Effect of Roux-en-Y gastric bypass on nonalcoholic fatty liver disease evaluated through NAFLD fibrosis score: a prospective study

Fibrotic NASH in Individuals with Obesity: a Cross-sectional Analysis of the Prevalence of this Significant Milestone of Disease Progression and Accuracy of a Non-invasive Marker for its Screening

BACKGROUND

Fibrotic non-alcoholic steatohepatitis (NASH), i.e., the concomitant presence of active inflammation and fibrosis, represents a milestone in the natural history of NAFLD and a critical time point in its progression. The purpose of this study was to analyze the diagnostic accuracy of the non-invasive Fibrotic NASH Index (FNI) in individuals with obesity undergoing bariatric surgery.

METHODS

This is a cross-sectional study, enrolling individuals who underwent bariatric surgery with liver biopsy at a tertiary university hospital. FNI was calculated, and a cutoff value was determined. Its diagnostic accuracy was then calculated through comparison with the gold standard test for this analysis (histopathological examination).

RESULTS

Of 128 participants, 83.6% were female, and the average age was 39.8 ± 8.7 years. The mean BMI was 38.7 ± 5.7 kg/m2. NAFLD was histologically confirmed in 76.6%, of which 81.6% had NASH. Histologically confirmed fibrotic NASH was observed in 22.7% of the general study population, 29.6% of individuals with NAFLD, and 36.3% of those with NASH. The mean FNI was 0.18 ± 0.19. An optimal cutoff point of 0.21 was determined, with an overall accuracy of 90.1%, an 82.8% sensitivity, a 90.8% specificity, a 72.6% positive predictive value, and a 94.7% negative predictive value.

CONCLUSIONS

FNI provided adequate accuracy in detecting and ruling out fibrotic NASH. Considering the importance of fibrotic NASH within the natural history of NAFLD progression and the fact that this marker uses simple variables, it may be of great importance in high-risk populations, and its external validation and use should be encouraged.

Relationship between dietary intake components and hepatic fibrosis in those with obesity before and 1 year after bariatric surgery

OBJECTIVES

Non-alcoholic fatty liver disease is highly prevalent in the bariatric population but not all patients develop liver fibrosis. Considering that fibrosis may affect clinical outcomes, it is important to assess and treat contributing factors. In this population, it is not clear whether dietary intake is a contributor. The objective was to determine the relationship between dietary intake components and liver fibrosis before and 1 y after Roux-en-Y gastric bypass (RYGB).

METHODS

This was a prospective cross-sectional (n = 133) study conducted between 2013 and 2022. In addition, a subgroup of 44 patients were followed for 1 y post-RYGB. Anthropometrics, biochemical measurements, and 3-d food records and liver biopsies were obtained presurgery and, in a subgroup of patients, as for the cohort, 1 y post-RYGB.

RESULTS

In the cross-sectional study, 78.2% were female, with a median age of 48 y and body mass index of 46.8 kg/m2; 33.8% had type 2 diabetes mellitus and 57.1% had metabolic syndrome. In a multivariate analysis, age (odds ratio; 95% CI) (1.076; 1.014-1.141), alanine transaminase (1.068; 1.025-1.112), calorie intake (1.001; 1.000-1.002), and dietary copper (0.127; 0.022-0.752) were independently associated with fibrosis (<0.05). At 1 y post-RYGB, no independent risk factors were associated with persistent fibrosis.

CONCLUSIONS

In bariatric patients before surgery, higher age, alanine transaminase, and total calorie and lower copper intakes were independent risk factors associated with liver fibrosis. These relationships were no longer observed after RYGB, likely due to the effect of surgery on weight and similar postsurgery diet among patients.

Bariatric surgery improves postprandial VLDL kinetics and restores insulin-mediated regulation of hepatic VLDL production

Dyslipidemia in obesity results from excessive production and impaired clearance of triglyceride-rich (TG-rich) lipoproteins, which are particularly pronounced in the postprandial state. Here, we investigated the impact of Roux-en-Y gastric bypass (RYGB) surgery on postprandial VLDL1 and VLDL2 apoB and TG kinetics and their relationship with insulin-responsiveness indices. Morbidly obese patients without diabetes who were scheduled for RYGB surgery (n = 24) underwent a lipoprotein kinetics study during a mixed-meal test and a hyperinsulinemic-euglycemic clamp study before the surgery and 1 year later. A physiologically based computational model was developed to investigate the impact of RYGB surgery and plasma insulin on postprandial VLDL kinetics. After the surgery, VLDL1 apoB and TG production rates were significantly decreased, whereas VLDL2 apoB and TG production rates remained unchanged. The TG catabolic rate was increased in both VLDL1 and VLDL2 fractions, but only the VLDL2 apoB catabolic rate tended to increase. Furthermore, postsurgery VLDL1 apoB and TG production rates, but not those of VLDL2, were positively correlated with insulin resistance. Insulin-mediated stimulation of peripheral lipoprotein lipolysis was also improved after the surgery. In summary, RYGB resulted in reduced hepatic VLDL1 production that correlated with reduced insulin resistance, elevated VLDL2 clearance, and improved insulin sensitivity in lipoprotein lipolysis pathways.

Effect of Transoral Outlet Reduction on Hepatic Fibrosis in Roux-en-Y Gastric Bypass Patients with Weight Regain and Non-alcoholic Fatty Liver Disease

PURPOSE

Weight regain after Roux-en-Y gastric bypass (RYGB) is associated with worsening of liver outcomes. However, the effect of transoral outlet reduction (TORe) on liver fibrosis in RYGB patients with weight regain and possible advanced fibrosis remains unknown.

MATERIALS AND METHODS

This was a retrospective analysis of prospectively collected data of RYGB patients who underwent TORe for weight regain. Only patients with possible advanced fibrosis were included. TORe was performed using either an endoscopic suturing device (S-TORe) or plication device (P-TORe) to reduce the gastrojejunal anastomosis (GJA) and pouch sizes. Primary outcomes included changes in non-invasive tests (NITs) for fibrosis at 6-12 months. Secondary outcomes included weight loss and changes in insulin resistance and lipid profile at 6-12 months.

RESULTS

Fifty RYGB patients were included. Baseline age and BMI were 55 ± 11 years and 40.1 ± 7.3 kg/m2. Baseline GJA and pouch sizes were 20 ± 7 mm and 5 ± 2 cm, respectively. Thirty patients (60%) underwent S-TORe and 20 patients (40%) underwent P-TORe. At 12 months following TORe, there were statistically significant improvements in NITs for fibrosis, including ALT, AST and FIB-4. There was a trend towards significant improvement in liver stiffness measurement on transient elastography. Patients experienced 8.8 ± 11.2% total weight loss (TWL) (p < 0.0001), with 60% experiencing at least 10% TWL. Additionally, there was a significant improvement in HbA1c and a trend toward significant improvement in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), suggestive of improved insulin sensitivity.

CONCLUSION

TORe is associated with an improvement in hepatic fibrosis in patients with NAFLD and possible advanced fibrosis.

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.

Application of Scores Assessing Histological Activity and Estimated Long-Term Risk Analysis of Hepatic Decompensation of Non-Alcoholic Fatty Liver Disease in Individuals Undergoing Bariatric Surgery

BACKGROUND

Histological scores can estimate disease staging, allowing a standardization of the assessment of non-alcoholic fatty liver disease (NAFLD). The prediction of risk of NAFLD progression is relevant to allow the planning of interventions.

OBJECTIVE

To analyze the application of the Iowa NAFLD decompensation risk score, the NAFLD activity score (NAS), and steatosis-activity-fibrosis score (SAF) and to assess correlations between these scores.

METHODS

This is a retrospective cross-sectional study enrolling 76 individuals who underwent bariatric surgery at a tertiary university hospital. Liver biopsy was performed during procedures; histological scores were then assessed. The Iowa score was calculated using age, diabetes, and platelet count.

RESULTS

89.5% were female and mean age was 39.1 ± 9.6 years. Mean BMI was 38.2 ± 3.7 kg/m². Steatosis (92.1%), hepatocellular ballooning (93.4%), lobular inflammation (93.4%), and fibrosis (97.4%) were the commonest histopathological findings. According to NAS, 22.4% had definite non-alcoholic steatohepatitis (NASH). According to SAF, 89.5% had moderate or severe NAFLD. The mean risks of NAFLD decompensation at 5, 10, and 12 years were 0.8%, 2.5%, and 2.9%, respectively. The group whose risk of decompensation was above 10% comprised 2.6% and 5.3% at 10 and 12 years, respectively. The severity assessed by SAF significantly associated with definite NASH diagnosis through NAS (p < 0.001). Iowa score did not correlate with both NAS/SAF scores.

CONCLUSION

The Iowa score demonstrated that individuals with obesity present with a significant long-term risk of NAFLD-related events. There were high rates of moderate/severe forms of NAFLD assessed by NAS and SAF scores. There were no significant correlations between Iowa and NAS/SAF scores.

Microvesicular Steatosis in Individuals with Obesity: a Histological Marker of Non-alcoholic Fatty Liver Disease Severity

BACKGROUND

In non-alcoholic fatty liver disease (NAFLD), steatosis can manifest through two distinct forms: macrovesicular (macroS) and microvesicular (microS).

OBJECTIVE

To investigate the prevalence of microS and its association with biochemical parameters and NAFLD-related histological findings in individuals with obesity.

METHODS

This is an observational retrospective cross-sectional study, enrolling individuals who underwent bariatric surgery and liver biopsy at a university hospital. A 1:2 propensity matching was performed to pair microS with isolated macroS; this matching enrolled variables "age," "gender," "body mass index (BMI)," and "obesity-associated medical problems." Clinical, biochemical, and histopathological aspects were then analyzed and compared.

RESULTS

Of 115 participants, 88.7% were female; average age was 40.5 ± 5 years and mean BMI was 37.9 ± 3.3 kg/m². Steatosis occurred in 82.6% (67.8% isolated macroS and 14.8% microS). MicroS is significantly associated with higher levels of alanine aminotransferase (ALT) (39.8 ± 26.4 vs. 26.7 ± 17.5; p = 0.04) and glucose (103.8 ± 52.6 vs. 83.3 ± 10.8; p = 0.03) and higher frequencies of moderate to severe macroS (41.2% vs. 2.0%; p < 0.001), portal fibrosis (100% vs. 50%; p < 0.001), perisinusoidal fibrosis (100% vs. 55.9%; p < 0.001), lobular inflammation (100% vs. 41.1%; p < 0.001), and portal inflammation (100% vs. 41.1%; p < 0.001). An independently positive association was observed between intensities of microS and macroS (p < 0.001).

CONCLUSION

MicroS is significantly associated with higher levels of ALT and glucose and higher frequencies of moderate to severe macroS, hepatocellular ballooning, portal fibrosis, perisinusoidal fibrosis, lobular inflammation, and portal inflammation. These findings indicate that microS could be considered a reliable histological marker of NAFLD severity.

Trajectory of NAFLD characteristics after Roux-en-Y gastric bypass: a five-year historical cohort study

BACKGROUND

The long-term effects of bariatric surgery on the course of non-alcoholic fatty hepatopathy (NAFLD) are not fully understood.

OBJECTIVE

To analyze the evolution of NAFLD characteristics through noninvasive markers after Roux-en-Y gastric bypass (RYGB) over a five-year period.

DESIGN AND SETTING

Historical cohort study; tertiary-level university hospital.

METHODS

The evolution of NAFLD-related characteristics was evaluated among 49 individuals who underwent RYGB, with a five-year follow-up. Steatosis was evaluated through the hepatic steatosis index (HSI), steatohepatitis through the clinical score for non-alcoholic steatohepatitis (C-NASH) and fibrosis through the NAFLD fibrosis score (NFS).

RESULTS

91.8% of the individuals were female. The mean age was 38.3 ± 10 years and average body mass index (BMI), 37.4 ± 2.3 kg/m2. HSI significantly decreased from 47.15 ± 4.27 to 36.03 ± 3.72 at 12 months (P &lt; 0.01), without other significant changes up to 60 months. C-NASH significantly decreased from 0.75 ± 1.25 to 0.29 ± 0.7 at 12 months (P &lt; 0.01), without other significant changes up to 60 months. NFS decreased from 1.14 ± 1.23 to 0.27 ± 0.99 at 12 months (P &lt; 0.01), and then followed a slightly ascending course, with a marked increase by 60 months (0.82 ± 0.89), but still lower than at baseline (P &lt; 0.05). HSI variation strongly correlated with the five-year percentage total weight loss (R = 0.8; P &lt; 0.0001).

CONCLUSION

RYGB led to significant improvement of steatosis, steatohepatitis and fibrosis after five years. Fibrosis was the most refractory abnormality, with a slightly ascending trend after two years. Steatosis improvement directly correlated with weight loss.

Nonalcoholic fatty liver disease and diabetes

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in the world and represents a clinical-histopathologic entity where the steatosis component may vary in degree and may or may not have fibrotic progression. The key concept of NAFLD pathogenesis is excessive triglyceride hepatic accumulation because of an imbalance between free fatty acid influx and efflux. Strong epidemiological, biochemical, and therapeutic evidence supports the premise that the primary pathophysiological derangement in most patients with NAFLD is insulin resistance; thus the association between diabetes and NAFLD is widely recognized in the literature. Since NAFLD is the hepatic manifestation of a metabolic disease, it is also associated with a higher cardio-vascular risk. Conventional B-mode ultrasound is widely adopted as a first-line imaging modality for hepatic steatosis, although magnetic resonance imaging represents the gold standard noninvasive modality for quantifying the amount of fat in these patients. Treatment of NAFLD patients depends on the disease severity, ranging from a more benign condition of nonalcoholic fatty liver to nonalcoholic steatohepatitis. Abstinence from alcohol, a Mediterranean diet, and modification of risk factors are recommended for patients suffering from NAFLD to avoid major cardiovascular events, as per all diabetic patients. In addition, weight loss induced by bariatric surgery seems to also be effective in improving liver features, together with the benefits for diabetes control or resolution, dyslipidemia, and hypertension. Finally, liver transplantation represents the ultimate treatment for severe nonalcoholic fatty liver disease and is growing rapidly as a main indication in Western countries. This review offers a comprehensive multidisciplinary approach to NAFLD, highlighting its connection with diabetes.

The Effect of Roux-en-Y Gastric Bypass on Non-Alcoholic Fatty Liver Disease Fibrosis Assessed by FIB-4 and NFS Scores-An 11.6-Year Follow-Up Study

Severe obesity is a strong risk factor for non-alcoholic fatty liver disease (NAFLD). Roux-en-Y gastric bypass (RYGB) surgery effectively induces weight loss, but few studies have described the long-term effects of RYGB on NAFLD-related fibrosis. Data from 220 patients with severe obesity operated by RYGB in Central Norway were analysed. Variables incorporated in NAFLD Fibrosis Score (NFS), Fibrosis-4 (FIB-4) index and anthropometric data were collected before surgery and a mean of 11.6 years postoperatively. FIB-4 > 1.3 or NFS > 0.675 were used as cut-off values for advanced fibrosis. Proportions with advanced fibrosis decreased from 24% to 14% assessed by FIB-4 and from 8.6% to 2.3% using NFS, with resolution rates of advanced fibrosis of 42% and 73%, respectively. The shift towards lower fibrosis categories was significant (NFS p < 0.0001; FIB-4 p = 0.002). NFS decreased from −1.32 (IQR −2.33−−0.39) to −1.71 (IQR −2.49−−0.95, p < 0.001) 11.6 years after surgery, whereas FIB-4 did not change: 0.81 (IQR 0.59−1.25) to 0.89 (IQR 0.69−1.16, p = 0.556). There were weak correlations between change in fibrosis scores and weight loss. In conclusion, the majority of patients with advanced fibrosis at baseline had improvement after 11.6 years. Factors associated with reduction in fibrosis were not identified.

The Benefit of Bariatric Surgery on Histological Features of Metabolic Associated Fatty Liver Disease Assessed Through Noninvasive Methods

BACKGROUND

In patients with clinically severe obesity, metabolic associated fatty liver disease (MAFLD) and steatohepatitis are highly prevalent. There is a lack of prospective studies evaluating the impact of bariatric surgery (BS) on MAFLD using both noninvasive and histological criteria. The present study aims to assess the impact of BS on MAFLD using histological and biochemical criteria.

METHODS

This is a prospective study of 52 patients subjected to BS. Noninvasive fibrosis risk scores (NIFRS) along with anthropometric, clinical, and biochemical parameters were recorded pre- and 12 months post-BS. Liver biopsy was obtained in all individuals at baseline (wedge biopsy) and was repeated at 12 months (percutaneous Tru-cut) in those diagnosed with steatohepatitis. The primary outcome was the change in the degree of steatohepatitis and fibrosis. The secondary outcome was the change in scores for hepatocellular ballooning, lobular inflammation, steatosis, and fibrosis.

RESULTS

One year after BS, steatohepatitis resolved in core biopsies with no worsening of fibrosis in 95.7% of individuals (n = 21, 95% CI: 87.3-100), and 13 (56.5%) exhibited complete resolution. Of 15 patients with fibrosis at baseline, 13 (86.7%) showed improvement and 12 exhibited fibrosis resolution. The values of transaminases improved, but only gamma glutamyl transferase (GGT) showed statistical significance. Among the NIFRS, NAFLD fibrosis score (NFS) and Hepamet fibrosis score (HFS) showed significant improvement.

CONCLUSIONS

In the setting it was studied, BS improved or resolved steatohepatitis and fibrosis in patients with obesity. NIFRS, especially NFS and HFS, and levels of GGT could be used as markers of recovery of liver function after BS.

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.

Bariatric Surgery in NAFLD

Currently, there are no approved medications to treat patients with nonalcoholic steatohepatitis (NASH) with fibrosis or cirrhosis. Although the management goal in these patients is weight reduction by 7-10% with lifestyle modifications, only less than 10% of patients achieve this target at 1-year, and fewer maintain the weight loss at 5 years. Bariatric surgery is an option that may be considered in those who fail to lose weight by lifestyle changes. Bariatric surgery has been shown to improve liver histology including fibrosis secondary to NASH, in addition to other benefits including an improvement or resolution of type 2 diabetes mellitus, dyslipidemia, and hypertension, and a reduction of cardiovascular morbidity or mortality. There are no guidelines of bariatric surgery indications for the management of NASH. The purpose of this review is to critically appraise the current knowledge of the role of bariatric surgery and the potential mechanisms for its perceived benefits in the management of patients with NASH-related liver disease.

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.

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.

Effect of bariatric surgery on fatty liver disease in obese patients: A prospective one year follow-up study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), often associated with obesity and metabolic syndrome, manifests itself as steatosis, hepatic fibrosis, cirrhosis, or even end-stage liver disease. NAFLD causes inflammation, insulin resistance and cardiovascular complications. The current study aimed to evaluate the beneficial effects of bariatric surgery on biochemical parameters of hepatic functions in obese patients by comparing them before and one-year after the surgery.

METHODS

A total of 72 morbidly obese patients underwent bariatric surgery between 2016 and 2018. The incidence of diabetes mellitus in this group was 29%, median body weight was 124.5 kg (109.0-140.0) and mean body mass index (BMI) was 44.38 ± 6.770 kg/m². The used surgical procedures included gastric bypass, sleeve gastrectomy, laparoscopic gastric plication, and single anastomosis duodeno-ileal bypass-sleeve gastrectomy. Biochemical parameters including ALT/AST ratio (AAR), NAFLD fibrosis score (NFS), hepatic fibrosis index (FIB-4) and Fatty Liver Index (FLI) were evaluated in all patients at the time of surgery and one year after the intervention.

RESULTS

Significant improvement after the intervention was observed in 64 patients. A significant reduction in body weight (P<0.0001), waist circumference (P<0.0001), and body mass index (P<0.0001) were observed. NAFLD liver fibrosis index changed significantly (P<0.0001), suggesting a trend of improvement from advanced fibrosis towards stages 0-2. The FIB-4 fibrosis index indicated significant improvement (P=0.0136). Besides, a significant decline in hepatic steatosis (P<0.0001) was observed after bariatric surgery as compared to the pre-surgery fatty liver conditions.

CONCLUSION

Among the strategies to overcome NAFLD-associated impediments, bariatric surgery can be considered effective in reducing obesity and metabolic co-morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04569396).

Are Noninvasive Methods Comparable to Liver Biopsy in Postoperative Patients After Roux-en-Y Gastric Bypass?

INTRODUCTION

Transient tissue elastography (TTE) may estimate the degree of hepatic fibrosis in patients with obesity, but the method has restrictions that are mainly related to patients' BMI.

PURPOSE

To compare the results of the evaluation of hepatic fibrosis by biochemical methods and TTE with those determined by liver biopsy in patients after RYGB.

METHODS

This was a cross-sectional study involving patient data, TTE, and liver biopsy 1 year after RYGB.

RESULTS

Of the 94 selected patients, 33 underwent TTE and liver biopsy. The average weight of patients was 84.4 ± 15.4 kg. The mean APRI was 0.2 ± 0.1, and 36 patients (97.3%) were classified as F0-F1. The average NFS was - 2.0 ± 1.0, with 25 patients (67%) classified as F0-F1 and 12 patients (32.4%) classified as F2. The agreement rate between Fibroscan and liver biopsy was 80.0%. Histological analysis revealed regression of inflammatory changes in all patients: 26 patients (72.2%) had some degree of non-alcoholic steatohepatitis (NAS ≥ 5), and after surgery, no patient presented inflammation upon biopsy. Nine patients (24.3%) had fibrosis at surgery, and only two (5.4%) still had fibrosis 1 year later (p < 0.008).

CONCLUSIONS

The use of APRI and Fibroscan is promising, but more studies are needed to evaluate patients with an advanced degree of NAFLD and confirm the entire spectrum of the disease.

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.

Clinical heterogeneity in patients with non-alcoholic fatty liver disease-associated hepatocellular carcinoma

INTRODUCTION

The indisputable increase in nonalcoholic Fatty Liver Disease (NAFLD) prevalence (25% of population) has consequently led to an increase in Hepatocellular Carcinoma (HCC) and liver-related mortality worldwide. The characteristics of patients with HCC, secondary to NAFLD, are older age, large tumors due to late diagnosis, often without cirrhosis and high prevalence of the metabolic syndrome components, leading to an increased mortality rate. Although the mechanisms of disease remain partially obscure, insulin resistance, oxidative stress, apoptosis, iron overload, and excessive local and systemic inflammation are identified as culprits for hepatocarcinogenesis in the presence of NAFLD.

AREA COVERED

In this review, the authors report that there are no uniform guidelines for surveillance and early diagnosis in this patient group. Barcelona Clinic Liver Cancer staging is generally applicable to HCC due to NAFLD and management depends on liver function, tumor characteristics, and cardiovascular comorbidity. Evidence suggests that HCC due to NAFLD can be associated with worse survival due to late diagnosis.

EXPERT OPINION

The need for effective early diagnosis and management of NAFLD is urgent, considering the galloping incidence of the obesity and the fact that liver cirrhosis and HCC due to NAFLD will become the first indication for liver transplantation in foreseeable future.

Hyposalivation is prevalent in bariatric patients but improves after surgery

BACKGROUND

Obesity and type 2 diabetes can be associated with poor oral health. This can be because of hyposalivation leading to chronic oral inflammation (OI) and periodontal disease.

OBJECTIVE

To assess the prevalence of hyposalivation and OI in individuals undergoing Roux-en-Y gastric bypass (RYGB) and determine the relationship with metabolic and anthropometric parameters before and after RYGB.

SETTING

University hospital in Canada.

METHODS

This was a cross-sectional and prospective cohort study of 59 patients undergoing RYGB from September 2015 to December 2019. Anthropometric, biochemical, and oral measurements were taken before surgery and 1 and 6 months post RYGB. Oral parameters included salivary flow rate and neutrophil count as marker of OI.

RESULTS

Fifty-nine patients were enrolled with 29 completing this study. At baseline, the median age was 47 years and body mass index was 46.5 kg/m², 52 (88.1%) were female and 14 individuals (23.7%) had type 2 diabetes; 54.2% (n = 32) of patients had hyposalivation and 13.6% (n = 8) had high neutrophil count. Patients with hyposalivation had significantly higher fasting glucose (5.7 mmol/L) compared with those without hyposalivation (5.2 mmol/L) but no difference was found between high versus low neutrophil count. At 6 months post RYGB, all variables except oral neutrophil count significantly improved. Hyposalivation persisted in 7 (24%) individuals.

CONCLUSIONS

In our bariatric patients, more than half the patients had hyposalivation before RYGB and this was associated with higher fasting glucose. Hyposalivation improved post RYGB in parallel with improvements in metabolic parameters but there was no change in OI. Increased salivation may reduce the risk of periodontal disease.

Improvement in Non-alcoholic Fatty Liver Disease Score Correlates with Weight Loss in Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: a Two-Centre Study from an Asian Cohort

PURPOSE

Incidence of non-alcoholic fatty liver disease (NAFLD) is on the rise and is one of the most common causes of chronic liver disease worldwide. Obesity and metabolic syndrome are considered the most significant risk factors. Bariatric surgery is the only treatment modality in morbid obesity which allows long-term weight loss with improvement in associated co-morbid conditions. However, the effects of bariatric surgery on NAFLD are not well established. NAFLD fibrosis score (NFS) is a validated non-invasive scoring system used to assess advanced fibrosis. We used the NFS to analyse the impact of weight loss on NAFLD following sleeve gastrectomy.

MATERIALS AND METHODS

174 patients who underwent bariatric surgery between 2010 and 2016 were retrospectively reviewed. Multivariate analysis was performed using pre-operative patient characteristics, biochemical markers and TANITA body analysis measurements to determine significant risk factors for NFS > 0.675. Additionally, the NFS was calculated at 6 months, 1 year and 2 years post-operatively to determine correlation with weight loss.

RESULTS

Pre-operatively, 13.8% of our patients had significant fibrosis by NFS. Mean change in NFS was - 0.46 ± 1.02, - 0.55 ± 0.98 and - 0.55 ± 1.12 at 6 months, 1 year and 2 years respectively. This was significantly correlated with percent of total weight loss with R coefficients of 0.253, 0.292 and 0.274 respectively (P < 0.05). 79.2% of patients with NFS > 0.675 achieved resolution by 2 years post-operatively.

CONCLUSION

Based on our study, we conclude that sleeve gastrectomy may be a viable treatment option for management of NAFLD in the obese.

Impact of Weight Regain on the Evolution of Non-alcoholic Fatty Liver Disease After Roux-en-Y Gastric Bypass: a 3-Year Follow-up

BACKGROUND

The influence of post-surgical weight regain on the course of non-alcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVE

To evaluate the influence of weight regain on the NAFLD assessed by means of a non-invasive score after Roux-en-gastric bypass (RYGB) over a 3-year period.

METHODS

This is a prospective observational cohort study which evaluated individuals who underwent RYGB. Comparisons were made between the periods immediately before surgery and 12, 24, and 36 months following surgery. Liver disease was estimated by means of the NAFLD fibrosis score. Individuals were classified into three categories according to weight regain status: (1) no weight regain, (2) expected weight regain (regain less or equal than 20% of the maximal weight lost), (3) obesity recidivism (regain above 20% of the maximal weight lost).

RESULTS

Of 90 patients analyzed after 3 years of surgery, 35.6% presented obesity recidivism and 28.8% of the expected regain; 35.6% presented no regain. There was no difference in baseline fibrosis score between groups; at 3 years, the score observed in the relapse group was significantly higher than that observed in the other two groups (p = 0.015). The percent variation of the fibrosis score was significantly higher in the recidivism group (+ 11.8 ± 77.2%) than in the expected regain (- 45.6 ± 64.5%) and no regain (- 37.8 ± 63.2%) groups (p = 0.013).

CONCLUSION

Long-term significant post-RYGB weight regain is associated with a significantly attenuated improvement of NAFLD evaluated by means of liver fibrosis score.

Non-Alcoholic Fatty Liver Disease Is Associated with Impairment of Ejection Fraction Among Individuals with Obesity Undergoing Bariatric Surgery: Results of a Cross-Sectional Study

BACKGROUND

The relationship between non-alcoholic fatty liver disease (NAFLD) and myocardial function seems to be more than just the effect of mutual metabolic risk factors.

OBJECTIVE

To determine whether there is a significant association between NAFLD assessed by means of liver biopsy and left ventricular function expressed by the estimated ejection fraction among individuals with obesity.

METHODS

This is a cross-sectional study which enrolled individuals who consecutively underwent bariatric surgery. NAFLD was assessed by means of liver biopsies which were systematically collected during the procedures. The estimated ejection fraction was obtained by means of transthoracic echocardiograms. The main outcome evaluated was a possible association between NAFLD features and ejection fraction. The results of liver biopsies and the respective degrees of severity of each NAFLD feature were also correlated with the ejection fraction and main anthropometric, biochemical, and clinical variables.

RESULTS

Of 112 individuals, 86.6% were female and the mean age was 38.5 ± 9.3 years. It was observed that the average estimated ejection fraction (EEF) was significantly lower among individuals with liver fibrosis (67.6 ± 5.5% vs. 70.8 ± 4.9%, p = 0.008). After adjustment for confounding variables in a multivariate model, the degree of liver fibrosis was independently associated with the EEF (R = - 0.3, p = 0.02).

CONCLUSION

Among individuals with morbid obesity, the findings of this study are suggestive that liver fibrosis confirmed by histopathological examination is associated with a slight impairment of left ventricular function. Further studies are needed to confirm this association.

Systematic review and meta-analysis of Roux-en-Y gastric bypass against laparoscopic sleeve gastrectomy for amelioration of NAFLD using four criteria

Nonalcoholic fatty liver disease (NAFLD) prevalence is rising worldwide, as a direct consequence of the obesity epidemic. Bariatric surgery provides proven NAFLD amelioration, although questions remain regarding whether Roux-en-Y gastric bypass (RYGB) or laparoscopic sleeve gastrectomy (LSG) is more effective. To answer this question, we conducted a systematic review and meta-analysis exclusively comparing RYGB and LSG for amelioration of NAFLD using 4 separate criteria: alanine transaminase, aspartate transaminase, NAFLD activity score, and NAFLD fibrosis score. Our search included 1290 initial studies, which were narrowed to 20 final studies in the meta-analysis. Overall, both RYGB and LSG significantly improved alanine transaminase, aspartate transaminase, NAFLD activity score, and NAFLD fibrosis score postoperatively. Direct comparisons of RYGB to LSG in any of the 4 criteria failed to demonstrate superiority. Our findings corroborate the current literature showing that bariatric surgery significantly improves biochemical and histologic parameters in patients with NAFLD. The novel individual comparisons of 4 criteria failed to show superiority between RYGB and LSG in ameliorating NAFLD. Despite several limitations, our study can assist clinicians by supporting the notion that RYGB and LSG may be equally efficacious in ameliorating NAFLD.

Effects of sleeve gastrectomy on liver enzymes, non-alcoholic fatty liver disease-related fibrosis and steatosis scores in morbidly obese patients: first year follow-up

Background

Non-alcoholic fatty liver disease (NAFLD) has a high prevalence among patients undergoing laparoscopic sleeve gastrectomy (LSG). Although liver biopsy is the gold standard for assessing histopathologic changes in the liver, it is an invasive procedure. The objective of this study was to evaluate the effect of sleeve gastrectomy on liver enzymes, fibrosis and steatosis scores; ultrasonographic findings; biochemical parameters; and anthropometric measurements in morbidly obese patients with NAFLD.

Methods

Ninety-seven obese patients who underwent LSG were included in this study. Sex, age, body mass index (BMI), comorbidities, liver enzymes, ultrasonographic findings and laboratory parameters to calculate fibrosis and steatosis scores were collected before surgery and after 1 year of follow-up.

Results

A total of 88.7% of patients had liver steatosis at the pre-surgical ultrasonographic evaluation and this ratio decreased to 46.4% 1 year after surgery. Alanine aminotransferase (ALT), homeostatic model assessment of insulin resistance index (HOMA-IR), aspartate aminotransferase-to-platelet ratio index (APRI) and liver fat score (LFS) were significantly higher in patients with steatosis grade III vs. others. There were improvements in high-density lipoprotein (HDL), triglycerides (TG), glycated hemoglobin (HbA1c), glucose, insulin, BMI, liver enzymes and all NAFLD-related fibrosis and steatosis scores.

Conclusions

HOMA-IR, ALT, LFS and APRI scores can be used for follow-up procedures in morbidly obese patients with NAFLD who underwent LSG.

Bariatric surgery in patients with non-alcoholic fatty liver disease - from pathophysiology to clinical effects

Non-alcoholic fatty liver disease (NAFLD) is increasingly recognized as a significant liver disease, and it covers the disease spectrum from simple steatosis with a risk of development of non-alcoholic steatohepatitis (NASH) to fibrosis, subsequent cirrhosis, end-stage liver failure, and liver cancer with a potential need for liver transplantation. NAFLD and NASH are closely related to obesity, metabolic syndrome, and type 2 diabetes (T2D). The role of gut hormones, especially glucagon-like peptide 1 (GLP-1), is important in NAFLD. Bariatric surgery has the potential for inducing great weight loss and may improve the symptoms of metabolic syndrome and T2D. Recent data demonstrated significant effects of bariatric surgery on GLP-1 and other gut hormones and important lipid metabolic and inflammatory abnormalities in the pathophysiology of NAFLD. Therefore, bariatric surgery may reverse the pathological liver changes in NAFLD and NASH patients. In the present review, we describe NAFLD and NASH pathophysiology and the primary effects of bariatric surgery on metabolic pathways. We performed a systematic review of the beneficial and harmful effects and focused on changes in liver disease severity in NAFLD and NASH patients. The specific focus was liver histopathology as assessed by the invasive liver biopsy. Additionally, we reviewed several non-invasive methods used for the assessment of liver disease severity following bariatric surgery.

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.

CORRELATION BETWEEN NONALCOHOLIC FATTY LIVER DISEASE FEATURES AND LEVELS OF ADIPOKINES AND INFLAMMATORY CYTOKINES AMONG MORBIDLY OBESE INDIVIDUALS

ABSTRACT BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the commonest hepatopathy worldwide. OBJECTIVE: To investigate the correlations between NAFLD histopathological features and the levels of adipokines (adiponectin, leptin, and resistin) and circulating inflammatory markers (interleukin-6 [IL-6], interleukin-8 [IL-8], tumor necrosis factor alpha [TNF-α], and C-reactive protein [CRP]). METHODS: This is an exploratory cross-sectional study, which enrolled 19 women with obesity who underwent bariatric surgery. Biochemical characteristics evaluated included the levels of adiponectin, leptin, resistin, IL-6, IL-8, TNF-α, and CRP. NAFLD was assessed through histological examination of liver biopsies carried out during the surgical procedures. RESULTS: The mean age of the study group was 37.3±8.2 years old; mean BMI was 36.2±2.5 kg/m2. Among individuals with liver fibrosis, the levels of IL-8 were significantly higher (24.4 ± 9.7 versus 12.7 ± 6.6; P=0.016726). The intensity of fibrosis presented a significant negative correlation with the levels of adiponectin (R= -0.49379; P=0.03166); i.e. the higher the levels of adiponectin, the lower the intensity of fibrosis. The intensity of steatohepatitis presented a significant negative correlation with the levels of adiponectin (R= -0.562321; P=0.01221); this means that the higher the levels of adiponectin, the lower the intensity of steatohepatitis. CONCLUSION: Adiponectin levels were inversely correlated with the severity of fibrosis and steatohepatitis, whereas IL-8 levels were higher in individuals with liver fibrosis among individuals with obesity and NAFLD undergoing bariatric surgery. The use of these markers to assess NAFLD may bring significant information within similar populations.

Long-Term Follow-Up Study of Liver-Related Outcome After Bilio-Pancreatic Diversion in Patients with Initial, Significant Liver Damage

BACKGROUND

Obesity is associated with NAFLD, and bariatric surgery has significant impact on this liver disease, with reported improvement in hepatic fibrosis.

AIMS

To investigate the effects of bariatric surgery on long-term liver disease-related outcome in obese patients with nonalcoholic fatty liver disease (NAFLD) and significant liver damage.

METHODS

This study included 56 NAFLD patients who underwent bilio-pancreatic diversion for morbid obesity and who had significant fibrosis at intraoperative liver biopsy. Data were analyzed at 1, 3, and 5 years of follow-up, and at the latest available visit in patients who had longer follow-up. We assessed the incidence of clinically relevant liver events (ascites, hepatic encephalopathy, portal hypertension-related bleeding, and jaundice) as well as modifications of a validated biochemical index such as the NAFLD score.

RESULTS

During a median follow-up of 78 months, median weight decreased from 119 to 78 kg (P < 0.0001), and median body mass index decreased from 45.2 to 29.0 kg/m² (P < 0.0001). None of the patients developed clinical complications of liver disease, and none died due to liver-related causes. Median NAFLD score significantly decreased (P = 0.0005) during follow-up from - 0.929 (- 1.543 to - 0.561) to - 1.609 (- 2.056 to - 1.102). The NAFLD score category was unchanged in 32 patients (57%), improved in 18 (32%), and worsened in 6 (11%).

CONCLUSIONS

Patients with NAFLD and proven histological liver damage at surgery do not develop complications of liver disease in long term after bilio-pancreatic diversion. Moreover, noninvasive parameters of liver damage improve. Thus, preexisting liver damage does not seem to be a contraindication to bilio-pancreatic diversion.

Body mass index trajectories in young adulthood predict non-alcoholic fatty liver disease in middle age: The CARDIA cohort study

BACKGROUND & AIMS

Non-alcoholic fatty liver disease is an epidemic. Identifying modifiable risk factors for non-alcoholic fatty liver disease development is essential to design effective prevention programmes. We tested whether 25-year patterns of body mass index change are associated with midlife non-alcoholic fatty liver disease.

METHODS

In all, 4423 participants from Coronary Artery Risk Development in Young Adults, a prospective population-based biracial cohort (age 18-30), underwent body mass index measurement at baseline (1985-1986) and 3 or more times over 25 years. At Year 25, 3115 had liver fat assessed by non-contrast computed tomography. Non-alcoholic fatty liver disease was defined as liver attenuation ≤40 Hounsfield Units after exclusions. Latent mixture modelling identified 25-year trajectories in body mass index per cent change (%Δ) from baseline.

RESULTS

We identified four distinct trajectories of BMI%Δ: stable (26.2% of cohort, 25-year BMI %Δ = 3.1%), moderate increase (46.0%, BMI%Δ = 21.7%), high increase (20.9%, BMI%Δ = 41.9%) and extreme increase (6.9%, BMI%Δ = 65.9%). Y25 non-alcoholic fatty liver disease prevalence was higher in groups with greater BMI %Δ: 4.1%, 9.3%, 13.0%, and 17.6%, respectively (P-trend <.0001). In multivariable analyses, participants with increasing BMI%Δ had increasingly greater odds of non-alcoholic fatty liver disease compared to the stable group: OR: 3.35 (95% CI: 2.07-5.42), 7.80 (4.60-13.23) and 12.68 (6.68-24.09) for moderate, high and extreme body mass index increase, respectively. Associations were only moderately attenuated when adjusted for baseline or Y25 body mass index.

CONCLUSIONS

Trajectories of weight gain during young adulthood are associated with greater non-alcoholic fatty liver disease prevalence in midlife independent of metabolic covariates and baseline or concurrent body mass index highlighting the importance of weight maintenance throughout adulthood as a target for primary non-alcoholic fatty liver disease prevention.

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.

Radiographic Improvement of Hepatic Steatosis After Laparoscopic Roux-en-Y Gastric Bypass

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease and the leading cause of cirrhosis in developed nations. Studies confirm improvement of liver histopathology after significant weight loss, but biochemistry and sonography do not always show this. Computed tomographic (CT) findings of NAFLD include low attenuation of liver parenchyma and hepatomegaly. We hypothesized that patients experiencing significant weight loss after laparoscopic Roux-en-Y gastric bypass (LRYGB) would show CT improvement of NAFLD.

METHODS

A retrospective review was performed on primary LRYGB patients at this institution from 2006 to 2014. We identified patients with either a preoperative abdominal CT or an early postoperative scan (prior to significant weight loss) as well as those with scans performed at >60 days postoperation. Radiologic interpretations were reviewed; descriptions of steatosis, hypodensity, fatty infiltration, fatty liver, fatty changes, or liver parenchyma measuring ≤40 Hounsfield units averaged at three locations on non-contrast CT were documented. Later, scans were reviewed for improvement by these criteria.

RESULTS

Nineteen patients had perioperative radiographic evidence of NAFLD, with 89.5 % female, average age 41.5, and median body mass index (BMI) 46.9 kg/m². Sixteen (84.2 %) showed radiographic improvement of NAFLD. The median time between scans was 826 days, with median BMI at that point of 30.5 kg/m². The three without radiographic improvement still experienced significant weight loss (average BMI points lost = 19.3 kg/m², ±5.6).

CONCLUSIONS

While weight loss and comorbidity improvement are common, they are not universal after LRYGB. Radiographic improvement of NAFLD in 84 % of patients was salutary.

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.

Effect of bariatric surgery on adiposity and metabolic profiles: A prospective cohort study in Middle-Eastern patients

AIM

To investigate changes in adiposity and cardio-metabolic risk profile following Roux-en-Y gastric bypass in patients of Middle Eastern ethnicity with severe obesity.

METHODS

This prospective cohort study involved 92 patients who met the indications of bariatric surgery. Post-procedure markers of obesity and cardiometabolic profile were monitored regularly for a year.

RESULTS

Mean body mass index decreased by 29.5% from 41.9 to 29.5 kg/m2 between baseline and 12-mo follow-up, while mean fat mass decreased by 45.9% from 64.2 kg to 34.7 kg. An improvement was also observed in the gluco-metabolic profile with both fasting glucose and HbA1c substantially decreasing (P < 0.001).

CONCLUSION

The present study shows the short to medium term (1 year) health benefits of bariatric surgery for patients of Middle Eastern ethnicity.

Gastric Bypass and Influence on Improvement of NAFLD

PURPOSE OF REVIEW

Obesity is recognized as a chronic and recurring disease, often accompanied by other weight-related comorbid conditions such as obstructive sleep apnea, hypertension, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). This chapter will seek to focus on the effect of weight loss surgery (WLS), in particular Roux-en-Y gastric bypass (RYGB), on NAFLD.

RECENT FINDINGS

Among several modalities available to treat NAFLD, the one most likely to achieve rapid, significant, and sustained improvement of liver disease is WLS. The most commonly studied WLS procedure at this time is RYGB, and there is significant evidence that this is a safe and effective procedure both for weight loss and to bring about improvement of multiple associated comorbid conditions, including NAFLD. Further research focusing on non-surgical approaches that might mimic the effect of WLS on liver pathology is needed.

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.

The Effects of Metabolic Surgery on Fatty Liver Disease and Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is an under-recognized but increasingly important manifestation of the metabolic syndrome. Bariatric surgery, both through direct weight loss and more indirect effects on insulin resistance and improvements in inflammatory proteins, can have a profound effect on NAFLD, resulting in improvement or resolution of even high-grade liver disease.

Longitudinal Changes in Serum Levels of Angiopoietin-Like Protein 6 and Selenoprotein P After Gastric Bypass Surgery

BACKGROUND

Bariatric surgery has beneficial effects on weight loss and metabolic profiles. Recent evidence suggests that liver-derived hepatokines play a role in the pathophysiology of metabolic diseases. However, few studies have reported longitudinal changes in hepatokines after gastric bypass surgery. We investigated changes in the serum levels of angiopoietin-like protein 6 (Angptl6) and selenoprotein P after gastric bypass surgery.

METHODS

We followed 10 patients who were treated with gastric bypass for weight loss. We measured metabolic parameters and the serum levels of Angptl6 and selenoprotein P before, 1 month after, and 9 months after surgery. We investigated the changes in those hepatokines after surgery and the associations between changes in Angptl6 and selenoprotein P, respectively, and metabolic parameters.

RESULTS

Body mass index decreased linearly. Levels of hemoglobin A1c (HbA1c), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), total cholesterol, triglyceride, LDL cholesterol, and Angptl6 were significantly lower 1 and 9 months after surgery. Fasting plasma glucose was normal throughout the study. Fasting insulin decreased 1 month after surgery but increased 9 months post-surgery. Levels of selenoprotein P increased linearly. Significant correlations were detected between the levels of Angptl6 and LDL cholesterol and fasting insulin. Changes in Angptl6 levels were significantly correlated with changes in total cholesterol and LDL cholesterol. Selenoprotein P levels were inversely correlated with GGT, and changes in selenoprotein P were inversely correlated with changes in homeostasis model assessment for insulin resistance (HOMA-IR).

CONCLUSIONS

Our results suggest that gastric bypass may alter the serum levels of hepatokines independent of weight loss, and these changes are related to certain hepatic metabolic changes.

Advances in research of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease worldwide. It is related with increased morbidity and mortality of cirrhosis and hepatocellular carcinoma (HCC); however, its main health implications are increased risks of developing type 2 diabetes (T2D), cardiovascular diseases and malignancies. This paper reviews the advances in research of NAFLD in terms of epidemiology, risk factors, assessment of disease progression and risks for combined cardiovascular diseases and/or T2D as well as management.

The role of bariatric surgery in the management of nonalcoholic fatty liver disease and metabolic syndrome

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. NAFLD is strongly associated with obesity and metabolic syndrome (MetS). Current treatment of NAFLD is based on weight reduction. Bariatric surgery is the most effective treatment for morbid obesity and its associated metabolic comorbidities. There is evidence indicating that bariatric surgery improves histological and biochemical parameters of NAFLD, but currently is not considered a treatment option for NAFLD. The aim of this work is to review the evidence for the effects of bariatric surgery on NAFLD and the MetS. We found that insulin resistance, alterations in glucose metabolism, hypertension, plasma lipids, transaminases, liver steatosis, steatohepatitis and fibrosis improve after bariatric surgery. Weight loss and improvement of NAFLD are greater after RYGB than after other interventions. These findings were obtained from retrospective or cohort studies. There are no studies designed to evaluate liver-specific mortality, liver transplantation, or quality of life. Patients with indications for bariatric surgery will benefit from the improvements in the MetS and NAFLD.

Non-Alcoholic Fatty Liver Disease (NAFLD): The Search for a Cure

An alarming rise of obesity and, along with it, non-alcoholic fatty liver disease (NAFLD), has been observed in the USA and the rest of the world. NAFLD, the most common cause of chronic liver disease in many developed countries, is not always a benign disorder and considering its growing nature, will have a serious impact on healthcare systems worldwide. The search continues for a suitable therapy for this disorder; the therapy ideally needs to be safe, effective, and affordable. The biggest hurdle in the process of developing such a therapy is our lack of a complete understanding of the pathogenesis of the disease.

Influence of type 2 diabetes mellitus on liver histology among morbidly obese individuals. A cross-sectional study

CONTEXT AND OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has become a public health concern. It encompasses a wide spectrum of histological abnormalities and has close relationships with insulin resistance and type 2 diabetes mellitus (T2DM). This study sought to compare the histological alterations observed in morbidly obese individuals with and without T2DM who underwent Roux-en-Y gastric bypass.

DESIGN AND SETTING

Cross-sectional study in a tertiary-level public hospital.

METHODS

This was a cross-sectional study on 197 individuals who underwent gastric bypass surgery between 2011 and 2013. NAFLD was assessed through liver biopsies. T2DM was diagnosed through the International Diabetes Federation criteria.

RESULTS

Non-diabetics presented significantly more biopsies without any histological abnormalities, regarding steatosis (42.6% versus 25.5%; P = 0.0400), fibrosis (60.6% versus 36.2%; P = 0.0042) and steatohepatitis (27.3% versus 12.8%; P = 0.0495), while diabetics presented significantly higher frequency of moderate forms of steatosis (36.2% versus 20%; P = 0.0307) and fibrosis (23.4% versus 4%; P = 0.0002).

DISCUSSION

T2DM was associated with more advanced forms of NAFLD within the population studied. NAFLD has previously been correlated with severe forms of heart disease.

CONCLUSION

Screening for and early detecting of NAFLD in high-risk populations are important for avoiding further development of severe forms and the need for liver transplantation.