of bariatric surgery but continued monitoring of the liver function is indicated.

Increased Bile Acid Signals After Duodenal-Jejunal Bypass Improve Non-alcoholic Steatohepatitis (NASH) in a Rodent Model of Diet-Induced NASH

BACKGROUND

The increasing incidence of non-alcoholic steatohepatitis (NASH) has resulted in it becoming a common cause of liver-related mortality; however, no efficient treatment has been established. It has been reported that bariatric surgery improves metabolic comorbidities, such as diabetes mellitus and NASH. Although the mechanism is unclear, it is thought that the changes in bile acid (BA) signaling via its nuclear receptor, farnesoid X receptor (FXR), produce various metabolic effects. We sought to investigate the effects and mechanisms of bariatric surgery on NASH improvement.

METHODS

Male Sprague-Dawley rats were fed by a high-fat and high-fructose diet, which results in obesity, insulin resistance, and NASH. Rats underwent duodenal-jejunal bypass (DJB), which is a main component of bariatric procedures. The liver pathological findings and the expression level of mRNA of FXR were investigated. The plasma BA level was measured in peripheral and portal vein blood.

RESULTS

DJB suppressed weight gain, improved insulin resistance, and ameliorated NASH mainly in a point of inflammation. The plasma BA level along with the expression of FXR and its target transcriptional factor, small heterodimer partner (SHP), in the liver were elevated.

CONCLUSIONS

DJB has a direct effect on NASH improvement, and there is a possibility that an anti-inflammatory effect is functioning as a part of the mechanism. The increase of plasma bile acid level followed by the stimulation of FXR signaling may contribute to this phenomenon.

Complete Resolution of Nonalcoholic Fatty Liver Disease After Bariatric Surgery: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Bariatric surgery has been reported to lead to complete resolution of nonalcoholic fatty liver disease (NAFLD) following the sustained weight loss induced in obese patients. We performed a systematic review and meta-analysis to evaluate the effects of bariatric surgery on NAFLD in obese patients.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and Web of Science databases through May 2018 for studies that compared liver biopsy results before and after bariatric surgery in obese patients. Primary outcomes were biopsy-confirmed resolution of NAFLD and NAFLD activity score. Secondary outcomes were worsening of NAFLD after surgery and liver volume. The Grading of Recommendations, Assessment, Development, and Evidence approach was conducted to assess overall quality of evidence.

RESULTS

We analyzed data from 32 cohort studies comprising 3093 biopsy specimens. Bariatric surgery resulted in a biopsy-confirmed resolution of steatosis in 66% of patients (95% CI, 56%-75%), inflammation in 50% (95% CI, 35%-64%), ballooning degeneration in 76% (95% CI, 64%-86%), and fibrosis in 40% (95% CI, 29%-51%). Patients' mean NAFLD activity score was reduced significantly after bariatric surgery (mean difference, 2.39; 95% CI, 1.58-3.20; P < .001). However, bariatric surgery resulted in new or worsening features of NAFLD, such as fibrosis, in 12% of patients (95% CI, 5%-20%). The overall Grading of Recommendations, Assessment, Development, and Evidence quality of evidence was very low.

CONCLUSIONS

Through this systematic review and meta-analysis, we found that bariatric surgery leads to complete resolution of NAFLD in obese patients. However, some patients develop new or worsened features of NAFLD. Randomized controlled trials are needed to further examine the therapeutic benefits of bariatric surgery for patients with NAFLD.

Risk factors and prevalence of liver disease in review of 2557 routine liver biopsies performed during bariatric surgery

BACKGROUND

Obesity is a known risk factor for nonalcoholic fatty liver disease (NAFLD). However, among individuals undergoing bariatric surgery, the prevalence and risk factors for NAFLD, as well as distinct phenotypes of steatosis, nonalcoholic steatohepatitis (NASH), and fibrosis remain incompletely understood.

OBJECTIVES

To determine the prevalence and risk factors for steatosis, NASH, and fibrosis in individuals undergoing routine bariatric surgery.

SETTING

Academic medical center in the United States.

METHODS

Liver wedge biopsies were performed at the time of surgery between 2001 and 2017. Pathology reports were reviewed, and individuals were grouped by NAFLD phenotype. Covariates including demographic characteristics, co-morbidities, and preoperative laboratory values were compared between groups using Student's t test, Pearson's χ², and logistic regression.

RESULTS

Liver biopsies were obtained in 97.7% of first-time bariatric procedures, representing 2557 patients. Mean age was 45.6 years, mean body mass index was 46.7, and most were non-Hispanic white (76.1%) and female (71.6%). On histologic review 61.2% had steatosis and 30.9% NASH. Fibrosis was identified in 29.3% of individuals, and 7.8% had stage ≥2 fibrosis. On logistic regression, elevated aspartate aminotransferase (odds ratio [OR] 1.87; P < .001) and elevated alanine aminotransferase (OR 1.62; P < .001) were independently associated with fibrosis. Elevated hemoglobin A1C of 5.7% to 6.5% (OR 1.29; P < .01) and >6.5% (OR 3.23; P < .001) were also associated with fibrosis. A similar trend was seen for NASH.

CONCLUSIONS

NASH and/or fibrosis is present in nearly one third of patients undergoing routine bariatric surgery. Risk factors include diabetes, elevated liver enzymes, and diabetes. Risk assessment and aggressive screening should be considered in patients undergoing bariatric surgery.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Bariatric surgery improves nonalcoholic fatty liver disease: a contemporary systematic review and meta-analysis

High-level evidence of the impact of bariatric surgery on nonalcoholic fatty liver disease (NAFLD) is lacking. We conducted a systematic review and meta-analysis according to the Cochrane guidelines to assess the resolution of NAFLD after bariatric surgery. We searched PubMed, EMBASE, Web of Science, and CENTRAL for English language publications on bariatric surgery and NAFLD. We included randomized controlled trials and observational studies of patients with NAFLD who underwent bariatric surgery and were assessed by liver biopsy or liver function tests. Duodenal switch and biliopancreatic diversion were excluded. Our primary outcome was histologic or biochemical improvement of NAFLD. Twenty-one studies (12 Roux-en-Y gastric bypass [RYGB], 3 adjustable gastric banding, 2 sleeve gastrectomy, 1 vertical banded gastroplasty, 3 multiple procedures) enrolling 2374 patients were included. The pooled proportion of patients who had improvement of steatosis was 88% (95% confidence interval [CI]: .80, .94). Steatohepatitis improved in 59% (95% CI: .38, .78) and fibrosis improved or resolved in 30% of patients (95% CI: .21, .41). Similarly, aspartate aminotransferase (AST) improved in 32% of patients (95% CI: .22, .42) and alanine aminotransferase improved in 62% of patients (95% CI: .42, .82). After RYGB, the number of patients who had improvement in NAFLD was higher than the average of all the pooled studies. Bariatric surgery improves steatosis and steatohepatitis in the majority of patients and improves or resolves liver fibrosis in 30% of patients. RYGB has a greater impact on NAFLD histology compared with other procedures. This contemporary meta-analysis strongly suggests that bariatric surgery should be considered as a treatment of NAFLD.

Significant Liver-Related Morbidity After Bariatric Surgery and Its Reversal-a Case Series

Background

Nonalcoholic fatty liver disease (NAFLD) occurs in up to 80% of patients with obesity. Current data suggest an improvement of NAFLD after established bariatric procedures.

Objectives

This study investigated liver function impairment after Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB).

Setting

University Hospital, Bariatric Surgery Unit

Methods

In this single-center case series, consecutive in- and outpatients after bariatric surgery who presented with severe liver dysfunction from March 2014 to February 2017 were included and followed until March 2017.

Results

In total, 10 patients (m:f = 2:8; median age 48 years, range 22–66 years) were included. Liver dysfunction occurred after a median postoperative time of 15 months (range 2–88 months). Median %excess weight loss at that time was 110.6% (range 85.2–155.5%). Liver steatosis/fibrosis occurred in 70%, cirrhosis in 30% of patients, and led to fatigue (90%), ascites (70%), hepatic encephalopathy (30%), and upper gastrointestinal bleeding (20%). Elevation of transaminases, impairment of coagulation parameters, thrombocytopenia, and hypoalbuminemia were present in 70, 80, 70, and 100%, respectively. In eight patients, lengthening of the alimentary/common limb led to an improvement or complete remission of symptoms. In one patient, liver transplantation was required, one patient deceased due to septic shock and decompensated liver disease.

Conclusions

Severe liver dysfunction may also occur after bariatric procedures such as OAGB and RYGB. A comprehensive, meticulous follow-up for early identification of postoperative liver impairment should be aspired. Bypass length reduction led to a fast improvement in all patients.

Nonalcoholic steatohepatitis, obesity, and cardiac dysfunction

PURPOSE OF REVIEW

Obesity and nonalcoholic steatohepatitis (NASH) are epidemiologically and pathophysiologically linked disorders. Here, we summarize the effect of obesity on NASH and how it has a cascading effect on cardiovascular dysfunction. We also review the current and emerging treatment options for NASH.

RECENT FINDINGS

The link between NASH and cardiac dysfunction has been further delineated in recent studies demonstrating endothelial dysfunction, diastolic dysfunction, and increased coronary artery calcification in patients with known NASH. Standard treatment of obesity with lifestyle interventions including diet, exercise, and behavioral modification has been shown to improve NASH as well as reduce cardiovascular dysfunction. In addition to FDA-approved drugs like vitamin E and pioglitazone, several agents including NGM282, obeticholic acid, elafibranor, and liraglutide are currently being investigated for their therapeutic potential in NASH. Recent studies show that bariatric surgery results in significant improvement or resolution of NASH.

SUMMARY

Obesity is a major factor in the development of nonalcoholic fatty liver disease (NAFLD) and its progression to steatohepatitis. Patients with NAFLD have a significant increase in cardiovascular disease risk. For biopsy-proven NASH, vitamin E and pioglitazone are the recommended medical treatments in addition to lifestyle modification.

Long-term effect of bariatric surgery on resolution of nonalcoholic steatohepatitis (NASH): An external validation and application of a clinical NASH score

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is an important etiology of end-stage liver disease. Long-term effect of bariatric surgery in improvement of NASH is not clear.

OBJECTIVES

To validate a scoring system for predicting NASH in morbidly obese patients and using it to evaluate the long-term effect of bariatric surgery on NASH.

SETTING

Tertiary referral hospital, Taiwan.

METHODS

A new 5-point clinical NASH (C-NASH) score incorporating body mass index, alanine aminotransferase, and triglyceride was validated in a group of 307 bariatric patients (mean age 30.2 years, incorporating body mass index 45.0 kg/m²) with concurrent liver biopsy from 2003 to 2008. Remission of NASH in 5741 obese patients undergoing bariatric/metabolic surgery with long-term follow-up was then evaluated using the C-NASH score.

RESULTS

Among 307 patients with liver biopsy, the prevalence of NASH was 44.0%. At baseline, the NASH group had significantly worse fasting glucose levels, triglycerides, uric acid, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, and glycated hemoglobin. The diagnostic sensitivity of C-NASH score was 84.4%, and the accuracy was 68.4%. Among 5741 bariatric patients, the prevalence of high risk for NASH evaluated by C-NASH score was 40.9%. Postoperative follow-up showed good weight loss and almost complete remission of high risk for NASH up to 10 years. Patients with gastric banding had less weight loss, higher mean level of C-NASH score, and a higher incidence of high risk for NASH compared with other procedures at follow-up.

CONCLUSION

This study demonstrated that improvement in C-NASH score suggesting remission of NASH is durable up to 10 years in all kinds of bariatric procedures.

Nonalcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) commonly exist together. It has been regarded as a manifestation of the metabolic syndrome. The presentations of NAFLD range from simple steatosis (NAFL), nonalcoholic steatohepatitis (NASH), and cirrhosis. NAFLD has a prevalence of 70% among T2DM patients. Overweight/obesity and insulin resistance (IR) have been strongly linked with NAFLD. Noninvasive assessment and staging of disease are based on clinical parameters such as age, sex, liver function test, platelet count, lipid profile, BMI, and imaging modalities such as USG, transient elastography (TE), and magnetic resonance imaging mass spectroscopy. Such clinical scoring systems and TE are useful in the early detection of NAFLD and predicting fibrosis. The principle behind the management of NAFLD with T2DM involves an indirect effect through improvement in IR and glycemia and thus is used for the treatment of T2DM as well.

Vertical sleeve gastrectomy improves indices of metabolic disease in rodent model of surgical menopause

OBJECTIVE

Although women are the most common recipients of weight loss surgeries for the amelioration of the comorbidities of obesity, few studies have addressed the efficacy of these procedures with specific attention to reproductive stage. Here we ask in a rodent model of vertical sleeve gastrectomy (VSG) whether improvements to metabolic health are realized in women having received surgical menopause. Specifically we were interested in knowing whether rats made menopausal through surgical means would exhibit persistent hepatic steatosis as reported in previously pregnant, freely cycling female VSG rats or if it is resolved as reported in male VSG rats.

METHODS

All the rats first received ovariectomy (OVX) and then were placed on high-fat diet before either sham or VSG surgery (N = 12, 9) and then were monitored for resolution of obesity-related comorbidities.

RESULTS

VSG was sufficient to reduce weight and adiposity in OVX females in comparison to obese rats (P < 0.001). Glucose tolerance (P < 0.05) was improved in OVX-VSG females with no change in insulin sensitivity. Both circulating (P < 0.01) and hepatic triglyceride (P < 0.01) levels were also reduced after VSG. Liver integrity was improved in OVX-VSG in comparison to OVX-obese as reflected by reduced aspartate aminotransferase levels (P < 0.05). The ability of mitochondria to generate adenosine triphosphate was maintained, and an increase in complex IV may decrease the production of mitochondrial reactive oxygen species.

CONCLUSIONS

Taken together, VSG in OVX rats experience many positive benefits including the resolution of hepatic steatosis that persists in reproductively intact female rats after VSG.

Evolution of Liver Steatosis Quantified by MR Imaging and MR Spectroscopy, in Morbidly Obese Patients Undergoing Sleeve Gastrectomy: Short-Term Outcomes

BACKGROUND

Currently, the standard procedure used to evaluate hepatic steatosis is the liver biopsy. This is an invasive practice that presents inherent risks. Increasing evidence suggests that magnetic resonance imaging (MRI) and MR spectroscopy (MRS) may represent an accurate method to determine the hepatic lipid content. The aim of this study was to evaluate the effect of sleeve gastrectomy on liver steatosis, quantified by MRI and MRS.

PATIENTS AND METHODS

A prospective observational study of patients undergoing laparoscopic sleeve gastrectomy was performed. All patients underwent a MRI and a MRS study 2 weeks before the intervention and 6 months after the surgery. Anthropometric, biochemical, and radiological parameters were analyzed.

RESULTS

Twenty-three patients were included, 21 females and 2 males, with a mean age of 47.6 ± 10.6 years and mean pre-op BMI 47.6 ± 6.7 Kg/m². Six months after surgery, mean BMI was 32.2 ± 5.1 Kg/m², with a mean excess weight loss of 68.2 ± 18.6%. Mean preoperative hepatic volume was 1999.9 ± 436.2 ml and 6 months after surgery it decreased to 1568 ± 170.3 ml (p = 0.005). Mean preoperative percentage of lipid content was 14.2 ± 15.4% and 6 months after surgery, it decreased to 4.3 ± 3.2% (p = 0.007). A significant reduction of steatosis grade was observed, with disappearance of preoperative steatosis in 54.9% of the patients.

CONCLUSION

Six months after sleeve gastrectomy, a significant reduction of liver steatosis is observed, as demonstrated by reduction in the percentage of intrahepatocitary lipids and liver volume, determined by MRS and MRI. These imaging techniques can be considered as noninvasive, accurate methods for monitoring liver steatosis in morbidly obese patients undergoing bariatric surgery.

Improvement of nonalcoholic fatty liver disease in morbidly obese patients after sleeve gastrectomy: association of ultrasonographic findings with lipid profile and liver enzymes

BACKGROUND

After bariatric surgery an improvement or even complete resolution of nonalcoholic fatty liver disease (NAFLD) in morbidly obese patients is achieved, but little is known about the effect of laparoscopic sleeve gastrectomy (LSG).

PATIENTS AND METHODS

A prospective observational study of patients undergoing LSG was performed. An abdominal ultrasonography and blood sample extraction (investigating liver enzymes and lipid profile) were performed preoperatively and 12 months after surgery.

RESULTS

Fifty patients were included in the study. Preoperatively, 84% of the patients presented liver steatosis. A significant reduction of steatosis could be observed 12 months after surgery (p < .001). Preoperative degree of steatosis showed a direct correlation with AST (p = .008) and ALT (p = .007) and an inverse correlation with HDL-cholesterol (p = .019). The reduction of liver steatosis showed an inverse correlation with the increase of HDL-cholesterol between pre- and postoperative determinations (p = .008).

CONCLUSIONS

Liver steatosis, as measured by ultrasonography, improves after sleeve gastrectomy, achieving a complete resolution in 90% of the cases. Preoperative steatosis correlates directly with AST and ALT levels and inversely with HDL-cholesterol. The postoperative increase of HDL-cholesterol shows an inverse correlation with liver steatosis improvement, suggesting that it could be a good marker for monitoring the postoperative liver status.

Monitoring of Liver Function Tests after Roux-en-Y Gastric Bypass: An Examination of Evidence Base

There is no consensus on the monitoring of liver function tests after Roux-en-Y gastric bypass (RYGB). Since the main objective of such monitoring would be to diagnose early those who will eventually develop liver failure after RYGB, we performed a systematic review on this topic. An extensive search of literature revealed only 10 such cases in 6 published articles. It would hence appear that liver failure is a rare problem after RYGB. Routine lifelong monitoring of liver function tests is therefore unnecessary for otherwise asymptomatic individuals. Such monitoring should hence be reserved for high-risk groups, such as patients with liver cirrhosis, those undergoing extended limb/distal RYGB, patients with new illnesses, those abusing alcohol, those on hepatotoxic drugs and those presenting with a surgical complication.

Pediatric Nonalcoholic Fatty Liver Disease: the Rise of a Lethal Disease Among Mexican American Hispanic Children

Hispanic children of Mexican origin have a high incidence of NAFLD. Susceptibility has been linked to a combination of factors including an increasing epidemic of obesity in children and adolescents, an allele substitution in the PNPLA3 gene that reduces hepatic lipid catabolism, and an altered microbiome that may increase hepatic endotoxins. The combination of NAFLD and portal vein toxins secondary to an indigenous gut microbiome appear to lead to the early occurrence of NASH, which progresses to cirrhosis and early hepatocellular carcinoma. Early detection and treatment of hepatic changes are needed. Given the success of gastric bypass in reducing body weight, modifying the gut microbiome, and improving NAFLD/NASH in adults, a trial of gastric bypass in predisposed pediatric candidates should be undertaken.

The Role of Metabolic Surgery in Non-alcoholic Steatohepatitis Improvement

PURPOSE OF REVIEW

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity and overweight. It has a broad spectrum of clinical and histological presentations, such as steatosis, inflammation (known as non-alcoholic steatohepatitis or NASH), fibrosis, and cirrhosis. There is increasing evidence that marked weight loss following bariatric surgery is associated with NASH resolution; however, little is known about the mechanisms that may lead to this beneficial condition and if it is due to weight loss alone. In this review, the authors present the latest data regarding NASH resolution following metabolic surgery and try to answer the following questions: is NASH resolution due to weight loss alone or is it related to weight-independent effects similarly to T2D? In such case, can NASH be considered as a sole criterion for metabolic surgery?

RECENT FINDINGS

Most data evaluating NAFLD and bariatric and metabolic surgery are derived from cohort studies. Available data are extremely variable, but in general show a dramatic regression of steatosis, inflammatory changes, and in some cases even fibrosis that is probably linked to major weight loss following surgery. There are no randomized controlled trials evaluating the effects of metabolic surgery over NASH vs. lifestyle modifications. To consider NASH a sole indication for metabolic surgery regardless of BMI, such studies are desperately needed and should be the primary focus of future research in metabolic surgery.

The role of bariatric surgery in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) affects between 25% and 33% of the population, is more common in obese individuals, and is the most common cause of chronic liver disease in the United States. However, despite rising prevalence, effective treatments remain limited. Areas covered: We performed a literature search across multiple databases (Pubmed, Medline, etc.) to identify significant original research and review articles to provide an up-to-date and concise overview of disease pathogenesis and diagnostic evaluation and to expand on available treatment options with a specific focus on the potential role of bariatric surgery. Here we provide the most comprehensive review of bariatric surgery for the management of NAFLD, noting benefits from different procedures and multiple reports showing improvements in steatosis, inflammation and fibrosis over the duration of follow-up. Expert commentary: The morbidity of NAFLD is significant as it may become the most common indication for liver transplantation within the next 5 years. In addition to known benefits of weight loss and diabetes resolution, bariatric surgery has the potential to halt and reverse disease progression and future controlled trials should be performed to further define its benefit in the treatment of NAFLD in morbidly obese patients.

Nonalcoholic fatty liver disease and bariatric surgery: a comprehensive review

CONTEXT AND OBJECTIVE:

Nonalcoholic fatty liver disease (NAFLD) has been increasingly diagnosed worldwide and is now recognized as a source of public health concern. It comprises a wide spectrum of histological features that range from simple steatosis to severe forms of fibrosis, steatohepatitis and even cirrhosis. The impact of bariatric surgery on the course of NAFLD in individuals with obesity has been extensively studied.

DESIGN AND SETTING:

Narrative review; public university hospital.

METHODS:

A comprehensive review was conducted based on an online search on the electronic databases MEDLINE and LILACS using the MeSH terms "fatty liver" and "bariatric surgery".

RESULTS:

The exact mechanisms that lead to improvement in NAFLD following bariatric surgery are not completely understood. Since Roux-en-Y gastric bypass (RYGB) is the bariatric surgical procedure most performed worldwide, it is also the one from which the effects on NAFLD have been most studied, although there is also consistent evidence regarding the effects from gastric banding, sleeve gastrectomy and biliopancreatic diversions.

CONCLUSION:

According to the currently available evidence, bariatric surgery leads to significant improvement in NAFLD. Further research, especially by means of randomized controlled trials enrolling larger cohorts of individuals, is needed to determine the optimal procedure for this group of subjects.

Gastrointestinal Complications of Obesity

Obesity usually is associated with morbidity related to diabetes mellitus and cardiovascular diseases. However, there are many gastrointestinal and hepatic diseases for which obesity is the direct cause (eg, nonalcoholic fatty liver disease) or is a significant risk factor, such as reflux esophagitis and gallstones. When obesity is a risk factor, it may interact with other mechanisms and result in earlier presentation or complicated diseases. There are increased odds ratios or relative risks of several gastrointestinal complications of obesity: gastroesophageal reflux disease, erosive esophagitis, Barrett's esophagus, esophageal adenocarcinoma, erosive gastritis, gastric cancer, diarrhea, colonic diverticular disease, polyps, cancer, liver disease including nonalcoholic fatty liver disease, cirrhosis, hepatocellular carcinoma, gallstones, acute pancreatitis, and pancreatic cancer. Gastroenterologists are uniquely poised to participate in the multidisciplinary management of obesity as physicians caring for people with obesity-related diseases, in addition to their expertise in nutrition and endoscopic interventions.

Roux-en-Y gastric bypass improves glucose homeostasis, reduces oxidative stress and inflammation in livers of obese rats and in Kupffer cells via an AMPK-dependent pathway

BACKGROUND

Oxidative stress and inflammation are implicated in the pathogenesis of steatohepatitis. We hypothesize that Roux-en-Y gastric bypass reduces oxidative stress and inflammation in the liver of obese rats via activation of AMPK-α.

METHODS

Obese Sprague-Dawley male rats underwent either sham operation or Roux-en-Y gastric bypass. Hepatic TNF-α, NF-κB, IRS-2, PI3 kinase, PKC-ζ, NOX2, and AMPK-α were measured. Mechanistic studies were done in a rat Kupffer cell line (RKC1) that was treated with free fatty acids to mimic lipotoxicity and then transfected with AMPK-α siRNA. Reactive oxygen species, TNF-α, NF-κB, AMPK-α, p-AMPK-α, PPAR-γ, and NOX2 were measured. A t test was used.

RESULTS

Roux-en-Y gastric bypass lowered nonfasting serum glucose, improved the glucose tolerance test, and induced IRS2/PI3 kinase interaction. Additionally, Roux-en-Y gastric bypass decreased hepatic NOX2, PKC-ζ, TNF-α expression and activation of NF-κB. Free fatty acids increased reactive oxygen species, TNF-α protein, NOX2 protein, and activated NF-κB. Rosiglitazone attenuated the free fatty acids-induced increase in reactive oxygen species, TNF-α, NOX2, and NF-κB; blocking AMPK-α by siRNA abolished the effects of rosiglitazone.

CONCLUSION

Roux-en-Y gastric bypass exhibits antidiabetic properties and is associated with downregulation of proinflammation genes and oxidative stress in the liver and within Kupffer cells via activation of AMPK-α.