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

Effect of Cytokeratin-18, C-peptide, MHR, and MACK-3 Biomarkers in Metabolic Dysfunction-Associated Fatty Liver Disease After Laparoscopic Sleeve Gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) has emerged as a valuable treatment for various metabolic disorders, including metabolic dysfunction-associated fatty liver disease (MAFLD) in patients with obesity. Consequently, there is a pressing need to develop noninvasive biomarkers for diagnosing and monitoring disease progression.

Objectives

This study aimed to evaluate specific biomarkers, including Cytokeratin-18 (CK-18), C-peptide, monocyte to HDL cholesterol ratio (MHR), and MACK-3, in patients with obesity with MAFLD undergoing LSG.

Design

A prospective cohort study on patients with obesity before and 6 months after the LSG procedure.

Methods

70 patients with obesity with confirmed MAFLD, determined by Transient Elastography (TE), were pre- and 6 months postoperatively tested. Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), lipid profile, ghrelin, leptin, peptide YY, GLP-1, and liver fibrosis scores, including AST/ALT ratio (AAR), Fibrosis-4 index (FIB-4), and BARD Score were tested.

Results

BMI significantly decreased in all participants, with a % excess weight loss of 62.0% ± 15.4%. TE measurements revealed a significant postoperative reduction from 100% to 87.1% (P = .006). All selected biomarkers showed significant postoperative improvement-a significant association of CK-18 with MAFLD markers, including AAR, FIB-4, and BARD score, were found. MACK-3 had positive associations with FIB-4. C-peptide and MHR showed no association with MAFLD markers. Furthermore, there was a positive correlation between CK-18 and MACK-3 tests and between C-peptide and CK-18 and MACK-3. Additionally, a receiver operating characteristic (ROC) curve was constructed, with CK-18 performing the best, with an estimated area under the curve of 0.863.

Conclusion

Serum CK-18 outperformed other selected biomarkers in predicting and monitoring MAFLD in patients with obesity, suggesting its prospective utility in clinical practice. Further studies are needed to validate the accuracy of the MACK-3 test.

Multiomics Picture of Obesity in Young Adults

Obesity is a socially significant disease that is characterized by a disproportionate accumulation of fat. It is also associated with chronic inflammation, cancer, diabetes, and other comorbidities. Investigating biomarkers and pathological processes linked to obesity is especially vital for young individuals, given their increased potential for lifestyle modifications. By comparing the genetic, proteomic, and metabolomic profiles of individuals categorized as underweight, normal, overweight, and obese, we aimed to determine which omics layer most accurately reflects the phenotypic changes in an organism that result from obesity. We profiled blood plasma samples by employing three omics methodologies. The untargeted GC×GC-MS metabolomics approach identified 313 metabolites. To augment the metabolomic dataset, we integrated a label-free HPLC-MS/MS proteomics method, leading to the identification of 708 proteins. The genomic layer encompassed the genotyping of 647,250 SNPs. Utilizing omics data, we trained sparse Partial Least Squares models to predict body mass index. Molecular features exhibiting frequently non-zero coefficients were selected as potential biomarkers, and we further explored enriched biological pathways. Proteomics was the most effective in single-omics analyses, with a median absolute error (MAE) of 5.44 ± 0.31 kg/m2, incorporating an average of 24 proteins per model. Metabolomics showed slightly lower performance (MAE = 6.06 ± 0.33 kg/m2), followed by genomics (MAE = 6.20 ± 0.34 kg/m2). As expected, multiomic models demonstrated better accuracy, particularly the combination of proteomics and metabolomics (MAE = 4.77 ± 0.33 kg/m2), while including genomics data did not enhance the results. This manuscript is the first multiomics study of obesity in a gender-balanced cohort of young adults profiled by genomic, proteomic, and metabolomic methods. The comprehensive approach provides novel insights into the molecular mechanisms of obesity, opening avenues for more targeted interventions.

Mid-term Effects of Bariatric Surgery on Metabolic Dysfunction-Associated Fatty Liver Disease Remission and Predictive Factors: A Prospective Study with a Focus on Non-invasive Diagnosis

PURPOSE

Non-alcoholic fatty liver disease (NAFLD), now termed metabolic dysfunction-associated fatty liver disease (MAFLD), is a growing health concern associated with obesity and type 2 diabetes. Bariatric surgery offers potential benefits, but its impact on MAFLD remains incompletely understood, with scarce long-term follow-up prospective studies. Moreover, being liver biopsy the gold standard for liver condition measurement, the need for non-invasive techniques that allow the assessment of MAFLD development after bariatric surgery is imperative. OWLiver® Care and OWLiver® represent two serum lipidomic tests, featuring panels comprising 11 and 20 triglycerides, respectively.

MATERIALS AND METHODS

We conducted a prospective study involving 80 Caucasians to assess the effects of bariatric surgery on MAFLD using non-invasive diagnostics and to identify baseline predictors of MAFLD remission. Serum samples were collected before surgery and at a 3-year follow-up.

RESULTS

After 3 years, the proportion of patients exhibiting a healthy liver escalated from 5.0% at baseline to 26.3%. Conversely, the percentage of steatohepatitis declined from 35.1% to a mere 7.6%. Younger age, female gender, and the absence of type 2 diabetes were associated with MAFLD remission. However, age stood as the only independent variable associated with this favorable liver evolution (R2 = 0.112).

CONCLUSION

Bariatric surgery demonstrates mid-term benefits in improving MAFLD, with younger age as a baseline predictor of remission. Non-invasive diagnostic methods, like OWLiver®, are valuable tools for monitoring MAFLD evolution. Further research with larger populations and longer follow-up periods is warranted to refine personalized treatment approaches.

Bariatric Surgery and Metabolic Dysfunction-Associated Fatty Liver Disease: a 2022 Update

Non-alcoholic fatty liver disease (NAFLD) has been recently termed metabolic dysfunction-associated fatty liver disease (MAFLD) to address the strong association with the metabolic syndrome. The prevalence of MAFLD is significantly increased in obese individuals and treatment of obesity is currently the cornerstone of management of MAFLD. Bariatric and metabolic surgery nowadays emerges as a key therapeutic strategy for the treatment of the MAFLD. This review aims to provide an update on the novel studies reporting the outcomes of bariatric surgery on the spectrum of MAFLD, from hepatic steatosis to cirrhosis.

Circulating adiponectin in patients with nonalcoholic fatty liver disease-related liver fibrosis: A systematic review and a meta-analysis

BACKGROUND AND AIM

There are conflicting data on adiponectin concentrations in nonalcoholic fatty liver disease (NAFLD). The main aim was to compare circulating total adiponectin concentrations in NAFLD patients with versus without liver fibrosis.

METHODS

A systematic search was performed in PubMed, Scopus, and Cochrane Library. Twenty-two studies comprising 1753 biopsy-proven NAFLD individuals (1290 with and 463 without fibrosis) were included in the meta-analysis.

RESULTS

There was no difference in adiponectin concentration between NAFLD patients with versus without fibrosis (standardized mean difference [SMD]: -0.15; 95% confidence interval [95% CI]: -0.35 to 0.05). Heterogeneity was moderate among studies (Ι² : 60%, P < 0.001); no risk of publication bias was observed (Egger's test; P = 0.37). The sensitivity analysis, performed after the exclusion of studies with (i) children/adolescents and morbidly obese patients (n = 3) and (ii) adiponectin measurement with other methods than enzyme-linked immunosorbent assay (ELISA) (n = 9), revealed significantly lower adiponectin concentrations in NAFLD patients with fibrosis (i) SMD: -0.23, 95% CI: -0.41 to -0.04; (ii) SMD: -0.30, 95% CI: -0.55 to -0.04, respectively). Meta-regression analysis revealed no significant association of adiponectin SMD with age, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl-transferase, homeostasis model assessment insulin resistance and the proportion of men.

CONCLUSIONS

Overall, patients with NAFLD and fibrosis had similar adiponectin concentrations with patients with NAFLD without fibrosis. However, adiponectin concentration was lower in NAFLD patients with fibrosis than those without fibrosis within the adult patients without morbid obesity and in studies in which adiponectin was measured with the same method (ELISA).

Association between Dietary Pattern, Nutritional Status, Metabolic Factors, and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) can be harmful to the body to varying degrees, and over a prolonged period, patients may develop steatotic cirrhosis or even develop liver cancer based on cirrhosis. Moreover, its harms are related to its severity. Patients with severe steatosis develop hepatocyte destruction, transaminase abnormalities, and long-term progression to steatotic cirrhosis, or even liver cancer, which should be treated aggressively. In order to provide theoretical basis for the prevention and early intervention of NAFLD, we analysis the relationship between nonalcoholic fatty liver disease(NAFLD) and dietary pattern, nutritional status, metabolic factor A total of 517 participants (200 males and 317 females) recruited in this study were gained from the health check center of The Ningbo Seventh Hospital, Ningbo, China, from September 2018 to August 2019. Patients diagnosed with NAFLD were selected as the study subjects. The data on the dietary pattern, nutritional status, and metabolic factors were collected for further analysis. A total of 517 eligible participants (317 females and 200 males) were involved in this study, with a mean age of 54.7 ± 16.7 years. Dessert and fruit diet, healthy dietary pattern, animal food dietary pattern, high salt diet mode, triglyceride, uric acid, adiponectin, and waist-hip ratio were significantly different between the two groups (P < 0.05). Dietary patterns, nutritional status, metabolic factors, and NAFLD are correlated. Furthermore, applying this correlation law can better manage NAFLD patients.

Clinical Interest of Serum Alpha-2 Macroglobulin, Apolipoprotein A1, and Haptoglobin in Patients with Non-Alcoholic Fatty Liver Disease, with and without Type 2 Diabetes, before or during COVID-19

In patients with non-alcoholic fatty liver disease (NAFLD) with or without type 2 diabetes mellitus (T2DM), alpha-2 macroglobulin (A2M), apolipoprotein A1 (ApoA1), and haptoglobin are associated with the risk of liver fibrosis, inflammation (NASH), and COVID-19. We assessed if these associations were worsened by T2DM after adjustment by age, sex, obesity, and COVID-19. Three datasets were used: the “Control Population”, which enabled standardization of protein serum levels according to age and sex (N = 27,382); the “NAFLD-Biopsy” cohort for associations with liver features (N = 926); and the USA “NAFLD-Serum” cohort for protein kinetics before and during COVID-19 (N = 421,021). The impact of T2DM was assessed by comparing regression curves adjusted by age, sex, and obesity for the liver features in “NAFLD-Biopsy”, and before and during COVID-19 pandemic peaks in “NAFLD-Serum”. Patients with NAFLD without T2DM, compared with the values of controls, had increased A2M, decreased ApoA1, and increased haptoglobin serum levels. In patients with both NAFLD and T2DM, these significant mean differences were magnified, and even more during the COVID-19 pandemic in comparison with the year 2019 (all p < 0.001), with a maximum ApoA1 decrease of 0.21 g/L in women, and a maximum haptoglobin increase of 0.17 g/L in men. In conclusion, T2DM is associated with abnormal levels of A2M, ApoA1, and haptoglobin independently of NAFLD, age, sex, obesity, and COVID-19.

Bariatric endoscopic-surgical therapies for NAFLD. Should they be considered viable options among current treatments?

Nowadays, non-alcoholic fatty liver disease is one of the first causes of liver transplant worldwide; many efforts have been done to find the perfect drug for this multifactorial disease. Presently we just have a few drugs that could be used in specific and limited clinical scenarios. Current evidence suggests that bariatric endoscopic and surgical therapies could be strategies with optimal outcomes, with high impact in quality of life, decrease of cardiovascular risk, and improvement in metabolic profile, despite being considered expensive procedures. This review proposes to consider these therapies early together with liver fibrosis evaluation, with long term cost-effectiveness benefits in the absence of response to lifestyle modifications and pharmacological treatments.

Bariatric Surgery Improves the Atherogenic Profile of Circulating Methylarginines in Obese Patients: Results from a Pilot Study

Bariatric surgery improves obesity-related comorbidities. Methylarginines are biomarkers of cardiometabolic risk, liver steatosis, and insulin resistance. Here, we aimed to investigate methylarginines in obese patients undergoing bariatric surgery and compared them to age- and sex-matched healthy subjects. Thirty-one obese patients who underwent bariatric surgery and 31 healthy individuals were used for this retrospective study. The basal serum methylarginine levels were determined in the healthy individuals and the obese patients, before surgery and 6 and 12 months after surgery, by mass spectrometry. Compared with the healthy individuals, the obese patients displayed elevated monomethylarginine (mean change: +95%, p < 0.001), asymmetric-dimethylarginine (+105%, p < 0.001), symmetric-dimethylarginine (+25%, p = 0.003), and dimethylguanidino valerate (+32%, p = 0.008) concentrations. Bariatric surgery durably reduced the body mass index by 28% (12 months, 95%CI: 24–33, p = 0.002) and improved plasma lipids, insulin resistance, and liver function. Bariatric surgery reduced the serum levels of monomethylarginine and asymmetric-dimethylarginine by 12% (95%CI: 6–17) and 36% (95%CI: 27–45) (12 months, p = 0.003), respectively, but not symmetric-dimethylarginine or dimethylguanidino valerate. The monomethylarginine and asymmetric-dimethylarginine concentrations were strongly correlated with markers of dyslipidemia, insulin resistance, and a fatty liver. Serum dimethylguanidino valerate was primarily correlated with glycemia and renal function, whereas serum symmetric-dimethylarginine was almost exclusively associated with renal function. In conclusion, the monomethylarginine and asymmetric-dimethylarginine levels are efficiently decreased by bariatric surgery, leading to a reduced atherogenic profile in obese patients. Methylarginines follow different metabolic patterns, which could help for the stratification of cardiometabolic disorders in obese patients.

Expert opinion on the preoperative medical optimization of adults with diabetes undergoing metabolic surgery

Diabetes mellitus (DM) and obesity are interrelated in a complex manner, and their coexistence predisposes patients to a plethora of medical problems. Metabolic surgery has evolved as a promising therapeutic option for both conditions. It is recommended that patients, particularly those of Asian origin, maintain a lower body mass index threshold in the presence of uncontrolled DM. However, several comorbidities often accompany these chronic diseases and need to be addressed for successful surgical outcome. Laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are the most commonly used bariatric procedures worldwide. The bariatric benefits of RYGB and LSG are similar, but emerging evidence indicates that RYGB is more effective than LSG in improving glycemic control and induces higher rates of long-term DM remission. Several scoring systems have been formulated that are utilized to predict the chances of remission. A glycemic target of glycated hemoglobin < 7% is a reasonable goal before surgery. Cardiovascular, pulmonary, gastrointestinal, hepatic, renal, endocrine, nutritional, and psychological optimization of surgical candidates improves perioperative and long-term outcomes. Various guidelines for preoperative care of individuals with obesity have been formulated, but very few specifically focus on the concerns arising from the presence of concomitant DM. It is hoped that this statement will lead to the standardization of presurgical management of individuals with DM undergoing metabolic surgery.