Non-alcoholic fatty liver disease resolution following sleeve gastrectomy

The Use of Noninvasive Scores in Predicting NAFLD Progression After Bariatric Surgery

BACKGROUND

Bariatric surgery has been postulated to impact liver function resulting in favorable effects on nonalcoholic fatty liver disease (NAFLD). We aimed to analyze the long-term impact of bariatric surgery on noninvasive scores predicting the progression of liver fibrosis in a bariatric population.

METHODS

We retrospectively reviewed the records of patients without pre-existing liver disease who underwent sleeve gastrectomy or Roux-en-Y gastric bypass (RYGB) at our center between 2010 and 2018. Four predictive scores for liver fibrosis (AST/ALT, APRI, Fib-4, and BARD) were calculated preoperatively, 6 months post-operatively, and annually up to 5 years. Correlations were analyzed with Pearson R. Subgroup and sensitivity analyses were performed to identify populations at increased risk.

RESULTS

A total of 2769 patients were included. The mean age was 40 years, and the majority was females (88.5%) and of Hispanic ethnicity (59.2%). There was a steady post-operative increase in the percentage of patients at increased risk of progression of liver fibrosis. The Fib-4 score showed the largest increase in the population at risk for liver fibrosis (11.3% preoperatively to 28.9% at 5 years). Patients with diabetes and those who underwent a sleeve gastrectomy continued to display a higher risk for liver fibrosis than did patients without diabetes and those who underwent RYGB, respectively.

CONCLUSION

There was an overall trend to increased liver fibrosis scores over the 5-year post-operative follow-up, but this increase remained lower than that reported in previous literature. Bariatric surgery offers NAFLD risk reduction in a high-risk population.

The Effect of Laparoscopic Sleeve Gastrectomy on the Course of Non-Alcoholic Fatty Liver Disease in Morbidly Obese Patients during One Year of Follow Up

BACKGROUND

Morbid obesity co-exists with non-alcoholic fatty liver disease in up to 90% of cases. Laparoscopic sleeve gastrectomy leads to a reduction in body mass and thus may improve the course of non-alcoholic fatty liver disease. The aim of this study was to evaluate the effect of laparoscopic sleeve gastrectomy on the resolution of non-alcoholic fatty liver disease.

METHODS

The study included 55 patients with non-alcoholic fatty liver disease who underwent laparoscopic sleeve gastrectomy at a tertiary institution. The analysis consisted of preoperative liver biopsy, abdominal ultrasound, weight loss parameters, Non-Alcoholic Fatty Liver Fibrosis Score and selected laboratory parameters.

RESULTS

Before the surgery, 6 patients were diagnosed with grade 1 liver steatosis, 33 patients with grade 2 and 16 patients with grade 3. One year after the surgery, only 21 patients had features of liver steatosis at ultrasound. All weight loss parameters showed statistically significant changes during the observation; the median percentage of total weight loss was 31.0% (IQR: 27.5; 34.5) with p = 0.0003, the median percentage of excess weight loss was 61.8% (IQR: 52.4; 72.3) with p = 0.0013 and the median percentage of excess body mass index loss was 71.0% (IQR: 61.3; 86.9) with p = 0.0036 12 months after laparoscopic sleeve gastrectomy. The median Non-Alcoholic Fatty Liver Fibrosis Score at baseline was 0.2 (IQR: -0.8; 1.0) and decreased to -1.6 (IQR: -2.4; -0.4) (p < 0.0001). Moderate negative correlations between Non-Alcoholic Fatty Liver Fibrosis Score and percentage of total weight loss (r = -0.434, p < 0.0001), percentage of excess weight loss (r = -0.456, p < 0.0001) and percentage of excess body mass index loss (r = -0.512, p < 0.0001) were found.

CONCLUSIONS

The study supports the thesis that laparoscopic sleeve gastrectomy is an effective method for treatment of non-alcoholic fatty liver disease in patients with morbid obesity.

The Role Bariatric Surgery and Endobariatric Therapies in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Disease spectrum varies from steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved medical therapies, and weight loss through lifestyle modifications remains a mainstay of therapy. Bariatric surgery is the most effective therapy for weight loss and has been shown to improve liver histology. Recently, endoscopic bariatric metabolic therapies have also emerged as effective treatments for patients with obesity and NAFLD. This review summarizes the role of bariatric surgery and endoscopic therapies in the management of patients with NAFLD.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

The effect of 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.

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.

Sleeve gastrectomy ameliorated high-fat diet (HFD)-induced non-alcoholic fatty liver disease and upregulated the nicotinamide adenine dinucleotide +/ Sirtuin-1 pathway in mice

BACKGROUND

/Objective: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, and effective treatments are lacking. Bariatric surgery, including sleeve gastrectomy (SG), is a potential therapeutic strategy for NAFLD, but the molecular mechanisms underlying its effects are not fully understood. In this study, the effects of SG and the underlying mechanisms were evaluated in a mouse model of high-fat diet (HFD)-induced NAFLD.

METHODS

C57BL/6 mice were randomly divided into three groups: normal diet with sham operation (NC-Sham group), HFD with sham operation (HFD-Sham group), and HFD with sleeve gastrectomy (HFD-SG group). Glucose metabolism and fat accumulation in the body and liver were analyzed before and after SG. Lipid metabolism and inflammation in the liver were evaluated. Nicotinamide adenine dinucleotide (NAD+) levels as well as nicotinamide riboside kinase (NRK1) and Sirtuin-1 (SIRT1) expression levels were evaluated.

RESULTS

SG attenuated the HFD-induced increases in glucose and insulin levels, fat accumulation, and lipid droplet accumulation. Fatty acid biosynthesis, the expression of the metabolism-related genes ACC1, FASN, SCD1, and DGAT1, and the levels of inflammatory factors were higher in HFD mice than in NC mice and decreased after SG. NAD + concentrations were 54.9 ± 13.4 μmol/mg in NC-Sham mice, 37.6 ± 8.1 μmol/mg in HFD-Sham mice, and 79.9 ± 13.0 μmol/mg in HFD-SG mice (p < 0.05). NRK1 and SIRT1 expression increased dramatically after SG at both the RNA and protein levels.

CONCLUSION

SG significantly alleviated NAFLD in HFD-induced obese mice with increasing the hepatic NAD + levels and upregulating the NRK1/NAD+/SIRT1 pathway.

The impact of bariatric surgery on nonalcoholic fatty liver disease as measured using non-invasive tests

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is common in bariatric surgery candidates. We evaluated the effect of sleeve gastrectomy (SG) on NAFLD using validated non-invasive measures.

METHODS

Patients with morbid obesity and NAFLD, planned for SG, were evaluated before and after surgery. Data collected included anthropometrics, biochemistry, adiponectin, SteatoTest™, NashTest™, FibroTest™, OWLiver® test and real-time ShearWave™ elastography (SWE).

RESULTS

Twenty-six subjects were included in the study, mean age 44.1 ± 4.8 years, 69.2% males. One year following SG, body mass index decreased significantly from 41.7 ± 4.8 kg/m² to 29.6 ± 4.5 kg/m². Concomitantly, significant improvements in triglycerides, ALT, diabetes markers and adiponectin were observed. Mean steatosis, as measured by SteatoTest™, was significantly improved. Steatohepatitis score measured by NashTest™ and OWLiver® significantly decreased. Mean fibrosis, as measured by SWE liver stiffness and FibroTest™, did not change over time.

CONCLUSION

Steatosis and steatohepatitis are significantly improved by SG as measured by non-invasive measures.

Clinical utility of transient elastography as an imaging tool to assess the short-term impact of laparoscopic sleeve gastrectomy, together with clinical and biochemical parameters and clinico-biochemical indices, on obese patients with nonalcoholic fatty liver disease: An Egyptian pilot study

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a metabolic liver disorder commonly attributed to fatty acid deposition that can induce hepatic necroinflammation, defined as nonalcoholic steatohepatitis (NASH). It is strongly associated with obesity. Laparoscopic sleeve gastrectomy (LSG) is a favorable surgical modality for the treatment of morbid obesity.

AIM

Our study evaluated the impact of LSG on patients with NAFLD and morbid obesity, 3 months after the operation, through clinical and biochemical characteristics, clinico-biochemical indices, and imaging parameters.

PATIENTS AND METHODS

Morbidly obese patients with NAFLD±NASH underwent LSG. They were thoroughly evaluated clinically (body weight, body mass index, waist circumference) and biochemically (transaminases and triglycerides), as well as through the fatty liver index (FLI), the hepatic steatosis index (HSI), and ultrasound elastography imaging studies (liver stiffness measurement [LSM] and the controlled attenuation parameter [CAP]), before and 3 months after the LSG.

RESULTS

Twenty-six obese patients with NAFLD underwent LSG that resulted in a significantly high reduction in all the parameters analyzed, except for liver transaminases.

CONCLUSION

LSG is considered an efficient surgical modality for the treatment of morbidly obese patients with 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.

Physical activity impacts insulin sensitivity post metabolic bariatric surgery in adolescents with severe obesity

BACKGROUND/OBJECTIVES

We hypothesized that physical activity (PA) improves insulin sensitivity in adolescents with severe obesity beyond that attributable to metabolic bariatric surgery (MBS).

SUBJECTS/METHODS

StepWatch^TM monitors objectively measured PA in 88 participants in the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. Primary outcomes included absolute change in fasting insulin, HOMA-IR, and fasting glucose from pre-surgery (baseline) to 6, 12, 24, and 36 months post-MBS. SAS PROC TRAJ generated activity trajectories based on probability and individual participant step count trajectories. Linear regression models were used, adjusted for baseline value, visit, surgical procedure, sex, and percent change in BMI. Additional models adjusted for percent change in iliac waist circumference (IWC) or percent body fat (BF), measured by bio-impedance.

RESULTS

Two activity trajectories were identified: more active (MA, n = 13) and less active (LA, n = 75). MA baseline mean daily step count was >6000, increasing to >9000 at 2 years. LA mean daily step count remained at ~4000. Few participants recorded moderate step activity (cadence >80 steps/minute). Still, fasting insulin and HOMA-IR differed in association with activity trajectoy. MA was associated with a greater absolute decrease in fasting insulin (-7.8 μU/ml [95% CI: (-11.8, -3.7)], p ≤ 0.001) and a greater decrease in HOMA-IR (-1.9 [95% CI: (-3.0, -0.7)], p = 0.001), when adjusted for percent change in BMI. The significant independent effect of MA remained when adjusted for percent change in IWC or percent BF. Clinically, 100% of MA trajectory participants normalized fasting insulin, HOMA-IR, and fasting glucose by 6 months and normalization remained throughout the 36 months follow up. In contrast, 76.3 and 65.8% of LA trajectory participants normalized fasting insulin and HOMA-IR, respectively, by 12 months with 28.6% of both remaining normalized at 36 months.

CONCLUSIONS

PA is independently associated with improved insulin sensitivity beyond that attributable to MBS in adolescents with severe obesity.

Impact of sleeve gastrectomy and dietary change on metabolic and hepatic function in an obesity rat model - Experimental research

PURPOSE

Sleeve gastrectomy (SG) is an effective procedure to treat morbid obesity. SG induces remission of type 2 diabetes and metabolic syndrome and improves non-alcoholic fatty liver disease (NAFLD). However, it is imperative to clarify the extent to which these beneficial effects may be attributed to SG among other concomitant changes including postoperative diet. The current study addresses this question in a rodent model of obesity by subjecting it to SG, normal diet, or a combination of the two.

METHODS

Male Wistar-rats were fed with either high fat diet (HF, n = 32) or received chow diet (CD, n = 8). After 15 weeks, the HF-fed rats underwent either SG or sham operation, following which they were randomised to either continue HF or switched to CD for another 6 weeks. Body weight, fasting blood glucose level, blood pressure, and adipokine expression (leptin, adiponectin, MCP-1) in the adipose tissue along with triglycerides level in the blood serum were assessed to evaluate metabolic function. Hepatic function was assessed by histological evaluation of liver fibrosis (Hydroxyproline, Sirius Red) and reverse transcription polymerase chain reaction (RT-PCR) of the inflammation marker monocyte chemoattractant protein-1 (MCP-1).

RESULTS

Postoperative dietary change improved adipose tissue inflammation and arterial blood pressure regardless of the surgical intervention, while SG improved hyperglycaemia, blood triglyceride levels and, regardless of the postoperative diet, hepatic inflammation and fibrosis. However, combined administration of SG with post-operative normal diet was the most effective with regard to reducing the body weight.

CONCLUSION

HF for 15 weeks induced obesity with metabolic syndrome and NAFLD in rats. SG and dietary intervention improved metabolic state and NAFLD; however, their combination was significantly more effective.

The advantages and disadvantages of sleeve gastrectomy; clinical laboratory to bedside review

Sleeve gastrectomy is a surgical technique and a leading method in metabolic surgery. Sleeve gastrectomy gained ever-increasing popularity among laparoscopic surgeons involved in bariatric surgery and has proved to be a successful method in achieving considerable weight loss in a short time. There are some disparate effects that patients may experience after sleeve gastrectomy including a reduction in BMI, weight, blood pressure, stroke, and cancer and also a significant remission in obesity-related diseases including type 2 diabetes (T2D), Non-alcoholic fatty liver (NAFLD), cardiovascular disease, obstructive sleep apnea, and craniopharyngioma-related hypothalamic obesity as well as non-obesity-related diseases such as gout, musculoskeletal problems, ovarian disorders and urinary incontinence. The most common complications of sleeve gastrectomy are bleeding, nutrient deficiencies, and leakage. There are several studies on the impact of gender and ethnic disparities on post-operative complications. This study collects state of the art of reports on sleeve gastrectomy. The aim of this study was to analyze recent studies and review the advantages and disadvantages of sleeve gastrectomy.

Evolution of NAFLD and Its Management

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is estimated to be 25% and continues to rise worldwide in the setting of the obesity epidemic. This increase is especially concerning because NAFLD is often a progressive disease that can be associated with significant complications such as liver cirrhosis, hepatocellular carcinoma, and an increase in liver-related and overall mortality. Because of the devastating complications and comorbidities, NAFLD is a very costly disease for the healthcare system, with estimated annual direct medical costs exceeding $100 billion in the United States alone. Given this progressive course, it is imperative to make the diagnosis in patients with risk factors (metabolic syndrome, weight gain, and insulin resistance/diabetes). Once the diagnosis is made, the focus should shift to treatment and monitoring for the development of associated complications. Given that currently no pharmaceutical intervention is approved for the treatment of NAFLD, focus shifts instead to mitigation of risk factors through avoidance of foods that are rich in red meat, trans fats, refined carbohydrates, and high-fructose corn syrup; are low fiber; and have high energy density. The landmark of treatment, however, continues to be weight loss and improvement of insulin resistance, often through a multimodality approach. The current manuscript reviews the clinical phenotypes of NAFLD, its risk factors, and pathogenesis, as well as treatment options including lifestyle modifications and dietary interventions, medical therapies, endoscopic bariatric interventions, and bariatric surgery.

Bariatric Surgery as an Efficient Treatment for Non-Alcoholic Fatty Liver Disease in a Prospective Study with 1-Year Follow-up : BariScan Study

BACKGROUND

Bariatric surgery gains attention as a potential treatment for non-alcoholic fatty liver disease (NAFLD). The present study aimed to evaluate improvement of NAFLD after the two most common bariatric procedures with validated non-invasive instruments.

MATERIAL AND METHODS

N = 100 patients scheduled for laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB) were included. NAFLD was evaluated preoperatively and postoperatively with liver stiffness measurement by transient elastography and laboratory-based fibrosis scores. Clinical data included body mass index (BMI), total weight loss (%TWL), excess weight loss (%EWL), age, gender, comorbidities, and the Edmonton obesity staging system (EOSS).

RESULTS

There were significant improvements of BMI, %TWL, %EWL, and EOSS after bariatric surgery. Liver stiffness was significantly improved from pre- to postoperative (12.9 ± 10.4 vs. 7.1 ± 3.7 kPa, p < 0.001) at median follow-up of 12.5 months. Additionally, there were significant improvements of liver fibrosis scores (aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio 0.8 ± 0.3 vs. 1.1 ± 0.4, p < 0.001; NAFLD fibrosis score - 1.0 ± 1.8 vs. - 1.7 ± 1.3, p < 0.001; APRI score 0.3 ± 0.2 vs. 0.3 ± 0.1, p = 0.009; BARD score 2.3 ± 1.2 vs. 2.8 ± 1.1, p = 0.008) and laboratory parameters (ALT, AST, and GGT). After adjustment for baseline liver stiffness, RYGB showed higher improvements than LSG, and there was no gender difference. Improvement of liver stiffness was not correlated to improvement of BMI, %TWL, %EWL, or EOSS.

CONCLUSIONS

NAFLD seems to be improved by bariatric surgery as measured by validated non-invasive instruments. Furthermore, it appears that RYGB is more effective than LSG. No correlation could be detected between NAFLD and weight loss. The present study highlights the potential of bariatric surgery for successful treatment of NAFLD. Further research is required to understand the exact mechanisms.

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.

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.

Prospective Longitudinal Trends in Body Composition and Clinical Outcomes 3 Years Following Sleeve Gastrectomy

BACKGROUND AND AIMS

Longitudinal assessment of body composition following bariatric surgery allows monitoring of health status. Our aim was to elucidate trends of anthropometric and clinical outcomes 3 years following sleeve gastrectomy (SG).

METHODS

A prospective cohort study of 60 patients who underwent SG. Anthropometrics including body composition analysis measured by multi-frequency bioelectrical impedance analysis, blood tests, liver fat content measured by abdominal ultrasound and habitual physical activity were evaluated at baseline and at 6 (M6), 12 (M12), and 36 (M36) months post-surgery.

RESULTS

Sixty patients (55% women, age 44.7 ± 8.7 years) who completed the entire follow-up were included. Fat mass (FM) was reduced significantly 1 year post-surgery (55.8 ± 11.3 to 26.7 ± 8.3 kg; P < 0.001) and then increased between 1 and 3 years post-operatively, but remained below baseline level (26.7 ± 8.3 to 33.1 ± 11.1 kg; P < 0.001). Fat free mass (FFM) decreased significantly during the first 6 months (64.7 ± 14.3 to 56.9 ± 11.8 kg; P < 0.001), slightly decreased between M6 and M12 and then reached a plateau through M36. Weight loss "failure" (< 50% excess weight loss) was noticed in 5.0% and 28.3% of patients at M12 and M36, respectively. Markers of lipid and glucose metabolism changed thereafter in parallel to the changes observed in FM, with the exception of HDL-C, which increased continuingly from M6 throughout the whole period analyzed (45.0 ± 10.2 to 59.5 ± 15.4 mg/dl; P < 0.001) and HbA1c which continued to decrease between M12 and M36 (5.5 ± 0.4 to 5.3 ± 0.4%; P < 0.001). There were marked within-person variations in trends of anthropometric and clinical parameters during the 3-year follow-up.

CONCLUSIONS

Weight regain primarily attributed to FM with no further decrease in FFM occurs between 1 and 3 years post-SG. FM increase at mid-term may underlie the recurrence of metabolic risk factors and can govern clinical interventions.

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.

SCCA-IgM as a Potential Biomarker of Non-Alcoholic Fatty Liver Disease in Patients with Obesity, Prediabetes and Diabetes Undergoing Sleeve Gastrectomy

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has a high prevalence in obesity and its presence should be screened. Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity, but its effects on NAFLD are still to be firmly established. The diagnosis of non-alcoholic steatohepatitis (NASH) is currently performed by liver biopsy, a costly and invasive procedure. Squamous cell carcinoma antigen-IgM (SCCA-IgM) is a biomarker of viral hepatitis to hepatocellular carcinoma development and its role in NAFLD to NASH progression has not yet been investigated.

OBJECTIVE

The aim of this study was to evaluate SCCA-IgM as a non-invasive biomarker of NAFLD/NASH in patients with different degrees of metabolic-complicated obesity before and after LSG.

METHOD

Fifty-six patients with obesity were studied before and 12 months after LSG; anthropometric, biochemical, clinical, and imaging data were collected.

RESULTS

At baseline steatosis was strongly associated with the glycaemic profile (p = 0.016) and was already present in prediabetic patients with obesity (82%). Only 3 patients had an SCCA-IgM level above the normal cut-off. SCCA-IgM titre did not change according to glycaemic profile or steatosis. Metabolic and inflammatory factors and transaminases significantly reduced after LSG-induced weight loss, except for SCCA-IgM. The ALT/AST ratio decreased post-LSG correlated with BMI (r = 0.297, p = 0.031), insulin (r = 0.354, p = 0.014), and triglycerides (r = 0.355, p = 0.009) reduction.

CONCLUSIONS

Our results confirm the tight link between NAFLD and metabolic complications, suggesting prediabetes as a new risk factor of steatosis. SCCA-IgM does not seem to have a role in the identification and prognosis of NAFLD.

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.

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 Benefit of Sleeve Gastrectomy in Obese Adolescents on Nonalcoholic Steatohepatitis and Hepatic Fibrosis

OBJECTIVE

To determine whether bariatric surgery is effective for the treatment of nonalcoholic steatohepatitis (NASH) in adolescence, we compared the efficacy of laparoscopic sleeve gastrectomy (LSG) with that of lifestyle intervention (nonsurgical weight loss [NSWL]) for NASH reversal in obese adolescents.

STUDY DESIGN

Obese (body mass index ≥ 35 kg/m²) adolescents (13-17 years of age) with biopsy-proven NAFLD underwent LSG, lifestyle intervention plus intragastric weight loss devices (IGWLD), or only NSWL. At baseline and 1 year after treatment, patients underwent clinical and psychosocial evaluation, blood tests, liver biopsy, polysomnography, and 24-hour ambulatory blood pressure estimation.

RESULTS

Twenty patients (21%) underwent LSG, 20 (21%) underwent IGWLD, and 53 (58%) received lifestyle intervention alone (NSWL). One year after treatment, patients who underwent LSG lost 21.5% of their baseline body weight, whereas patients who underwent IGWLD lost 3.4%, and patients who underwent NSWL increase 1.7%. In patients who underwent LSG, NASH reverted completely in all patients and hepatic fibrosis stage 2 disappeared in 18 patients (90%). After IGWLD, NASH reverted in 6 patients (24%) and fibrosis in 7 (37%). Patients who received the NSWL intervention did not improve significantly. Hypertension resolved in all patients who underwent LSG with preoperative hypertension (12/12) versus 50% (4/8) of the patients who underwent IGWLD (P = .02). The cohort-specific changes in impaired glucose metabolism were similar: 100% (9/9) of affected patients who underwent LSG versus 50% (1/2) of patients who underwent IGWLD (P = .02). LSG was also more affective in resolving dyslipidemia (55% [7/12] vs 26% [10/19]; P = .05) and sleep apnea (78% [2/9] vs 30% [11/20]; P = .001).

CONCLUSION

LSG was more effective than lifestyle intervention, even when combined with intragastric devices, for reducing NASH and liver fibrosis in obese adolescents after 1 year of treatment.