Nonalcoholic fatty future disease

Partial validation of a six-month high-fat diet and fructose-glucose drink combination as a mouse model of nonalcoholic fatty liver disease

PURPOSE

The need to investigate the pathogenesis and treatment of nonalcoholic fatty liver disease (NAFLD) has led to the development of multiple mouse models. The aim of this study was to validate a fast food diet (FFD) mouse model that is introduced as being close to the human disease.

METHODS

Eight to nine weeks old male and female C57BL/6 J mice were randomly allocated to a FFD group or to a chow diet (CD) group. Every four weeks, mice were weighed, and blood samples were collected for the measurement of glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TGs) and total cholesterol. After 25 weeks, mice were sacrificed, and liver tissue was histologically evaluated.

RESULTS

FFD mice gained more weight (p = 0.049) and presented a higher liver-to-body weight ratio (p < 0.001) compared to CD mice. FFD group presented with greater steatosis, hepatocellular ballooning and NAFLD activity score (NAS), whereas lobular inflammation and fibrosis were not significantly different compared to CD. When stratified by sex, NAS was different between FFD and CD groups in both male and female mice. Group by time interaction was significant for weight, ALT and cholesterol, but not for glucose, AST and TGs.

CONCLUSION

FFD mice presented with morphologic and biochemical features of NAFLD and with greater hepatic steatosis, hepatocellular ballooning and NAS, but not lobular inflammation and fibrosis, compared to CD mice. These results only partly validate the FFD mouse model for NAFLD, at least for a 6-month feeding period.

Spirulina (Arthrospira platensis) Improved Nonalcoholic Fatty Liver Disease Characteristics and Microbiota and Did Not Affect Organ Fibrosis Induced by a Fructose-Enriched Diet in Wistar Male Rats

Spirulina (Arthrospira platensis) is reported to play a role in improving nonalcoholic fatty liver disease (NAFLD) and intestinal microbiota (IM). To study spirulina's effects in the improvement of NAFLD characteristics, IM, and pancreatic-renal lesions induced by a fructose-enriched diet, 40 Wistar healthy male rats, weighing 200-250 g, were randomly divided into four groups of 10, and each rat per group was assigned a diet of equal quantities (20 g/day) for 18 weeks. The first control group (CT) was fed a standardized diet, the second group received a 40% fructose-enriched diet (HFr), and the third (HFr-S5) and fourth groups (HFr-S10) were assigned the same diet composition as the second group but enriched with 5% and 10% spirulina, respectively. At week 18, the HFr-S10 group maintained its level of serum triglycerides and had the lowest liver fat between the groups. At the phylae and family level, and for the same period, the HFr-S10 group had the lowest increase in the Firmicutes/Bacteroidetes ratio and the Ruminococcaceae and the highest fecal alpha diversity compared to all other groups (p < 0.05). These findings suggest that at a 10% concentration, spirulina could be used in nutritional intervention to improve IM, fatty liver, metabolic, and inflammatory parameters associated with NAFLD.

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

BACKGROUND AND AIM

Clinical data on the association between leptin levels and nonalcoholic fatty liver disease (NAFLD)-related liver fibrosis are conflicting. This meta-analysis aimed to compare circulating leptin between NAFLD patients with versus without liver fibrosis or non-NAFLD controls.

METHODS

A systematic search was conducted in PubMed, Scopus, and the Cochrane Library. Fifteen studies were included, reporting data from 964 individuals (422 NAFLD patients with fibrosis, 297 NAFLD patients without fibrosis, 245 no-NAFLD controls).

RESULTS

Leptin standardized mean difference (SMD) was higher in NAFLD patients with fibrosis (F1-F4) than in controls (SMD: 2.27; 95% confidence interval [CI]: 0.81-3.73); however, this association did not remain robust after the exclusion of studies with morbidly obese individuals. No difference was observed in leptin SMD between NAFLD patients with fibrosis and those without fibrosis (F0), and NAFLD patients without fibrosis versus controls. Heterogeneity was high (I2: 66-98%) among studies. Meta-regression analysis revealed a positive association of leptin SMD with homeostasis model assessment-insulin resistance, when comparing NAFLD patients with fibrosis versus NAFLD patients without fibrosis (beta: 0.53; 95% CI: 0.04-1.03), and a negative association of leptin SMD with age, when comparing NAFLD patients with fibrosis versus controls (beta: -0.29; 95% CI: -0.53 to -0.05).

CONCLUSION

Circulating leptin was higher in NAFLD patients with liver fibrosis than non-NAFLD controls, an association, however, attenuated after the exclusion of a study with morbidly obese individuals. Circulating leptin was not different between NAFLD patients with and without fibrosis, or NAFLD patients without fibrosis and controls.

Mitochondrial Dysfunction in Metabolic Dysfunction Fatty Liver Disease (MAFLD)

Nonalcoholic fatty liver disease (NAFLD) has become an increasingly common disease in Western countries and has become the major cause of liver cirrhosis or hepatocellular carcinoma (HCC) in addition to viral hepatitis in recent decades. Furthermore, studies have shown that NAFLD is inextricably linked to the development of extrahepatic diseases. However, there is currently no effective treatment to cure NAFLD. In addition, in 2020, NAFLD was renamed metabolic dysfunction fatty liver disease (MAFLD) to show that its pathogenesis is closely related to metabolic disorders. Recent studies have reported that the development of MAFLD is inextricably associated with mitochondrial dysfunction in hepatocytes and hepatic stellate cells (HSCs). Simultaneously, mitochondrial stress caused by structural and functional disorders stimulates the occurrence and accumulation of fat and lipo-toxicity in hepatocytes and HSCs. In addition, the interaction between mitochondrial dysfunction and the liver-gut axis has also become a new point during the development of MAFLD. In this review, we summarize the effects of several potential treatment strategies for MAFLD, including antioxidants, reagents, and intestinal microorganisms and metabolites.

Fibrosis-4 Index Predicts Long-Term All-Cause, Cardiovascular and Liver-Related Mortality in the Adult Korean Population

BACKGROUND & AIMS

Associations between hepatic fibrosis and mortality remain to be fully elucidated in large population-based studies. This study aimed to evaluate the associations of the fibrosis-4 index (FIB-4) with all-cause, cardiovascular, cancer, and liver-related mortality in the adult Korean population without viral hepatitis.

METHODS

Baseline data were retrieved from the Korea National Health and Nutrition Examination Survey, and mortality data were retrieved from the Korean Cause of Death data registry. Adults (age, ≥19 y) without viral hepatitis B or C, liver cirrhosis, any cancer, stroke, myocardial infarction, angina pectoris, or renal failure at baseline were eligible. Presumed hepatic fibrosis was evaluated with FIB-4. Hazard ratios (HRs) and 95% CIs were calculated using multivariable Cox regression analysis, and Kaplan-Meier estimates of the cumulative mortality were evaluated.

RESULTS

There were 46,456 individuals with a median follow-up period of 8.6 years (interquartile range, 6.3-10.6 y). Kaplan-Meier curves for cumulative mortality showed that participants with a FIB-4 of ≥2.67 (vs FIB-4, <2.67) had higher cumulative all-cause, cardiovascular, cancer, and liver-related mortality. In the fully adjusted model, Cox regression analysis revealed that presumed advanced hepatic fibrosis (FIB-4, ≥2.67) remained associated with all-cause mortality (HR, 1.64; 95% CI, 1.23-2.18), cardiovascular mortality (HR, 2.96; 95% CI, 1.60-5.46), and liver-related mortality (HR, 10.50; 95% CI, 4.70-23.44), but not cancer mortality, after adjusting for confounders including central obesity and insulin resistance. Excluding participants with an estimated alcohol intake of 30 grams or more for men and 20 grams or more for women did not affect the results.

CONCLUSIONS

At the population level, liver fibrosis estimated by FIB-4 was associated with increased cumulative all-cause, cardiovascular, and liver-related mortality.

Nonalcoholic fatty liver disease and hepatocellular carcinoma:Insights in epidemiology, pathogenesis, imaging, prevention and therapy

Hepatocellular carcinoma (HCC) is estimated to be the third leading cause of cancer-related mortality and is characterized by low survival rates. Nonalcoholic fatty liver disease (NAFLD) is emerging as a leading cause of HCC, whose rates are increasing, owing to the increasing prevalence of NAFLD. The pathogenesis of NAFLD-associated HCC is multifactorial: insulin resistance, obesity, diabetes and the low-grade hepatic inflammation, which characterizes NAFLD, seem to play key roles in the development and progression of HCC. The diagnosis of NAFLD-associated HCC is based on imaging in the presence of liver cirrhosis, preferably computerized tomography or magnetic resonance imaging, but liver biopsy for histological confirmation is usually required in the absence of liver cirrhosis. Some preventive measures have been recommended for NAFLD-associated HCC, including weight loss, cessation of even moderate alcohol drinking and smoking, as well as the use of metformin, statins and aspirin. However, these preventive measures are mainly based on observational studies, thus they need validation in trials of different design before introducing in clinical practice. The treatment of NAFLD should be tailored on an individual basis and should be ideally determined by a multidisciplinary team. In the last two decades, new medications, including tyrosine kinase inhibitors and immune checkpoints inhibitors, have improved the survival of patients with advanced HCC, but trials specifically designed for patients with NAFLD-associated HCC are scarce. The aim of this review was to overview evidence on the epidemiology and pathophysiology of NAFLD-associated HCC, then to comment on imaging tools for its appropriate screening and diagnosis, and finally to critically summarize the currently available options for its prevention and treatment.

Retinal Vascular Lesions in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis aimed to summarize and compare data on retinal vascular lesions between patients with nonalcoholic fatty liver disease (NAFLD) and individuals without the disease. Methods: Search was performed in PubMed, Scopus and Cochrane Library, complemented by handsearching (PROSPERO ID: CRD42022345558). Thirty-six studies comprising 24,985 individuals (12,387 NAFLD patients and 12,598 controls) were selected for the meta-analysis. Results: Apart from retinopathy, no study with a different type of retinal vascular lesion was retrieved. Overall, there was no significant difference in the presence of retinopathy in NAFLD patients compared to controls (Odds Ratio (OR) = 1.20; 95% Confidence Interval (CI): 0.91-1.59). Heterogeneity among studies was high (I² = 93%; p < 0.00001), while Egger's test revealed no publication bias (p = 0.60). However, subgroup analysis showed positive association between retinopathy and NAFLD in type 1 diabetes mellitus (T1DM) (OR = 2.35; 95% CI: 1.53-3.60), but not in type 2 diabetes mellitus patients. Meta-regression analysis exploring potential confounders revealed no significant association. Conclusions: The presence of retinopathy was not overall different between individuals with and without NAFLD; however, T1DM patients with NAFLD had higher rates of retinopathy compared to T1DM patients without NAFLD, a finding warranting further research to show whether NAFLD may predict retinopathy in T1DM patients.

Non-alcoholic fatty liver disease-related hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD), one of the most common causes of liver disease, is an increasingly common cause of hepatocellular carcinoma (HCC). Several demographic, clinical, and genetic factors contribute to HCC risk in NAFLD patients, which may inform risk stratification scores. Proven efficacious approaches to primary prevention approach in patients with non-viral liver disease remain an area of need. Semi-annual surveillance is associated with improved early tumor detection and reduced HCC-related mortality; however, patients with NAFLD have several challenges to effective surveillance, including under-recognition of at-risk patients, low surveillance utilization in clinical practice, and lower sensitivity of current tools for early-stage HCC detection. Treatment decisions are best made in a multidisciplinary fashion and are informed by several factors including tumor burden, liver dysfunction, performance status, and patient preferences. Although patients with NAFLD often have larger tumor burden and increased comorbidities compared to counterparts, they can achieve similar post-treatment survival with careful patient selection. Therefore, surgical therapies continue to provide a curative treatment option for patients diagnosed at an early stage. Although there has been debate about the efficacy of immune checkpoint inhibitors in patients with NAFLD, current data are insufficient to change treatment selection based on liver disease etiology.

A New In Vivo Zebrafish Bioassay Evaluating Liver Steatosis Identifies DDE as a Steatogenic Endocrine Disruptor, Partly through SCD1 Regulation

Non-alcoholic fatty liver disease (NAFLD), which starts with liver steatosis, is a growing worldwide epidemic responsible for chronic liver diseases. Among its risk factors, exposure to environmental contaminants, such as endocrine disrupting compounds (EDC), has been recently emphasized. Given this important public health concern, regulation agencies need novel simple and fast biological tests to evaluate chemical risks. In this context, we developed a new in vivo bioassay called StAZ (Steatogenic Assay on Zebrafish) using an alternative model to animal experimentation, the zebrafish larva, to screen EDCs for their steatogenic properties. Taking advantage of the transparency of zebrafish larvae, we established a method based on fluorescent staining with Nile red to estimate liver lipid content. Following testing of known steatogenic molecules, 10 EDCs suspected to induce metabolic disorders were screened and DDE, the main metabolite of the insecticide DDT, was identified as a potent inducer of steatosis. To confirm this and optimize the assay, we used it in a transgenic zebrafish line expressing a blue fluorescent liver protein reporter. To obtain insight into DDE's effect, the expression of several genes related to steatosis was analyzed; an up-regulation of scd1 expression, probably relying on PXR activation, was found, partly responsible for both membrane remodeling and steatosis.

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).

Menopausal hormone therapy in women with dyslipidemia and nonalcoholic fatty liver disease

The cessation of ovarian function is associated with an increase in abdominal adipose tissue, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD), which may contribute to the augmented cardiovascular risk observed in postmenopausal women. After ovarian function stops, circulating triglyceride, total cholesterol, and low-density lipoprotein-cholesterol (LDL-C) concentrations increase, whereas high-density lipoprotein-cholesterol (HDL-C) and lipoprotein (Lp(a)) remain essentially unchanged. Similarly, the rates of NAFLD, possibly including the advanced forms of the disease (e.g., hepatic fibrosis), increase in postmenopausal compared with premenopausal women. These effects make menopausal hormone therapy (MHT) an attractive way to restore them. Estrogen per os decreases LDL-C and Lp(a) and increases HDL-C and triglyceride concentrations. The transdermal administration of estrogen has a more neutral effect on triglycerides, albeit a less beneficial effect on LDL-C, HDL-C, and Lp(a). Co-administration of a progestagen diminishes the effect of estrogen on LDL-C, HDL-C, and Lp(a), which, however, remains beneficial. Importantly, the effect may vary with different progestagens, being lesser with natural progesterone and dydrogesterone. Regarding the effect of MHT on NAFLD, though experimental data are currently favorable, clinical evidence is to date limited and controversial. Therefore, there is a need for specifically designed clinical trials, ideally with paired liver biopsies, to demonstrate the effect of different MHT schemes on NAFLD, which is of considerable importance, given that NAFLD is more prevalent after the cessation of ovarian function.

Anti-obesity Medications for the Management of Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Obesity is closely associated with nonalcoholic fatty liver disease (NAFLD), a highly prevalent disease without any approved medication. The aim of this review was to summarize the evidence on the effect of anti-obesity medications on NAFLD, especially focusing on hepatic histology.

RECENT FINDINGS

Orlistat and some glucagon-like peptide-1 receptor analogs, including liraglutide and semaglutide, have beneficial effects on hepatic steatosis and inflammation, but not fibrosis. Other anti-obesity medications, including lorcaserin, setmelanotide, phentermine hydrochloric, phentermine/topiramate, and naltrexone/bupropion, have been minimally investigated in NAFLD. Furthermore, medications like sodium-glucose cotransporter-2 inhibitors and farnesoid X receptor have shown beneficial effects in both NAFLD and obesity, but they have not been licensed for either disease. Liraglutide, semaglutide, and orlistat may be currently used in selected patients with obesity and NAFLD. Further research is warranted, since targeting obesity may provide additional benefits on its comorbidities, including NAFLD.

Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Identification of Shared Gene Signatures in Different Stages of Nonalcoholic Fatty Liver Disease Using Integrated Microarray Datasets

Background: Nonalcoholic fatty liver disease (NAFLD) is the most common type of chronic liver disease worldwide. Left untreated, it can be a risk factor for developing cirrhosis or hepatocellular carcinoma (HCC). Although experts have made many efforts to find the underlying mechanisms of NAFLD, they remain a mystery. Objectives: This study aimed to distinguish common gene signatures and pathways in the human liver during NAFLD progression through systems biology. Methods: In this study, the researchers selected three microarray datasets, GSE48452, GSE63067, and GSE89632, from the NCBI GEO database to explore differentially expressed genes (DEGs) among healthy controls, simple steatosis, and nonalcoholic steatohepatitis (NASH) patients. Furthermore, protein-protein interaction (PPI) networks and pathway enrichment analyses were used to detect common genes and biological pathways in different stages of NAFLD. Results: The current study included 45 healthy participants, 36 simple steatosis patients, and 46 NASH patients. Common genes for NAFLD progression were Chi3L1, ICAM1, MT1A, MT1H, ABCB11, ACOT1, CYP2C9, HSP90B1, and CPB2, which are involved in inflammation and oxidative stress pathways. Conclusions: The present study investigated the shared vital genes and pathways between different stages of NAFLD, which may facilitate understanding NAFLD mechanisms and identifying potential therapeutic targets in this disease.

Combination Therapies for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is considered a highly prevalent disease associated with various co-morbidities that lead to socioeconomic burden. Despite large-scale investigation, no pharmacological treatment has been approved specifically for NAFLD to date. Lifestyle modifications and diet are regarded as highly beneficial for the management of NAFLD, albeit with poor compliance, thus rendering pharmacological treatment highly important. Based on the current failure to discover a “magic bullet” to treat all patients with NAFLD and considering the multifaceted pathophysiology of the disease, combination therapies may be considered to be a rational alternative approach. In this regard, several drug categories have been considered, including, but not limited to, lipid-lowering, anti-hypertensive, glucose-lowering, anti-obesity, anti-oxidant, anti-inflammatory and anti-fibrotic medications. The aim of this review is, in addition to summarizing some of the multiple factors contributing to the pathophysiology of NAFLD, to focus on the efficacy of pharmacological combinations on the management of NAFLD. This may provide evidence for a more personalized treatment of patients with NAFLD in the future.

Mongolian medicine in treating type 2 diabetes mellitus combined with nonalcoholic fatty liver disease via FXR/LXR-mediated P2X7R/NLRP3/NF-κB pathway activation

Type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) are the most problematic metabolic diseases in the world. NAFLD encompasses a spectrum of severity, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) and fibrosis, increasing the risk of cirrhosis and hepatocellular carcinoma. Importantly, NAFLD is closely linked to obesity and tightly interrelated with insulin resistance and T2DM. T2DM and NAFLD (T2DM-NAFLD) are called as the Xike Rixijing Disease and Tonglaga Indigestion Disease respectively, in Mongolian medicine. Xike Rixijing Disease maybe develop into Tonglaga Indigestion Disease. Forturnately many Mongolian medicines show efficient treatment of T2DM-NAFLD, such as Agriophyllum squarrosum, Haliyasu (dried powder of camel placenta), Digeda-4 (herbs of Lomatogonium carinthiacum, rhizomata of Coptis chinensis, ripe fruits of Gardenia jasminoides, herbs of Dianthus superbus), Guangmingyan Siwei Decoction Powder (Halite, ripe fruits of Terminalia chebula, rhizomata of Zingiber officinale, fruit clusters of Piper longum), Tonglaga-5 (ripe fruits of Punica granatum, barks of Cinnamomum cassia, ripe fruits of Amomum kravanh, fruit clusters of Piper longum, flowers of Carthamus tinctorius), Tegexidegeqi (rhizomata of Inula helenium, ripe fruits of Gardenia jasminoides, rhizomata of Platycodon grandiflorum, rhizomata of Coptis chinensis, heartwood of Caesalpinia sappan), Ligan Shiliu Bawei San (ripe fruits of Punica granatum, barks of Cinnamomum cassia, ripe fruits of Amomum kravanh, fruit clusters of Piper longum, flowers of Carthamus tinctorius, ripe fruits of Amomum tsao-ko, rhizomata of Zingiber officinale), etc. Principles of Mongolian medicine in treating diseases: by balancing “three essences or roots” and “seven elements”, strengthening liver and kidney function, transporting nutrients to enhance physical strength and disease resistance, and combined with drugs for comprehensive conditioning treatment. However, their molecular mechanisms remain unclear. In this review, we prospect that Mongolian medicines might be a promising treatment for T2DM-NAFLD by activating P2X7R/NLRP3/NF-κB inflammatory pathway via lipid-sensitive nuclear receptors (i.e., FXR and LXR).

An Overview of the TRP-Oxidative Stress Axis in Metabolic Syndrome: Insights for Novel Therapeutic Approaches

Metabolic syndrome (MS) is a complex pathology characterized by visceral adiposity, insulin resistance, arterial hypertension, and dyslipidaemia. It has become a global epidemic associated with increased consumption of high-calorie, low-fibre food and sedentary habits. Some of its underlying mechanisms have been identified, with hypoadiponectinemia, inflammation and oxidative stress as important factors for MS establishment and progression. Alterations in adipokine levels may favour glucotoxicity and lipotoxicity which, in turn, contribute to inflammation and cellular stress responses within the adipose, pancreatic and liver tissues, in addition to hepatic steatosis. The multiple mechanisms of MS make its clinical management difficult, involving both non-pharmacological and pharmacological interventions. Transient receptor potential (TRP) channels are non-selective calcium channels involved in a plethora of physiological events, including energy balance, inflammation and oxidative stress. Evidence from animal models of disease has contributed to identify their specific contributions to MS and may help to tailor clinical trials for the disease. In this context, the oxidative stress sensors TRPV1, TRPA1 and TRPC5, play major roles in regulating inflammatory responses, thermogenesis and energy expenditure. Here, the interplay between these TRP channels and oxidative stress in MS is discussed in the light of novel therapies to treat this syndrome.

Effect of omega-3 supplementation on cardiometabolic indices in diabetic patients with non-alcoholic fatty liver disease: a randomized controlled trial

Background

Patients with non-alcoholic fatty liver disease (NAFLD) as well as type 2 diabetes mellitus (T2DM) are at increased risk for cardiovascular diseases (CVD). Omega-3 supplementation has been proposed as a possible strategy for management of cardiometabolic risk. Cardiometabolic indices can predict and evaluate the cardiometabolic risk.

Aims

We investigated the effect of omega-3 supplementation on accurate and available cardiometabolic indices including atherogenic index of plasma (AIP), Castelli risk index I, Castelli risk index II and atherogenic coefficient (AC) in diabetic patients with NAFLD.

Methods

We conducted a double-blind, randomized controlled trial (RCT) for 12 weeks. From August 2016 to March 2017, the subjects referred to Faghihi hospital in Shiraz, Iran, were recruited. Sixty diabetic patients with NAFLD were randomly assigned into the omega-3 (2000 mg/d omega-3 capsule contained 360 mg/d eicosapentaenoic acid and 240 mg/d docosahexaenoic acid) and the placebo (liquid paraffin) groups using computer-generated random number table.

Results

Omega-3 supplementation compared to the placebo had no significant effect on AIP (− 0.11 ± 0.20 vs. -0.03 ± 0.16; P = 0.11), Castelli risk index I (− 0.25 ± 0.6 vs. -0.07 ± 0.7; P = 0.42), Castelli risk index II (− 0.24 ± 0.5 vs. -0.14 ± 0.5; P = 0.63) and AC (− 0.25 ± 0.6 vs. -0.07 ± 0.7; P = 0.42). After adjusting for confounding factors, the findings remained without change.

Conclusion

Omega-3 supplementation (2000 mg/d) for 12 weeks has no effect on cardiometabolic risk. It seems, higher doses of omega-3 can improve cordiometabolic risk. The trial was registered at Iranian Registry of Clinical Trials IRCT2016102530489N1.

Circulating tumor necrosis factor-α levels in non-alcoholic fatty liver disease: A systematic review and a meta-analysis

BACKGROUND AND AIM

To synthesize data on circulating tumor necrosis factor (TNF)-α levels between patients with histologically confirmed non-alcoholic fatty liver disease (NAFLD) (simple steatosis or non-alcoholic fatty liver [NAFL] and/or non-alcoholic steatohepatitis [NASH]) and controls.

METHODS

We performed a systematic search in PubMed, Scopus, and Cochrane Library. Fifty-six studies, published between 2003 and 2019, were finally included, reporting data from 5848 individuals (1634 controls and 4214 NAFLD patients).

RESULTS

Higher circulating TNF-α levels were observed in NAFLD patients than controls (standardized mean difference [SMD] 0.84; 95% confidence interval [95% CI] 0.59-1.09), NAFL patients than controls (SMD 0.56; 95% CI 0.27-0.85), NASH patients than controls (SMD 0.93; 95% CI 0.64-1.22), and NASH than NAFL patients (SMD 0.31; 95% CI 0.16-0.46). There were only minimal changes in the comparisons between groups after excluding studies with morbidly obese populations (n = 11), or pediatric/adolescent populations (n = 6), or other than enzyme-linked immunosorbent assay method of TNF-α measurement (n = 8). There was high heterogeneity among studies in all comparisons, which was not essentially affected after sensitivity analyses. The meta-regression analysis revealed that the male ratio was positively associated with TNF-α SMD in the comparison between patients with NASH and NAFL (beta = 0.809; 95% CI 0.052-1.566) and accounted for 36% (P = 0.037) of the heterogeneity in this pair of comparison. TNF-α SMD was not associated with age, body mass index, and alanine aminotransferase in any pair of comparisons.

CONCLUSIONS

Circulating TNF-α levels were higher in patients with NAFLD compared with controls. Higher levels of circulating TNF-α were also associated with the severity of NAFLD.

Review article: non-alcoholic fatty liver disease and cardiovascular diseases: associations and treatment considerations

BACKGROUND

There are increasing data on the association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD).

AIM

To summarise evidence on the association between NAFLD and CVD in the clinical setting and provide potential therapeutic implications.

METHODS

We searched PubMed. Evidence was primarily derived from meta-analyses. and then, if data were insufficient, from clinical trials, and then from observational studies.

RESULTS

NAFLD has been linked to arterial hypertension, arterial stiffness, atherosclerosis, coronary artery disease, atrial fibrillation and aortic valvular sclerosis. Advanced liver fibrosis is a crucial prognostic factor for end-stage liver disease and for cardiovascular and overall mortality. Weight loss through lifestyle modifications (diet and exercise) remains the cornerstone of the management of both NAFLD and CVD, but is difficult to achieve and possibly more difficult to sustain long term. Therefore, pharmacological management of NAFLD seems to be important, although no licenced medication currently exists. Pioglitazone, proposed for non-alcoholic steatohepatitis (NASH) by most guidelines, increases weight and should be avoided in congestive heart failure. Statins should not be avoided in NAFLD patients at risk for CVD. Glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter-2 inhibitors, two classes of anti-diabetic drugs, have shown promising results in NAFLD and CVD, but more studies with hard end points are needed. Obeticholic acid, a promising medication for NASH under investigation, should be carefully considered, owing to its adverse effect on lipid profile.

CONCLUSIONS

NAFLD is associated with CVD, which may have certain clinical and therapeutic implications.

Sodium-glucose co-transporter 2 inhibitors in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is considered the most prevalent chronic hepatic disease, as it has been estimated that one of four individuals in the general population has been affected by NAFLD. The evolution of the referred entity, which includes nonalcoholic steatohepatitis (NASH) and hepatic fibrosis, may have crucial and even fatal consequences, leading to cirrhosis and hepatocellular carcinoma. Although NAFLD has also been linked with cardiovascular and renal diseases, and all-cause mortality increment, pharmacological therapy is as yet an unfulfilled demand. Since NAFLD is closely associated with type 2 diabetes mellitus (T2DM), a variety of anti-diabetic drugs have been investigated for their effectiveness towards NAFLD. Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) improve blood glucose levels through increasing renal glucose excretion and they are recommended as one of standard therapeutic categories for T2DM patients. Based on preclinical animal studies, SGLT-2i have shown a beneficial effect on NAFLD, inducing histologically proven amelioration of hepatic steatosis, inflammation and fibrosis. Promising data have been also derived by clinical trials, which have indicated a potentially beneficial effect of SGLT-2i on NAFLD, at least in terms of liver function tests and imaging. Thus, it is not strange that there are many ongoing trials on the effect of various SGLT-2i in NAFLD. In conclusion, current evidence concerning the effect of SGLT-2i on NAFLD is encouraging; however, data from ongoing clinical trials with histological endpoints are awaited.

Prevalence of asymptomatic bronchiectasis and associations among the health screening population in South Korea

Despite the burden of bronchiectasis, there is little data from South Korea regarding asymptomatic bronchiectasis. We aimed to investigate the prevalence of bronchiectasis based on computed tomography (CT) findings, with emphasis on asymptomatic bronchiectasis (CT-proven) and its related factors. We analysed data of individuals who underwent chest CT at a South Korean health screening centre from 2016 to 2017. The prevalence of bronchiectasis was evaluated and adjusted by sex, age, and corresponding year for the Korean general population. Logistic regression analysis was performed to identify factors related to asymptomatic bronchiectasis by comparison between a group without bronchiectasis and a group with symptomatic bronchiectasis. Among the 27 617 subjects screened, 1005 were diagnosed with bronchiectasis based on CT findings, representing an adjusted prevalence of 2329 out of 100 000. The adjusted prevalence of asymptomatic bronchiectasis was 1235 out of 100 000, and that of symptomatic bronchiectasis was 1094 out of 100 000. Compared with the non-bronchiectasis group, the factors related to asymptomatic bronchiectasis were female sex (OR 1.41; 95% CI 1.18-1.70), older age (OR 1.06; 95% CI 1.05-1.07), comorbid liver disease (OR 1.32; 95% CI 1.07-1.63) or COPD (OR 4.99; 95% CI 2.88-8.64), history of tuberculosis (OR 1.98; 95% CI 1.46-2.68) and low forced expiratory volume in 1 s (FEV₁; OR 0.99; 95% CI 0.98-0.998). In South Korea, the prevalence of asymptomatic bronchiectasis appeared higher than that of symptomatic bronchiectasis. Female sex, older age, liver disease, COPD, history of tuberculosis and low FEV₁ may be the factors related to asymptomatic bronchiectasis.

New insight and potential therapy for NAFLD: CYP2E1 and flavonoids

Over the years, the prevalence of nonalcoholic fatty liver disease (NAFLD) has increased year by year; however, due to its complicated pathogenesis, there is no effective treatment so far. It is reported that Cytochrome P450 2E1 (CYP2E1) plays an indispensable role in the development of NAFLD, and numerous studies have shown that flavonoids have a hepatoprotective effect and can exert a beneficial effect on NAFLD by regulating the activity of CYP2E1. Therefore, flavonoids may become effective drugs for the treatment of NAFLD in the future. This prompted us to review the research progress of the pathological mechanism of NAFLD and the impact of CYP2E1 activity changes during the pathological process, and to summarize the protective effect of flavonoids against CYP2E1 activity.

The protective effect of shrimp cooked in different methods on high-cholesterol- induced fatty liver in rats

This study examined the impact of different cooking methods on fatty acid (FAs) composition of shrimp meat and the ability of these foods to protect against high cholesterol (HC) diet-induced non-alcoholic fatty liver disease (NAFLD) in rats. Shrimp were cooked for 10 min boiled, grilled, or fried in sunflower oil. Rats (n = 6/group) were fed a normal diet (ND)or high-cholesterol diet (HC) each containing boiled, grilled or fried shrimp powder (15% w/w) (NDBS, NDFS, NDGS for ND or HCBS, HCFS, HCDGS for HC diet). Frying alone significantly reduced total levels of saturated FAs (SFA) and increased total mono- and polyunsaturated FAs (MSFA, and PUFAs, respectively) in shrimp meat. It also increased levels of n-6 PUFAs and linoleic acid (LA) and decreased levels of n-3 PUFAs including eicosapentaenoic FAs (EPA) and docosahexaenoic fatty acid (DHA). When fed to HC rats, only diets containing the grilled and boiled shrimp powders significantly prevented the weight loss, lowered fasting and glucose levels, improved glucose and insulin tolerance, and prevented the increase in serum liver markers, ALT and AST. They also reduced hepatic fat accumulation, reduced serum levels and hepatic levels of cholesterol and triglycerides (TGs), reduced hepatic levels of MDA, tumor necrosis factor-alpha (TNF-α), and IL-6, and increased those of glutathione (GSH) and superoxide dismutase (SOD). No alterations in all these parameters were observed in HC-fed rats which fed fried shrimp. In conclusion, boiling and grilling but not frying are the best method to cook shrimp to preserve their fatty acid content and its nutritional value in ameliorating NAFLD.

Epidemiology, Pathogenesis, Diagnosis and Emerging Treatment of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, with an estimated rising prevalence, in concert with the epidemics of obesity and type 2 diabetes. The pathogenesis of NAFLD is not fully elucidated. Besides weight gain and insulin resistance, many other factors seem to contribute, including adipokines, gut microbiota and genetic predisposition. The disease starts as hepatic steatosis, which may proceed to nonalcoholic steatohepatitis (NASH); if fibrosis is added, the risk of cirrhosis and/or hepatocellular carcinoma is augmented. Liver biopsy is considered the gold standard for the diagnosis and staging of NAFLD; the early use of reliable and easily applied diagnostic tools, such as noninvasive biomarkers, is needed to identify patients at different-preferably early-stages of disease however. Whilst lifestyle modification is the first step to manage NAFLD, there is poor compliance, leading to the need of drug therapy. Accordingly, a variety of medications is under investigation. Given the multifaceted pathophysiology of NAFLD, probably, a combination of approaches in an individualized basis may be a more appropriate management. This review summarizes evidence on the epidemiology, pathogenesis, diagnosis and treatment of NAFLD.

Comparative effectiveness of glucagon-like peptide-1 receptor agonists versus dipeptidyl peptidase-4 inhibitors on noninvasive indices of hepatic steatosis and fibrosis in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with type 2 diabetes mellitus (T2DM). There is currently no approved treatment for NAFLD. The main aim was the evaluation of the effect of glucagon-like peptide-1 receptor agonists (GLP-1 RA) vs. dipeptidyl peptidase-4 inhibitor (DPP-4i) treatment on noninvasive indices of hepatic steatosis and fibrosis in patients with T2DM.

METHODS

In this retrospective study, three noninvasive indices of hepatic steatosis [HSI, NAFLD ridge score, and triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) ratio] and five of fibrosis (APRI, FIB-4, NAFLD fibrosis score, BAAT and BARD) were calculated before and after (6-18 months) the addition of a DPP-4i (n = 152) or a GLP-1 RA (n = 37) in patients with T2DM.

RESULTS

Regarding steatosis indices, NAFLD ridge score was significantly decreased in the GLP-1 RA group (baseline: 0.90 ± 0.34, follow-up: 0.67 ± 0.24; p = 0.001), but not in the DPP-4i group (p = 0.25); the difference for group∗time interaction was significant (p = 0.02). HSI showed a trend between groups, being significantly different at baseline and follow-up (p < 0.001) with no significant difference in group∗time interaction. Indices of fibrosis were not essentially changed within or between groups.

CONCLUSIONS

NAFLD ridge score was significantly decreased after the addition of GLP-1 RA in patients with T2DM. This study warrants further prospective clinical trials.

Making progress in nonalcoholic fatty liver disease (NAFLD) as we are transitioning from the era of NAFLD to dys-metabolism associated fatty liver disease (DAFLD)

• This is a special issue of “Metabolism” dedicated to nonalcoholic fatty liver disease. • Experts in the field provide an overview of recent progress and developments in NAFLD and offer their expert opinion on future directions. • NAFLD remains a highly prevalent disease without an approved treatment.

The effect of adiponectin in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) and the potential role of polyphenols in the modulation of adiponectin signaling

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide, as it affects up to 30 % of adults in Western countries. Moreover, NAFLD is also considered an independent risk factor for cardiovascular diseases. Insulin resistance and inflammation have been identified as key factors in the pathophysiology of NAFLD. Although the mechanisms associated with the development of NAFLD remain to be fully elucidated, a complex interaction between adipokines and cytokines appear to play a crucial role in the development of this condition. Adiponectin is the most common adipokine known to be inversely linked with insulin resistance, lipid accumulation, inflammation and NAFLD. Consequently, the focus has been on the use of new therapies that may enhance hepatic expression of adiponectin downstream targets or increase the serum levels of adiponectin in the treatment NAFLD. While currently used therapies show limited efficacy in this aspect, accumulating evidence suggest that various dietary polyphenols may stimulate adiponectin levels, offering potential protection against the development of insulin resistance, inflammation and NAFLD as well as associated conditions of metabolic syndrome. As such, this review provides a better understanding of the role polyphenols play in modulating adiponectin signaling to protect against NAFLD. A brief discussion on the regulation of adiponectin during disease pathophysiology is also covered to underscore the potential protective effects of polyphenols against NAFLD. Some of the prominent polyphenols described in the manuscript include aspalathin, berberine, catechins, chlorogenic acid, curcumin, genistein, piperine, quercetin, and resveratrol.

The therapeutic potential of C-C chemokine receptor antagonists in nonalcoholic steatohepatitis

Pooled prevalence of nonalcoholic fatty liver disease (NAFLD) globally is about 25%. Nonalcoholic steatohepatitis (NASH) with advanced fibrosis has been linked with substantial morbidity and mortality, without having to-date any licensed treatment. C-C chemokine receptor (CCR) antagonists have been investigated as candidates for the treatment of NASH. Inhibition of CCR2 is expected to mitigate hepatic inflammation, through reducing the activation of Kupffer cells, as well as the infiltration of monocytes and macrophages into the liver. Inhibition of CCR5 is expected to mitigate hepatic fibrogenesis, through impairing the activation of hepatic stellate cells, as well as to mitigate hepatic inflammation, through impairing the activation of Kupffer cells and macrophages. Cenicriviroc (CVC) is the first in class, dual inhibitor of CCR2 and CCR5. After exhibiting favorable results in animal models, CVC was shown to be beneficial in NASH patients with more severe fibrosis at a phase 2b trial (CENTAUR) and is currently at a phase 3 clinical trial (AURORA). Apart from CVC, other CCR5 mono-antagonists, such as maraviroc, are under evaluation in clinical trials with human immunodeficiency virus patients with NAFLD. The aim of this review was to summarize existing evidence on CVC and other CCR antagonists in NASH patients, primarily focusing on their clinical efficacy and safety.

Menopause and Non-Alcoholic Fatty Liver Disease: A Review Focusing on Therapeutic Perspectives

There is increasing evidence that menopause is associated with the progression and severity of non-alcoholic fatty liver disease (NAFLD). Estrogen deficiency worsens non-alcoholic steatohepatitis (NASH) in mice models with fatty liver. The prevalence of NAFLD seems to be higher in postmenopausal compared with premenopausal women. Although more data are needed, lower serum estradiol levels are associated with NASH in postmenopausal women. Apart from estrogen deficiency, relative androgen excess and decrease in sex hormone-binding protein are observed in postmenopausal women. These hormonal changes seem to interplay with an increase in abdominal adipose mass, also observed in postmenopausal women, and aging, which are both closely related to the severity and progressive forms of NAFLD. NAFLD adds extra morbidity to postmenopausal women, possibly increasing the risk of type 2 diabetes mellitus and cardiovascular disease. Improving parameters of the metabolic syndrome via modifications in diet and physical exercise may reduce the risk of NAFLD and its related morbidity. Limited studies have shown a beneficial effect of hormone replacement therapy (HRT) on NAFLD, although adverse hepatic effects have been attributed to progesterone in one study. Phytoestrogens may be alternatives to HRT, but their long-term efficacy and safety remain to be shown. The aim of this review was to summarize evidence linking menopause with NAFLD with a special focus on potential therapeutic perspectives.

Effect of garlic powder supplementation on hepatic steatosis, liver enzymes and lipid profile in patients with non-alcoholic fatty liver disease: a double-blind randomised controlled clinical trial

Non-alcoholic fatty liver disease (NAFLD) includes a range of disorders from simple steatosis to non-alcoholic steatohepatitis. There is no proven drug treatment for NAFLD, and diet modification is considered part of the main line of treatment for this disease. The aim of this study was to investigate the efficacy of garlic supplementation in NAFLD patients. The effect of garlic powder supplementation on hepatic steatosis, liver enzymes and lipid profile was investigated in NAFLD patients. Ninety NAFLD patients were randomly assigned to take either a garlic powder supplement or a placebo for 12 weeks. The treatment group received four tablets of garlic daily (each tablet contained 400 mg garlic powder). The control group received four tablets of placebo (each placebo contained 400 mg starch). At the end of the study, hepatic steatosis was significantly reduced in the treatment group compared with the control group (P = 0·001). In addition, a significant decrease was seen in the serum concentration of alanine transaminase (P < 0·001), aspartate transaminase (P = 0·002), γ-glutamyltransferase (P = 0·003) as well as total cholesterol (P = 0·009), TAG (P < 0·001), HDL-cholesterol (P < 0·001) and LDL-cholesterol (P = 0·01) in the treatment group compared with the control group. No significant difference was seen between the two groups in serum concentration of alkaline phosphatase. Overall, garlic powder supplementation improved hepatic features and lipid profile among NAFLD patients.

Selenium and selenoprotein P in nonalcoholic fatty liver disease

Conflicting data link nonalcoholic fatty liver disease (NAFLD), a disease with no currently approved treatment, with selenium (Se) and selenoprotein P (SELENOP), a glycoprotein synthesized and primarily secreted by the hepatocytes, functioning as a Se transporter from the liver to other tissues. This review aims to summarize the evidence between Se, SELENOP, and NAFLD, which may hopefully clarify whether current data on Se and SELENOP in NAFLD warrant further investigation for their diagnostic and therapeutic potential. Most, albeit not all, experimental data show a favorable effect of Se on hepatic steatosis, inflammation, and fibrosis. It seems that Se may exert an antioxidant effect on the liver, at least partly via increasing the activity of glutathione peroxidase, whose depletion contributes to the pathogenesis of hepatic inflammation and fibrosis. Se may also affect metalloproteinases, cytokines, and growth factors participating in the pathogenesis of NAFLD and, most importantly, may induce the apoptosis of hepatic stellate cells, the key players in hepatic fibrosis. However, the association between Se or SELENOP and insulin resistance, which is a principal pathogenetic factor of NAFLD, remains inconclusive. Clinical studies on Se or SELENOP in NAFLD are conflicting, apart from those in advanced liver disease (cirrhosis or hepatocellular carcinoma), in which lower circulating Se and SELENOP are constant findings. Existing data warrant further mechanistic studies in valid animal models of human NAFLD. Prospective cohort studies and possibly randomized controlled trials are also needed to elucidate the diagnostic and therapeutic potential of Se supplementation in selected NAFLD individuals with Se deficiency.

Targeted Analysis of Three Hormonal Systems Identifies Molecules Associated with the Presence and Severity of NAFLD

AIMS

To investigate circulating levels and liver gene expression of 3 hormonal pathways associated with obesity, insulin resistance, and inflammation to identify leads towards potential diagnostic markers and therapeutic targets in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

We compared circulating levels of (1) proglucagon-derived hormones (glucagon-like peptide [GLP]-1, GLP-2, glicentin, oxyntomodulin, glucagon, major proglucagon fragment [MPGF]), (2) follistatins-activins (follistatin-like [FSTL]3, activin B), (3) IGF axis (insulin-like growth factor [IGF]-1, total and intact IGF binding protein [IGFBP]-3 and IGFBP-4, and pregnancy-associated plasma protein [PAPP]-A) in 2 studies: (1) 18 individuals with early stage NAFLD versus 14 controls (study 1; early NAFLD study) and in (2) 31 individuals with biopsy proven NAFLD (15 with simple steatosis [SS] and 16 with nonalcoholic steatohepatitis [NASH]), vs 50 controls (24 lean and 26 obese) (study 2). Liver gene expression was assessed in 22 subjects (12 controls, 5 NASH, 5 NASH-related cirrhosis).

RESULTS

Patients in early stages of NAFLD demonstrate higher fasting MPGF and lower incremental increase of glicentin during oral glucose tolerance test than controls. In more advanced stages, FSTL3 levels are higher in NASH than simple steatosis and, within NAFLD patients, in those with more severe lobular and portal inflammation. The IGF-1/intact IGFBP-3 ratio is lower in patients with liver fibrosis. Genes encoding follistatin, activin A, activin B, and the IGF-1 receptor are higher in NASH.

CONCLUSION

MPGF and glicentin may be involved in early stages of NAFLD, whereas FSTL3 and IGF-1/intact IGFBP3 in the progression to NASH and liver fibrosis respectively, suggesting potential as diagnostic markers or therapeutic targets.

Nonalcoholic fatty liver disease in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects 6-15% of women of reproductive age. Nonalcoholic fatty liver disease (NAFLD) affects 25-30% of the general population and its prevalence increases in parallel with the epidemics of obesity and type 2 diabetes mellitus. A growing body of evidence suggests that NAFLD and PCOS quite often co-exist. The aim of this article is to summarize and critically appraise the literature regarding: (1) the rates of co-existence of the two entities, (2) the possible pathophysiological links, (3) the proper diagnostic assessment and (4) the appropriate management of women with NAFLD and PCOS. Data from clinical studies and meta-analyses indicate a higher prevalence of NAFLD in women with PCOS ranging from 34% to 70% compared with 14% to 34% in healthy women. Inversely, women with NAFLD are more often diagnosed with PCOS. Insulin resistance (IR) and hyperandrogenism are two main potential pathophysiological links between the two entities. In this regard, IR seems to interplay with obesity and hyperandrogenism, thus affecting NAFLD and PCOS and being affected by them. Women with PCOS, particularly those with IR and/or hyperandrogenism, are suggested to be screened for NAFLD, while premenopausal women with NAFLD is suggested to be screened for PCOS. Lifestyle recommendations with a change in dietary habits, weight loss and exercise, constitute currently the cornerstone of the management of both NAFLD and PCOS. Insulin sensitizers maybe used for the treatment of these women, while there are limited promising data for the use of liraglutide.

Farnesoid X nuclear receptor agonists for the treatment of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) affects 20-40% of the general population. Despite significant disease burden and mortality associated with advanced disease, i.e., nonalcoholic steatohepatitis (NASH), there is currently no approved medication for NASH. Farnesoid X receptor agonists have been investigated as candidates for the treatment of NASH. Obeticholic acid, approved for the treatment of primary biliary cholangitis, has gained significant attention after showing promising results in patients with NASH and fibrosis. Three trials investigating the effect of obeticholic acid in patients with NASH have been completed and the preliminary results of an ongoing one have also been made public. Generally, treatment with obeticholic acid improved hepatic histology, including inflammation and fibrosis, the latter being the main histological predictor of advanced disease. Nonetheless, there were adverse effects, the most common being pruritus and unfavorable changes in the lipid profile. Pruritus led to discontinuation of treatment in some patients. Obeticholic acid, however, is not the only farnesoid X receptor agonist currently investigated for the treatment of NASH. Another farnesoid X receptor agonist, cilofexor, in combination with firsocostat, an acetyl-CoA carboxylase inhibitor, improved hepatic steatosis, liver stiffness, liver function tests and serum fibrosis markers, without causing pruritus after 12 weeks of treatment. In conclusion, current evidence regarding the effect of farnesoid X receptor agonists on hepatic histology in patients with NASH is promising, but several safety issues need further evaluation.

Fatty liver in lipodystrophy: A review with a focus on therapeutic perspectives of adiponectin and/or leptin replacement

Lipodystrophy is a group of clinically heterogeneous, inherited or acquired, disorders characterized by complete or partial absence of subcutaneous adipose tissue that may occur simultaneously with the pathological, ectopic, accumulation of fat in other regions of the body, including the liver. Fatty liver adds significantly to hepatic and extra-hepatic morbidity in patients with lipodystrophy. Lipodystrophy is strongly associated with severe insulin resistance and related comorbidities, such as hyperglycemia, hyperlipidemia and nonalcoholic fatty liver disease (NAFLD), but other hepatic diseases may co-exist in some types of lipodystrophy, including autoimmune hepatitis in acquired lipodystrophies, or viral hepatitis in human immunodeficiency virus (HIV)-associated lipodystrophy. The aim of this review is to summarize evidence linking lipodystrophy with hepatic disease and to provide a special focus on potential therapeutic perspectives of leptin replacement therapy and adiponectin upregulation in lipodystrophy.

Obesity and nonalcoholic fatty liver disease: From pathophysiology to therapeutics

The obesity epidemic is closely associated with the rising prevalence and severity of nonalcoholic fatty liver disease (NAFLD): obesity has been linked not only with simple steatosis (SS), but also with advanced disease, i.e., nonalcoholic steatohepatitis (NASH), NASH-related cirrhosis and hepatocellular carcinoma. As a consequence, apart from increasing all-cause mortality, obesity seems to increase liver-specific mortality in NAFLD patients. Given the lack of approved pharmacological interventions for NAFLD, targeting obesity is a rational option for its management. As the first step, lifestyle modification (diet and exercise) is recommended, although it is difficult to achieve and sustain. When the first step fails, adding pharmacotherapy is recommended. Several anti-obesity medications have been investigated in NAFLD (e.g., orlistat, glucagon-like peptide-1 analogs), other anti-obesity medications have not been investigated (e.g., lorcaserin, phentermine hydrochloric, phentermine/topiramate and naltrexone/bupropion), whereas some medications with weight-lowering efficacy have not been approved for obesity (e.g., sodium-glucose cotransporter-2 inhibitors, farnesoid X receptor ligands). If the combination of lifestyle modification and pharmacotherapy also fails, then bariatric surgery should be considered in selected morbidly obese individuals. This review summarizes best evidence linking obesity with NAFLD and presents related therapeutic options.

Noggin levels in nonalcoholic fatty liver disease: the effect of vitamin E treatment

AIM

The evaluation of (a) noggin levels in patients with simple steatosis (SS) vs. nonalcoholic steatohepatitis (NASH) vs. controls, and (b) the effect of combined spironolactone plus vitamin E vs. vitamin E monotherapy on noggin levels in biopsy-proven patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

In the case-control study, 15 patients with SS, 16 with NASH, and 24 controls were included. In the randomized controlled trial, NAFLD patients were assigned to vitamin E (400 IU/d) or spironolactone (25 mg/d) plus vitamin E for 52 weeks.

RESULTS

Noggin levels were lower in SS (5.8 ± 1.5 pmol/l) and NASH (8.7 ± 2.4 pmol/l) patients than in controls (13.7 ± 2.7 pmol/l; p for trend = 0.040), but were similar in SS and NASH patients. After adjustment for potential cofounders, log(noggin) remained different between groups. Log(noggin) levels similarly increased post-treatment in both groups: log(noggin) was not different between groups (p = 0.20), but increased within groups over time (p < 0.001), without a significant group × time interaction (p = 0.62). Log(noggin) significantly increased at month 2 post-treatment (p = 0.008 vs. baseline) and remained stable thereafter.

CONCLUSIONS

Lower noggin levels were observed in NAFLD patients than in controls. Noggin levels increased similarly by either combined low-dose spironolactone plus vitamin E or vitamin E monotherapy.

TRIAL REGISTRATION

NCT01147523.

Therapeutic inhibition of spleen tyrosine kinase in inflammatory macrophages using PLGA nanoparticles for the treatment of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the leading cause of cirrhosis worldwide and the most rapidly growing indication for liver transplantation. Macrophages are the important cellular component in the inflammatory milieu in NASH. Inflammatory and pro-fibrotic mediators produced by macrophages causes significant tissue injury in many inflammatory diseases. Therefore, inhibition of the inflammatory macrophages would be a promising approach to attenuate NASH. In this study, we studied the implication of SYK pathway in NASH, and investigated PLGA nanoparticles-based delivery of SYK pathway inhibitor as an effective and promising therapeutic approach for the treatment of NASH. We found positive correlation between SYK expression with the pathogenesis of NASH and alcoholic hepatitis in patients. Importantly, SYK expression was significantly induced in M1-differentiated inflammatory macrophages. To inhibit SYK pathway specifically, we used a small-molecule inhibitor R406 that blocks Fc-receptor signaling pathway and reduces immune complex-mediated inflammation. R406 dose-dependently inhibited nitric-oxide release and M1-specific markers in M1-differentiated macrophages. Thereafter, we synthesized PLGA nanoparticles to deliver R406 to increase the drug pharmacokinetics for the efficient treatment of NASH. We investigated the therapeutic efficacy of R406-PLGA in-vitro in differentiated macrophages, and in-vivo in Methionine-Choline-deficient (MCD)-diet induced NASH mouse model. R406-PLGA inhibited M1-specific differentiation markers in RAW and bone-marrow-derived macrophages. In-vivo, R406 and more strongly R406-PLGA ameliorated fibrosis, inflammation and steatosis in mice. R406 and more significantly R406-PLGA reduced ALT, AST, cholesterol and triglyceride plasma levels. These results suggest that delivery of SYK inhibitor using PLGA nanoparticles can be a potential therapeutic approach for the treatment of Non-alcoholic steatohepatitis.

Polycystic ovarian syndrome (PCOS): Long-term metabolic consequences

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women during their reproductive ages, associated with a plethora of cardiometabolic consequences, with obesity, insulin resistance and hyperandrogenemia playing a major role in the degree of such manifestations. These consequences include increased risk of glucose intolerance and diabetes mellitus (both type 2 and gestational), atherogenic dyslipidemia, systemic inflammation, non-alcoholic fatty liver disease, hypertension and coagulation disorders. Whether this cluster of metabolic abnormalities is also translated in increased cardiovascular disease (CVD) morbidity and mortality in later life, remains to be established. Data so far based on markers of subclinical atherosclerosis as well as retrospective and prospective cohort studies indicate a possible increased CVD risk, mainly for coronary heart disease. Future studies are needed to further elucidate this issue.

Relationship between obstructive lung disease and non-alcoholic fatty liver disease in the Korean population: Korea National Health and Nutrition Examination Survey, 2007-2010

Purpose

Previous studies have shown that progressive forms of non-alcoholic fatty liver disease (NAFLD) occur frequently in patients with obstructive lung disease (OLD). However, few studies have written about this relationship. This study aimed to investigate the relationship between OLD and NAFLD.

Subjects and methods

The Korea National Health and Nutrition Examination Survey is a national population-based, cross-sectional surveillance program that was initiated to assess the health and nutritional status of the Korean population. From 2007 to 2010, 11,738 subjects were enrolled. The subjects were defined as having NAFLD when they had scores higher than -0.640 in a NAFLD liver fat score prediction model, which was a previously validated prediction score. Individuals with forced expiratory volume in one second/forced vital capacity <0.7 were considered to have OLD. The subjects were divided into non-OLD and OLD groups and non-NAFLD and NAFLD groups. All analyses were performed using sample weighting using the complex samples plan.

Results

The prevalences of NAFLD and OLD were 30.2% and 8.9%, respectively. Although not statistically significant, subjects in the NAFLD group involved a higher tendency of having OLD than did those in the non-NAFLD group (8.5% vs 10.0%, respectively, P=0.060). Subjects with OLD showed a higher tendency to have NAFLD than non-OLD subjects (30.0% vs 33.7%, respectively, P=0.060). NAFLD subjects were at higher odds of OLD (odds ratio=1.334; 95% confidence interval=1.108-1.607, P=0.002) than non-NAFLD subjects, after adjusting for age, sex, and smoking history. OLD subjects were at higher odds of NAFLD (odds ratio=1.556; 95% confidence interval=1.288-1.879, P<0.001) than non-OLD subjects, after adjusting for age, sex, and smoking history.

Conclusion

This study showed that NAFLD is related to OLD. Clinicians should be aware of possible liver comorbidities in OLD patients and that extrahepatic disease in NAFLD patients may vary more than previously thought.

Association of Adipokines with Development and Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease affecting 30% of the general population and 40% to 70% of obese individuals. Adipose tissue plays a crucial role in its pathogenesis, as it produces and secretes pro- and anti-inflammatory cytokines called adipokines. Adiponectin and leptin have well-determined actions in terms of NAFLD pathophysiology. Adiponectin deficiency is associated with a pro-inflammatory condition, as it is observed in obesity and other metabolic disorders. On the other hand, increased leptin levels, above the normal levels, act as a pro-inflammatory stimulus. Regarding other adipokines (resistin, visfatin, chemerin, retinol-binding protein 4, irisin), data about their contribution to NAFLD pathogenesis and progression are inconclusive. In addition, pharmacological agents like thiazolidinediones (pioglitazone and rosiglitazone), that are used in the management of NAFLD exert favourable effects on adipokine levels, which in turn may contribute to the improvement of liver function. This review summarizes the current knowledge and developments in the association between adipokines and NAFLD and discusses possible therapeutic implications targeting the modulation of adipokine levels as a potential tool for the treatment of NAFLD.