Pleiotropic Effects of Statins in the Light of Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis

Effect of Statins for Primary Prevention of Cardiovascular Disease According to the Fatty Liver Index

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is associated with increased risk of cardiovascular disease (CVD). We investigated the primary preventive effect of statins on CVD according to the level of fatty liver index (FLI), which is a marker of NAFLD.

METHODS

We conducted a nested case-control study on the basis of a nationwide health screening cohort in Korea. The participants were divided into tertiles (T1, T2, and T3) according to their FLI score. Cases were defined as individuals who developed CVD (composite of myocardial infarction and stroke). Three controls were matched to each case and multivariable conditional logistic regression analysis was performed.

RESULTS

Within a cohort of 206,263 participants without prior CVD, 7044 individuals suffered the primary outcome. For the nested case-control study, we selected these 7044 cases along with their corresponding 20,641 matched controls. Individuals in the T3 tertiles of FLI had a higher risk of CVD than those in the T1 tertile [adjusted odds ratio (OR) 1.30; 95% confidence interval (CI) 1.20-1.40, P < 0.001]. In sub-analyses based on FLI tertiles, statin therapy was associated with a lower risk of CVD (adjusted OR 0.72; 95% CI 0.61-0.85, P < 0.001) in the T3 tertile but not in the T1 and T2 tertiles.

CONCLUSIONS

Statin therapy was associated with a reduced risk of CVD in individuals with high FLI but not in those with low FLI. Further research is needed to determine the pathophysiologic mechanism between statin and NAFLD.

Statin therapy: a potential adjuvant to immunotherapies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide and accounts for more than 90% of primary liver cancer. The advent of immune checkpoint inhibitor (ICI)-related therapies combined with angiogenesis inhibition has revolutionized the treatment of HCC in late-stage and unresectable HCC, as ICIs alone were disappointing in treating HCC. In addition to the altered immune microenvironment, abnormal lipid metabolism in the liver has been extensively characterized in various types of HCC. Stains are known for their cholesterol-lowering properties and their long history of treating hypercholesterolemia and reducing cardiovascular disease risk. Apart from ICI and other conventional therapies, statins are frequently used by advanced HCC patients with dyslipidemia, which is often marked by the abnormal accumulation of cholesterol and fatty acids in the liver. Supported by a body of preclinical and clinical studies, statins may unexpectedly enhance the efficacy of ICI therapy in HCC patients through the regulation of inflammatory responses and the immune microenvironment. This review discusses the abnormal changes in lipid metabolism in HCC, summarizes the clinical evidence and benefits of stain use in HCC, and prospects the possible mechanistic actions of statins in transforming the immune microenvironment in HCC when combined with immunotherapies. Consequently, the use of statin therapy may emerge as a novel and valuable adjuvant for immunotherapies in HCC.

Metabolic-associated fatty liver disease: a selective review of pathogenesis, diagnostic approaches, and therapeutic strategies

Background

Metabolic associated fatty liver disease (MAFLD) is a novel terminology introduced in 2020 to provide a more accurate description of fatty liver disease associated with metabolic dysfunction. It replaces the outdated term nonalcoholic fatty liver disease (NAFLD) and aims to improve diagnostic criteria and tailored treatment strategies for the disease. NAFLD, the most prevalent liver disease in western industrialized nations, has been steadily increasing in prevalence and is associated with serious complications such as cirrhosis and hepatocellular carcinoma. It is also linked to insulin resistance syndrome and cardiovascular diseases. However, current studies on NAFLD have limitations in meeting necessary histological endpoints.

Objective

This literature review aims to consolidate recent knowledge and discoveries concerning MAFLD, integrating the diverse aspects of the disease. Specifically, it focuses on analyzing the diagnostic criteria for MAFLD, differentiating it from NAFLD and alcoholic fatty liver disease (AFLD), and exploring the epidemiology, clinical manifestations, pathogenesis, and management approaches associated with MAFLD. The review also explores the associations between MAFLD and other conditions. It discusses the heightened mortality risk associated with MAFLD and its link to chronic kidney disease (CKD), showing that MAFLD exhibits enhanced diagnostic accuracy for identifying patients with CKD compared to NAFLD. The association between MAFLD and incident/prevalent CKD is supported by cohort studies and meta-analyses.

Conclusion

This literature review highlights the importance of MAFLD as a distinct terminology for fatty liver disease associated with metabolic dysfunction. The review provides insights into the diagnostic criteria, associations with CKD, and management approaches for MAFLD. Further research is needed to develop more accurate diagnostic tools for advanced fibrosis in MAFLD and to explore the underlying mechanisms linking MAFLD with other conditions. This review serves as a valuable resource for researchers and healthcare professionals seeking a comprehensive understanding of MAFLD.

Atorvastatin on Treatment of Nonalcoholic Fatty Liver Disease Patients

Non-alcoholic fatty liver disease (NAFLD) is a condition in which excess fat builds up in the liver, often related to obesity and insulin resistance, which can lead to inflammation and scarring of the liver tissue. While efforts have been made to develop effective treatments for NAFLD, the need for pharmaceutical interventions remains unmet. Large clinical trials investigating the association between statin use and NAFLD are scarce, leading to contradictory results. Statins play a crucial role in cholesterol synthesis in the liver. Several studies have demonstrated that statins possess anti-inflammatory, anti-thrombotic, and anti-fibrotic properties. These properties make statins potentially useful in preventing the progression of NAFLD from simple steatosis to more severe forms like non-alcoholic steatohepatitis (NASH) and fibrosis. The results indicate that statin use is associated with a lower prevalence of NASH and fibrosis and may have a preventive effect on NAFLD.

Atorvastatin and Flaxseed Effects on Biochemical Indices and Hepatic Fat of NAFLD Model in Rats

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease that affects about 25% of the general population. No definitive treatment for NAFLD has been identified yet. The aim was to determine the effect of atorvastatin (ATO) and flaxseed on related indicators of NAFLD-induced fat/fructose-enriched diet (FFD).

Materials and Methods

Forty male Wistar rats were divided into five groups. NAFLD groups received FFD and carbon tetrachloride (CCl4) to induce NAFLD. After intervention with ATO (10 mg/kg/day) and/or flaxseed (7.5 g/kg/day), liver enzymes and lipid profiles in serum were determined at eight week of interventions.

Results

Triglycerides (TG) and cholesterol (CHO) in FFD + ATO, FFD + flaxseed, and FFD + ATO + flaxseed had a significant decrease and low-density lipoprotein (LDL) level and LDL/high-density lipoprotein (HDL) ratio showed a significant increase in the FFD + flaxseed compared to the FFD. The levels of aspartate transaminase (AST), alanine transaminase (ALT), and gamma-glutamyltransferase (GGT) were significantly reduced in the FFD + ATO, FFD + flaxseed, and the FFD + ATO + flaxseed. In addition, Alkaline phosphatase (ALP) levels were significantly different between normal and FFD. Fasting blood sugar (FBS) levels were significantly different in the FFD + flaxseed and the FFD + ATO + flaxseed compared to the FFD.

Conclusion

ATO therapy along with flaxseed controls NAFLD-related indices and FBS. Therefore, it can be stated with caution that ATO and flaxseed can be used to improve lipid profile and reduce the complications of NAFLD.

Investigation of the potential mechanism of the Shugan Xiaozhi decoction for the treatment of nonalcoholic fatty liver disease based on network pharmacology, molecular docking and molecular dynamics simulation

Background

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disease, the incidence of which increases annually. Shugan Xiaozhi (SGXZ) decoction, a composite traditional Chinese medicinal prescription, has been demonstrated to exert a therapeutic effect on NAFLD. In this study, the potential bioactive ingredients and mechanism of SGXZ decoction against NAFLD were explored via network pharmacology, molecular docking, and molecular dynamics simulation.

Methods

Compounds in SGXZ decoction were identified and collected from the literature, and the corresponding targets were predicted through the Similarity Ensemble Approach database. Potential targets related to NAFLD were searched on DisGeNET and GeneCards databases. The compound-target-disease and protein-protein interaction (PPI) networks were constructed to recognize key compounds and targets. Functional enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was performed on the targets. Molecular docking was used to further screen the potent active compounds in SGXZ. Finally, molecular dynamics (MD) simulation was applied to verify and validate the binding between the most potent compound and targets.

Results

A total of 31 active compounds and 220 corresponding targets in SGXZ decoction were collected. Moreover, 1,544 targets of NAFLD were obtained, of which 78 targets intersected with the targets of SGXZ decoction. Key compounds and targets were recognized through the compound-target-disease and PPI network. Multiple biological pathways were annotated, including PI3K-Akt, MAPK, insulin resistance, HIF-1, and tryptophan metabolism. Molecular docking showed that gallic acid, chlorogenic acid and isochlorogenic acid A could combine with the key targets. Molecular dynamics simulations suggested that isochlorogenic acid A might potentially bind directly with RELA, IL-6, VEGFA, and MMP9 in the regulation of PI3K-Akt signaling pathway.

Conclusion

This study investigated the active substances and key targets of SGXZ decoction in the regulation of multiple-pathways based on network pharmacology and computational approaches, providing a theoretical basis for further pharmacological research into the potential mechanism of SGXZ in NAFLD.

Association of Statin Adherence With the Development of Nonalcoholic Fatty Liver Disease: A Nested Case-Control Study Using a Japanese Claims Database

BACKGROUND

Statins are expected to have beneficial effects on nonalcoholic fatty liver disease (NAFLD); however, evidence remains insufficient.

OBJECTIVE

In this study, we aim to investigate the association between statin adherence and NAFLD development.

METHODS

We conducted a nested case-control study of statin users using the Japan Medical Data Center administrative claims database (January 2005 to January 2020). Individuals who developed NAFLD were designated as cases. For each case, we randomly selected a maximum of 10 controls using risk set sampling. Good adherence was defined as the proportion of days covered (PDC) of ≥0.80. Higher intensity was defined as the median or higher of a cumulative defined daily dose (cDDD) per day covered by statin prescription. Conditional logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

In this study, 253 383 patients with the first statin prescription were identified. Of them, 7080 were selected and matched to 70 734 controls. The medians of PDC and intensity were 0.88 (interquartile range [IQR], 0.61-0.96) and 0.32 (IQR, 0.25-0.50) cDDD/day, respectively. Good adherence was significantly associated with a reduced risk of NAFLD development (adjusted OR, 0.82; 95% CI, 0.78-0.86). Higher intensity was not significantly associated with a reduced risk of NAFLD development (adjusted OR, 1.02; 95% CI, 0.97-1.08).

CONCLUSION AND RELEVANCE

Good adherence to statins is associated with a reduced risk of NAFLD development, regardless of the statin intensity. Appropriate statin therapy could reduce the risk of NAFLD development.

Pathogenesis from Inflammation to Cancer in NASH-Derived HCC

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and one of the deadliest cancers worldwide. As opposed to the majority of patients with HCC, approximately 20–30% of cases of non-alcoholic steatohepatitis (NASH)-derived HCC develop malignant tumours in the absence of liver cirrhosis. NASH is characterized by metabolic dysregulation, chronic inflammation and cell death in the liver, which provide a favorable setting for the transformation of inflammation into cancer. This review aims to describe the pathogenesis and the underlying mechanism of the transition from inflammation to cancer in NASH.

A Differentiation-Related Gene Prognostic Index Contributes to Prognosis and Immunotherapy Evaluation in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common gastrointestinal tumor with a poor prognosis, which is associated with poor differentiation of tumor cells. However, the potential value of cell differentiation-related molecules in predicting the benefit and prognosis of immune checkpoint inhibitors (ICI) therapy remains unknown. Herein, to investigate the differentiation trajectory of HCC cells and their clinical significance, a differentiation-related gene prognostic index (DRGPI) based on HCC differentiation-related genes (HDRGs) was constructed to elucidate the immune characteristics and therapeutic benefits of ICI in the HCC subgroup defined by DRGPI. Single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data from four HCC samples were integrated for bioinformatics analysis. Then, PON1, ADH4, SQSTM1, HSP90AA1, and STMN1 were screened out to construct a DRGPI. More intriguingly, RT-qPCR validation of the expression of these genes yielded consistent results with the TCGA database. Next, the risk scoring (RS) constructed based on DRGPI suggested that the overall survival (OS) of the DRGPI-high patients was significantly worse than that of the DRGPI-low patients. A nomogram was constructed based on DRGPI-RS and clinical characteristics, which showed strong predictive performance and high accuracy. The comprehensive results indicated that a low DRGPI score was associated with low TP53 mutation rates, high CD8 T cell infiltration, and more benefit from ICI therapy. Homoplastically, the high DRGPI score reflected the opposite results. Taken together, our study highlights the significance of HCC cell differentiation in predicting prognosis, indicating immune characteristics, and understanding the therapeutic benefits of ICI, and suggests that DRGPI is a valuable prognostic biomarker for HCC.

Er-Chen Decoction Alleviates High-Fat Diet-Induced Nonalcoholic Fatty Liver Disease in Rats through Remodeling Gut Microbiota and Regulating the Serum Metabolism

Many studies have found that the dysfunction in gut microbiota and the metabolic dysfunction can promote nonalcoholic fatty liver disease (NAFLD) development. Er-Chen decoction (EC) can be used in the treatment of NAFLD. However, the mechanism of this hepatoprotection is still unknown. In this study, we constructed a rat model with NAFLD fed with high-fat chow and administered EC treatment. The therapeutic effects of EC on NAFLD were evaluated by measuring transaminases, blood lipid levels, and pathological changes in the liver. In addition, we measured the effects of EC on liver inflammatory response and oxidative stress. The changes in gut microbiota after EC treatment were studied using 16S rRNA sequencing. Serum untargeted metabolomics analysis was also used to study the metabolic regulatory mechanisms of EC on NAFLD. The results showed that EC decreased the serum transaminases and lipid levels and improved the pathological changes in NAFLD rats. Furthermore, EC enhanced the activities of SOD and GSH-Px and decreased MDA level in the liver. EC treatment also decreased the gene and protein levels of IL-6, IL-1β, and TNF-α in the liver and serum. The 16S rRNA sequencing and untargeted metabolomics indicated that EC treatment affected the gut microbiota and regulated serum metabolism. Correlation analysis showed that the effects of EC on taurine and hypotaurine metabolism, cysteine and methionine metabolism, and vitamin B6 metabolism pathways were associated with affecting in the abundance of Lactobacillus, Dubosiella, Lachnospiraceae, Desulfovibri, Romboutsia, Akkermansia, Intestinimonas, and Candidatus_saccharimonas in the gut. In conclusion, our study confirmed the protective effect of EC on NAFLD. EC could treat NAFLD by inhibiting oxidative stress, reducing inflammatory responses, and improving the dysbiosis of gut microbiota and the modulation of the taurine and hypotaurine metabolism, cysteine and methionine metabolism, and vitamin B6 metabolism pathways in serum.

Is there a role of lipid-lowering therapies in the management of fatty liver disease?

Atherogenic dyslipidemia is characterized by increased triglyceride-rich lipoproteins and low high-density lipoprotein cholesterol concentrations. It is highly prevalent in non-alcoholic fatty liver disease (NAFLD) and contributes to the increased cardiovascular risk associated with this condition. Alongside insulin resistance it plays an important pathogenetic role in NAFLD/non-alcoholic steatohepatitis (NASH) development and progression. It has been shown that cholesterol-lowering reduces cardiovascular risk more in NAFLD vs non-NAFLD high-risk individuals. This evidence highlights the importance of effective lipid modulation in NAFLD. In this narrative review the effects of the most commonly used lipid-lowering therapies on liver outcomes alongside their therapeutic implications in NAFLD/NASH are critically discussed. Preclinical and clinical evidence suggests that statins reduce hepatic steatosis, inflammation and fibrosis in patients with NAFLD/NASH. Most data are derived from observational and small prospective clinical studies using changes in liver enzyme activities, steatosis/fibrosis scores, and imaging evidence of steatosis as surrogates. Also, relevant histologic benefits were noted in small biopsy studies. Atorvastatin and rosuvastatin showed greater benefits, whereas data for other statins are scarce and sometimes conflicting. Similar studies to those of statins showed efficacy of ezetimibe against hepatic steatosis. However, no significant anti-inflammatory and anti-fibrotic actions of ezetimibe have been shown. Preclinical studies showed that fibrates through peroxisome proliferator-activated receptor (PPAR)α activation may have a role in NAFLD prevention and management. Nevertheless, no relevant benefits have been noted in human studies. Species-related differences in PPARα expression and its activation responsiveness may help explain this discrepancy. Omega-3 fatty acids reduced hepatic steatosis in numerous heterogeneous studies, but their benefits on hepatic inflammation and fibrosis have not been established. Promising preliminary data for the highly purified eicosapentaenoic acid require further confirmation. Observational studies suggest that proprotein convertase subtilisin/kexin9 inhibitors may also have a role in the management of NAFLD, though this needs to be established by future prospective studies.

Lipid-Lowering Responses to Dyslipidemia Determine the Efficacy on Liver Enzymes in Metabolic Dysfunction-Associated Fatty Liver Disease with Hepatic Injuries: A Prospective Cohort Study

PURPOSE

Effective treatment of dyslipidemia with lipid-lowering agents is pivotal in the management of metabolic-associated fatty liver disease (MAFLD) for preventing cardiovascular complications. We explored the associations between improvements in liver injuries indicated by changes in transaminases and a reduction in lipid levels in MAFLD patients with dyslipidemia and elevated transaminases during lipid-lowering therapies.

METHODS

This prospective, cohort study enrolled consecutive MAFLD patients with hyperlipidemia and elevated transaminases. Patients were divided into a group receiving lipid-lowering agents and an age-, sex- and baseline lipid level-matched control group without receiving lipid-lowering agents. Clinical visits were performed at the 1st month and then every 3 months for 1 year.

RESULTS

This study included 541 MAFLD patients (lipid-lowering group: 325 patients; control group: 216 patients). Compared with controls, there was a substantially greater reduction in alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT), triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) in the lipid-lowering group after 12 months (all P < 0.05). The decrease in ALT was positively correlated with the decrease in TC (r = 0.332), TG (r = 0.180), LDL-c (r = 0.253) and apolipoprotein E (ApoE) (r = 0.119), while the decrease in AST was positively correlated with the decrease in TC (r = 0.228) and LDL-c (r = 0.192) (all P<0.05). The greater range of reduction in blood lipids (TC/TG/LDL-c), the higher the transaminase and GGT normalization rate (all P<0.05). Multivariate analysis confirmed that a TG decrease of over 50% remained an independent predictor of transaminase and GGT normalization (OR 2.07, 95% CI 1.12-3.84, P=0.020).

CONCLUSION

Lipid-lowering to target levels might be beneficial to liver injury improvements in MAFLD patients with dyslipidemia when receiving lipid-lowering agents.

Obesity-Specific Association of Statin Use and Reduced Risk of Recurrence of Early Stage NSCLC

Introduction

Statins, used for their lipid-lowering activity, have anti-inflammatory and anticancer properties as well. We evaluated this potential benefit of statin use in patients with NSCLC.

Methods

All 613 patients with pathologic stage 1 or 2 NSCLC who had lobectomy without neoadjuvant therapy at our institution during 2008 to 2015 were included. Association between presurgery statin use and overall survival and recurrence-free survival (RFS) was analyzed using Cox proportional hazards regression. Association of statin use with tumor transcriptome was evaluated in another 350 lung cancer cases.

Results

Univariable analyses did not reveal a statistically significant association of statin use with either overall survival or RFS, with hazard ratio equals to 1.19 and 0.70 (Wald p = 0.28 and 0.09), respectively. In subgroup analyses, significantly improved RFS was found in statin users, but only in overweight/obese patients (body mass index [BMI] > 25; n = 422), with univariable and multivariable hazard ratio of 0.49 and 0.46 (p = 0.005 and 0.002), respectively, but not in patients with BMI less than or equal to 25 (n = 191; univariable p = 0.21). Transcriptomes of tumor statin users had high expression of tumoricidal genes such as granzyme A and interferon-γ compared with those of nonusers among high- but not low-BMI patients with lung cancer.

Conclusions

Our study suggests that statins may improve the outcome of early stage NSCLC but only in overweight or obese patients. This benefit may stem from a favorable reprogramming of the antitumor immune response that statins perpetrate specifically in the obese.

Targeting Liver Sinusoidal Endothelial Cells: An Attractive Therapeutic Strategy to Control Inflammation in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), especially its advanced stage nonalcoholic steatohepatitis (NASH), has become a threatened public health problem worldwide. However, no specific drug has been approved for clinical use to treat patients with NASH, though there are many promising candidates against NAFLD in the drug development pipeline. Recently, accumulated evidence showed that liver sinusoidal endothelial cells (LSECs) play an essential role in the occurrence and development of liver inflammation in patients with NAFLD. LSECs, as highly specialized endothelial cells with unique structure and anatomical location, contribute to the maintenance of liver homeostasis and could be a promising therapeutic target to control liver inflammation of NAFLD. In this review, we outline the pathophysiological roles of LSECs related to inflammation of NAFLD, highlight the pro-inflammatory and anti-inflammatory effects of LSECs, and discuss the potential drug development strategies against NAFLD based on targeting to LSECs.