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

Target Therapies for NASH/NAFLD: From the Molecular Aspect to the Pharmacological and Surgical Alternatives

Non-alcoholic fatty liver disease represents an increasing cause of chronic hepatic disease in recent years. This condition usually arises in patients with multiple comorbidities, the so-called metabolic syndrome. The therapeutic options are multiple, ranging from lifestyle modifications, pharmacological options, to liver transplantation in selected cases. The choice of the most beneficial one and their interactions can be challenging. It is mandatory to stratify the patients according to the severity of their disease to tailor the available treatments. In our contribution, we review the most recent pharmacological target therapies, the role of bariatric surgery, and the impact of liver transplantation on the NAFLD outcome.

Non-alcoholic fatty liver disease, insulin resistance, metabolic syndrome and their association with vascular risk

The prevalence of non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases, is rising. About 25% of adults worldwide are probably affected by NAFLD. Insulin resistance (IR) and fat accumulation in the liver are strongly related. The association between NAFLD, metabolic syndrome (MetS) and IR is established, but an independent impact of NAFLD on vascular risk and progression of cardiovascular (CV) disease (CVD) still needs to be confirmed. This narrative review considers the evidence regarding the link between NAFLD, IR and CVD risk. There is strong evidence for a "concomitantly rising incidence" of NAFLD, IR, MetS and CVD but there is no definitive evidence regarding whether NAFLD is, or is not, an independent and significant risk factor the development of CVD. There are also considerations that type 2 diabetes mellitus (T2DM) may be a common link between NAFLD/non-alcoholic steatohepatitis (NASH) and CVD. NAFLD may be associated with widespread abnormal peri-organ or intra-organ fat (APIFat) deposition (e.g. epicardial adipose tissue) which may further contribute to CV risk. It is clear that NAFLD patients have a greater CV risk (independent or not) which needs to be addressed in clinical practice.

Therapeutic pipeline in nonalcoholic steatohepatitis

Our understanding of nonalcoholic fatty liver disease pathophysiology continues to advance rapidly. Accordingly, the field has moved from describing the clinical phenotype through the presence of nonalcoholic steatohepatitis (NASH) and degree of fibrosis to deep phenotyping with a description of associated comorbidities, genetic polymorphisms and environmental influences that could be associated with disease progression. These insights have fuelled a robust therapeutic pipeline across a variety of new targets to resolve steatohepatitis or reverse fibrosis, or both. Additionally, some of these therapies have beneficial effects that extend beyond the liver, such as effects on glycaemic control, lipid profile and weight loss. In addition, emerging therapies for NASH cirrhosis would have to demonstrate either reversal of fibrosis with associated reduction in portal hypertension or at least delay the progression with eventual decrease in liver-related outcomes. For non-cirrhotic NASH, it is the expectation that reversal of fibrosis by one stage or resolution of NASH with no worsening in fibrosis will need to be accompanied by overall survival benefits. In this Review, we summarize NASH therapies that have progressed to phase II and beyond. We also discuss some of the potential clinical challenges with the use of these new therapies when approved.

Leptin Receptors Are Not Required for Roux-en-Y Gastric Bypass Surgery to Normalize Energy and Glucose Homeostasis in Rats

Sensitization to the adipokine leptin is a promising therapeutic strategy against obesity and its comorbidities and has been proposed to contribute to the lasting metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We formally tested this idea using Zucker fatty fa/fa rats as an established genetic model of obesity, glucose intolerance, and fatty liver due to leptin receptor deficiency. We show that the changes in body weight in these rats following RYGB largely overlaps with that of diet-induced obese Wistar rats with intact leptin receptors. Further, food intake and oral glucose tolerance were normalized in RYGB-treated Zucker fatty fa/fa rats to the levels of lean Zucker fatty fa/+ controls, in association with increased glucagon-like peptide 1 (GLP-1) and insulin release. In contrast, while fatty liver was also normalized in RYGB-treated Zucker fatty fa/fa rats, their circulating levels of the liver enzyme alanine aminotransferase (ALT) remained elevated at the level of obese Zucker fatty fa/fa controls. These findings suggest that the leptin system is not required for the normalization of energy and glucose homeostasis associated with RYGB, but that its potential contribution to the improvements in liver health postoperatively merits further investigation.

The role of bariatric surgery in the management of nonalcoholic steatohepatitis

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in the United States and increasing globally. The progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), can lead to cirrhosis and complications of end-stage liver disease. No FDA-approved therapy for NAFLD/NASH exists. Treatment of NAFLD/NASH includes effective and sustained life-style modification and weight loss. This review reports on the recent findings of bariatric surgery in the management of NASH.

RECENT FINDINGS

NAFLD, at all stages, is common in those who meet indication for bariatric surgery. Bariatric surgery resolves NAFLD/NASH and reverses early stages of fibrosis. Although randomized controlled trials of bariatric surgery in NASH are infeasible, studies defining the metabolic changes induced by bariatric surgery, and their effect on NASH, provide insight for plausible pharmacologic targets for the nonsurgical treatment of NASH.

SUMMARY

Resolution of NASH and fibrosis regression can occur after bariatric surgery. Although the exact mechanism(s) underlying the improvement of NASH and hepatic fibrosis following bariatric surgery is not fully elucidated, emerging data on this topic is vitally important for lending insight into the pharmacotherapies for NASH for patients who are not otherwise suitable candidates for bariatric surgery.

Associations between Pre-Bariatric High-Sensitivity C-Reactive Protein and Post-Surgery Outcomes

Background: Obesity is a chronic inflammatory condition associated with increased circulating levels of C-reactive protein (CRP). Bariatric surgery has been reported to be effective in improving both inflammatory and liver status. Our aims were to elucidate the relationships between pre-surgery high sensitivity-CRP (hs-CRP) values and post-surgery weight loss and liver steatosis and fibrosis in patients with severe obesity undergoing Roux-en-Y gastric bypass. Methods: We conducted an observational prospective study on 90 individuals with morbid obesity, who underwent gastric bypass. Anthropometric indices, laboratory assessment (lipid panel, glycemic status, liver enzymes, and hs-CRP), liver stiffness and steatosis were evaluated at baseline and 6-months after surgery. Results: There was a significant post-surgery reduction in all the anthropometric variables, with an average weight loss of 33.93 ± 11.79 kg; the mean percentage of total weight loss (TWL) was 27.96 ± 6.43%. Liver elasticity was significantly reduced (from 6.1 ± 1.25 to 5.42 ± 1.52 kPa; p = 0.002), as well as liver aminotransferases, nonalcoholic fatty liver disease fibrosis score (NFS) and the grade of steatosis. Serum hs-CRP levels significantly reduced (from 9.26 ± 8.45 to 3.29 ± 4.41 mg/L; p < 0.001). The correlations between hs-CRP levels and liver fibrosis (elastography), steatosis (ultrasonography), fibrosis-4 index, NFS, and surgery success rate were not significant. Regression analyses showed that serum hs-CRP levels were not predictive of liver status and success rate after surgery in both unadjusted and adjusted models. Conclusions: In patients with morbid obesity, bariatric surgery caused a significant decrease in hs-CRP levels, liver stiffness and steatosis. Baseline hs-CRP values did not predict the weight-loss success rate and post-surgery liver status.

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

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

Evolution of Non-alcoholic Fatty Liver Disease (NAFLD) Biomarkers in Response to Weight Loss 1 Year After Bariatric Surgery-a Post Hoc Analysis of the FibroTest Prospective Study

BACKGROUND

Bariatric surgery is among the therapeutic options for non-alcoholic fatty liver disease (NAFLD), affecting 90% of patients with obesity. The aim of this study was to evaluate the evolution of NAFLD lesions 1 year after surgery using noninvasive markers.

METHODS

From November 2011 to November 2012, 253 patients with obesity undergoing bariatric surgery in three French University Hospitals were included. Histological data regarding intraoperative liver biopsy were collected at baseline, clinical, and biological data, including FibroTest®, SteatoTest®, and NASHTest®, before and after surgery.

RESULTS

Fibrosis' prevalence was 74.2% with a positive predictive value (PPV) for FibroTest® of 78.6% and 43.4% for significant fibrosis (Kleiner ≥ F2) with a negative predictive value (NPV) of 56.1%. NAFLD's prevalence was 84% with a PPV for SteatoTest® of 85.9% and 7.7% for NASH with an NPV for NASHTest® of 93.8%. One year after bariatric surgery, mean BMI had significantly decreased from 46.5 to 31.7 kg/m² (p < 0.001). Fibrosis assessed by the FibroTest® showed that 82.5% of patients were F0 after surgery compared to 90.9% before. Using SteatoTest®, the percent of patient without steatosis (S0) increased from 1.6 to 49.6% after surgery, and rate of severe steatosis (S3) improved from 43.3 to 3.9%. NASHTest® revealed that the percent of patients without NASH increased from 12.8 to 73.6% and rates of NASH improved from 12 to 0.8%.

CONCLUSIONS

Validated noninvasive biomarkers SteatoTest® and NASHTest® suggested NAFLD and steatohepatitis improvement after bariatric surgery and might be useful tools for patient follow-up. Regarding fibrosis, FibroTest® was not accurate in patients with extreme obesity.

A prospective 5-year study on the use of transient elastography to monitor the improvement of non-alcoholic fatty liver disease following bariatric surgery

Liver stiffness measurement (LSM) by transient elastography (TE) is a non-invasive assessment for diagnosing and staging liver fibrosis in non-alcoholic fatty liver disease (NAFLD). Evidence on its role as a longitudinal monitoring tool is lacking. This study aims to evaluate the role of TE in monitoring NAFLD improvement following bariatric surgery. This study prospectively recruited 101 morbidly obese patients undergoing laparoscopic bariatric surgery for intraoperative liver biopsy. Thirty-seven patients of the cohort received perioperative TE. Postoperative anthropometric, biochemical and LSM data were collected annually for 5 years. In 101 patients receiving liver biopsy (mean age 40.0 ± 10.3 years, mean body-mass-index (BMI) 40.0 ± 5.7 kg/m²), NASH and liver fibrosis were diagnosed in 42 (41.6%) and 48 (47.5%) patients respectively. There were 29 (28.7%) stage 1, 11 (10.9%) stage 2, 7 (6.9%) stage 3, and 1 (1.0%) stage 4 fibrosis. In 37 patients receiving TE (mean age 38.9 ± 10.8 years, mean BMI 41.1 ± 5.6 kg/m²), the percentages of total weight loss were 21.1 ± 7.6% at 1 year, 19.7 ± 8.3% at 3 years, and 17.1 ± 7.0% at 5 years after surgery. The mean LSM reduced significantly from 9.8 ± 4.6 kPa at baseline to 6.9 ± 3.4 kPa at 1 year, 7.3 ± 3.0 kPa at 3 years, and 6.8 ± 2.6 kPa at 5 years (P = 0.002). Using pre-defined LSM cut-offs, the rates of significant fibrosis, advanced fibrosis and cirrhosis being ruled out at 5 years improved from baseline values of 43.7 to 87.5% (P < 0.001), 56.8 to 91.7% (P < 0.001), and 64.9 to 91.7% (P < 0.001), respectively. TE was a useful monitoring tool in demonstrating the improvement of liver fibrosis following bariatric surgery.

Duodenal-jejunal bypass maintains hepatic S-adenosylmethionine/S-homocysteine ratio in diet-induced obese rats

We previously reported that the duodenal-jejunal bypass (DJB) surgery altered transsulfuration and purine metabolism via flux changes in 1-carbon metabolism in the liver. In this study, we extended our study to gain further insight into mechanistic details of how the DJB-induced flux changes in 1-carbon metabolism contributes to the improvement of diet-induced nonalcoholic fatty liver disease. Rodents were subjected to surgical (sham operation and DJB) or dietary (reduced food supply to follow the weight changes in the DJB group) interventions. The microscopic features of the liver were examined by immunohistochemistry. The expressions of genes in lipid synthesis and in 1-carbon cycle in the liver were analyzed by real-time polymerase chain reaction and western blotting. Metabolic changes in the liver were determined. We observed that DJB reduces hepatic steatosis and improves insulin sensitivity in both high-fat diet-fed rats and mice. Metabolic analyses revealed that the possible underlying mechanism may involve decreased S-adenosylmethionine (SAM)-to-S-adenosylhomocysteine ratio via downregulation of SAM synthesizing enzyme and upregulation of SAM catabolizing enzyme. We also found in mice that DJB-mediated attenuation of hepatic steatosis is independent of weight loss. DJB also increased hepatic expression levels of GNMT while decreasing those of PEMT and BHMT, a change in 1-carbon metabolism that may decrease the ratio of SAM to S-adenosylhomocysteine, thereby resulting in the prevention of fat accumulation in the liver. Thus, we suggest that the change in 1-carbon metabolism, especially the SAM metabolism, may contribute to the improvement of diet-induced fatty liver disease after DJB surgery.

The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Trials show that weight loss interventions improve biomarkers of non-alcoholic fatty liver disease (NAFLD), but it is unclear if a dose-response relationship exists.

OBJECTIVE

We aimed to quantify the dose-response relationship between the magnitude of weight loss and improvements in NAFLD.

METHODS

Nine databases and trial registries were searched until October 2020. Single-arm, non-randomized comparative, or randomized trials of weight loss interventions (behavioral weight loss programs [BWLPs], pharmacotherapy, or bariatric surgery) in people with NAFLD were eligible for inclusion if they reported an association between changes in weight and changes in blood, radiological, or histological biomarkers of liver disease. The review followed Cochrane methods and the risk of bias was assessed using the Newcastle-Ottawa scale. Pooled unstandardized b coefficients were calculated using random-effect meta-analyses.

RESULTS

Forty-three studies (BWMPs: 26, pharmacotherapy: 9, surgery: 8) with 2809 participants were included. The median follow-up was 6 (interquartile range: 6) months. The direction of effect was generally consistent but the estimates imprecise. Every 1 kg of weight lost was associated with a 0.83-unit (95% CI: 0.53 to 1.14, p < 0.0001, I² = 92%, n = 18) reduction in alanine aminotransferase (U/L), a 0.56-unit (95% CI: 0.32 to 0.79, p < 0.0001, I² = 68%, n = 11) reduction in aspartate transaminase (U/L), and a 0.77 percentage point (95% CI: 0.51 to 1.03, p < 0.0001, I² = 72%, n = 11) reduction in steatosis assessed by radiology or histology. There was evidence of a dose-response relationship with liver inflammation, ballooning, and resolution of NAFLD or NASH, but limited evidence of a dose-response relationship with fibrosis or NAFLD activity score. On average, the risk of bias for selection and outcome was medium and low, respectively.

CONCLUSION

Clinically significant improvements in NAFLD are achieved even with modest weight loss, but greater weight loss is associated with greater improvements. Embedding support for formal weight loss programs as part of the care pathway for the treatment of NAFLD could reduce the burden of disease.

PROSPERO

CRD42018093676.

NAFLD in type 2 diabetes mellitus: Still many challenging questions

Epidemiologic data consistently show that in patients with type 2 diabetes (T2DM) the prevalence of non-alcoholic fatty liver disease (NAFLD), including advanced fibrosis, is double compared to the general population, and it associates with high risk of liver-related morbidity (advanced fibrosis, hepatocellular carcinoma) and mortality, but also with other systemic consequences, such as cardiovascular (CV) disease, chronic kidney disease, and overall mortality. There are still many answers that need to be clarified regarding NAFLD in T2DM, including deciphering the complex pathogenetic mechanisms, the intertwined relationships with the extrahepatic organs and tissues (mainly heart, kidneys, adipose tissue, gut), the prognostic value of NAFLD for CV risk stratification, and more importantly, what would be the most appropriate screening algorithm, diagnostic method and therapeutic approach. We advocate here for proactive action, in order to identify NAFLD in a timely manner, and suggest a simple algorithm to be used in clinical practice, based on risk stratification and on experts' opinions. We discuss the current therapeutic options for NAFLD in T2DM, for which a multifactorial approach is needed, that concomitantly addresses the liver and the cardio-reno-metabolic disturbances.

Malnutrition and Alcohol in Patients Presenting with Severe Complications of Cirrhosis After Laparoscopic Bariatric Surgery

Factors and outcomes associated with decompensation of liver disease and liver failure in obese patients who underwent modern bariatric surgery are unclear. We present here a cohort of seventeen consecutive patients referred because of decompensation of liver disease following laparoscopic bariatric surgery. All patients showed signs of malnutrition (sarcopenia in 76.5%). In ten (58.8%), decompensation was associated with alcohol ingestion, which started after bariatric surgery in six patients. One patient died and three patients required liver transplantation, in one case preceded by transjugular intrahepatic portosystemic shunt (TIPS). However, thirteen patients achieved stabilization or full re-compensation with medical therapy and nutritional support. Our cases underline the risk of alcohol intake and malnutrition after laparoscopic bariatric surgery as causes of severe liver decompensation and underline the need for careful interdisciplinary care of these patients after surgery to early identify and treat alcohol misuse, malnutrition, and liver disease.

Safety of liver biopsy at the time of bariatric surgery: an analysis of the MBSAQIP database

BACKGROUND

The majority of patients undergoing bariatric surgery have hepatic steatosis. Liver biopsy is not technically difficult to perform at the time of metabolic and bariatric surgery (MBS), but there may be concerns for bleeding complications. The safety of liver biopsy (LBx) at the time of MBS has been studied in single institutional studies but has not been studied on a national level.

METHODS

The MBSAQIP database for 2015-2018 was examined. The codes for Roux-en-Y gastric bypass (RYGB) of 43644 and sleeve gastrectomy (SG) 43775 were used along with 47000 (percutaneous liver biopsy), 47001 (percutaneous liver biopsy at time of other procedure), and 47379 (unlisted laparoscopic procedure, liver). Outcomes such as operative time, complications, and length of stay were examined. Propensity-matched analysis was performed to evaluate for adjusted associations.

RESULTS

There were 546,532 patients that met our inclusion criteria. Of those, 21,367 (3.9%) underwent LBx. Only 5.5% (8012) of patients undergoing RYGB had a LBx and 3.3% (13,355) of SG patients. Patients who underwent a LBx had a longer operative time before (103 min vs 84 min, p < 0.001) and after propensity matching [regression coefficient (RC): 10.7 (8.87, 12.5)]. There was no increase in length of stay. There was an increased risk in mortality in the unadjusted analysis (prevalence ratio = 1.61, p = 0.02), but when propensity-matched analysis was done, there was no statistically significant difference between the two groups. Concerning bleeding or transfusion, there was no difference in bleeding or rates of transfusion (p= 0.22, p = 0.21).

CONCLUSION

Liver biopsy at the time of MBS is safe. It adds operative time, but there is no increase in length of stay, bleeding complications, morbidity, or death.

Efficacy and Safety of Intragastric Balloon (IGB) in Non-alcoholic Fatty Liver Disease (NAFLD): a Comprehensive Review and Meta-analysis

Intragastric balloon (IGB) therapy has shown efficacy in weight loss but its role in NAFLD remains unknown. We conducted a systematic review and meta-analysis to evaluate the efficacy of IGB in NAFLD. Meta-analysis was performed to estimate the pooled proportion of patients with improvement in steatosis as determined by imaging and histology following IGB placement. Nine studies were included in our analysis. Four hundred forty-two IGBs were placed. Improvement in steatosis was seen in 79.2% of patients and NAS in 83.5% of patients, and HOMA-IR score improved in 64.5% of patients. A reduction in liver volume by CT scan was noticed in 93.9% of patients undergoing IGB placement. IGB is an effective and safe short-term therapeutic modality for patients with NAFLD.

A look to the future in non-alcoholic fatty liver disease: Are glucagon-like peptide-1 analogues or sodium-glucose co-transporter-2 inhibitors the answer?

The increasing prevalence of diabetes and non-alcoholic fatty liver disease (NAFLD) is a growing public health concern associated with significant morbidity, mortality and economic cost, particularly in those who progress to cirrhosis. Medical treatment is frequently limited, with no specific licensed treatments currently available for people with NAFLD. Its association with diabetes raises the possibility of shared mechanisms of disease progression and treatment. With the ever-growing interest in the non-glycaemic effects of diabetes medications, studies and clinical trials have investigated hepatic outcomes associated with the use of drug classes used for people with type 2 diabetes (T2D), such as glucagon-like peptide-1 (GLP-1) analogues or sodium-glucose co-transporter-2 (SGLT2) inhibitors. Studies exploring the use of GLP-1 analogues or SGLT2 inhibitors in people with NAFLD have observed improved measures of hepatic inflammation, liver enzymes and radiological features over short periods. However, these studies tend to have variable study populations and inconsistent reported outcomes, limiting comparison between drugs and drug classes. As these drugs appear to improve biomarkers of NAFLD, clinicians should consider their use in patients with NAFLD and T2D. However, further evidence with greater participant numbers and longer trial durations is required to support specific licensing for people with NAFLD. Larger trials would allow reporting of major adverse hepatic events, akin to cardiovascular and renal outcome trials, to be determined. This would provide a more meaningful evaluation of the impact of these drugs in NAFLD. Nevertheless, these drugs represent a future potential therapeutic avenue in this difficult-to-treat population and may beget significant health and economic impacts.

The Asian Pacific Association for the Study of the Liver clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is the principal worldwide cause of liver disease and affects nearly a quarter of the global population. The objective of this work was to present the clinical practice guidelines of the Asian Pacific Association for the Study of the Liver (APASL) on MAFLD. The guidelines cover various aspects of MAFLD including its epidemiology, diagnosis, screening, assessment, and treatment. The document is intended for practical use and for setting the stage for advancing clinical practice, knowledge, and research of MAFLD in adults, with specific reference to special groups as necessary. The guidelines also seek to improve patient care and awareness of the disease and assist stakeholders in the decision-making process by providing evidence-based data. The guidelines take into consideration the burden of clinical management for the healthcare sector.

Short-term multiorgan metabolic benefits of rapid weight loss after sleeve gastrectomy in severely obese patients

BACKGROUND

Sleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.

OBJECTIVE

Comprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.

SETTING

Academic hospital, United States.

METHODS

We retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.

RESULTS

A total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.

CONCLUSION

There are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.

A Nomogram Model Based on Noninvasive Bioindicators to Predict 3-Year Risk of Nonalcoholic Fatty Liver in Nonobese Mainland Chinese: A Prospective Cohort Study

The purpose of this study is to establish and validate an accurate and personalized nonalcoholic fatty liver disease (NAFLD) prediction model based on the nonobese population in China. This study is a secondary analysis of a prospective study. We included 6,155 nonobese adults without NAFLD at baseline, with a median follow-up of 2.3 years. Univariate and multivariate Cox regression analyses were used to determine independent predictors. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to optimize the selection of variables. Based on the results of multivariate analysis, a prediction model was established. Harrell's consistency index (C-index) and area under the curve (AUC) were used to determine the discrimination of the proposed model. The goodness of fit of the calibration model was tested, and the clinical application value of the model was evaluated by decision curve analysis (DCA). The participants were randomly divided into a training cohort (n = 4,605) and a validation cohort (n = 1,550). Finally, seven of the variables (HDL-c, BMI, GGT, ALT, TB, DBIL, and TG) were included in the prediction model. In the training cohort, the C-index and AUC value of this prediction model were 0.832 (95% confidence interval (CI), 0.820-0.844) and 0.861 (95% CI, 0.849-0.873), respectively. In the validation cohort, the C-index and AUC values of this prediction model were 0.829 (95% CI, 0.806-0.852) and 0.859 (95% CI, 0.841-0.877), respectively. The calibration plots demonstrated good agreement between the estimated probability and the actual observation. DCA demonstrated a clinically effective predictive model. Our nomogram can be used as a simple, reasonable, economical, and widely used tool to predict the 3-year risk of NAFLD in nonobese populations in China, which is helpful for timely intervention and reducing the incidence of NAFLD.

British Obesity and Metabolic Surgery Society Guidelines on perioperative and postoperative biochemical monitoring and micronutrient replacement for patients undergoing bariatric surgery-2020 update

Bariatric surgery is recognized as the most clinically and cost-effective treatment for people with severe and complex obesity. Many people presenting for surgery have pre-existing low vitamin and mineral concentrations. The incidence of these may increase after bariatric surgery as all procedures potentially cause clinically significant micronutrient deficiencies. Therefore, preparation for surgery and long-term nutritional monitoring and follow-up are essential components of bariatric surgical care. These guidelines update the 2014 British Obesity and Metabolic Surgery Society nutritional guidelines. Since the 2014 guidelines, the working group has been expanded to include healthcare professionals working in specialist and non-specialist care as well as patient representatives. In addition, in these updated guidelines, the current evidence has been systematically reviewed for adults and adolescents undergoing the following procedures: adjustable gastric band, sleeve gastrectomy, Roux-en-Y gastric bypass and biliopancreatic diversion/duodenal switch. Using methods based on Scottish Intercollegiate Guidelines Network methodology, the levels of evidence and recommendations have been graded. These guidelines are comprehensive, encompassing preoperative and postoperative biochemical monitoring, vitamin and mineral supplementation and correction of nutrition deficiencies before, and following bariatric surgery, and make recommendations for safe clinical practice in the U.K. setting.

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

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

Glucagon-Like Peptide 1 Receptor Agonists and Heart Failure

With worsening epidemiological trends for both the incidence and prevalence of type 2 diabetes mellitus (T2DM) and heart failure (HF) worldwide, it is critical to implement optimal prevention and treatment strategies for patients with these comorbidities, either alone or concomitantly. Several guidelines and consensus statements have recommended glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter type 2 inhibitors as add-ons to lifestyle interventions with or without metformin in those at high atherosclerotic cardiovascular disease risk. However, these recommendations are either silent about HF or fail to differentiate between the prevention of HF in those at risk versus the treatment of individuals with manifest HF. Furthermore, these documents do not differentiate among those with different HF phenotypes. This distinction, even though important, may not be critical for sodium-glucose cotransporter type 2 inhibitors in view of the consistent data for benefit for both atherosclerotic cardiovascular disease– and HF-related outcomes that have emerged from the regulatory-mandated cardiovascular outcome trials for all sodium-glucose cotransporter type 2 inhibitors and the recent DAPA-HF trial (Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction)demonstrating the benefit of dapagliflozin on HF-related outcomes in patients with HF with reduced ejection fraction with or without T2DM. However, the distinction may be crucial for glucagon-like peptide-1 receptor agonists and other antihyperglycemic agents. Indeed, in several of the new statements, glucagon-like peptide-1 receptor agonists are suggested treatment not only for patients with T2DM and atherosclerotic cardiovascular disease, but also in those with manifest HF, despite a lack of evidence for the latter recommendation. Although glucagon-like peptide-1 receptor agonists may be appropriate to use in patients at risk for HF, mechanistic insights and observations from randomized trials suggest no clear benefit on HF-related outcomes and even uncertainty regarding the safety in those with HF with reduced ejection fraction. Conversely, theoretical rationales suggest that these agents may benefit patients with HF with preserved ejection fraction. Considering that millions of patients with T2DM have HF, these concerns have public health implications that necessitate the thoughtful use of these therapies. Achieving this aim will require dedicated trials with these drugs in both patients who have HF with reduced ejection fraction and HF with preserved ejection fraction with T2DM to assess their efficacy, safety, and risk-benefit profile.

Peroxisome Proliferator-Activated Receptors and Their Novel Ligands as Candidates for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a major health issue worldwide, frequently associated with obesity and type 2 diabetes. Steatosis is the initial stage of the disease, which is characterized by lipid accumulation in hepatocytes, which can progress to non-alcoholic steatohepatitis (NASH) with inflammation and various levels of fibrosis that further increase the risk of developing cirrhosis and hepatocellular carcinoma. The pathogenesis of NAFLD is influenced by interactions between genetic and environmental factors and involves several biological processes in multiple organs. No effective therapy is currently available for the treatment of NAFLD. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that regulate many functions that are disturbed in NAFLD, including glucose and lipid metabolism, as well as inflammation. Thus, they represent relevant clinical targets for NAFLD. In this review, we describe the determinants and mechanisms underlying the pathogenesis of NAFLD, its progression and complications, as well as the current therapeutic strategies that are employed. We also focus on the complementary and distinct roles of PPAR isotypes in many biological processes and on the effects of first-generation PPAR agonists. Finally, we review novel and safe PPAR agonists with improved efficacy and their potential use in the treatment of NAFLD.

Long-term effects of one-anastomosis gastric bypass on liver histopathology in NAFLD cases: a prospective study

PURPOSE

Weight reduction can effectively improve nonalcoholic fatty liver disease (NAFLD), which is a constant companion of severe obesity. This study aimed to determine the effect of one-anastomosis gastric bypass (OAGB) on pathological liver changes in severely obese cases with NAFLD.

METHODS

The present prospective research comprised 67 subjects with morbid obesity scheduled for OAGB during the period from February 2015 to August 2018. Clinical, biological, and histologic data were evaluated pre and 15 months postoperatively.

RESULTS

Fifteen months after surgery, a considerable reduction was noted in the grades of fat deposition, liver cell ballooning, and lobular inflammatory changes, in addition to the total NAS score. Fifteen months after surgery, nonalcoholic steatohepatitis (NASH) disappeared in 42% of the patients. A significant regression of fibrosis stage occurred after surgery in 79.1% of patients (p < 0.001). After surgery, patients had substantial reductions in aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, HbA1c, total cholesterol, and Low-density lipoprotein (p < 0.001, for all comparisons). Diabetes mellitus, hypertension, and dyslipidemia resolved in 54%, 59%, and 69% of the patients, respectively.

CONCLUSION

OAGB resolved NASH from nearly 42% of patients and reduced the histological features of NAFLD 15 months after surgery. Bariatric procedures might be adopted as a therapeutic modality in severely obese cases with NAFLD after the failure of lifestyle modifications.

Mechanisms of Fibrosis Development in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is the most prevalent liver disease worldwide, affecting 20%-25% of the adult population. In 25% of patients, nonalcoholic fatty liver disease progresses to nonalcoholic steatohepatitis (NASH), which increases the risk for the development of cirrhosis, liver failure, and hepatocellular carcinoma. In patients with NASH, liver fibrosis is the main determinant of mortality. Here, we review how interactions between different liver cells culminate in fibrosis development in NASH, focusing on triggers and consequences of hepatocyte-macrophage-hepatic stellate cell (HSC) crosstalk. We discuss pathways through which stressed and dead hepatocytes instigate the profibrogenic crosstalk with HSC and macrophages, including the reactivation of developmental pathways such as TAZ, Notch, and hedgehog; how clearance of dead cells in NASH via efferocytosis may affect inflammation and fibrogenesis; and insights into HSC and macrophage heterogeneity revealed by single-cell RNA sequencing. Finally, we summarize options to therapeutically interrupt this profibrogenic hepatocyte-macrophage-HSC network in NASH.

Microbial Adaptation Due to Gastric Bypass Surgery: The Nutritional Impact

Bariatric surgery leads to sustained weight loss and the resolution of obesity-related comorbidities. Recent studies have suggested that changes in gut microbiota are associated with the weight loss induced by bariatric surgery. Several studies have observed major changes in the microbial composition following gastric bypass surgery. However, there are inconsistencies between the reported alterations in microbial compositions in different studies. Furthermore, it is well established that diet is an important factor shaping the composition and function of intestinal microbiota. However, most studies on gastric bypass have not assessed the impact of dietary intake on the microbiome composition in general, let alone the impact of restrictive diets prior to bariatric surgery, which are recommended for reducing liver fat content and size. Thus, the relative impact of bariatric surgery on weight loss and gut microbiota remains unclear. Therefore, this review aims to provide a deeper understanding of the current knowledge of the changes in intestinal microbiota induced by bariatric surgery considering pre-surgical nutritional changes.

Management of nonalcoholic fatty liver disease and the role of bariatric surgery: a brief review for surgeons

Nonalcoholic fatty liver disease (NAFLD) is closely linked to the metabolic syndrome and is highly prevalent in bariatric patients. The criterion standard to diagnose NAFLD is a liver biopsy specifically to detect inflammatory changes characteristic of nonalcoholic steatohepatitis. Technologic advancements will improve the accuracy of current noninvasive modalities. Modification of risk factors via food management is important to prevent the progression of NAFLD to nonalcoholic steatohepatitis and cirrhosis. Several clinical trials are underway for pharmacologic treatment of NAFLD; currently the mainstay of treatment is insulin sensitizers and vitamin E. There is strong evidence bariatric surgery improves biochemical and histologic features of NAFLD and therefore, bariatric surgery should be considered as a treatment of NAFLD in patients with obesity. Gastric bypass exhibits antilipogenic, antiinflammatory, antioxidant, and antidiabetic properties in the livers of laboratory animals; thereby, providing a unique window to study regulation of body adiposity and insulin resistance.

Atrial Fibrillation and Heart Failure With Preserved Ejection Fraction in Patients With Nonalcoholic Fatty Liver Disease

The most common causes of chronic liver disease in the developed world-nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH)-are the hepatic manifestations of an insulin-resistant state that is linked to visceral adiposity and systemic inflammation. NAFLD and NASH lead to an expansion of epicardial adipose tissue and the release of proinflammatory adipocytokines that cause microcirculatory dysfunction and fibrosis of the adjoining myocardium, resulting in atrial fibrillation as well as heart failure with a preserved ejection fraction (HFpEF). Inflammatory changes in the left atrium lead to electroanatomical remodeling; thus, NAFLD and NASH markedly increase the risk of atrial fibrillation. Simultaneously, patients with NAFLD or NASH commonly show diastolic dysfunction or latent HFpEF. Interventions include 1) weight loss by caloric restriction, bariatric surgery, or intensive exercise, and 2) drugs that ameliorate fat-mediated inflammation in both the liver and heart (eg, statins, metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and pioglitazone). Patients with NAFLD or NASH commonly have an inflammation-related atrial and ventricular myopathy, which may contribute to symptoms and long-term outcomes.

Treatment of non-alcoholic fatty liver disease - Current perspectives

Therapeutics aimed at treating non-alcoholic fatty liver disease (NAFLD) target the pathogenic process from deranged metabolism leading to steatosis to cell stress and death, leading to a cascade of inflammation and fibrosis, ultimately culminating into cirrhosis. The development of drugs for management of NAFLD has bloomed over the past decade, although at present there is no approved pharmacological agent for its management. Not all patients with the disease progress to cirrhosis and decompensation; hence, treatment specifically is provided for those with a high risk of progression such as those with biopsy-proven steatohepatitis or fibrosis. Along with disease-specific management, all patients must receive therapies directed at risk factors such as dyslipidemia, insulin resistance, type 2 diabetes mellitus and obesity. Comorbidities such as cardiovascular disease, sleep apnoea and chronic kidney disease need management. A current perspective on the therapeutic options is detailed in this review.

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

BACKGROUND

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

MAIN TEXT

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

CONCLUSION

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

Non-alcoholic Fatty Liver Disease and Diabetes Mellitus

Nonalcoholic fatty liver disease (NAFLD) has emerged as the leading liver disease globally. NAFLD patients can have a progressive phenotype, non-alcoholic steatohepatitis (NASH) that could lead to cirrhosis, liver failure and cancer. There is a close bi-directional relationship between NAFLD and type 2 diabetes mellitus (T2DM); NAFLD increases the risk for T2DM and its complications whereas T2DM increases the severity of NAFLD and its complications. The large global impact of NAFLD and T2DM on healthcare systems requires a paradigm shift from specialty care to early identification and risk stratification of NAFLD in primary care and diabetes clinics. Approach to diagnosis, risk stratification and management of NAFLD is discussed. In addition to optimizing the control of coexisting cardiometabolic comorbidities, early referral of NAFLD patients at high risk of having NASH or significant fibrosis to hepatology specialist care may improve management and allow access for clinical trials. Lifestyle modifications, vitamin E, pioglitazone and metformin are currently available options that may benefit patients with T2DM and NAFLD. The burst of clinical trials investigating newer therapeutic agents for NAFLD and NASH offer hope for new, effective and safe therapies in the near future.

Roux-en-Y Gastric Bypass in Obese Diabetic Rats Promotes Autophagy to Improve Lipid Metabolism through mTOR/p70S6K Signaling Pathway

PURPOSE

To investigate the effects of Roux-en-Y gastric bypass (RYGB) surgery on markers of liver mitochondrial dynamics and find new therapeutic basis on obese type 2 diabetes mellitus (T2DM) patients. Materials and Methods. Thirty-two rats were divided into nondiabetic group, diabetic group, sham group, and RYGB group. The Dual-energy X-ray absorptiometry (DEXA) was used to detect short-term curriculum vitae for rat body component and fat and lean mass. Hepatic lipid content and triglyceride levels were detected by Oil Red O staining. Western blotting was used to examine autophagy and mammalian target of rapamycin/P70S6 kinase (mTOR/p70S6K) pathway-related proteins. The carbon dioxide production from the oxidation of [¹⁴C] oleate was measured. Plasma glucose was measured by glucose oxidase assay. The insulin and C-peptide were detected. Triacylglyceride (TG) and free fat acid (FFA) in plasma were determined by enzymatic colorimetric assays.

RESULTS

RYGB improved metabolic parameters and enhanced plasma GLP-1 level, ameliorated the lipopexia, and increased insulin sensitivity in the liver; RYGB promoted the hepatic autophagy and inhibited the mTOR/p70S6K signaling pathway. GLP-1 reduced fat load and increased fatty acid β-oxidation by activated autophagy to regulate the hepatic lipid pathway through mTOR/p70S6K signaling pathway.

CONCLUSIONS

RYGB may reduce liver lipid toxicity and improve insulin sensitivity through activating the hepatic fat hydrolysis pathway and inhibiting the liver fat synthesis pathway. However, the transport pathway of liver fat does not play a key role.

A retrospective case control study identifies peripheral blood mononuclear cell albumin RNA expression as a biomarker for non-alcoholic fatty liver disease

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) improves after bariatric surgery. The aim of this study was to determine whether peripheral blood mononuclear cell albumin gene expression was related to NAFLD and whether albumin (ALB) and alpha fetoprotein (AFP) expression could be detected in whole blood and visceral adipose tissue.

METHODS

Using a retrospective case control study design, RNA isolated from peripheral blood mononuclear cells from patients prior to undergoing bariatric surgery was used for pooled microarray analysis. Quantitative polymerase chain reaction (QPCR) was used to analyze whole blood and visceral adipose tissue. Liver histology was obtained via intra-operative biopsy and clinical data extracted from the electronic health record.

RESULTS

The albumin (ALB) gene was the second most up-regulated found in microarray analysis of peripheral blood mononuclear cell RNA from patients with hepatic lobular inflammation versus normal liver histology. Transcript levels of ALB were significantly different across those with normal (n = 50), steatosis (n = 50), lobular inflammation (n = 50), and peri-sinusoidal fibrosis (n = 50) liver histologies, with lobular inflammation 3.9 times higher than those with normal histology (p < 0.017). Albumin expression levels decreased in 11/13 patients in paired samples obtained prior to and at 1 year after Roux-en-Y gastric bypass surgery. ALB expression could be detected in 23 visceral adipose tissue samples obtained intra-operatively and in 18/19 available paired whole blood samples. No significant correlation was found between ALB expression in visceral adipose tissue and whole blood RNA samples. Alpha fetoprotein expression as a marker of early hepatocytic differentiation was detected in 17/17 available VAT RNA samples, but in only 2/17 whole blood RNA samples.

CONCLUSION

Albumin RNA expression from blood cells may serve as a biomarker of NAFLD. Albumin and alpha fetoprotein appear to be ubiquitously expressed in visceral adipose tissue in patients with extreme obesity.

Dietary Patterns and Components in Nonalcoholic Fatty Liver Disease (NAFLD): What Key Messages Can Health Care Providers Offer?

Nonalcoholic fatty liver disease (NAFLD) is a rising epidemic worldwide and will be the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplant within the next decade. NAFLD is considered as the hepatic manifestation of metabolic syndrome. Behaviors, such as a sedentary lifestyle and consuming a Western diet, have led to substantial challenges in managing NAFLD patients. With no curative pharmaceutical therapies, lifestyle modifications, including dietary changes and exercise, that ultimately lead to weight loss remain the only effective therapy for NAFLD. Multiple diets, including low-carbohydrate, low-fat, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean (MD) diets, have been evaluated. NAFLD patients have shown better outcomes with a modified diet, such as the MD diet, where patients are encouraged to increase the consumption of fruits and vegetables, whole grains, and olive oil. It is increasingly clear that a personalized approach to managing NAFLD patients, based on their preferences and needs, should be implemented. In our review, we cover NAFLD management, with a specific focus on dietary patterns and their components. We emphasize the successful approaches highlighted in recent studies to provide recommendations that health care providers could apply in managing their NAFLD patients.

Will medications that mimic gut hormones or target their receptors eventually replace bariatric surgery?

Bariatric surgery is currently the most effective therapeutic modality through which sustained beneficial effects on weight loss and metabolic improvement are achieved. During recent years, indications for bariatric surgery have been expanded to include cases of poorly controlled type 2 (T2DM) diabetes mellitus in lesser extremes of body weight. A spectrum of the beneficial effects of surgery is attributed to robust changes of postprandial gut peptide responses that are observed post operatively. Consolidated knowledge regarding gut peptide physiology as well as emerging new evidence shedding light on the mode of action of previously overlooked gut hormones provide appealing potential obesity and T2DM therapeutic perspectives. The accumulation of evidence from the effect of exogenous administration of native gut peptides alone or in combinations to humans as well as the development of mimetic agents exerting agonistic effects on combinations of gut hormone receptors pave the way for future integrated gut peptide-based treatments, which may mimic the effects of bariatric surgery.

Impact of sleeve gastrectomy and Roux-en-Y gastric bypass on biopsy-proven non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome. Our aim was to study the long-term effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on NAFLD/NASH.

METHODS

Between 2008 and 2015, 3813 patients had an intraoperative liver biopsy performed at the time of primary RYGB and SG at a single academic center. Utilizing strict inclusion criteria, 487 patients with biopsy-proven NAFLD who had abnormal alanine aminotransferase (ALT) or aspartate aminotransferase (AST) values (≥ 40 IU/L) at baseline were identified. Matching of SG to RYGB patients (1:4) was performed via logistic regression and propensity scores adjusting for clinical and liver histological characteristics. Changes in liver function tests (LFTs) at least 1 year after surgery were compared to baseline values and between the surgical groups.

RESULTS

A total of 310 (weighted) patients (SG n = 62, and RYGB n = 248) with a median follow-up time of 4 years (range, 1-10) were included in the analysis. The distribution of covariates was well-balanced after propensity matching. In 84% of patients, LFT values normalized after bariatric surgery at the last follow-up time. The proportions of patients having normalized LFT values did not differ significantly between the SG and RYGB groups (82% vs. 84%, p = 0.66). The AST decreased from (SG: 49.1 ± 21.5 vs. RYGB: 49.3 ± 22.0, p = 0.93) at baseline to (SG: 28.0 ± 16.5 vs. RYGB: 26.5 ± 15.5, p = 0.33) at the last follow-up. Similarly, a significant reduction in ALT values from (SG: 61.7 ± 30.0 vs. RYGB 59.4 ± 24.9, p = 0.75) at baseline to (SG: 27.2 ± 21.5 vs. RYGB: 26.1 ± 19.2, p = 0.52) at the last follow-up was observed.

CONCLUSIONS

In patients with biopsy-proven NAFLD/NASH, abnormal LFTs are normalized in most SG and RYGB patients by the end of the first postoperative year and remain normal until the last follow-up. This study also suggests that both bariatric procedures are similarly effective in improving liver function.

Validation of biochemical scores for liver steatosis before and 1 year after sleeve gastrectomy

BACKGROUND

Bariatric surgery is a potential treatment for liver steatosis in morbidly obese patients, showing an improvement in approximately 90% of cases of fatty liver after surgery. Liver biopsy is the gold standard method to monitor liver steatosis. Imaging tests, such as magnetic resonance (MR) spectroscopy, have shown a good accuracy in the diagnosis of liver steatosis. Several biochemical markers have been proposed as diagnostic alternatives to evaluate fatty liver.

OBJECTIVES

The aim of this study was to analyze the potential of different biochemical markers for evaluating liver steatosis in morbidly obese patients before and after undergoing sleeve gastrectomy.

SETTING

Garcilaso Clinic, Madrid, Spain.

METHODS

A prospective observational study of patients undergoing sleeve gastrectomy was performed. Diverse biochemical markers were assessed and correlated with MR spectroscopy as the diagnostic method for liver steatosis.

RESULTS

One hundred consecutive patients were included. Twelve months after surgery, mean body mass index was 28.3 ± 3.7 kg/m² and mean excess weight loss 82.5% ± 17.8%. Preoperatively, 67% of the patients had liver steatosis and 12 months after surgery the steatosis rate was reduced to 23%, as measured by MR spectroscopy. A significant direct correlation could only be observed between the percentage of lipid content, determined by MR spectroscopy and the liver fat score, at baseline and in the preoperative score. A cut-off point for liver fat score to determine the presence of liver steatosis was established at 1.22, for baseline and postoperative determinations.

CONCLUSION

The liver fat score is the most accurate biochemical score to correlate with the percentage of lipid content of the liver, determined by MR spectroscopy.