The severity of non-alcoholic fatty liver disease correlates with high sensitivity C-reactive protein value and is independently associated with increased cardiovascular risk in healthy population

Endotoxin Inflammatory Action on Cells by Dysregulated-Immunological-Barrier-Linked ROS-Apoptosis Mechanisms in Gut-Liver Axis

Our study highlighted the immune changes by pro-inflammatory biomarkers in the gut-liver-axis-linked ROS-cell death mechanisms in chronic and acute inflammations when gut cells are exposed to endotoxins in patients with hepatic cirrhosis or steatosis. In duodenal tissue samples, gut immune barrier dysfunction was analyzed by pro-inflammatory biomarker expressions, oxidative stress, and cell death by flow cytometry methods. A significant innate and adaptative immune system reaction was observed as result of persistent endotoxin action in gut cells in chronic inflammation tissue samples recovered from hepatic cirrhosis with the A-B child stage. Instead, in patients with C child stage of HC, the endotoxin tolerance was installed in cells, characterized by T lymphocyte silent activation and increased Th1 cytokines expression. Interesting mechanisms of ROS-cell death were observed in chronic and acute inflammation samples when gut cells were exposed to endotoxins and immune changes in the gut-liver axis. Late apoptosis represents the chronic response to injury induction by the gut immune barrier dysfunction, oxidative stress, and liver-dysregulated barrier. Meanwhile, necrosis represents an acute and severe reply to endotoxin action on gut cells when the immune system reacts to pro-inflammatory Th1 and Th2 cytokines releasing, offering protection against PAMPs/DAMPs by monocytes and T lymphocyte activation. Flow cytometric analysis of pro-inflammatory biomarkers linked to oxidative stress-cell death mechanisms shown in our study recommends laboratory techniques in diagnostic fields.

Biomarkers of Hepatic Dysfunction and Cardiovascular Risk

PURPOSE OF REVIEW

The objective of this manuscript is to examine the current literature on non-alcoholic fatty liver disease (NAFLD) biomarkers and their correlation with cardiovascular disease (CVD) outcomes and cardiovascular risk scores.

RECENT FINDINGS

There has been a growing appreciation for an independent link between NAFLD and CVD, culminating in a scientific statement by the American Heart Association in 2022. More recently, studies have begun to identify biomarkers of the three NAFLD phases as potent predictors of cardiovascular risk. Despite the body of evidence supporting a connection between hepatic biomarkers and CVD, more research is certainly needed, as some studies find no significant relationship. If this relationship continues to be robust and readily reproducible, NAFLD and its biomarkers may have an exciting role in the future of cardiovascular risk prediction, possibly as risk-enhancing factors or as components of novel cardiovascular risk prediction models.

Therapies for patients with coexisting heart failure with reduced ejection fraction and non-alcoholic fatty liver disease

Heart failure with reduced ejection fraction (HFrEF) and nonalcoholic fatty liver disease (NAFLD) are two common comorbidities that share similar pathophysiological mechanisms. There is a growing interest in the potential of targeted therapies to improve outcomes in patients with coexisting HFrEF and NAFLD. This manuscript reviews current and potential therapies for patients with coexisting HFrEF and NAFLD. Pharmacological therapies, including angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoids receptor antagonist, and sodium-glucose cotransporter-2 inhibitors, have been shown to reduce fibrosis and fat deposits in the liver. However, there are currently no data showing the beneficial effects of sacubitril/valsartan, ivabradine, hydralazine, isosorbide nitrates, digoxin, or beta blockers on NAFLD in patients with HFrEF. This study highlights the importance of considering HFrEF and NAFLD when developing treatment plans for patients with these comorbidities. Further research is needed in patients with coexisting HFrEF and NAFLD, with an emphasis on novel therapies and the importance of a multidisciplinary approach for managing these complex comorbidities.

Association of C-reactive protein with histological, elastographic, and sonographic indices of non-alcoholic fatty liver disease in individuals with severe obesity

BACKGROUND

Inflammation is critical in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). hs-CRP, an inflammatory marker, is considered one of the prognostic predictors of hepatic damage progression in NAFLD in some studies.

METHODS

We assessed the concordance of hs-CRP concentrations and liver steatosis, steatohepatitis, and fibrosis based on elastography, sonography and liver biopsy findings in patients with severe obesity undergoing bariatric surgery.

RESULTS

Among 90 patients, 56.7% showed steatohepatitis and 8.9% severe fibrosis. Hs-CRP were significantly associated with liver histology in an adjusted regression model (OR 1.155, 95% CI 1.029-1.297, p = 0.014; OR 1.155, 1.029-1.297, p = 0.014; OR 1.130, 1.017-1.257, p = 0.024 for steatosis, steatohepatitis, and fibrosis, respectively). The ROC curve, a cutoff of hs-CRP = 7 mg/L, showed a reasonable specificity (76%) for detecting biopsy-proven fibrosis and steatosis.

CONCLUSION

hs-CRP was associated with any degree of histologically diagnosed liver damage, and it had a reasonable specificity for predicting biopsy-proven steatosis and fibrosis in obese individuals. Further studies are needed to identify non-invasive biomarkers that could predict NALFD progression due to the relevant health risks linked to liver fibrosis.

Effect of Dietary Intervention, with or without Cointerventions, on Inflammatory Markers in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease from simple steatosis to nonalcoholic steatohepatitis, with inflammatory cytokines and adipokines identified as drivers of disease progression. Poor dietary patterns are known to promote an inflammatory milieu, although the effects of specific diets remain largely unknown. This review aimed to gather and summarize new and existing evidence on the effect of dietary intervention on inflammatory markers in patients with NAFLD. The electronic databases MEDLINE, EMBASE, CINAHL, and Cochrane were searched for clinical trials which investigated outcomes of inflammatory cytokines and adipokines. Eligible studies included adults >18 y with NAFLD, which compared a dietary intervention with an alternative diet or control (no intervention) group or were accompanied by supplementation or other lifestyle interventions. Outcomes for inflammatory markers were grouped and pooled for meta-analysis where heterogeneity was allowed. Methodological quality and risk of bias were assessed using the Academy of Nutrition and Dietetics Criteria. Overall, 44 studies with a total of 2579 participants were included. Meta-analyses indicated intervention with an isocaloric diet plus supplement was more effective in reducing C-reactive protein (CRP) [standard mean difference (SMD): 0.44; 95% CI: 0.20, 0.68; P = 0.0003] and tumor necrosis factor-alpha (TNF-α) (SMD: 0.74; 95% CI: 0.02, 1.46; P = 0.03) than an isocaloric diet alone. No significant weighting was shown between a hypocaloric diet with or without supplementation for CRP (SMD: 0.30; 95% CI: -0.84, 1.44; P = 0.60) and TNF-α (SMD: 0.01; 95% CI: -0.43, 0.45; P = 0.97). In conclusion, hypocaloric and energy-restricted diets alone or with supplementation, and isocaloric diets with supplementation were shown to be most effective in improving the inflammatory profile of patients with NAFLD. To better determine the effectiveness of dietary intervention alone on a NAFLD population, further investigations of longer durations, with larger sample sizes are required.

Alpha-fetoprotein and high sensitive C-reactive protein levels in Iraqi patients with liver cirrhosis

BACKGROUND

Liver-related death globally is caused mainly by cirrhosis. It is the final grade of extensive liver fibrosis, in which the hepatic architecture is modified. Cirrhosis is a common disease worldwide and can be the end stage for several reasons such as obesity, non-alcoholic fatty liver, alcoholism, viral infection such as viral hepatitis, immune disorders, bile duct obstruction, and metabolic diseases. Alpha-fetoprotein (AFP) is defined as a protein secreted by the germinal yolk sac and liver. AFP level is used as a marker to diagnose inherited disorders and chromosomal anomaly, whereas the high-sensitivity C-reactive protein (hs-CRP) has a separate correlation with NAFLD. Therefore, hs-CRP can be used as a beneficial marker for identifying liver defects.

SUBJECTS AND METHODS

Thirty participants with liver cirrhosis and 30 healthy participants as control (male and female) were enrolled. The participants from Baghdad, Iraq, were enrolled in this study. Blood and serum samples were obtained for the estimation of hemoglobin, serum AFP, and hs-CRP levels.

RESULTS

The pooled data of participants showed that hs-CRP and alpha-fetoprotein levels in the participants with cirrhosis were significantly higher than in the control group, P<0.0001. There were no significant differences in the sexes while considering alpha-fetoprotein, whereas hs-CRP levels were higher in males compared with females.

CONCLUSION

This research shows a significantly high level of hs-CRP and alpha-fetoprotein in patients with liver cirrhosis compared with the control participants. There were non-significant gender differences concerning alpha-fetoprotein with significantly high level of hs-CRP in males compared with females.

Abdominal obesity, chronic inflammation and the risk of non-alcoholic fatty liver disease

OBJECTIVE

The purpose of this study was to evaluate the effect of abdominal obesity and chronic inflammation on risk of non-alcoholic fatty liver disease (NAFLD) among Chinese population.

METHODS

Overall, 50776 staff from the Kailuan Group who participated in and finished physical examinations between 2006 and 2007 were included in the cohort study. Their medical information was collected and they were followed after examination. The correlations of waist-to-height ratio (WHtR) or serum high-sensitivity C-reactive protein (hs-crp) with NAFLD were analyzed. Then, we categorized all participants into four groups: non-abdominal obesity and non-chronic inflammation group, abdominal obesity and non-chronic inflammation group, non-abdominal obesity and chronic inflammation group, abdominal obesity and chronic inflammation group, and non-abdominal obesity and non-chronic inflammation group was used as a control group. The combined effects of abdominal obesity and chronic inflammation with NAFLD were analyzed using the Cox proportional hazard regression model.

RESULTS

After a mean follow-up of 5.59±1.79 years, a total of 15451 NAFLD cases occurred. We found the WHtR and hs-crp increase the risk for NAFLD, respectively. Compared with the non-abdominal obesity and non-chronic inflammation group, the risk of NAFLD was significantly increased in the abdominal obesity and non-chronic inflammation group (HR 1.21, 95%CI 1.11-1.32), non-abdominal obesity and chronic inflammation group (HR 1.32, 95%CI 1.27-1.38), abdominal obesity and chronic inflammation group (HR 1.60, 95% CI 1.52-1.70). And, a significant interaction effect was found of abdominal obesity and chronic inflammation on NAFLD.

CONCLUSION

In this study, it was demonstrated in the Chinese population that both abdominal obesity and chronic inflammation increase the risk of NAFLD, and there is an interaction between the two factors in the incidence of NAFLD.

Intestinal Barrier and Permeability in Health, Obesity and NAFLD

The largest surface of the human body exposed to the external environment is the gut. At this level, the intestinal barrier includes luminal microbes, the mucin layer, gastrointestinal motility and secretion, enterocytes, immune cells, gut vascular barrier, and liver barrier. A healthy intestinal barrier is characterized by the selective permeability of nutrients, metabolites, water, and bacterial products, and processes are governed by cellular, neural, immune, and hormonal factors. Disrupted gut permeability (leaky gut syndrome) can represent a predisposing or aggravating condition in obesity and the metabolically associated liver steatosis (nonalcoholic fatty liver disease, NAFLD). In what follows, we describe the morphological-functional features of the intestinal barrier, the role of major modifiers of the intestinal barrier, and discuss the recent evidence pointing to the key role of intestinal permeability in obesity/NAFLD.

Controversies and Opportunities in the Use of Inflammatory Markers for Diagnosis or Risk Prediction in Fatty Liver Disease

In the Western society, non-alcoholic fatty liver disease (NAFLD), characterized by the excessive accumulation of fat in the liver, represents the most common cause of chronic liver disease. If left untreated, approximately 15%-20% of patients with NAFLD will progress to non-alcoholic steatohepatitis (NASH), in which lobular inflammation, hepatocyte ballooning and fibrogenesis further contribute to a distorted liver architecture and function. NASH initiation has significant effects on liver-related mortality, as even the presence of early stage fibrosis increases the chances of adverse patient outcome. Therefore, adequate diagnostic tools for NASH are needed, to ensure that relevant therapeutic actions can be taken as soon as necessary. To date, the diagnostic gold standard remains the invasive liver biopsy, which is associated with several drawbacks such as high financial costs, procedural risks, and inter/intra-observer variability in histology analysis. As liver inflammation is a major hallmark of disease progression, inflammation-related circulating markers may represent an interesting source of non-invasive biomarkers for NAFLD/NASH. Examples for such markers include cytokines, chemokines or shed receptors from immune cells, circulating exosomes related to inflammation, and changing proportions of peripheral blood mononuclear cell (PBMC) subtypes. This review aims at documenting and critically discussing the utility of such novel inflammatory markers for NAFLD/NASH-diagnosis, patient stratification and risk prediction.

Nonalcoholic Fatty Liver Disease and Cardiovascular Diseases: The Heart of the Matter

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most frequent cause of liver disease worldwide, comprising a plethora of conditions, ranging from steatosis to end-stage liver disease. Cardiovascular disease (CVD) has been associated with NAFLD and CVD-related events represent the main cause of death in patients with NAFLD, surpassing liver-related mortality. This association is not surprising as NAFLD has been considered a part of the metabolic syndrome and has been related to numerous CVD risk factors, namely, insulin resistance, abdominal obesity, dyslipidemia, hyperuricemia, chronic kidney disease, and type 2 diabetes. Moreover, both NAFLD and CVD present similar pathophysiological mechanisms, such as increased visceral adiposity, altered lipid metabolism, increased oxidative stress, and systemic inflammation that could explain their association. Whether NAFLD increases the risk for CVD or these diagnostic entities represent distinct manifestations of the metabolic syndrome has not yet been clarified. This review focuses on the relation between NAFLD and the spectrum of CVD, considering the pathophysiological mechanisms, risk factors, current evidence, and future directions.

The association of the steatosis severity in fatty liver disease with coronary plaque pattern in general population

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is commonly observed in patients with cardiovascular disease (CVD). However, whether the steatosis severity of NAFLD is independently associated with coronary artery atherosclerosis is still controversial.

METHODS

Consecutive Taiwanese individuals (1502) who received coronary computed tomography angiography (CCTA) and abdominal sonography as part of a general routine health evaluation were enrolled. The association between steatosis severity, coronary atherosclerosis involvement and various plaque patterns were analysed.

RESULTS

Compared with non-steatosis, NAFLD subjects had more cardiovascular risk factors that correlated with the severity of steatosis (P for the trend <.05). The presence of atherosclerotic plaques correlated with the severity of steatosis (none: 53%, mild: 64.1%, and moderate to severe: 66.9%; P for the trend <.001). Parameters of coronary atherosclerosis, including atheroma burden obstructive score (ABOS), segment involvement score (SIS) and segment stenosis score (SSS), were higher in the moderate to severe steatosis group. After adjusting for major confounding factors, the severity of steatosis still correlated with the mixed plaque pattern (P = .043). Subgroup analysis of the risk of the presence of overall coronary and mixed plaques showed a significant association with increasing severity of steatosis, especially among these who were <65 years old, male, without metabolic syndrome, and with lower low-density lipoprotein choleseterol values.

CONCLUSION

In this general population, steatosis severity of NAFLD is associated with coronary artery atherosclerosis burden. Furthermore, steatosis severity correlated with the risk of the presence of coronary plaques, especially high-risk plaques, and was independent of traditional risk factors.

Factor analysis for the clustering of cardiometabolic risk factors and sedentary behavior, a cross-sectional study

Background

Few studies have reported on the clustering pattern of CVD risk factors, including sedentary behavior, systemic inflammation, and cadiometabolic components in the general population.

Objective

We aimed to explore the clustering pattern of CVD risk factors using exploratory factor analysis to investigate the underlying relationships between various CVD risk factors.

Methods

A total of 5606 subjects (3157 male, 51.5±11.7 y/o) were enrolled, and 14 cardiovascular risk factors were analyzed in an exploratory group (n = 3926) and a validation group (n = 1676), including sedentary behaviors.

Results

Five factor clusters were identified to explain 69.4% of the total variance, including adiposity (BMI, TG, HDL, UA, and HsCRP; 21.3%), lipids (total cholesterol and LDL-cholesterol; 14.0%), blood pressure (SBP and DBP; 13.3%), glucose (HbA1C, fasting glucose; 12.9%), and sedentary behavior (MET and sitting time; 8.0%). The inflammation biomarker HsCRP was clustered with only adiposity factors and not with other cardiometabolic risk factors, and the clustering pattern was verified in the validation group.

Conclusion

This study confirmed the clustering structure of cardiometabolic risk factors in the general population, including sedentary behavior. HsCRP was clustered with adiposity factors, while physical inactivity and sedentary behavior were clustered with each other.

Association of high-sensitivity C-reactive protein (hs-CRP) with non-alcoholic fatty liver disease (NAFLD) in Asian Indians: A cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is an important etiology for the development of chronic liver disease worldwide. Its pathophysiology includes chronic low-grade inflammation. There are limited studies on the association of inflammatory markers with NAFLD. Hence, in the present research, we aimed to study the association of one such inflammatory marker hs-CRP with NAFLD in north Indian population.

Materials and Methods

For this cross-sectional study, 100 subjects of either sex above 18 years of age, being diagnosed as a case of NAFLD on the basis of ultrasonography and age, sex and BMI matched subjects fulfilling the inclusion and exclusion criteria were included. Anthropometric profile, high-sensitivity C-reactive protein (hs-CRP), HbA1c, and hepatic function tests were recorded.

Results

The baseline variables were matched for age, weight, BMI, waist-hip circumference ratio, and blood pressure. The HbA1c (P < 0.001), alanine aminotransferase (P = 0.002), alkaline phosphatase (0.002), and hs-CRP (P < 0.001) were elevated in subjects with NAFLD. The mean level of hs-CRP was significantly higher in subjects with NAFLD as compared to the control group (3.12 ± 1.42 mg/L vs 1.05 ± 0.44 mg/L, P < 0.001). The mean hs-CRP level was 1.42 ± 0.55 mg/L in grade 1, 0.98 ± 0.72 mg/L in grade 2 with P < 0.001, and 4.5 ± 1.11 mg/L in grade 3 with P < 0.001 when compared to grade 1.The comparative value of hs-CRP in the control group was found to be 1.05 ± 0.44 mg/L. On univariate analysis waist-hip circumference ratio (P = 0.035), HbA1c (P < 0.001), and hs-CRP (P < 0.001), showed a significant association with NAFLD. On logistic regression hs-CRP was found to have significant association with NAFLD even after adjusting waist-hip circumference ratio and HbA1C (odds ratio 1.311, 95% confidence interval 1.146-1.488, P < 0.001).

Conclusion

In this cohort of north Indian population, hs-CRP showed independent relationships with NAFLD. Thus, hs-CRP may be used as a surrogate marker for the disease severity in NAFLD.

The Role of Thyroid Hormones and Autoantibodies in Metabolic Dysfunction Associated Fatty Liver Disease: TgAb May Be a Potential Protective Factor

BACKGROUND

Previous studies have shown that metabolic dysfunction associated fatty liver disease (MAFLD) is associated with thyroid hormones (THs), immunity, and inflammation status, but few studies involved thyroid autoimmunity. This study aimed to evaluate the role of THs, thyroid autoantibodies, inflammatory biomarkers in MAFLD, its cofactors, and other possible determinants.

MATERIALS AND METHODS

In the study, a total of 424 Chinese patients were selected and categorized as non-MAFLD and MAFLD. Serum thyroid hormone, thyroid autoantibody and high-sensitive C-reactive protein (hsCRP) levels were measured. The data of blood pressure, the serum lipid profile, glucose and liver enzymes were collected. The differences and association between research findings were examined and analyzed by Wilcoxon Signed Rank Test, One-Way ANOVA test and Multiple Logistic Regression models.

RESULTS

The study showed significant increase in the prevalence of MAFLD with high thyroid stimulating hormone (TSH) levels (P < 0.01) and abnormal high-sensitive C-reactive protein (hsCRP) levels (P < 0.01). The proportion of MAFLD patients decreased significantly with the rise of free thyroxine (FT4) (P = 0.04), thyrotropin receptor antibodies (TRAb) (P < 0.01), anti-thyroglobulin antibodies (TgAb) (P < 0.01), and thyroid peroxidase antibodies (TPOAb) levels (P < 0.01). Based on logistic regression analysis, MAFLD was significantly associated with lower levels of TgAb (P < 0.01), TPOAb (P < 0.01), and higher levels of hsCRP (P < 0.01) in male. In female, elevated TgAb (P < 0.01) may be a protective factor, while higher levels of hsCRP (P < 0.01) showed increased risk of MAFLD. Logistic models were adjusted for age, BMI, SBP, DBP, FBG, ALT, AST, TC, TG, LDL, HDL.

CONCLUSIONS

Taken together, TgAb may be a potential protective factor for MAFLD and elevated hsCRP level should be considered as an independent risk factor for MAFLD in both genders. TPOAb also demonstrated protective effect, but only in male. The prevalence of MAFLD increased with higher TSH levels and lower FT4, TRAb levels, but no significant association were found. However, Our findings provide a new insight into the pathogenesis of MAFLD by further investigating the impact of THs, thyroid autoimmunity, and inflammation on MAFLD patients.

Gut Dysfunction and Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the leading liver diseases worldwide. NAFLD is characterized by hepatic steatosis and may progress to an inflammatory condition termed non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. It became evident in the last years that NAFLD pathophysiology is complex and involves diverse immunological and metabolic pathways. An association between intestinal signals (e.g., derived from the gut microbiota) and the development of obesity and its metabolic consequences such as NAFLD are increasingly recognized. Pre-clinical studies have shown that germ-free mice are protected against obesity and hepatic steatosis. Several human studies from the past years have demonstrated that NAFLD contains a disease-specific gut microbiome signature. Controlled studies propose that certain bacteria with rather pro-inflammatory features such as Proteobacteria or Escherichia coli are dominantly present in these patients. In contrast, rather protective bacteria such as Faecalibacterium prausnitzii are decreased in NAFLD patients. Furthermore, various bacterial metabolites and microbiota-generated secondary bile acids are involved in NAFLD-associated metabolic dysfunction. Although these findings are exciting, research currently lack evidence that interference at the level of the gut microbiome is beneficial for these diseases. Further preclinical and clinical studies are needed to advance this aspect of NAFLD research and to support the notion that the intestinal microbiota is indeed of major relevance in this disorder.

Effects of SGLT2 inhibitors on systemic and tissue low-grade inflammation: The potential contribution to diabetes complications and cardiovascular disease

Chronic low-grade inflammation is a recognized key feature associated with type 2 diabetes mellitus (T2DM) and its complications. In prospective randomized trials, sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated benefits related to several cardiovascular and renal risk factors, including HbA_1c, blood pressure, body weight, renal hyperfiltration, and improvement of cardiorenal outcomes. SGLT2 inhibitors may improve adipose tissue function and induce decreases in serum leptin, TNF-α and IL-6 while increasing adiponectin. While data on high-sensitivity C-reactive protein and other inflammatory markers are relatively scarce in humans, in animals, a number of reports have shown reductions in cytokine and chemokine concentrations in parallel with protective effects against progression of atherosclerotic lesions. Experimental findings also suggest that part of the renoprotective effects of SGLT2 inhibition may be related to anti-inflammatory actions at the kidney level. Underlying mechanisms to explain this anti-inflammatory effect are multiple, but may involve weight loss, and reduction in adipose tissue inflammation, slight increase in ketone bodies and diminution of uric acid levels or attenuation of oxidative stress. However, further studies in diabetes patients with specific assessment of inflammatory markers are still necessary to determine the specific contribution of the anti-inflammatory action of SGLT2 inhibitors to the reduction of cardiovascular and renal complications and mortality observed with this class of antidiabetic drugs.

Clinical relevance of liver histopathology and different histological classifications of NASH in adults

Nonalcoholic fatty liver disease (NAFLD) encompasses simple steatosis and steatohepatitis (NASH) with or without fibrosis/cirrhosis and hepatocellular carcinoma. NAFLD occurs epidemically in most areas of the world, contributes to cardiovascular events and liver-related mortality and therefore exacts a major economic toll. Areas covered: Here we summarize what clinicians should know about NAFLD histopathology in adults. We report on the individual histological features and scoring systems of NAFLD: the NAFLD activity score (NAS) introduced by the NASH-Clinical Research Network, the 'Fatty Liver Inhibition of Progression' algorithm and Steatosis, Activity, and Fibrosis (SAF) score. Pros and cons of histological classifications in NASH are discussed. Special emphasis is given to liver histopathology in some high-risk patient groups, such as those with severe obesity and type 2 diabetes. Moreover, we also examine the relationship between liver histopathology and clinical features, and the impact of liver histopathology on the long-term prognosis of NAFLD. Finally, we propose an integrated diagnostic approach which utilizes both non-invasive tools and liver biopsy in those individual patients with suspected NAFLD. Expert commentary: Based on expert opinions, we conclude with a research agenda on NAFLD which focuses on the most burning topics to be addressed over the next five years.

Intestinal Microbiome Shifts, Dysbiosis, Inflammation, and Non-alcoholic Fatty Liver Disease

Adverse fluctuations in the distribution of the intestinal microbiome cohort has been associated with the onset of intra- and extra-intestinal inflammatory conditions, like the metabolic syndrome (MetS) and it's hepatic manifestation, non-alcoholic fatty liver disease (NAFLD). The intestinal microbial community of obese compared to lean subjects has been shown to undergo configurational shifts in various genera, including but not limited to increased abundances of Prevotella, Escherichia, Peptoniphilus, and Parabacteroides and decreased levels of Bifidobacteria, Roseburia, and Eubacteria genera. At the phylum level, decreased Bacteroidetes and increased Firmicutes have been reported. The intestinal microbiota therefore presents an important target for designing novel therapeutic modalities that target extra-intestinal inflammatory disorders, such as NAFLD. This review hypothesizes that disruption of the intestinal-mucosal macrophage interface is a key factor in intestinal-liver axis disturbances. Intestinal immune responses implicated in the manifestation, maintenance and progression of NAFLD provide insights into the dialogue between the intestinal microbiome, the epithelia and mucosal immunity. The pro-inflammatory activity and immune imbalances implicated in NAFLD pathophysiology are reported to stem from dysbiosis of the intestinal epithelia which can serve as a source of hepatoxic effects. We posit that the hepatotoxic consequences of intestinal dysbiosis are compounded through intestinal microbiota-mediated inflammation of the local mucosa that encourages mucosal immune dysfunction, thus contributing important plausible insight in NAFLD pathogenesis. The administration of probiotics and prebiotics as a cure-all remedy for all chronic diseases is not advocated, instead, the incorporation of evidence based probiotic/prebiotic formulations as adjunctive modalities may enhance lifestyle modification management strategies for the amelioration of NAFLD.

Effect of Nonalcoholic Fatty Liver Disease on In-Hospital and Long-Term Outcomes in Patients With ST-Segment Elevation Myocardial Infarction

Nonalcoholic fatty liver disease (NAFLD) is a risk factor for coronary artery disease. We investigated the effect of NAFLD grade on in-hospital and long-term outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The study group consisted of 360 patients with STEMI. The patients were classified according to the grade of the NAFLD using ultrasonography. Based on this classification, all patients were divided into 4 subgroups as grade 0 (no fatty liver disease), grade 1, grade 2, and grade 3. Hierarchical logistic regression and Cox proportional regression analysis were used to establish the relation between NAFLD grade and outcomes. In-hospital mortality for grade 0, 1, 2, and 3 NAFLDs were 4.7%, 8.3%, 11.3%, and 33.9%, respectively. Three-year mortality for grade 0, 1, 2, and 3 NAFLDs were 5.6%, 7.8%, 9.5%, and 33.3%, respectively. In the multivariable hierarchical logistic regression analysis, in-hospital mortality risks were higher for patients with grade 3 NAFLD (odds ratio 4.2). In a multivariable Cox proportional regression analysis, the mortality risk was higher for patients with grade 3 NAFLD (hazard ratio 4.0). In conclusion, in patients with STEMI, the presence of NAFLD is associated with unfavorable clinical outcomes. Among these patients, grade 3 NAFLD had the highest mortality rates. The present study supports NAFLD screening in patients with STEMI.

High-normal levels of hs-CRP predict the development of non-alcoholic fatty liver in healthy men

We performed a follow-up study to address whether high sensitivity C-reactive protein (hs-CRP) levels within the normal range can predict the development of non-alcoholic fatty liver disease (NAFLD) in healthy male subjects. Among15347 male workers between 30 and 59 years old who received annual health check-ups in 2002, a NAFLD-free cohort of 4,138 was followed through December 2009. Alcohol consumption was assessed with a questionnaire. At each visit, abdominal ultrasonography was performed to identify fatty liver disease. The COX proportional hazard model was used to evaluate the relationship between hs-CRP and incident NAFLD. During the follow-up period, 28.8% (1191 of 4138) of participants developed NAFLD. The hazard ratios of NAFLD were increased by hs-CRP categories within the normal range in the non-adjusted model and age-adjusted model. After adjusting for age, exercise, smoking, BMI, systolic BP, triglyceride, and fasting glucose, these incidences were only increased between the lowest and the highest hs-CRP categories. The risk for NAFLD increased as the hs-CRP level increased (p< 0.001). As the hs-CRP level increased within the healthy cohort, the risk of developing NAFLD increased. This trend remained true even if the hs-CRP level remained within the normal range. hs-CRP can be used as a predictor of NAFLD, as well as other obesity-associated diseases. Therefore, individuals with higher hs-CRP levels (even within the normal range) may require appropriate follow-up and management to prevent NAFLD development.

Immune Imbalances in Non-Alcoholic Fatty Liver Disease: From General Biomarkers and Neutrophils to Interleukin-17 Axis Activation and New Therapeutic Targets

Non-alcoholic fatty liver disease (NAFLD) is an increasing problem worldwide and is associated with negative outcomes such as cirrhosis, hepatocellular carcinoma, insulin resistance, diabetes, and cardiovascular events. Current evidence shows that the immune response has an important participation driving the initiation, maintenance, and progression of the disease. So, various immune imbalances, from cellular to cytokines levels, have been studied, either for better compression of the disease pathophysiology or as biomarkers for severity assessment and outcome prediction. In this article, we performed a thorough review of studies that evaluated the role of inflammatory/immune imbalances in the NAFLD. At the cellular level, we gave special focus on the imbalance between neutrophils and lymphocytes counts (the neutrophil-to-lymphocyte ratio), and that which occurs between T helper 17 (Th17) and regulatory T cells as emerging biomarkers. By extension, we reviewed the reflection of these imbalances at the molecular level through pro-inflammatory cytokines including those involved in Th17 differentiation (IL-6, IL-21, IL-23, and transforming growth factor-beta), and those released by Th17 cells (IL-17A, IL-17F, IL-21, and IL-22). We gave particular attention to the role of IL-17, either produced by Th17 cells or neutrophils, in fibrogenesis and steatohepatitis. Finally, we reviewed the potential of these pathways as new therapeutic targets in NAFLD.

Association of non-alcoholic fatty liver disease with major adverse cardiovascular events: A systematic review and meta-analysis

Increasing evidence connects non-alcoholic fatty liver disease (NAFLD) to cardiovascular disease (CVD). The aim of this study is to assess whether and to what extent the excess risk of CVD is conferred by NAFLD in a meta-analysis. We systematically searched PubMed, EmBase, Web of Science, and Cochrane Library for reports published between 1965 and July 3, 2015. Studies that reported data on association between NAFLD and adverse cardiovascular events or mortality were included. Thirty-four studies (164,494 participants, 21 cross-sectional studies, and 13 cohort studies) were included. NAFLD was not associated with overall mortality (HR = 1.14, 95% CI: 0.99–1.32) and CVD mortality (HR = 1.10, 95% CI: 0.86–1.41). However, NAFLD was associated with an increased risk of prevalent (OR = 1.81, 95% CI: 1.23–2.66) and incident (HR = 1.37, 95% CI: 1.10–1.72) CVD. For some specific CVDs, NAFLD was associated with an increased risk of prevalent (OR = 1.87, 95% CI: 1.47–2.37) and incident (HR = 2.31, 95% CI: 1.46–3.65) coronary artery disease (CAD), prevalent (OR = 1.24, 95% CI: 1.14–1.36) and incident (HR = 1.16, 95% CI: 1.06–1.27) hypertension, and prevalent (OR = 1.32, 95% CI: 1.07–1.62) atherosclerosis. In conclusion, the presence of NAFLD is associated with an increased risk of major adverse cardiovascular events, although it is not related to mortality from all causes or CVD.

Gene polymorphisms associated with non-alcoholic fatty liver disease and coronary artery disease: a concise review

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease which represents a wide spectrum of hepatic damage. Several studies have reported that NAFLD is a strong independent risk factor for coronary artery disease (CAD). And patients with NAFLD are at higher risk and suggested undergoperiodic cardiovascular risk assessment. Cardiovascular disease (CVD) is responsible for the main cause of death in patients with NAFLD, and is mostly influenced by genetic factors. Both NAFLD and CAD are heterogeneous disease. Common pathways involved in the pathogenesis of NAFLD and CAD includes insulin resistance (IR), atherogenic dyslipidemia, subclinical inflammation, oxidative stress, etc. Genomic characteristics of these two diseases have been widely studied, further research about the association of these two diseases draws attention. The gene polymorphisms of adiponectin-encoding gene (ADIPOQ), leptin receptor (LEPR), apolipoprotein C3 (APOC3), peroxisome proliferator-activated receptors (PPAR), sterol regulatory elementbinding proteins (SREBP), transmembrane 6 superfamily member 2 (TM6SF2), microsomal triglyceride transfer protein (MTTP), tumor necrosis factors-alpha (TNF-α) and manganese superoxide dismutase (MnSOD) have been reported to be related to NAFLD and CAD. In this review, we aimed to provide an overview of recent insights into the genetic basis of NAFLD and CAD.

The Relationship between 10-Year Cardiovascular Risk Calculated Using the Pooled Cohort Equation and the Severity of Non-Alcoholic Fatty Liver Disease

BACKGROUND

We investigated the association between the severity of non-alcoholic fatty liver disease (NAFLD) and the estimated 10-year risk of cardiovascular disease (CVD) calculated by Pooled Cohort Equation (PCE) and Framingham risk score (FRS).

METHODS

A total of 15,913 participants (mean age, 46.3 years) in a health screening program were selected for analysis. The presence and severity of fatty liver was assessed by abdominal ultrasonogram. Subjects who drank alcohol more than three times a week were excluded from the study.

RESULTS

Among the participants, 57.6% had no NAFLD, 35.4% had grade I, 6.5% had grade II, and 0.5% had grade III NAFLD. Mean estimated 10-year CVD risk was 2.59%, 3.93%, 4.68%, and 5.23% calculated using the PCE (P for trend <0.01) and 4.55%, 6.39%, 7.33%, and 7.13% calculated using FRS, according to NAFLD severity from none to severe (P for trend <0.01). The odds ratio for ≥7.5% estimated CVD risk calculated using the PCE showed a higher correlation with increasing severity of NAFLD even after adjustment for conventional CVD risk factors (1.52, 2.56, 3.35 vs. the no NAFLD group as a reference, P<0.01) compared with calculated risk using FRS (1.65, 1.62, 1.72 vs. no NAFLD group as a reference, P<0.01).

CONCLUSION

In our study of apparently healthy Korean adults, increasing severity of NAFLD showed a higher correlation with estimated 10-year CVD risk when calculated using the PCE than when calculated using FRS.

Role of Macrophage Migration Inhibitory Factor in Obesity, Insulin Resistance, Type 2 Diabetes, and Associated Hepatic Co-Morbidities: A Comprehensive Review of Human and Rodent Studies

Obesity is associated with a chronic low-grade inflammatory state that drives the ­development of obesity-related co-morbidities such as insulin resistance/type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular disease. This metabolic inflammation is thought to originate in the adipose tissue, which becomes inflamed and insulin resistant when it is no longer able to expand in response to excess caloric and nutrient intake. The production of inflammatory mediators by dysfunctional adipose tissue is thought to drive the development of more complex forms of disease such as type 2 diabetes and NAFLD. An important factor that may contribute to metabolic inflammation is the cytokine macrophage migration inhibitory factor (MIF). Increasing evidence suggests that MIF is released by adipose tissue in obesity and that it is also involved in metabolic and inflammatory processes that underlie the development of obesity-related pathologies. This review provides a comprehensive summary of our current knowledge on the role of MIF in obesity, its production by adipose tissue, and its involvement in the development of insulin resistance, type 2 diabetes, and NAFLD. We discuss the main findings from recent clinical studies in obese subjects and weight-loss intervention studies as well as results from clinical studies in patients with insulin resistance and type 2 diabetes. Furthermore, we summarize findings from experimental disease models studying the contribution of MIF in obesity and insulin resistance, type 2 diabetes, and hepatic lipid accumulation and fibrosis. Although many of the findings support a pro-inflammatory role of MIF in disease development, recent reports also provide indications that MIF may exert protective effects under certain conditions.

High-risk coronary plaque at coronary CT angiography is associated with nonalcoholic fatty liver disease, independent of coronary plaque and stenosis burden: results from the ROMICAT II trial

PURPOSE

To determine the association between nonalcoholic fatty liver disease (NAFLD) and the presence of high-risk coronary atherosclerotic plaque as assessed with coronary computed tomographic (CT) angiography.

MATERIALS AND METHODS

This study was approved by the local ethics committees; informed consent was obtained. Patients randomized to the coronary CT angiography arm of the Rule Out Myocardial Infarction using Computer Assisted Tomography, or ROMICAT, II trial who underwent both nonenhanced CT to assess calcium score and contrast material-enhanced coronary CT angiography were included. Readers assessed coronary CT angiography images for the presence of coronary plaque, significant stenosis (≥50%), and high-risk plaque features (positive remodeling, CT attenuation < 30 HU, napkin-ring sign, spotty calcium). NAFLD was defined as hepatic steatosis at nonenhanced CT (liver minus spleen CT attenuation < 1 HU) without evidence of clinical liver disease, liver cirrhosis, or alcohol abuse. To determine the association between high-risk plaque and NAFLD, univariable and multivariable logistic regression analyses were performed, with high-risk plaque as a dependent variable and NAFLD, traditional risk factors, and extent of coronary atherosclerosis as independent variables.

RESULTS

Overall, 182 (40.9%) of 445 patients had CT evidence of NAFLD. High-risk plaque was more frequent in patients with NAFLD than in patients without NAFLD (59.3% vs 19.0%, respectively; P < .001). The association between NAFLD and high-risk plaque (odds ratio, 2.13; 95% confidence interval: 1.18, 3.85) persisted after adjusting for the extent and severity of coronary atherosclerosis and traditional risk factors.

CONCLUSION

NAFLD is associated with advanced high-risk coronary plaque, independent of traditional cardiovascular risk factors and the extent and severity of coronary artery disease.

Nonalcoholic fatty liver disease and bariatric surgery in adolescents

Obesity is a multi-organ system disease with underlying insulin resistance and systemic chronic inflammation. Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of the underlying metabolic dysfunction. This review provides a highlight of the current understanding of NAFLD pathogenesis and disease characteristics, with updates on the challenges of NAFLD management in obese and severely obese (SO) patients and recommendations for the pediatric surgeons' role in the care of SO adolescents.

The liver and the kidney: two critical organs influencing the atherothrombotic risk in metabolic syndrome

The increased atherothrombotic risk in patients with metabolic syndrome (MetS) has been classically explained by the multiplicative effect of systemic concomitant pro-atherosclerotic factors. In particular, centripetal obesity, dyslipidaemia, glucose intolerance, hypertension (differently combined in the diagnosis of the disease) would be expected to act as classical cardiovascular risk conditions underlying accelerated atherogenesis. In order to better understand specific atherosclerotic pathophysiology in MetS, emerging evidence focused on the alterations in different organs that could serve as both pathophysiological targets and active players in the disease. Abnormalities in adipose tissue, heart and arteries have been widely investigated in a variety of basic research and clinical studies in MetS. In this narrative review, we focus on pathophysiological activities of the liver and kidney. Considering its key role in metabolism and production of soluble inflammatory mediators (such as C-reactive protein [CRP]), the liver in MetS has been shown to be altered both in its structure and function. In particular, a relevant amount of the fat accumulated within this organ has been shown to be associated with different degrees of inflammation and potential insulin resistance. In humans, non-alcoholic fatty liver disease (NAFLD) has been described as the hepatic manifestation of MetS. In an analogous manner, epidemiological evidence strongly suggested a "guilty" association between MetS and chronic kidney disease (CKD). Some biomarkers of hepatic (such as C-reactive protein, TNF-alpha or other cytokines) and renal diseases (such as uric acid) associated with MetS might be particularly useful to better manage and prevent the atherothrombotic risk.

Moderate oxidative stress and high antioxidative activity are associated with steatosis in Japanese males

BACKGROUND AND AIM

Steatosis is an increasingly common problem worldwide, accompanying increasing obesity. Recently, it has been suggested that oxidative stress plays an important role in development of fatty liver disease. We carried out an epidemiological study to clarify the role of oxidative stress and antioxidative activity in steatosis.

METHODS

This study was conducted with 184 male workers who had received their annual health checkup. Steatosis was confirmed using ultrasonography. Oxidative stress and antioxidative activity were assessed using the dROM test and the BAP test, respectively.

RESULTS

Steatosis was confirmed in 59 subjects (29.7%) by ultrasonography. There was no significant difference between cases and controls in BAP levels (2229.0 μmol/L vs. 2194.3μmol/L, p = 0.83). The steatosis group showed significantly lower dROM levels than the control group (332.7 U. CARR vs. 316.8 U. CARR, p < 0.05). In addition, we carried out logistic regression analysis to assess the combination between dROM levels and BAP levels. Subjects with high dROM levels and high BAP levels had 74% lower risk for steatosis than subjects with low dROM levels and high BAP levels.

CONCLUSIONS

Our results suggested that moderate oxidative stress and high antioxidative activity was associated with decreased steatosis risk in Japanese males.

Nonalcoholic fatty liver disease and vascular risk

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is an increasingly common condition, which is strongly associated with obesity and diabetes. The risk of cardiovascular disease is increased in NAFLD and represents the main cause of death in these patients. However, given the shared features between NAFLD, the metabolic syndrome and traditional cardiovascular risk factors, uncertainty exists as to whether NAFLD is an independent risk factor for increased cardiovascular disease.

RECENT FINDINGS

Multiple epidemiological and case-control studies now demonstrate that NAFLD is associated with increased vascular risk, independently of conventional cardiometabolic risk factors. Evidence also suggests a graded association between NAFLD severity and increased vascular risk. However, given the heterogeneous disease spectrum of NAFLD, these findings have limitations with respect to accuracy of diagnosis and staging of NAFLD in most studies.

SUMMARY

Although accumulating evidence points to NAFLD emerging as a novel cardiovascular risk factor, more research is needed to find suitable noninvasive biomarkers of NAFLD severity to allow better risk-stratification based on cardiovascular outcomes. Furthermore, with no established pharmacological treatment option for NAFLD currently available, any potential treatment must show efficacy not only in slowing liver disease progression, but also in ameliorating adverse cardiovascular outcomes.

Non-alcoholic fatty liver disease and outcomes in persons with acute coronary syndromes: insights from the GRACE-ALT analysis

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is associated with a higher risk of cardiovascular disease, but no data exist about the relation between NAFLD and adverse outcomes in persons with acute coronary syndromes (ACS). We evaluated elevated serum alanine aminotransferase (ALT) as a marker of NAFLD, in association adverse outcomes following ACS.

METHODS

We conducted a retrospective cohort study of participants enrolled in the Global Registry of Acute Coronary Events (GRACE) admitted for ACS to St Michael's Hospital, Toronto, between 1999 and 2007. Multivariable linear regression was used to determine the change in maximum measured cardiac troponin I (cTnI) per each 1 IU/l increase in serum ALT concentration. The association between an elevated ALT >90th centile, and adverse outcomes in-hospital and at 6 months were calculated using multiple logistic regression analyses, adjusting for age, sex, body mass index, serum creatinine, glucose, triglycerides and LDL-C, as well as chronic statin or other lipid-lowering agent use.

RESULTS

528 participants were included. Each 1 IU/l increase in ALT was associated with an increase in maximum measured cTnI of 0.16 µg/l (95% CI 0.10 to 0.22). An elevated ALT concentration >90th percentile was associated with a maximum measured cTnI in the highest quartile (adjusted OR 7.07, 95% CI 1.83 to 27.37). An elevated ALT >90th percentile was also significantly associated with all-cause mortality in-hospital, and up to 6 months after discharge (adjusted OR 8.96, 95% CI 3.28 to 24.49).

CONCLUSIONS

NAFLD, determined by an elevated serum ALT, is associated with a higher risk of adverse outcomes in persons with ACS. Whether ALT is a valid and independent prognostic marker in ACS remains to be determined.

Non-alcoholic fatty liver disease across the spectrum of hypothyroidism

BACKGROUND & AIMS

The aim of this study was to characterize the relationship between the broad spectrum of hypothyroidism and NAFLD.

METHODS

A cross-sectional study with 4648 health check-up subjects (2324 cases with hypothyroidism vs. age- and sex-matched controls) was conducted. The subjects were categorized as having either subclinical [thyroid-stimulating hormone (TSH) ≥4.1 mIU/L and normal free thyroixine (T(4)) level (0.7-1.8 ng/dl)] or overt hypothyroidism [free T(4)<0.7 ng/dl]. NAFLD was diagnosed on the basis of typical ultrasonographic findings, and alcohol consumption of less than 20 g/day in the absence of other causes of liver disease.

RESULTS

The mean age of the subjects was 48.6±11.8 years and 62.4% were female. NAFLD was significantly associated with hypothyroidism (30.2% patients vs. 19.5% control, p<0.001). The prevalence of NAFLD and abnormal liver enzyme levels (ALT>33/25 IU/L) increased steadily with increasing grades of hypothyroidism (for NAFLD, subclinical: 29.9% and overt: 36.3%; for abnormal ALT, 20.1% and 25.9%, p<0.001, respectively). Multivariate regression analysis showed that NAFLD was statistically significantly associated with hypothyroidism (odds ratio (OR) 1.38, 95% confidence interval (CI), 1.17-1.62) and the grade of hypothyroidism in a dose-dependent manner (OR 1.36, 95% CI, 1.16-1.61 in subclinical hypothyroidism and OR 1.71, 95% CI, 1.10-2.66 in overt hypothyroidism).

CONCLUSIONS

Subclinical hypothyroidism, even in the range of upper normal TSH levels, was found to be related to NAFLD in a dose-dependent manner. Hypothyroidism is closely associated with NAFLD independently of known metabolic risk factors, confirming a relevant clinical relationship between these two diseases.

Are hepatic steatosis and carotid intima media thickness associated in obese patients with normal or slightly elevated gamma-glutamyl-transferase?

BACKGROUND

Hepatic steatosis (HS) has been associated with obesity and metabolic syndrome (MS), conditions carrying a high risk of coronary artery disease. We aimed to determine whether HS was an independent factor of atherogenic risk beyond its association with MS and its components.

METHODS

We assessed the circulating levels of the heat shock protein-70 (HSP-70), a chaperone involved in inflammation, endoplasmic reticulum stress and apoptosis at liver and endothelial level and the gamma-glutamyl transferase activity (γ-GT) correlating them to carotid intima-media thickness (IMT), along with lipid profile, HOMA, C-reactive protein, fibrinogen, ferritin, adiposity type as well as spleen volume in 52 obese pts with grade 1, 128 with grade 2, and 20 with grade 3 of HS evaluated by sonography.

RESULTS

Patients with different grade of HS demonstrated overlapping HSP-70 levels; similarly performed obese subjects regarding IMT. Using multiple regression analysis, IMT was predicted by age, visceral adiposity and by HOMA (β = 0.50, p < 0.0001, β = 0.30, p = 0.01 and β = 0.18, p = 0.048 respectively, while the severity of HS was predicted by visceral and subcutaneous adiposity and HOMA (β = 0.50, p < 0.0001 and β = 0.27, p = 0.001 and β = 0.18, p = 0.024, respectively).

CONCLUSION

In our series of patients with normal or mild elevation of γ-GT, the severity of HS does not entail higher IMT, which may be linked to MS stigmata.

Metabolic syndrome and risk factors for non-alcoholic fatty liver disease

CONTEXT: Non-alcoholic fatty liver disease (NAFLD), hepatic manifestation of metabolic syndrome, has been considered the most common liver disease nowadays, which is also the most frequent cause of elevated transaminases and cryptogenic cirrhosis. The greatest input of fatty acids into the liver and consequent increased beta-oxidation contribute to the formation of free radicals, release of inflammatory cytokines and varying degrees of hepatocytic aggression, whose histological expression may vary from steatosis (HS) to non-alcoholic steatohepatitis (NASH). The differentiation of these forms is required by the potential risk of progression to cirrhosis and development of hepatocellular carcinoma. OBJECTIVE: To review the literature about the major risk factors for NAFLD in the context of metabolic syndrome, focusing on underlying mechanisms and prevention. METHOD: PubMed, MEDLINE and SciELO data basis analysis was performed to identify studies describing the link between risk factors for metabolic syndrome and NAFLD. A combination of descriptors was used, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, metabolic syndrome and risk factors. At the end, 96 clinical and experimental studies, cohorts, meta-analysis and systematic reviews of great impact and scientific relevance to the topic, were selected. RESULTS: The final analysis of all these data, pointed out the central obesity, type 2 diabetes, dyslipidemia and hypertension as the best risk factors related to NAFLD. However, other factors were highlighted, such as gender differences, ethnicity, genetic factors and the role of innate immunity system. How these additional factors may be involved in the installation, progression and disease prognosis is discussed. CONCLUSION: Risk factors for NAFLD in the context of metabolic syndrome expands the prospects to 1) recognize patients with metabolic syndrome at high risk for NAFLD, 2) elucidate pathways common to other co-morbidities, 3) determine risk factors associated with a worse prognosis, 4) develop therapeutic strategies with goal of reducing risk factors, 5) apply acquired knowledge in public health policies focusing on preventive strategies.

Decreased circulating endothelial progenitor cell levels and function in patients with nonalcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is associated with advanced atherosclerosis and a higher risk of cardiovascular disease. Increasing evidence suggests that injured endothelial monolayer is regenerated by circulating bone marrow derived-endothelial progenitor cells (EPCs), and levels of circulating EPCs reflect vascular repair capacity. However, the relation between NAFLD and EPC remains unclear. Here, we tested the hypothesis that patients with nonalcoholic fatty liver disease (NAFLD) might have decreased endothelial progenitor cell (EPC) levels and attenuated EPC function.

METHODS AND RESULTS

A total of 312 consecutive patients undergoing elective coronary angiography because of suspected coronary artery disease were screened and received examinations of abdominal ultrasonography between July 2009 and November 2010. Finally, 34 patients with an ultrasonographic diagnosis of NAFLD, and 68 age- and sex-matched controls without NAFLD were enrolled. Flow cytometry with quantification of EPC markers (defined as CD34(+), CD34(+)KDR(+), and CD34(+)KDR(+)CD133(+)) in peripheral blood samples was used to assess circulating EPC numbers. The adhesive function, and migration, and tube formation capacities of EPCs were also determined in NAFLD patients and controls. Patients with NAFLD had a significantly higher incidence of metabolic syndrome, previous myocardial infarction, hyperuricemia, and higher waist circumference, body mass index, fasting glucose and triglyceride levels. In addition, patients with NAFLD had significantly decreased circulating EPC levels (all P<0.05), attenuated EPC functions, and enhanced systemic inflammation compared to controls. Multivariate logistic regression analysis showed that circulating EPC level (CD34(+)KDR(+) [cells/10(5) events]) was an independent reverse predictor of NAFLD (Odds ratio: 0.78; 95% confidence interval: 0.69-0.89, P<0.001).

CONCLUSIONS

NAFLD patients have decreased circulating EPC numbers and functions than those without NAFLD, which may be one of the mechanisms to explain atherosclerotic disease progression and enhanced cardiovascular risk in patients with NAFLD.

Severity of fatty liver on ultrasound correlates with metabolic and cardiovascular risk

Non-alcoholic fatty liver disease is associated with an increased risk of metabolic and cardiovascular diseases. Whether the severity of fatty liver on ultrasound correlates with metabolic or cardiovascular risk remains unclear. A total of 1000 people receiving health examinations were enrolled, and 126 were excluded due to the presence of HBsAg, anti-HCV, known hepatic disorders or alcohol use (>140 g/wk). Significant fatty liver consisted of moderate and severe fatty liver on ultrasound. The definition of central obesity was modified to a waist circumference of >90 cm in men and >80 cm in women. Framingham risk score was used to estimate the risk of cardiovascular disease. A total of 874 subjects (485 women and 388 men with a mean age of 52.07 ± 11.68 years) were included in the final analysis. By using logistic regression analyses stratified by gender, the odds ratio for the prevalence of diabetes mellitus, metabolic syndrome and risk of cardiovascular disease increased with increasing fatty liver status in both genders (p ≤ 0.001). The difference was not only present between individuals with fatty liver vs. non-fatty liver but also between the mild fatty liver and significant fatty liver groups (p < 0.05). In conclusion, the severity of fatty liver on ultrasound could be useful for the risk stratification of metabolic syndrome, diabetes mellitus and cardiovascular disease in clinical practice.

NAFLD recurrence in liver transplant recipients

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is a common indication for liver transplantation and can recur in the graft. To describe this recurrence, we performed a cohort study of individuals undergoing liver transplantation for NAFLD-related cirrhosis between 1993 and 2007. Predictors of NAFLD recurrence and outcomes in this cohort were also studied.

METHODS

Eighty-eight liver transplant recipients were included in this study. NAFLD recurrence was described by performing a blinded reevaluation of posttransplant liver biopsies and classified according to histologic activity (NAFLD activity score) and fibrosis.

RESULTS

Recurrent NAFLD was seen in 34 (39%) recipients with isolated steatosis in 9 and steatohepatitis in 25 recipients. Severe recurrence was seen in 3 of 34 recipients (NAFLD activity score ≥ 5) and advanced fibrosis in 3 recipients. NAFLD recurrence correlated with higher pretransplant (P=0.001) and posttransplant body mass index (P<0.0001) and increased triglyceride levels posttransplantation. Serum triglyceride levels at 6 and 12 months were 280 ± 129 and 324 ± 265 mg/dL, respectively, in those with NAFLD recurrence versus 206 ± 96 mg/dL at 6 months and 190 ± 103 mg/dL in those without NAFLD recurrence (P=0.007 at 6 months and P=0.005 at 12 months). Average steroid dose at 6 months posttransplant was also higher in those with NALFD recurrence than those without (11 ± 8.5 and 7.2 ± 5.7 mg/day, P=0.04). Posttransplant survival did not differ between those with and without NAFLD recurrence during the entire follow-up period (P=0.78). Posttransplant cardiovascular disease was significantly and adversely correlated with posttransplant survival.

CONCLUSIONS

NAFLD recurrence is common in the first 5 years postliver transplantation and is associated with features of the metabolic syndrome. Although NAFLD recurrence was not associated with higher mortality in our cohort, cardiovascular mortality and morbidity were common, suggesting that the metabolic syndrome is an important link to NAFLD recurrence and cardiovascular deaths posttransplantation.

A preliminary investigation on the possible association between diminished copper availability and non-alcoholic fatty liver disease in epileptic patients treated with valproic acid

BACKGROUND

Patients treated with valproic acid (VPA) present a high incidence of non-alcoholic fatty liver disease (NAFLD) (around 61%). Several recent studies suggest that low copper stores could be associated with NAFLD, and a significant decrease of copper availability in VPA-treated patients has been described.

DESIGN AND METHODS

In 101 adult epileptic patients treated with valproic acid in monotherapy (n = 75) and polytherapy (n = 26) the copper availability was evaluated using the specific oxidase activity of ceruloplasmin (activity per unit mass of enzyme protein) and the copper/ceruloplasmin ratio. Copper deficiency was supposed in the cases in which this biochemical variable was smaller than the lower reference limit (333 U/g).

RESULTS

The differences between the groups of patients with ceruloplasmin oxidase activity smaller or greater than 333 U/g for the serum levels of aminotransferases, gamma-glutamyltransferase, butyrylcholinesterase, cholesterol, triglycerides, and C-reactive protein, and the APRI and FIB-4 liver fibrosis scores were not statistically significant. Most patients (93%) had low APRI and FIB-4 scores, suggesting absence of significant liver fibrosis.

CONCLUSIONS

The results obtained do not confirm the hypothesis of an association between diminished copper availability and NAFLD in patients treated with valproic acid.

Statin-based treatment for cardiovascular risk and non-alcoholic fatty liver disease. Killing two birds with one stone?

Cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD) share common risk factors and may have a parallel course. Statin treatment alone or in combination with other drugs has a substantially beneficial effect on CVD morbidity and mortality. The question was if these regimens were harmful for the liver. Mounting data suggest that statin monotherapy or statin-based treatments are safe in patients with NAFLD and can improve liver tests and liver ultrasonographic evidence of NAFLD. Recent data suggest that statin-based therapies are beneficial to the liver and at the same time reduce CVD morbidity and mortality in patients with NAFLD more than in subjects without it. These findings suggest that with statins we are able to get two birds with one stone.