Nonalcoholic fatty liver disease treated by gastroplasty

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.

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.

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.

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.

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.

Bariatric Surgery and Non-Alcoholic Fatty Liver Disease: a Systematic Review of Liver Biochemistry and Histology

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming a leading cause of global liver disease that is associated with the rising prevalence of obesity worldwide. There is now increasing clinical and mechanistic evidence reporting on the metabolic and weight loss effects of bariatric surgery on improving NAFLD in obese patients.

OBJECTIVES

The aim of this paper was to quantify the effects of bariatric surgery on NAFLD by appraising the modulation between pre- and post-operative liver enzyme levels (as markers of liver injury) and liver histology.

METHODS

A systematic review of studies reporting pre-operative and post-operative liver enzymes or liver histology was done in obese patients with NAFLD undergoing bariatric surgery. Data were meta-analysed using random-effects modelling. Subgroup analysis, quality scoring and risk of bias were assessed.

RESULTS

Bariatric surgery is associated with a significant reduction in the weighted incidence of a number of histological features of NAFLD including steatosis (50.2 and 95 %CI of 35.5-65.0), fibrosis (11.9 and 95 %CI of 7.4-16.3 %), hepatocyte ballooning (67.7 and 95 %CI 56.9-78.5) and lobular inflammation (50.7 and 95 %CI 26.6-74.8 %). Surgery is also associated with a reduction in liver enzyme levels, with statistically significant reductions in ALT (11.36 u/l, 95 %CI 8.36-14.39), AST (3.91 u/l, 95 %CI 2.23-5.59), ALP (10.55 u/l, 95 %CI 4.40-16.70) and gamma-GT (18.39 u/l, 95 %CI 12.62-24.16). Heterogeneity in results was high.

CONCLUSIONS

Bariatric surgery is associated with a significant improvement in both histological and biochemical markers of NAFLD. Future studies must focus on higher levels of evidence to better identify the benefits of bariatric surgery on liver disease in order to enhance future treatment strategies in the management of NAFLD.

Bariatric surgery and nonalcoholic fatty liver disease

The rising prevalence of nonalcoholic fatty liver disease (NAFLD) is associated with the increasing global pandemic of obesity. These conditions cluster with type II diabetes mellitus and the metabolic syndrome to result in obesity-associated liver disease. The benefits of bariatric procedures on diabetes and the metabolic syndrome have been recognized for some time, and there is now mounting evidence to suggest that bariatric procedures improve liver histology and contribute to the beneficial resolution of NAFLD in obese patients. These beneficial effects derive from a number of weight-dependent and weight-independent mechanisms including surgical BRAVE actions (bile flow changes, restriction of stomach size, anatomical gastrointestinal rearrangement, vagal manipulation, enteric hormonal modulation) and subsequent effects such as reduced lipid intake, adipocytokine secretion, modulation of gut flora, improvements in insulin resistance and reduced inflammation. Here, we review the clinical investigations on bariatric procedures for NAFLD, in addition to the mounting mechanistic data supporting these findings. Elucidating the mechanisms by which bariatric procedures may resolve NAFLD can help enhance surgical approaches for metabolic hepatic dysfunction and also contribute toward developing the next generation of therapies aimed at reducing the burden of obesity-associated liver disease.

The effect of surgically induced weight loss on nonalcoholic fatty liver disease in morbidly obese Indians: "NASHOST" prospective observational trial

BACKGROUND

Surgically induced weight loss improves nonalcoholic fatty liver disease (NAFLD) in morbidly obese Caucasian patients. Similar data are lacking from India.

OBJECTIVE

To compare the histologic features of NAFLD in morbidly obese Indian patients before and 6 months after bariatric surgery. Histologic changes were also separately assessed according to the type of bariatric intervention.

SETTING

Teaching institution, India; private practice.

METHODS

All patients undergoing bariatric surgery from July 2012 to July 2013 underwent a routine liver biopsy at the time of bariatric surgery. If the biopsy specimen indicated NAFLD, patients were asked to undergo a second biopsy after 6 months. Baseline anthropometry, clinical data, biochemistry, and pathology were recorded and repeated at follow-up.

RESULTS

Eighty-eight of 134 index biopsy specimens indicated NAFLD. Thirty patients had paired liver biopsies. Steatosis was present in all, 14 had lobular inflammation, 10 had ballooning degeneration, and 14 had fibrosis. Mean time between the biopsies was 7.1 months (range 6-8 months). At the second biopsy, steatosis had resolution in 19 and improvement in 11, lobular inflammation had resolution in 12 and improvement in 2, ballooning had resolution in 9 and improvement in 1 and fibrosis had resolution in 11 and improvement in 3 (P<0.05 for all). Improvement was greater among those who underwent a sleeve gastrectomy in comparison to a Roux-en-Y gastric bypass, although this difference was not statistically significant. None had worsening of liver histologic results.

CONCLUSIONS

Surgically induced weight loss significantly and rapidly improves liver histology in morbidly obese Indians with NAFLD.

Nonalcoholic fatty liver disease and bariatric surgery in adolescents

Obesity is a multi-organ system disease with underlying insulin resistance and systemic chronic inflammation. Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of the underlying metabolic dysfunction. This review provides a highlight of the current understanding of NAFLD pathogenesis and disease characteristics, with updates on the challenges of NAFLD management in obese and severely obese (SO) patients and recommendations for the pediatric surgeons' role in the care of SO adolescents.

Bariatric surgery as potential treatment for nonalcoholic fatty liver disease: a future treatment by choice or by chance?

Morbid obesity is strongly associated with nonalcoholic fatty liver disease (NAFLD) which is one of the most common causes of chronic liver disease worldwide. The current best treatment of NAFLD and NASH is weight reduction through life style modifications, antiobesity medication, and bariatric surgery. Importantly, bariatric surgery is the best alternative option for weight reduction if lifestyle modifications and pharmacological therapy have not yielded long-term success. Bariatric surgery is an effective treatment option for individuals who are grossly obese and associated with marked decrease in obesity-related morbidity and mortality. The most common performed bariatric surgery is Roux-en-Y gastric bypass (RYGB). The current evidence suggests that bariatric surgery in these patients will decrease the grade of steatosis, hepatic inflammation, and fibrosis. NAFLD per se is not an indication for bariatric surgery. Further research is urgently needed to determine (i) the benefit of bariatric surgery in NAFLD patients at high risk of developing liver cirrhosis (ii) the role of bariatric surgery in modulation of complications of NAFLD like diabetes and cardiovascular disease. The outcomes of the future research will determine whether bariatric surgery will be one of the recommended choice for treatment of the most progressive type of NAFLD.

Surgically induced weight loss by gastric bypass improves non alcoholic fatty liver disease in morbid obese patients

AIM

To evaluate the effects of surgical weight loss (Roux-en-Y gastric bypass with a modified Fobi-Capella technique) on non alcoholic fatty liver disease in obese patients.

METHODS

A group of 26 morbidly obese patients aged 45 ± 2 years and with a body mass index > 40 kg/m(2) who underwent open surgical weight loss operations had paired liver biopsies, the first at surgery and the second after 16 ± 3 mo of weight loss. Biopsies were evaluated and compared in a blinded fashion. The presence of metabolic syndrome, anthropometric and biochemical variables were also assessed at baseline and at the time of the second biopsy.

RESULTS

Percentage of excess weight loss was 72.1% ± 6.6%. There was a reduction in prevalence of metabolic syndrome from 57.7% (15 patients) to 7.7% (2 patients) (P < 0.001). Any significance difference was observed in aspartate aminotransferase or alanine aminotransferase between pre and postsurgery. There were improvements in steatosis (P < 0.001), lobular (P < 0.001) and portal (P < 0.05) inflammation and fibrosis (P < 0.001) at the second biopsy. There were 25 (96.1%) patients with non alcoholic steatohepatitis (NASH) in their index biopsy and only four (15.3%) of the repeat biopsies fulfilled the criteria for NASH. The persistence of fibrosis (F > 1) was present in five patients at second biopsy. Steatosis and fibrosis at surgery were predictors of significant fibrosis postsurgery.

CONCLUSION

Restrictive mildly malabsorptive surgery provides significant weight loss, resolution of metabolic syndrome and associated abnormal liver histological features in most obese patients.

Endocrine and nutritional management of the post-bariatric surgery patient: an Endocrine Society Clinical Practice Guideline

OBJECTIVE

We sought to provide guidelines for the nutritional and endocrine management of adults after bariatric surgery, including those with diabetes mellitus. The focus is on the immediate postoperative period and long-term management to prevent complications, weight regain, and progression of obesity-associated comorbidities. The treatment of specific disorders is only summarized.

PARTICIPANTS

The Task Force was composed of a chair, five additional experts, a methodologist, and a medical writer. It received no corporate funding or remuneration.

CONCLUSIONS

Bariatric surgery is not a guarantee of successful weight loss and maintenance. Increasingly, patients regain weight, especially those undergoing restrictive surgeries such as laparoscopic banding rather than malabsorptive surgeries such as Roux-en-Y bypass. Active nutritional patient education and clinical management to prevent and detect nutritional deficiencies are recommended for all patients undergoing bariatric surgery. Management of potential nutritional deficiencies is particularly important for patients undergoing malabsorptive procedures, and strategies should be employed to compensate for food intolerance in patients who have had a malabsorptive procedure to reduce the risk for clinically important nutritional deficiencies. To enhance the transition to life after bariatric surgery and to prevent weight regain and nutritional complications, all patients should receive care from a multidisciplinary team including an experienced primary care physician, endocrinologist, or gastroenterologist and consider enrolling postoperatively in a comprehensive program for nutrition and lifestyle management. Future research should address the effectiveness of intensive postoperative nutritional and endocrine care in reducing morbidity and mortality from obesity-associated chronic diseases.

Advances in the treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the Western world, and its prevalence is predicted to rise in the future in parallel with rising levels of obesity and type 2 diabetes mellitus. It is commonly associated with insulin resistance. Many patients have coexisting obesity, hypertension, dyslipidaemia or hyperglycaemia, and are at increased risk of developing cardiovascular disease. Although patients with simple steatosis have a good prognosis, a significant percentage will develop nonalcoholic steatohepatitis which may progress to cirrhosis, end-stage liver failure and hepatocellular carcinoma. Despite promising results from several pilot studies and small to medium randomized controlled trials, there is currently no pharmacological agent that is licensed for the treatment of NAFLD. At present the mainstay of treatment for all patients is lifestyle modification using a combination of diet, exercise and behavioural therapy. With recent advances in the understanding of the pathogenesis of NAFLD, the goal of treatment has shifted from simply trying to clear fat from the liver and prevent progressive liver damage to addressing and treating the metabolic risk factors for the condition. To reduce liver-related and cardiovascular morbidity and mortality, all patients with NAFLD should be invited to enrol in adequately powered, randomized controlled studies testing novel therapies, many of which are targeted at reducing insulin resistance or preventing progressive liver disease. Coexisting obesity, hypertension, dyslipidaemia or hyperglycaemia should be treated aggressively. Orlistat, bariatric surgery, angiotensin receptor blockers, statins, fibrates, metformin and thiazolidinediones should all be considered, but treatments should be carefully tailored to meet the specific requirements of each patient. The efficacy and safety of any new treatment, as well as its cost-effectiveness, will need to be carefully evaluated before it can be advocated for widespread clinical use.

Treatment options for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become increasingly recognized as the most common cause of abnormal liver enzymes in the last few decades and is among the most common forms of chronic liver disease in the Western world and across the globe. With the growing epidemic of obesity and diabetes, NAFLD is estimated to affect about one-quarter of the US population. Although most patients with NAFLD have nonprogressive bland steatosis, a minority of patients develop the histological subtype of nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis, hepatocellular carcinoma, and liver-related death. This is especially true when NASH patients have type 2 diabetes. Treatment of NAFLD should therefore be directed towards patients with established NASH. Sustained weight loss seems to improve insulin resistance and associated NASH. In fact, weight loss with bariatric surgery leads to biochemical and histological improvement in morbidly obese patients with NASH. Several pharmacologic agents have been studied in an effort to improve insulin resistance and pro-inflammatory mediators potentially responsible for the development and progression of NASH. While some studies have shown initial promise, none has established long-term efficacy using randomized clinical trials. This paper briefly reviews the epidemiology, natural history, and pathophysiology of NAFLD and NASH and then focuses on the clinical trials of various therapeutic modalities for NAFLD. These include weight loss agents, bariatric surgery, insulin-sensitizing agents, lipid-lowering agents, antioxidants, probiotics, anti-tumor necrosis factor agents, cytoprotective and other novel agents.

Bariatric surgery for non-alcoholic steatohepatitis in obese patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasingly recognised as a condition associated with overweight or obesity that may progress to end-stage liver disease. NAFLD histology resembles alcohol-induced liver injury, but occurs in patients with no history of alcohol abuse. NAFLD has a broad spectrum of clinical and histological manifestations, ranging from simple fatty liver to hepatic steatosis with inflammation, advanced fibrosis, and cirrhosis. The inflammatory stage is known as non-alcoholic steatohepatitis (NASH). Recent reports indicate that weight loss induced by bariatric procedures could be beneficial for NASH treatment.

OBJECTIVES

To assess the benefits and harms of bariatric surgery for NASH in obese patients.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded to October 2009.

SELECTION CRITERIA

All randomised clinical trials evaluating any bariatric procedure versus no intervention, placebo (sham procedure), or other interventions in patients with NASH regardless of publication status, number of patients randomised, language, or blinding. Quasi-randomised clinical studies were to be considered for the review if no randomised clinical trials were identified. If included, their bias towards positive findings was to be considered.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate, and we planned to analyse the data by intention-to-treat.

MAIN RESULTS

We could not find any randomised clinical trials or quasi-randomised clinical studies that fulfilled the inclusion criteria. Our search resulted in twenty-one prospective or retrospective cohort studies, in which improvement on steatosis or inflammation scores was reported. However, four studies also described some deterioration in the degree of fibrosis.

AUTHORS' CONCLUSIONS

The lack of randomised clinical trials and quasi-randomised clinical studies precludes us to assess the benefits and harms of bariatric surgery as a therapeutic approach for patients with NASH. Limitations of all other studies with inferior design did not allow us to draw any unbiased conclusion on bariatric surgery for treatment of NASH.

Best practice updates for multidisciplinary care in weight loss surgery

The objective of this study is to update evidence-based best practice guidelines for multidisciplinary care of weight loss surgery (WLS) patients. We performed systematic search of English-language literature on WLS, patient selection, and medical, multidisciplinary, and nutritional care published between April 2004 and May 2007 in MEDLINE and the Cochrane Library. Key words were used to narrow the search for a selective review of abstracts, retrieval of full articles, and grading of evidence according to systems used in established evidence-based models. A total of 150 papers were retrieved from the literature search and 112 were reviewed in detail. We made evidence-based best practice recommendations from the most recent literature on multidisciplinary care of WLS patients. New recommendations were developed in the areas of patient selection, medical evaluation, and treatment. Regular updates of evidence-based recommendations for best practices in multidisciplinary care are required to address changes in patient demographics and levels of obesity. Key factors in patient safety include comprehensive preoperative medical evaluation, patient education, appropriate perioperative care, and long-term follow-up.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist health-care professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Hypertension and hepatic steatosis

Hepatic steatosis (fatty liver) is increasingly recognized as a major component of the metabolic (insulin resistance) syndrome. It can progress to cirrhosis and hepatocellular carcinoma, leading to liver-related mortality. Increasing evidence shows a significant association between hepatic steatosis and hypertension; both are linked to the metabolic syndrome. This review discusses the evidence to support this association, and reviews the diagnosis and management of hepatic steatosis.

Effect of bariatric surgery on nonalcoholic fatty liver disease: systematic review and meta-analysis

BACKGROUND & AIMS

Weight loss in overweight or obese individuals results in marked improvement or resolution of hypertension, diabetes mellitus, and hyperlipidemia. However, the overall effect of weight loss on nonalcoholic fatty liver disease (NAFLD) remains unclear. This systematic review and meta-analysis is an effort to explore the effect of weight loss after bariatric surgical procedures on NAFLD.

METHODS

We performed an electronic literature search of published articles on bariatric surgery and liver histology since inception to September of 2007. Primary outcome measures were improvement and/or resolution in the 3 components of NAFLD (steatosis, steatohepatitis, and fibrosis) after bariatric surgery-induced weight loss. A pooled proportion of patients with improvement or resolution was calculated for steatosis, steatohepatitis, and fibrosis using a random effects model. Heterogeneity among the studies was assessed using the I(2) (inconsistency) statistic and subgroup analyses.

RESULTS

A total of 15 studies (766 paired liver biopsies) were selected for final data extraction. The percentage reduction in mean body mass index after bariatric surgeries ranged from 19.11 to 41.76. The pooled proportion of patients with improvement or resolution in steatosis was 91.6% (95% confidence interval [CI], 82.4%-97.6%), in steatohepatitis was 81.3% (95% CI, 61.9%-94.9%), in fibrosis was 65.5% (95% CI, 38.2%-88.1%), and for complete resolution of nonalcoholic steatohepatitis was 69.5 (95% CI, 42.4%-90.8%).

CONCLUSIONS

Steatosis, steatohepatitis, and fibrosis appear to improve or completely resolve in the majority of patients after bariatric surgery-induced weight loss.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist healthcare professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Nonalcoholic fatty liver disease

OBJECTIVE

The inflammatory subtype of nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, is becoming one of the most important causes of chronic liver disease. In this article, we discuss the epidemiology, pathogenesis, and clinical and radiologic diagnosis of the subtypes of nonalcoholic fatty liver disease.

CONCLUSION

We discuss the current and evolving imaging tests in the evaluation of hepatic fatty content, inflammation, and fibrosis.

The impact of bariatric surgery on nonalcoholic fatty liver disease

PURPOSE OF REVIEW

To analyze the effects of bariatric surgery on nonalcoholic fatty liver disease by reviewing the most important and recent studies.

RECENT FINDINGS

The prevalence of obesity has increased dramatically over the last decades. Comorbidities related to obesity, such as nonalcoholic fatty liver disease are also increasing. Nonalcoholic fatty liver disease is a progressive disease with potential evolution to liver cirrhosis and hepatocellular carcinoma. Overweight patients who have nonalcoholic fatty liver disease should be considered for a weight loss program; however, long-term result with dietary interventions and drug therapy has been disappointing. Bariatric surgery is effective in promoting long-term weight loss in morbidly obese patients with control of comorbidities, especially those associated with the metabolic syndrome. On the basis of the early experience with extensive intestinal bypass, it was believed that rapid weight loss could cause liver damage. In contrast, recent prospective and retrospective observational studies and case series have demonstrated that bariatric surgery is well tolerated and is associated with nonalcoholic fatty liver disease regression in a significant number of patients.

SUMMARY

There is good level of evidence that bariatric surgery is associated with nonalcoholic fatty liver disease regression in morbidly obese patients.

Emerging drugs for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a condition of emerging relevance that includes different forms of chronic liver damage, from a simple fatty infiltration (steatosis) of hepatocytes to steatohepatitis (NASH) with fibrosis. This last form may evolve to cirrhosis and hepatocellular carcinoma.

OBJECTIVE

To discuss therapeutic management of NAFLD. Theoretically, only patients with non-alcoholic steatohepatitis (NASH) need to be treated, as only NASH may evolve to cirrhosis. Differentiation between steatosis and NASH currently requires a liver biopsy.

METHODS

We discuss different therapeutic approaches proposed in literature for patients with NAFLD.

RESULTS

The treatment of associated conditions leads to an improvement of NAFLD and NASH. No specific drug is actually present to treat liver steatosis or NASH.

CONCLUSIONS

The treatment of NAFLD depends on the individual characteristics of each patient. Diet and physical exercise may be considered a basal universal approach. Future research will discover possible specific liver drugs.

Weight loss, dietary advice and statin therapy in non-alcoholic fatty liver disease: a retrospective study

BACKGROUND

Studies have shown that weight loss can have a favourable effect upon non-alcoholic fatty liver disease (NAFLD). However, the most effective means of achieving weight loss and safety profile of lipid-lowering drugs in the presence of NAFLD is unknown.

AIM

To investigate the effect of dietary advice and lipid-lowering drugs, particularly statins, on patients with NAFLD and dyslipidaemia.

DESIGN

Observational records based study.

METHODS

We studied 71 patients with NAFLD and dyslipidaemia diagnosed and treated between 1996 and 2002 at University Hospital Lewisham. Some were referred to a dietician for weight loss advice as part of their management. After treatment all patients were assessed for changes in weight, serum alanine transaminase (ALT) and serum lipids including serum cholesterol, serum high density lipoprotein (HDL) and serum triglycerides.

RESULTS

Thirty-seven male and 34 female patients with NAFLD and dyslipidaemia were followed up for a mean period of 440 +/- 374 days (median 335). Regression analysis revealed a significant association between changes in weight and changes in serum ALT (p < 0.039). Dietary advice failed to reduce body weight but significantly lowered the serum cholesterol to HDL ratio (p = 0.05). Only 15.4% of patients taking statins experienced a rise in serum ALT > or = 40 U/l, and in each case the rise was transient, returning near baseline or below without discontinuation of statin treatment.

CONCLUSIONS

Weight loss appears to improve NAFLD, and dietary advice and lipid-lowering drugs may be beneficial for patients with NAFLD and dyslipidaemia even if weight loss is not achieved. Statins appear to be safe and efficacious in this group.

Fibrogenesis in fatty liver associated with obesity and diabetes mellitus type 2

Fatty liver in obese patients is emerging as one of the most common causes of chronic liver disease. Obese patients are at risk of developing type 2 diabetes mellitus (DM), and aggravating non-alcoholic fatty liver disease (NAFLD), developing into steatohepatitis (NASH) and hepatic fibrosis. Little is known of the possible impact on liver fibrogenesis of diabetes type 2 associated with obesity and NAFLD. Fifty-two morbidly obese patients were evaluated with complete clinical and laboratory medical assessment. Liver biopsy material was fixed in formalin, routinely processed to paraffin blocks, cut into 4-microm sections, stained with HE, PAS, Masson's trichrome and reticulin. Immunohistochemical stains included collagen IV, SMA and laminin. Within the initial group of 52, 25 patients had DM type 2, mean age 45.8 years. Patients with diabetes were older; had higher BMI, liver enzyme tests, glucose, cholesterol, and triglycerides; and lower albumin concentration. Livers of diabetics had significantly more severe steatosis and rich perisinusoidal collagen IV, laminin and SMA accumulation without histologically detectable NASH and irrespective of the degree of steatosis. Obese patients with type 2 DM and insulin resistance develop more severe NAFLD and early sinusoidal fibrosclerosis.

Evolving trends in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common etiologies of chronic liver disease worldwide. NALFD encompasses a continuum of histological findings ranging from steatosis alone, to nonalcoholic steatohepatitis (NASH) with steatosis, inflammation, hepatocyte ballooning, fibrosis and eventually liver cirrhosis. The pathogenesis of NAFLD might be related to a deregulated cross-talk between liver and visceral adipose tissue, originating an impairment of normal insulin signaling. A better comprehension of the immunologic and metabolic roles of adipose tissue in modulating inflammatory pathways will enhance our understanding of the molecular mechanisms leading to progression of fatty liver disease. These insights, moreover, will suggest new strategies to improve insulin sensitivity and reduce obesity-associated morbidities and mortality.

Pathogenesis and management issues for non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has, although it is a very common disorder, only relatively recently gained broader interest among physicians and scientists. Fatty liver has been documented in up to 10 to 15 percent of normal individuals and 70 to 80 percent of obese individuals. Although the pathophysiology of NAFLD is still subject to intensive research, several players and mechanisms have been suggested based on the substantial evidence. Excessive hepatocyte triglyceride accumulation resulting from insulin resistance is the first step in the proposed ‘two hit’ model of the pathogenesis of NAFLD. Oxidative stress resulting from mitochondrial fatty acids oxidation, NF-κB-dependent inflammatory cytokine expression and adipocytokines are all considered to be the potential factors causing second hits which lead to hepatocyte injury, inflammation and fibrosis. Although it was initially believed that NAFLD is a completely benign disorder, histologic follow-up studies have showed that fibrosis progression occurs in about a third of patients. A small number of patients with NAFLD eventually ends up with end-stage liver disease and even hepatocellular carcinoma. Although liver biopsy is currently the only way to confirm the NAFLD diagnosis and distinguish between fatty liver alone and NASH, no guidelines or firm recommendations can still be made as for when and in whom it is necessary. Increased physical activity, gradual weight reduction and in selected cases bariatric surgery remain the mainstay of NAFLD therapy. Studies with pharmacologic agents are showing promising results, but available data are still insufficient to make specific recommendations; their use therefore remains highly individual.

Comparative review of diets for the metabolic syndrome: implications for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a significant health problem and affects 70 million adults in the United States (30% of the adult population), and an estimated 20% of these individuals have the most severe form of NAFLD-nonalcoholic steatohepatitis (NASH). The mechanisms underlying disease development and progression are awaiting clarification. Insulin resistance and obesity-related inflammation, among other possible genetic, dietary, and lifestyle factors, are thought to play a key role. A program targeting gradual weight reduction and physical exercise continues to be the gold standard of treatment for all forms of NAFLD. Even though weight loss and dietary and lifestyle changes are recommended as primary treatment for fatty liver, little to no scientific evidence is available on diet and NAFLD. This article reviews the implications of current dietary approaches, including national guidelines and popular weight-loss diets, with a focus on determining the optimal diet to prescribe for NAFLD and NASH patients. The effects of macronutrient content (carbohydrate, fat, and protein ratios) and specific food components, such as soluble fiber, n-3 fatty acids, and fructose, are discussed. The premises, effects, barriers, and issues related to current dietary guidelines and specific diets are discussed, and the question, "Will it work for the pathogenesis of NAFLD and NASH? ", is addressed.

A growing burden: the pathogenesis, investigation and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic disorder in western countries, and its incidence is increasing. This review outlines the significant health burden posed by NAFLD and discusses what is presently known about its pathogenesis, including the roles of the metabolic syndrome, obesity, insulin resistance, hepatic steatosis, reactive oxygen species, inflammatory cytokines and adipocytokines. The way in which NAFLD is clinically diagnosed is described, and areas of uncertainty surrounding its investigation are identified, before discussing the relative merits of the limited treatment options available and looking ahead to potential therapeutic strategies for the future.

Relationship between Obstructive Sleep Apnea and Liver Abnormalities in Morbidly Obese Patients: A Prospective Study

BACKGROUND

Morbid obesity is a risk factor of nonalcoholic steatohepatitis (NASH). Obstructive sleep apnea (OSA) could also be an independent risk factor for elevated liver enzymes and NASH. The relationships between liver injuries and OSA in morbidly obese patients requiring bariatric surgery were studied prospectively.

METHODS

Every consecutive morbidly obese patient (BMI > or =40 kg/m2 or > or =35 kg/m2 with severe comorbidities) requiring bariatric surgery was included between January 2003 and October 2004. Polygraphic recording, serum aminotransferases (ALT, AST), gamma-glutamyltransferase (GGT) and liver biopsy were systematically performed. OSA was present when the apnea-hypopnea index (AHI) was >10/h.

RESULTS

62 patients (54 F; age 38.5 +/- 11.0 (SD) yrs; BMI 47.8 +/- 8.4 kg/m2) were included. Liver enzymes (AST, ALT or GGT) were increased in 46.6%. NASH was present in 34.4% and OSA in 84.7%. Patients with OSA were significantly older (P = 0.015) and had a higher BMI (P = 0.003). In multivariate analysis, risk factors for elevated liver enzymes were the presence of OSA and male sex. The presence of NASH was similar in patients with or without OSA (32.7% vs 44.4% of patients, P = 0.76).

CONCLUSION

In this cohort of morbidly obese patients requiring bariatric surgery, one-third of patients had NASH, a prevalence similar to previous studies. OSA was found to be a risk factor for elevated liver enzymes but not for NASH.

Fatty liver and the metabolic syndrome

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease and its subset nonalcoholic steatohepatitis represent the liver manifestations of insulin resistance. This review briefly summarizes advances in our understanding of the pathogenesis of nonalcoholic fatty liver disease and its prevalence, natural history and treatment.

RECENT FINDINGS

The recognition of the role the renin-angiotensin system in promoting insulin resistance is worth noting because of available drugs. Endoplasmic reticulum stress has also become a recent target of investigation because endoplasmic reticulum stress is common in obesity, diabetes and various forms of liver disease including nonalcoholic fatty liver disease. Endoplasmic reticulum stress may be responsible for activation of c-Jun kinase, a process that may cause the hepatocellular injury in nonalcoholic steatohepatitis. Progress has also been made in estimating the prevalence of nonalcoholic fatty liver disease in adults and children. Patients enrolled in the Dallas Heart Study were found to have a 33% prevalence of nonalcoholic fatty liver disease and children dying of accidental deaths in San Diego were found to have a 13% prevalence of nonalcoholic fatty liver disease. Because about 10% of people with nonalcoholic fatty liver disease are at risk for progressive fibrosis, the burden of this disease is now quite substantial.

SUMMARY

Incremental progress in understanding nonalcoholic fatty liver disease and nonalcoholic steatohepatitis promises to lead to new therapeutic options for this common disease.

Surgical treatment for obesity and its impact on non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) in obese and severely obese populations is associated with the metabolic syndrome, with features of the syndrome predicting those who will have NASH rather than simple steatosis, a more benign form of non-alcoholic fatty liver disease. Substantial weight loss is proving the most effective therapy for obesity-related conditions. Improvements have seen the development of less invasive procedures. There is growing evidence that laparoscopic adjustable gastric banding and roux-en-Y gastric bypass provide effective therapy.

Treatment of patients with non-alcoholic fatty liver disease: current views and perspectives

Non-alcoholic fatty liver disease is considered a component of the metabolic syndrome associated with obesity. Problems still exist concerning non-alcoholic fatty liver disease patients in clinical practice, for example: (a) how to diagnose non-alcoholic fatty liver disease and its type; (b) how to select patients candidate to treatment; (c) how to treat selected patients. Non-alcoholic fatty liver disease includes steatosis and non-alcoholic steatohepatitis, but only non-alcoholic steatohepatitis evolves into cirrhosis and the absolute risk of mortality for non-alcoholic fatty liver disease is low. As yet, no tools, other than liver biopsy, are available to differentiate the various types of non-alcoholic fatty liver disease. Many drugs are, currently, under study to treat non-alcoholic fatty liver disease, even if well-performed trials are until necessary to define the best treatment. At the moment, the entity of the problem and the characteristics of patients frequently put the physician, in clinical practice, to choose the therapeutic approach arbitrarily which is considered more effective for each individual patient. Probably the future will consider the possibility of treating non-alcoholic fatty liver disease with more than one drug, by considering the various aspects and degree of this syndrome. Actually each physician should select the individual treatment on the basis of his/her knowledge and experience, by never forgetting the old saying 'primum non nocere'. However, the epidemiological entity of the problem, the characteristics of the patients, generally young, the frequent lack of clinical evidence of involvement of the liver, are all the factors that require vast well-performed clinical trials in order to define the best therapeutic approach for each individual patient.