Non-alcoholic fatty liver disease and its association with obesity, insulin resistance and increased serum levels of C-reactive protein in Hispanics

Liver-specific Coxsackievirus and adenovirus receptor deletion develop metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common liver disease associated with obesity and is caused by the accumulation of ectopic fat without alcohol consumption. Coxsackievirus and adenovirus receptor (CAR) are vital for cardiac myocyte-intercalated discs and endothelial cell-to-cell tight junctions. CAR has also been reported to be associated with obesity and high blood pressure. However, its function in the liver is still not well understood. The liver of obese mice exhibit elevated CAR mRNA and protein levels. Furthermore, in the liver of patients with non-alcoholic steatohepatitis, CAR is reduced in hepatocyte cell-cell junctions compared to normal levels. We generated liver-specific CAR knockout (KO) mice to investigate the role of CAR in the liver. Body and liver weights were not different between wild-type (WT) and KO mice fed a paired or high-fat diet (HFD). However, HFD induced significant liver damage and lipid accumulation in CAR KO mice compared with WT mice. Additionally, inflammatory cytokines transcription, hepatic permeability, and macrophage recruitment considerably increased in CAR KO mice. We identified a new interaction partner of CAR using a protein pull-down assay and mass spectrometry. Apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3C (APOBEC3C) demonstrated a complex relationship with CAR, and hepatic CAR expression tightly regulated its level. Moreover, Apolipoprotein B (ApoB) and Low-density lipoprotein receptor (LDLR) levels correlated with APOBEC3C expression in the liver of CAR KO mice, suggesting that CAR may regulate lipid accumulation by controlling APOBEC3C activity. In this study, we showed that hepatic CAR deficiency increased cell-to-cell permeability. In addition, CAR deletion significantly increased hepatic lipid accumulation by inducing ApoB and LDLR expression. Although the underlying mechanism is unclear, CARs may be a target for the development of novel therapies for MAFLD.

Coronary artery disease as a risk factor for metabolic dysfunction-associated steatotic liver disease and liver fibrosis

INTRODUCTION AND OBJECTIVES

Patients with metabolic dysfunction-associated steatotic liver disease (MASLD) are at an increased cardiovascular risk. On the contrary, non-alcoholic fatty liver disease (NAFLD) is highly prevalent in patients with coronary heart disease (CHD). However, it is not known whether patients with significant CHD show a higher frequency of liver fibrosis. This study aimed to determine the frequency of MASLD and liver fibrosis in patients with CHD and to assess whether coronary stenosis is significantly associated with MASLD and fibrosis.

PATIENTS AND METHODS

This observational and analytical study included adult patients without any known liver disease who underwent coronary angiography for suspected coronary artery disease (Jul 2021-Jul 2022). The presence of significant CHD (> 50% stenosis of at least one coronary artery) was determined. Liver elastography (FibroScan®) was performed up to 6 months after the coronary angiographic study to determine liver fibrosis, a measurement of liver stiffness (> 6.5 Kpa). Fisher's test, Mann-Whitney U test, and logistic regression models were used (p < 0.05).

RESULTS

The study included 113 patients (76% men, average age: 63 years [standard deviation: 9.9]), of which 72% presented with significant CHD. The prevalence rate of MASLD was 52%. Liver fibrosis was present in 12% of the patients and all patients in the significant CHD group (p = 0.007). An increase in the number of vessels with significant CHD increased the probability of liver fibrosis (odds ratio, 1.79; 95% confidence interval, 1.06-3.04; p = 0.029).

CONCLUSIONS

MASLD is highly prevalent in patients with significant CHD but without known liver damage. These data suggest that MASLD and liver fibrosis should be investigated in patients with CHD. The presence of confounding variables, especially the presence of type 2 diabetes mellitus, should be evaluated in further studies.

Prevalence of non-alcoholic fatty liver disease and its association with lifestyle habits in adults in Chile: a cross-sectional study from the National Health Survey 2016-2017

Non-alcoholic fatty liver disease (NAFLD) represents an excessive fat accumulation within the liver, usually associated with excess body weight. A liver biopsy is the gold standard for diagnosis, but it is inapplicable in population-based studies. In large populations, non-invasive methods could be used, which may also serve to identify potential protective factors. We aimed to (a) estimate NAFLD prevalence in the adult population in Chile by using non-invasive methods and (b) determine the association between the presence of NAFLD and lifestyle habits. The National Health Survey of Chile 2016–2017 was analysed. We included individuals aged 21–75 years, without infectious diseases nor risky alcohol consumption. NAFLD was detected by either fatty liver index (FLI; considers circulating TAG, circulating γ-glutamyl-transferase, BMI and waist circumference), lipid accumulation product (LAP; considers sex, circulating TAG and waist circumference) or their combination. Lifestyle habits were determined by questionnaires. We included 2774 participants, representative of 10 599 094 (9 831 644, 11 366 544) adults in Chile. NAFLD prevalence (95 % CI) was 39·4 % (36·2, 42·8) by FLI, 27·2 % (24·2, 30·4) by LAP and 23·5 % (20·7, 26·5) by their combination. The prevalence progressively increased with increasing BMI. Of note, less smoking and more moderate-vigorous physical activity and whole-grain consumption were associated with lower odds of having NAFLD, independently of BMI. At least one out of four adults in Chile is afflicted with NAFLD. Health promotion strategies focused on controlling excess body weight and promoting specific lifestyle habits are urgently required.

Nonalcoholic Fatty Liver Disease: Disease Burden and Disease Awareness

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide and has been implying an unprecedented burden to health care systems. The prevalence of NAFLD has exceeded 30% in developed countries. Considering the asymptomatic nature of undiagnosed NAFLD, high suspicion and noninvasive diagnosis have utmost importance especially in primary care level. At this point, patient and provider awareness should be optimal for early diagnosis and risk stratification for patients at risk of progression.

Nonalcoholic Fatty Liver Disease in Latin America and Australia

The epidemiologic and demographical features of nonalcoholic fatty liver disease (NAFLD) vary significantly across countries and continents. In this review, we analyze current data regarding prevalence of NAFLD in Latin America and Caribbean and Australia and review some peculiarities found in these regions. We stress the need of greater awareness of NAFLD and the development of cost-effective risk stratification strategies and clinical care pathways of the disease. Finally, we highlight the need of effective public health policies to control the main risk factors for NAFLD.

Prevalence of non-alcoholic fatty liver disease and liver fibrosis in a general population cohort from Argentina

INTRODUCTION AND OBJECTIVES

South America is one of the regions with the highest rates of non-alcoholic fatty liver disease (NAFLD). This study aimed to assess the prevalence and severity of NAFLD in suburban Argentina.

PATIENTS AND METHODS

The study involved a general community cohort of 993 subjects evaluated sequentially with a comprehensive lifestyle questionnaire, laboratory testing, abdominal ultrasound (US) and transient elastography with XL probe. NAFLD was diagnosed according to standard criteria.

RESULTS

The prevalence of NAFLD by the US was 37.2% (326/875) overall, 50.3% in subjects with overweight/obesity, 58.6% with hypertriglyceridemia, 62.3% with diabetes/hyperglycemia and 72.1% with all three risk factors. Male gender (OR 1.42, 95% CI 1.03-1.47, p=0.029), age (50-59 years: OR 1.98, 95 CI 1.16-3.39, p=0.013 and ≥60 years: OR 1.86, 95% CI 1.13-3.09, p=0.015), BMI (25-29: OR 2.87, 95% CI 1.86-4.51, p<0.001 and ≥30: OR 9.57, 95% CI 6.14-15.20, p<0.001), diabetes/hyperglycemia (OR 1.65, 95% CI 1.05-2.61, p=0.029) and hypertriglyceridemia (OR 1.73, 95% CI 1.20-2.48, p=0.002) were independent predictors of NAFLD. Among patients with steatosis, 22.2 % (69/311) had ≥F2 fibrosis (overweight 25%, hypertriglyceridemia 32%, diabetes/hyperglycemia 34%). BMI (OR 5.22, 95% CI 2.64-11.74, p<0.001), diabetes/hyperglycemia (OR 2.12, 95% CI 1.05-4.29, p=0.04) and hypertriglyceridemia (OR 1.94, 95% CI 1.03-3.68, p=0.040) were independent predictors of liver fibrosis.

CONCLUSIONS

This general population study from Argentina showed a high prevalence of NAFLD. Significant liver fibrosis was present in 22% of subjects with NAFLD. This information adds to the existing knowledge of NAFLD epidemiology in Latin America.

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.

Geographical similarity and differences in the burden and genetic predisposition of NAFLD

NAFLD has become a major public health problem for more than 2 decades with a growing prevalence in parallel with the epidemic of obesity and type 2 diabetes (T2D). The disease burden of NAFLD differs across geographical regions and ethnicities. Variations in prevalence of metabolic diseases, extent of urban-rural divide, dietary habits, lifestyles, and the prevalence of NAFLD risk and protective alleles can contribute to such differences. The rise in NAFLD has led to a remarkable increase in the number of cases of cirrhosis, hepatocellular carcinoma, hepatic decompensation, and liver-related mortality related to NAFLD. Moreover, NAFLD is associated with multiple extrahepatic manifestations. Most of them are risk factors for the progression of liver fibrosis and thus worsen the prognosis of NAFLD. All these comorbidities and complications affect the quality of life in subjects with NAFLD. Given the huge and growing size of the population with NAFLD, it is expected that patients, healthcare systems, and the economy will suffer from the ongoing burden related to NAFLD. In this review, we examine the disease burden of NAFLD across geographical areas and ethnicities, together with the distribution of some well-known genetic variants for NAFLD. We also describe some special populations including patients with T2D, lean patients, the pediatric population, and patients with concomitant liver diseases. We discuss extrahepatic outcomes, patient-reported outcomes, and economic burden related to NAFLD.

Non-alcoholic fatty liver disease prevalence in Latin America: A systematic review and meta-analysis

Non-alcoholic fatty liver disease (NAFLD) produces high morbidity and mortality rates. Its worldwide prevalence is 25%, but evidence from Latin America (LA) is lacking. We aimed to estimate the prevalence of NAFLD in the adult population of LA. We conducted a systematic review and meta-analysis. Data were collected from OVID, Cochrane Library and LILACS search engines. We used terms related to NAFLD and LA countries. Observational studies in adults who were born and live in LA were included. Two reviewers evaluated the articles, extracted data and assessed the risk of bias. Discrepancies were resolved by consensus or by a third reviewer. A validated tool was used to assess risk of bias. We found and analyzed 19 articles (n=5625). The prevalence in the general and captive population found was 24%. Populations with type 2 diabetes mellitus or obesity had a higher mean prevalence that reached 68%. We concluded that the average prevalence of NAFLD in LA is around 24%. Among high-risk groups, this value increases to 68%. Further studies in the general population using appropriate designs are required for an accurate estimate of the prevalence of NAFLD in LA.

Relationship between liver fat content and lifestyle factors in adults with metabolic syndrome

The aim of this study was to investigate the associations between liver fat content (LFC), sedentary behaviour (SB), physical activity (PA), fitness, diet, body composition, and cardiometabolic risk factors in adults with metabolic syndrome. A total of 44 sedentary adults (mean age 58 [SD 7] years; 25 women) with overweight or obesity participated. LFC was assessed with magnetic resonance spectroscopy and imaging, SB and PA with hip-worn accelerometers (26 [SD 3] days), fitness by maximal bicycle ergometry, body composition by air displacement plethysmography and nutrient intake by 4-day food diaries. LFC was not independently associated with SB, PA or fitness. Adjusted for sex and age, LFC was associated with body fat%, body mass index, waist circumference, triglycerides, alanine aminotransferase, and with insulin resistance markers. There was and inverse association between LFC and daily protein intake, which persisted after further adjusment with body fat%. LFC is positively associated with body adiposity and cardiometabolic risk factors, and inversely with daily protein intake. SB, habitual PA or fitness are not independent modulators of LFC. However, as PA is an essential component of healthy lifestyle, it may contribute to liver health indirectly through its effects on body composition in adults with metabolic syndrome.

Association of Inflammatory Cytokines With Non-Alcoholic Fatty Liver Disease

Background

Inflammatory cytokines have been considered to be significant factors contributing to the development and progression of non-alcoholic fatty liver disease (NAFLD). However, the role of inflammatory cytokines in NAFLD remains inconclusive.

Objective

This study aimed to evaluate the association between inflammatory cytokines and NAFLD.

Methods

PubMed, Web of Science, the Cochrane Library, and EMBASE databases were searched until 31 December 2021 to identify eligible studies that reported the association of inflammatory cytokine with NAFLD and its subtypes. We pooled odds ratios (ORs) and hazard risk (HRs) with 95% confidence intervals (CIs) and conducted heterogeneity tests. Sensitivity analysis and analysis for publication bias were also carried out.

Results

The search in the databases identified 51 relevant studies that investigated the association between 19 different inflammatory cytokines and NAFLD based on 36,074 patients and 47,052 controls. The results of the meta-analysis showed significant associations for C-reactive protein (CRP), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1) with NAFLD (ORs of 1.41, 1.08, 1.50, 1.15 and 2.17, respectively). In contrast, we observed non-significant associations for interferon-γ (IFN-γ), insulin-like growth factor (IGF-II), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-10 (IL-10), interleukin-12 (IL-12), monocyte chemoattractant protein-1(MCP-1), and transforming growth factor-β (TGF-β) with NAFLD. Our results also showed that CRP, IL-1β, and TNF-α were significantly associated with non-alcoholic steatohepatitis (NASH) and hepatic fibrosis.

Conclusions

Our results indicated that increased CRP, IL‐1β, IL-6, TNF‐α, and ICAM-1 concentrations were significantly associated with increased risks of NAFLD. These inflammatory mediators may serve as biomarkers for NAFLD subjects and expect to provide new insights into the aetiology of NAFLD as well as early diagnosis and intervention.

Effect of growth hormone therapy on liver enzyme and other cardiometabolic risk factors in boys with obesity and nonalcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the most common causes of liver disease in children and adolescents. Although several reports have confirmed the significant correlation between NAFLD and growth hormone (GH)-insulin-like growth factor 1(IGF-1) axis, no study further investigates whether or not recombinant human GH (rhGH) treatment can improve NAFLD in obese children.

METHODS

This study was a randomized, open-label study comprising 44 boys with obesity and NAFLD (11.76 ± 1.67 year) to evaluate the effects of 6 months of rhGH administration for boys with obesity and NAFLD. The subjects were randomized divided into treatment group (subjects with recombinant human GH (rhGH)) and control group for 6 months.

RESULTS

After 6 months, IGF-1 increased significantly during rhGH treatment, in comparison with the control group (582.45 ± 133.00 vs. 359.64 ± 129.00 ng/ml; p < 0.001). A significant reduction in serum alanine aminotransferase(ALT) (15.00 vs. 28.00 U/L; p = 0.001), aspartate aminotransferase(AST) (20.00 vs. 24.50U/L; p = 0.004), gamma glutamyl transferase(GGT) (14.50 vs. 28.50 U/L; p < 0.001) was observed in the GH-treated boys. In addition, the rhGH group showed a significant decrease in C reactive protein (CRP) (1.17 ± 0.76 vs. 2.26 ± 1.43 mg/L) and body mass index standard deviation scores (BMI SDS) (2.28 ± 0.80 vs. 2.71 ± 0.61) than the control group (p = 0.003, p = 0.049 respectively). GH treatment also reduced low density lipoprotein cholesterol (LDL-C) (2.19 ± 0.42 vs. 2.61 ± 0.66 mmol/L; p = 0.016) and increased high density lipoprotein cholesterol (HDL-C) (1.30 vs. 1.15 mmol/L; p = 0.005), and there were no changes in total cholesterol (TC), triglycerides (TG) and uric acid(UA) between the treatment group and the control group.

CONCLUSION

Our findings suggest that 6 months treatment with rhGH may be beneficial for liver enzyme and can improve obesity-related other cardiovascular and metabolic complications in boys with obesity and NAFLD.

Epidemiology and Clinical Outcomes of Metabolic (Dysfunction)-associated Fatty Liver Disease

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) is currently the most common chronic liver disease and affects at least a quarter of the global adult population. It has rapidly become one of the leading causes of hepatocellular carcinoma and cirrhosis in Western countries. In this review, we discuss the nomenclature and definition of MAFLD as well as its prevalence and incidence in different geographical regions. Although cardiovascular disease remains the leading cause of death in MAFLD patients, the proportion of patients dying from hepatic complications increases sharply as the disease progresses to advanced liver fibrosis and cirrhosis. In addition, patients with MAFLD are at increased risk of various extrahepatic cancers. Although a causal relationship between MAFLD and extrahepatic cancers has not been established, clinicians should recognize the association and consider cancer screening (e.g., for colorectal cancer) as appropriate.

Latin American Association for the study of the liver (ALEH) practice guidance for the diagnosis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chronic liver disease, affecting 20-30% of the general population. Furthermore, its prevalence is predicted to increase exponentially in the next decades, concomitantly with the global epidemic of obesity, type 2 diabetes mellitus (T2DM), and sedentary lifestyle. NAFLD is a clinical syndrome that encompasses a wide spectrum of associated diseases and hepatic complications such as hepatocellular carcinoma (HCC). Moreover, this disease is believed to become the main indication for liver transplantation in the near future. Since NAFLD management represents a growing challenge for primary care physicians, the Asociación Latinoamericana para el Estudio del Hígado (ALEH) has decided to organize this Practice Guidance for the Diagnosis and Treatment of Non-Alcoholic Fatty Liver Disease, written by Latin-American specialists in different clinical areas, and destined to general practitioners, internal medicine specialists, endocrinologists, diabetologists, gastroenterologists, and hepatologists. The main purpose of this document is to improve patient care and awareness of NAFLD. The information provided in this guidance may also be useful in assisting stakeholders in the decision-making process related to NAFLD. Since new evidence is constantly emerging on different aspects of the disease, updates to this guideline will be required in future.

Hematopoietic upstream stimulating factor 1 deficiency is associated with increased atherosclerosis susceptibility in LDL receptor knockout mice

Total body upstream stimulatory factor 1 (USF1) deficiency in mice is associated with brown adipose tissue activation and a marked protection against the development of obesity and atherosclerotic lesions. Functional expression of USF1 has also been detected in monocytes and monocyte-derived macrophages. In the current study we therefore tested whether selective hematopoietic USF1 deficiency can also beneficially impact the development of atherosclerosis. For this purpose, LDL receptor knockout mice were transplanted with bone marrow from USF1 knockout mice or their wild-type littermate controls and subsequently fed a Western-type diet for 20 weeks to stimulate atherosclerotic lesion development. Strikingly, absence of USF1 function in bone marrow-derived cells was associated with exacerbated blood leukocyte (+ 100%; P < 0.01) and peritoneal leukocyte (+ 50%; P < 0.05) lipid loading and an increased atherosclerosis susceptibility (+ 31%; P < 0.05). These effects could be attributed to aggravated hyperlipidemia, i.e. higher plasma free cholesterol (+ 33%; P < 0.001) and cholesteryl esters (+ 39%; P < 0.001), and the development of hepatosteatosis. In conclusion, we have shown that hematopoietic USF1 deficiency is associated with an increased atherosclerosis susceptibility in LDL receptor knockout mice. These findings argue against a contribution of macrophage-specific USF1 deficiency to the previously described beneficial effect of total body USF1 deficiency on atherosclerosis susceptibility in mice.

Association of Cardiovascular Risk Factors and Metabolic Syndrome with non-alcoholic and alcoholic fatty liver disease: a retrospective analysis

BACKGROUND

Although many studies on non-alcoholic fatty liver disease (NAFLD) are underway worldwide, and several existing studies have investigated the association between NAFLD and cardiovascular risk factors, studies comparing NAFLD and alcoholic fatty liver disease (AFLD) are scarce. This study aimed to evaluate differences between the incidence of cardiovascular risk factors and metabolic syndrome in NAFLD and AFLD.

METHODS

A retrospective analysis of 913 patients who underwent abdominal computed tomography (CT) was performed to compare the incidence of cardiovascular risk factors and metabolic syndrome between NAFLD and AFLD. Subjects were divided into three groups based on criteria: healthy (n = 572), NAFLD (n = 295), and AFLD (n = 46). The healthy group had no liver disease. NAFLD was defined as fatty liver diagnosed on CT and drinking less than 140 g/week for men or 70 g/week for women. AFLD was defined as fatty liver diagnosed on CT and drinking more than 140 g/week for men or 70 g/week for women. We compared the incidence of cardiovascular risk factors and metabolic syndrome between the three groups. The relationship between each group and the metabolic syndrome risk was analyzed through multivariate logistic regression analysis.

RESULTS

No significant differences in several cardiovascular risk factors were observed between the NAFLD and AFLD groups. Upon analyzing the metabolic syndrome status in each group after making appropriate adjustments, the odds ratios (ORs) in the NAFLD (OR = 2.397, P = 0.002) and AFLD groups (OR = 4.445, P = 0.001) were found to be significantly higher than that in the healthy group; the incidence rate of metabolic syndrome was similar in the NAFLD and AFLD groups.

CONCLUSIONS

Both the NAFLD and AFLD groups had more cardiovascular risk factors and higher metabolic syndrome risk than the healthy group. Thus, the prevention of fatty liver disease, regardless of the specific type, should involve the identification of cardiovascular and metabolic syndrome risk factors. If abdominal CT reveals a fatty liver, whether NAFLD or AFLD, the risk of cardiovascular disease and metabolic syndrome should be assessed.

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.

Women Have a Lower Risk of Nonalcoholic Fatty Liver Disease but a Higher Risk of Progression vs Men: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The risk of nonalcoholic fatty liver disease (NAFLD) and its progression may differ between men and women. We conducted a systematic review and meta-analysis to determine the relationship between sex and NAFLD, nonalcoholic steatohepatitis (NASH), and advanced NAFLD fibrosis.

METHODS

Studies reporting sex-stratified NAFLD prevalence among population-based samples and either NASH or advanced fibrosis among patients with biopsy-proven NAFLD were identified from MEDLINE, EMBASE, and Cochrane databases through December 2017. We calculated pooled relative risk ratios comparing women vs men for each outcome.

RESULTS

Our final analysis comprised 54 studies. Samples sizes were 62,239 for the NAFLD analysis, 5428 for the NASH analysis, and 6444 for the advanced fibrosis analysis. Women had a 19% lower risk of NAFLD than men in the general population (pooled risk ratio [RR], 0.81; 95% CI, 0.68-0.97; I² = 97.5%). Women had a similar risk of NASH (RR, 1.00; 95% CI, 0.88-1.14; I² = 85.1%), and a 37% higher risk of advanced fibrosis (RR, 1.37; 95% CI, 1.12-1.68; I² = 74.0%) than men. Age modified the effect of sex on NAFLD severity. Risks of NASH (RR, 1.17; 95% CI, 1.01-1.36) and advanced fibrosis (RR, 1.56; 95% CI, 1.36-1.80; I² = 0) were substantially higher in women in study populations with average ages of 50 years and older; sex differences in NASH and advanced fibrosis were attenuated in younger populations.

CONCLUSIONS

In a systematic review and meta-analysis, we found women to have a lower risk of NAFLD than men. However, once NAFLD is established, women have a higher risk of advanced fibrosis than men, especially after age 50 years.

Contemporary Epidemiology of Chronic Liver Disease and Cirrhosis

BACKGROUND & AIMS

Accurate estimates for the contemporary burden of chronic liver disease (CLD) are vital for setting clinical, research, and policy priorities. We aimed to review the incidence, prevalence, and mortality of CLD and its resulting complications, including cirrhosis and hepatocellular carcinoma (HCC).

METHODS

We reviewed the published literature on the incidence, prevalence, trends of various etiologies of CLD and its resulting complications. In addition, we provided updated data from the Centers for Disease Control and Global Burden of Disease Study on the morbidity and mortality of CLD, cirrhosis, and hepatocellular carcinoma (HCC). Lastly, we assessed the strengths and weaknesses of available sources of data in hopes of providing important context to these national estimates of cirrhosis burden.

RESULTS

An estimated 1.5 billion persons have CLD worldwide and the age-standardized incidence of CLD and cirrhosis is 20.7/100,000, a 13% increase since 2000. Similarly, cirrhosis prevalence and mortality has increased in recent years in the United States. The epidemiology of CLD is shifting, reflecting implementation of large-scale hepatitis B vaccination and hepatitis C treatment programs, the increasing prevalence of the metabolic syndrome, and increasing alcohol misuse.

CONCLUSIONS

The global burden of CLD and cirrhosis is substantial. Although vaccination, screening, and antiviral treatment campaigns for hepatitis B and C have reduced the CLD burden in some parts of the world, concomitant increases in injection drug use, alcohol misuse, and metabolic syndrome threaten these trends. Ongoing efforts to address CLD-related morbidity and mortality require accurate contemporary estimates of epidemiology and outcomes.

Accuracy of a Semi-Quantitative Ultrasound Method to Determine Liver Fat Infiltration in Early Adulthood

An inexpensive and simple method to determine non-alcoholic fatty liver disease (NAFLD) is the abdominal ultrasound, but there are still doubts about its accuracy. We assessed the precision of a semi-quantitative ultrasound method to determine liver fat infiltration, using magnetic resonance spectroscopy (MRS) as the reference. The study was conducted in youths from an ongoing cohort study. Clinical validation was performed, using receiver operating characteristic analysis, in n = 60 participants (22.6y; 50% males). Abdominal ultrasound was carried out with liver brightness (score 0-3), diaphragm attenuation (0-2) and liver vessel blurring (0-1) scored by two observers. Liver fat was estimated using MRS. Then, analytical validation was conducted in the remaining participants (n = 555; 22.7y; 51% males) using effects size estimates. An ultrasound score ≥4.0 had the highest sensitivity (78%) and specificity (85%) for NAFLD diagnosis. An area under the curve of 86% denotes a good diagnostic performance of the test, whereas a Kappa of 0.63 suggests substantial agreement of ultrasound vs. MRS. The analytical validation showed that participants having NAFLD according to ultrasound had an unhealthier cardiometabolic profile than participants without the condition. Abdominal ultrasound, combined with a semi-quantitative score system, is a reliable method to determine liver fat infiltration in young adults and should be encouraged whenever MRS is unavailable.

Baveno VI and Expanded Baveno VI criteria successfully predicts the absence of high-risk gastro-oesophageal varices in a Chilean cohort

BACKGROUND

Baveno VI and expanded Baveno VI criteria have been recommended to circumvent the need for endoscopy screening in patients with a very low probability of varices needing treatment (VNT).

AIM

To validate these criteria in a Latin American population.

METHODS

The ability of Baveno VI criteria (liver stiffness measurement (LSM) <20 kPa and platelet count >150 × 103/μL) and expanded Baveno VI criteria (LSM < 25kPa and platelet count >110 × 103/μL) to exclude the presence of VNT was tested in a prospectively recruited cohort of patients with Child-Pugh A liver cirrhosis and with no previous variceal haemorrhage who attended the liver clinics of three major hospitals in Chile.

RESULTS

Three hundred patients were included. The median (IQR) age was 61 [18-86] years, median MELD was 8.0 (6-17), median LSM was 17.2 (10.2-77) kPa and median platelet count was 137 (23-464) × 10³ /μL. The main aetiology was non-alcoholic fatty liver disease (67.3%). VNT were present in 18% of patients. The Baveno VI criteria had a sensitivity of 98.1% and a specificity of 38.2%, potentially sparing 31.3% of upper endoscopies with a very low risk of missing VNT (1.1%). The expanded Baveno VI criteria had a sensitivity of 90.7% and a specificity of 61%, potentially sparing 51.3% of upper endoscopies with a risk of missing VNT of 3.6%. Both criteria were independently associated with the absence of VNT.

CONCLUSION

We validated the Baveno VI and expanded Baveno VI criteria in Chilean population, potentially sparing 31.3% and 51.3% of endoscopies, respectively, with a very low risk of missing VNT. Fondecyt 1191183.

Early Obesity: Risk Factor for Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), defined as fat accumulation greater than 5% in hepatocytes, may progress to fibrosis or cirrhosis later in life. NAFLD prevalence in adolescents has increased significantly in direct relation with obesity prevalence. Fatty liver has become the most frequent indication for liver transplantation in adults.

OBJECTIVE

The aim of the study was to identify anthropometric variables during the first 10 years of life associated to the risk of developing NAFLD in adolescence.

METHODS

Longitudinal cohort study 'Growth and Obesity Chilean Cohort Study' (GOCS) consisting of 513 children born in 2002 to 2003, with yearly anthropometric data collected over a 10-year period. The presence of intrahepatic fat in the livers of subjects 14 to 16 years of age was determined using abdominal ultrasound. In addition, elastography was performed on all participants with ultrasound evidence of NAFLD.

RESULTS

9.7% of the participants presented findings compatible with NAFLD. After 2 years of age, obesity significantly and progressively increased the probability of NAFLD occurrence in adolescence. Obesity at 5 years of age was associated with the highest OR for NAFLD, reaching values of 8.91 (95% CI 3.03-16.11). Among participants with NAFLD, those with altered liver elasticity (≥7 kPa) had greater weight, BMI z-score, waist and hip circumference, and altered liver enzymes (P < 0.05).

CONCLUSION

The risk of developing NAFLD in adolescence increases progressively with early obesity starting at age 2 years.

Non-alcoholic fatty liver disease in lean individuals

Non-alcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, encompassing a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis, which can progress to cirrhosis. It has recently been recognised that NAFLD also occurs in individuals who are not obese, especially in Asian populations. In these patients, NAFLD manifests at lower overall body mass index thresholds in the presence of increased visceral adipose tissue. Currently, the principles of clinical management are similar to those in obese individuals, although, in specific regions and clinical situations, unique aetiologies of NAFLD must be treated specifically.

Inflammatory Effects of Subacute Exposure of Roundup in Rat Liver and Adipose Tissue

Roundup is a popular herbicide containing glyphosate as an active ingredient. The formulation of Roundup is speculated to have critical toxic effects, one among which is chronic inflammation. The present study analyzed adverse inflammatory effects in the liver and adipose tissue of rats after a subacute exposure of Roundup. Adult male rats were exposed to various doses of Roundup (0, 5, 10, 25, 50, 100 and 250 mg/kg bodyweight [bw] glyphosate) orally, everyday for 14 days. On day 15, liver and adipose tissues from dosed rats were analyzed for inflammation markers. C-reactive protein in liver, cytokines IL-1β, TNF-α, IL-6, and inflammatory response marker, and prostaglandin–endoperoxide synthase were upregulated in liver and adipose of rats exposed to higher (100 and 250 mg/kg bw/d) doses of Roundup. Cumulatively, our data suggest development of inflammation in lipid and hepatic organs upon exposure to Roundup. Furthermore, liver histological studies showed formation of vacuoles, fibroid tissue, and glycogen depletion in the groups treated with doses of higher Roundup. These observations suggest progression of fatty liver disease in Roundup-treated adult rats. In summary, our data suggest progression of multiorgan inflammation, liver scarring, and dysfunction post short-term exposure of Roundup in adult male rats.

Ethnic differences and heterogeneity in genetic and metabolic makeup contributing to nonalcoholic fatty liver disease

Obesity is the most prevalent noncommunicable disease in the 21st century, associated with triglyceride deposition in hepatocytes leading to nonalcoholic fatty liver disease (NAFLD). NAFLD is now present in around a third of the world's population. Epidemiological studies have concluded that ethnicity plays a role in complications and treatment response. However, definitive correlations of ethnicity with NAFLD are thoroughly under-reported. A comprehensive review was conducted on ethnic variation in NAFLD patients and its potential role as a crucial effector in complications and treatment response. The highest NAFLD prevalence is observed in Hispanic populations, exhibiting a worse disease progression. In contrast, African-Caribbeans exhibit the lowest risk, with less severe steatosis and inflammation, lower levels of triglycerides, and less metabolic derangement, but conversely higher prevalence of insulin resistance. The prevalence of NAFLD in Asian cohorts is under-reported, although reaching epidemic proportions in these populations. The most well-documented NAFLD patient population is that of Caucasian ethnicity, especially from the US. The relative paucity of available literature suggests there is a vital need for more large-scale multi-ethnic clinical cohort studies to determine the incidence of NAFLD within ethnic groups. This would improve therapy and drug development, as well as help identify candidate gene mutations which may differ within the population based on ethnic background.

High prevalence of non-alcoholic fatty liver disease and metabolic risk factors in Guatemala: A population-based study

BACKGROUND

There are no data on the prevalence of non-alcoholic fatty liver disease (NAFLD) in general population samples in Guatemala or in other Central American countries. The prevalence and distribution of NAFLD and its associated risk factors were evaluated in a population-based sample of adults in Guatemala.

METHODS

Cross-sectional study of 411 men and women 40 years of age or older residing in urban and rural areas of Guatemala. Metabolic outcomes included obesity, central obesity, hypercholesterolemia, diabetes, and metabolic syndrome (MetS). Liver disease outcomes included elevated liver enzymes, elevated Fatty Liver Index (FLI), and elevated FIB-4 score.

RESULTS

The overall prevalence of obesity, central obesity, diabetes, and MetS were 30.9, 74.3, 21.6, and 64.2%, respectively. The fully-adjusted prevalence ratios (95% CI) for obesity, central obesity, diabetes, and MetS comparing women to men were 2.83 (1.86-4.30), 1.72 (1.46-2.02), 1.18 (1.03-1.34), and 1.87 (1.53-2.29), respectively. The overall prevalence of elevated liver enzymes (ALT or AST), elevated FLI, and elevated FIB-4 scores were 38.4, 60.1, and 4.1%, respectively. The fully-adjusted prevalence ratios (95% CI) for elevated liver enzymes (either ALT or AST) and elevated FLI score comparing women to men were 2.99 (1.84-4.86) and 1.47 (1.18-1.84), respectively.

CONCLUSIONS

The prevalence of metabolic abnormalities and liver outcomes in this general population study was very high. The prevalence of metabolic and liver abnormalities was particularly high among women, an observation that could explain the atypical 1:1 male to female ratio of liver cancer in Guatemala.

Freshwater clam extract reduces liver injury by lowering cholesterol accumulation, improving dysregulated cholesterol synthesis and alleviating inflammation in high-fat, high-cholesterol and cholic acid diet-induced steatohepatitis in mice

Freshwater clam (Corbicula fluminea) is a traditional liver-protective food in Asia. Recent studies have renewed attention on high cholesterol accumulation and dysregulated cholesterol synthesis in the liver as a critical factor in the progression of nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH). In this study, we investigated the protective effects of freshwater clam extract (FCE) and its fat fraction (FCE oil) on high-fat, high-cholesterol and cholic acid (HFHC) diet-induced lean steatohepatitis in mice. Mice were fed a HFHC diet containing FCE or FCE oil for 6 weeks. FCE, but not FCE oil, feeding reduced liver injury as indicated by decreased plasma alanine aminotransferase activity. Liver total cholesterol accumulation was reduced after FCE and FCE oil treatment. Accumulation of squalene and desmosterol, the precursors of cholesterol, in the liver was reduced by FCE but not by FCE oil. The caspase-1 (p10) and interleukin (IL)-1β (p17) protein expressions in the liver were suppressed by both FCE and FCE oil. Therefore, FCE may act as functional food that can reduce steatohepatitis and liver injury by reducing cholesterol accumulation, improving dysregulated cholesterol synthesis and attenuating inflammation.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Visceral adiposity index as a predictor of NAFLD: A prospective study with 4-year follow-up

BACKGROUND & AIMS

Although evidence indicates that visceral adipose tissue is associated with nonalcoholic fatty liver disease (NAFLD), it is unclear whether the visceral adiposity index (VAI) can predict the onset of NAFLD. This study aimed to determine whether the VAI is an independent risk factor of NAFLD and whether there is a dose-response relationship.

METHODS

We explored the relationship between VAI levels and NAFLD in a health check-up cohort established in 2012. There were 4809 subjects with baseline data and results from 4 follow-up examinations. The diagnosis of NAFLD was established by demonstration of increased hepatic echogenicity with ultrasound and exclusion of alcohol overconsumption with questionnaires. We divided the subjects into 4 groups according to baseline VAI levels and used the Cox hazard regression model to estimate NAFLD risk by VAI quartile at baseline by adjusting for potential confounding factors. A Kaplan-Meier survival analysis was used to compare the risk of NAFLD incidence among individuals in each VAI quartile.

RESULTS

The 4-year cumulative incidence of NAFLD in this cohort was 13.9%. The hazard ratios (95% confidence intervals, 95% CI) for NAFLD in the second, third and fourth VAI quartiles compared with the first quartile were 1.42 (95% CI: 1.24-1.64), 1.73 (95% CI: 1.51-1.99) and 2.13(95% CI: 1.86-2.45) respectively. The Kaplan-Meier survival analysis suggested that higher VAI levels predict higher incidences of NAFLD in a dose-dependent relationship.

CONCLUSIONS

Our findings suggest that the VAI level is an independent risk factor of NAFLD and there is a dose-response relationship between VAI level and NAFLD risk.

Nonalcoholic fatty liver disease: current concepts, epidemiology and management strategies

Nonalcoholic fatty liver disease (NAFLD) is now the most prevalent liver disease in the world. It involves a spectrum of conditions from hepatic steatosis to nonalcoholic steatohepatitis and liver fibrosis, and is a major cause of cirrhosis and hepatocellular carcinoma. It is defined by presence of steatosis in 5% of hepatocytes or more in the absence of other causes of fatty liver. The metabolic syndrome is the major known risk factor for NAFLD. Dietary contributors such as high fructose intake and coffee consumption appear to increase and decrease the risk of disease respectively, but these links are unclear. Genetic associations have also been identified. The estimated prevalence of the disease varies according to diagnostic method and population demographics. It appears to be a major issue in Europe with population studies showing up to 50% of the individuals are affected while in the USA one in three adults are estimated to have NAFLD. Laboratory investigations and ultrasound are typically first-line investigations. Fibrosis may be assessed noninvasively through transient elastography and biomarkers but liver biopsy remains the gold standard to quantify hepatic damage. Associated comorbidities include cardiovascular disease and chronic kidney disease. Weight loss, dietary changes and exercise are recommended in management. Medications should be considered to manage underlying risk factors including insulin resistance. Surgical options include bariatric procedures and liver transplantation. The combination of rising prevalence and significant potential complications warrant further research into NAFLD, particularly in areas with research gaps including Eastern Europe.

Effects of Phytosterol Supplementation on Serum Levels of Lipid Profiles, Liver Enzymes, Inflammatory Markers, Adiponectin, and Leptin in Patients Affected by Nonalcoholic Fatty Liver Disease: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial

OBJECTIVE

Considering the high prevalence of nonalcoholic fatty liver disease and based on the evidence about the role of dietary cholesterol in liver inflammation, and also with regard to the effect of phytosterols on the metabolism of cholesterol, we aimed at exploring the therapeutic potential of phytosterol supplementation against nonalcoholic fatty liver disease.

METHOD

Thirty-eight patients with nonalcoholic fatty liver disease were randomly divided into two groups: The phytosterol group (n = 19) received a 1.6-g phytosterol supplement daily and the control group (n = 19) received 1.6 g starch daily as placebo for an 8-week period. Blood samples of all patients were taken at baseline (week 0) and at the end of the study (week 8) for measurement of lipid profiles, liver enzymes, inflammatory markers, adiponectin, and leptin.

RESULTS

Phytosterol supplementation significantly improved the levels of low-density lipoprotein cholesterol, aspartate aminotransferase, alanine aminotransferase, and tumor necrosis factor alpha compared to the placebo group. On the other hand, there were no significant differences between the two groups in total cholesterol, triglycerides, high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, ratios of low-density lipoprotein cholesterol/high-density lipoprotein cholesterol and total cholesterol/high-density lipoprotein cholesterol, gamma-glutamyl transferase, interleukin 6, high-sensitivity C-reactive protein, adiponectin, and leptin.

CONCLUSIONS

The present study suggested that daily consumption of 1.6 g phytosterols efficiently lowers low-density lipoprotein cholesterol, aspartate aminotransferase, alanine aminotransferase, and tumor necrosis factor alpha in patients with nonalcoholic fatty liver disease.

Somatotropic Axis Dysfunction in Non-Alcoholic Fatty Liver Disease: Beneficial Hepatic and Systemic Effects of Hormone Supplementation

Background: Somatotropic axis dysfunction associated with non-alcoholic fatty liver disease (NAFLD) has potential multisystemic detrimental effects. Here, we analysed the effects of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) supplementation on liver histology, adipokine profile and muscle function in an NAFLD model. Methods: C57BL/6 mice were fed with a high fat diet (HFD) for 12 weeks and were separated into three groups treated for 4 weeks with: (1) High fat diet (HFD) (n = 10); (2) HFD + GH 9 μg/g/d (n = 10); (3) HFD + IGF-1 0.02 µg/g/d (n = 9). A control group fed a chow diet was included (n = 6). Liver histology, liver triglycerides content, serum alanine aminotransferase (ALT) activity, adiponectin and leptin serum levels, in vivo muscle strength, tetanic force and muscle fibre cross-sectional area (CSA) were measured. Results: HFD + GH and HFD + IGF-1 groups showed significantly lower ALT activity compared to HFD (p < 0.01). Liver triglyceride content in HFD + GH was decreased compared to HFD (p < 0.01). Histologic steatosis score was increased in HFD and HFD + GH group (p < 0.01), whereas HFD + IGF-1 presented no difference compared to the chow group (p = 0.3). HFD + GH group presented lower serum leptin and adiponectin levels compared to HFD. GH and IGF-1 supplementation therapy reverted HFD-induced reduction in muscle strength and CSA (sarcopenia). Conclusions: GH and IGF-1 supplementation induced significant improvement in liver steatosis, aminotransferases and sarcopenia in a diet-induced NAFLD model.

Metabolic and genetic markers' associations with elevated levels of alanine aminotransferase in adolescents

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in adolescents, is a feature of metabolic syndrome (MetS). Obesity and insulin resistance (IR) are risk factors for NAFLD, as well as inflammation-related genetic markers. The relationship between metabolic or inflammation-related genetic markers and alanine aminotransferase (ALT) is not fully understood. We examined the relationship of MetS, metabolic and inflammation-related genetic markers with elevated ALT in adolescents.

METHODS

A total of 674 adolescents participated in a cross-sectional study in Guadalajara, Mexico. Elevated ALT (>40 IU/L), a surrogate marker of NAFLD, and MetS (International Diabetes Federation definition) were evaluated. Obesity, IR, lipids, C-reactive protein (CRP) and genetic markers (TNFA-308G>A, CRP+1444C>T, IL1RN and IL6-597/-572/-174 haplotype) were evaluated. Multivariate logistic regression was performed.

RESULTS

Elevated ALT was observed in 3% and 14.1% (total and obese, respectively) of the adolescents. Obesity (odds ratio [OR], 5.86; 95% confidence interval [95% CI], 1.16-25.89), insulin (OR, 8.51; 95% CI, 2.61-27.71), IR (OR, 9.10; 95% CI, 2.82-29.38), total cholesterol (TC) (OR, 3.67; 95% CI, 1.25-10.72), low-density lipoprotein-cholesterol (LDL-C) (OR, 3.06; 95% CI, 1.06-8.33), non-high-density lipoprotein-cholesterol (HDL-C) (OR, 3.88; 95% CI, 1.27-11.90) and IL1RN (OR, 4.64; 95% CI, 1.10-19.53) were associated with elevated ALT. Among males, ≥2 MetS criteria were associated with elevated ALT (OR, 4.22; 95% CI, 1.14-15.71).

CONCLUSIONS

Obesity, insulin, IR, high TC, high LDL-C, high non-HDL-C and IL1RN polymorphism were associated with elevated ALT. Among males, ≥2 MetS criteria were associated with elevated ALT. There is an urgent need to reduce obesity and IR in adolescents to prevent NAFLD.

Nonalcoholic fatty liver disease, cholesterol gallstones, and cholecystectomy: new insights on a complex relationship

PURPOSE OF REVIEW

Gallstone disease (GSD) and nonalcoholic fatty liver disease (NAFLD often coexist in a given patient and both conditions are associated to obesity and insulin resistance. The relationship between GSD and NAFLD is complex and bidirectional. In the present review, we summarize the existing information on the complex link between GSD and NAFLD and the potential implications for patient care.

RECENT FINDINGS

Several clinical studies and systematic reviews have addressed the association between NAFLD and GSD underscoring that NAFLD is an independent risk factor for GSD. Conversely, GSD has been found also to be an independent risk factor for NAFLD with GSD potentially being linked to greater disease severity. In addition to the data showing association of NAFLD and GSD, recent evidence has also showed that cholecystectomy may itself be a risk factor for NAFLD development. The complex and bidirectional relationship between these diseases is partially explained by a number of common pathogenic links but the precise underlying mechanisms of the association of GSD and NAFLD need to be better delineated. Also, although the mechanisms of the promotional effect of cholecystectomy on NAFLD development are unknown, recent findings unveiling new aspects of gallbladder physiology and endocrine actions of bile acids provide a framework to advance research in this field.

SUMMARY

In this review, we address the different aspects of the complex association between NAFLD and GSD. The potential underlying mechanisms and recent information on endocrine actions of bile acids and the gallbladder are reviewed.

Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention

NAFLD is one of the most important causes of liver disease worldwide and will probably emerge as the leading cause of end-stage liver disease in the coming decades, with the disease affecting both adults and children. The epidemiology and demographic characteristics of NAFLD vary worldwide, usually parallel to the prevalence of obesity, but a substantial proportion of patients are lean. The large number of patients with NAFLD with potential for progressive liver disease creates challenges for screening, as the diagnosis of NASH necessitates invasive liver biopsy. Furthermore, individuals with NAFLD have a high frequency of metabolic comorbidities and could place a growing strain on health-care systems from their need for management. While awaiting the development effective therapies, this disease warrants the attention of primary care physicians, specialists and health policy makers.

Nonalcoholic fatty liver disease: Diagnostic biomarkers

Nonalcoholic fatty liver disease is a common medical condition worldwide and its prevalence has increased notably in the past few years due to the increases in prevalence of obesity and metabolic syndrome. However, diagnosis of this disease is still a matter of debate because of disease variations and pathophysiologic alterations. Specific single markers have gained considerable attention recently, among them markers related to hepatic pathophysiology, inflammation, adipocytokines and so forth. But, it seems that no single marker is sufficient for diagnosis and staging of the disease, and applying a panel including different types of tests may be more useful.

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.

Decreased C-reactive protein induces abnormal vascular structure in a rat model of liver dysfunction induced by bile duct ligation

Background/Aims

Chronic liver disease leads to liver fibrosis, and although the liver does have a certain regenerative capacity, this disease is associated with dysfunction of the liver vessels. C-reactive protein (CRP) is produced in the liver and circulated from there for metabolism. CRP was recently shown to inhibit angiogenesis by inducing endothelial cell dysfunction. The objective of this study was to determine the effect of CRP levels on angiogenesis in a rat model of liver dysfunction induced by bile duct ligation (BDL).

Methods

The diameter of the hepatic vein was analyzed in rat liver tissues using hematoxylin and eosin (H&E) staining. The expression levels of angiogenic factors, albumin, and CRP were analyzed by real-time PCR and Western blotting. A tube formation assay was performed to confirm the effect of CRP on angiogenesis in human umbilical vein endothelial cells (HUVECs) treated with lithocholic acid (LCA) and siRNA-CRP.

Results

The diameter of the hepatic portal vein increased significantly with the progression of cirrhosis. The expression levels of angiogenic factors were increased in the cirrhotic liver. In contrast, the expression levels of albumin and CRP were significantly lower in the liver tissue obtained from the BDL rat model than in the normal liver. The CRP level was correlated with the expression of albumin in hepatocytes treated with LCA and siRNA-CRP. Tube formation was significantly decreased in HUVECs when they were treated with LCA or a combination of LCA and siRNA-CRP.

Conclusion

CRP seems to be involved in the abnormal formation of vessels in hepatic disease, and so it could be a useful diagnostic marker for hepatic disease.

Association between white blood cell count and non-alcoholic fatty liver disease in urban Han Chinese: a prospective cohort study

OBJECTIVES

The white blood cell (WBC) count is a simple and convenient marker of inflammation for use in medical practice; however, its association with non-alcoholic fatty liver disease (NAFLD) has not been determined. We examined the relationship between WBC and NAFLD to provide a convenient and useful marker for the prediction of NAFLD.

SETTING

A longitudinal cohort participating in a large health check-up programme for the Chinese population was selected and followed up from 2005 to 2011.

PARTICIPANTS

A total of 21 307 male and female participants without NAFLD who underwent health check-ups at least twice between 2005 and 2011 were included in this study. 15 201 participants (7286 men and 7915 women) were eligible for inclusion.

RESULTS

The baseline distribution of age, WBC, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), serum total protein (TP), albumin (ALB) and globin (GLO) and the prevalence of males, hypertension, hyperglycaemia, smoking and regular exercise were significantly different between the incident NAFLD and non-NAFLD groups (p<0.05). Cox proportional hazards regression analysis was performed to estimate the HRs and 95% CIs of WBC, which predicted the occurrence of NAFLD. Compared with the lowest WBC quartile (Q1), the HRs and 95% CIs of the other WBC quartiles (Q2, Q3 and Q4) for incident NAFLD were 1.090 (0.978 to 1.215), 1.174 (1.055 to 1.305) and 1.152 (1.035 to 1.281), respectively, after adjusting for age, gender, smoking, regular exercise, BMI, hypertension, hyperglycaemia, TC, TG, HDL-C, LDL-C, ALB and GLO.

CONCLUSIONS

Our study clearly showed that WBC count was a significant factor associated with incident NAFLD in Han Chinese.

Subclinical inflammation in relation to insulin resistance in prediabetic subjects with nonalcoholic fatty liver disease

Background

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disease commonly associated with obesity, type 2 diabetes, and inflammation-all features of insulin resistant syndrome. However, very limited data are available regarding the association of subclinical inflammation and insulin resistance with NAFLD in a prediabetic state. We, therefore, conducted the study to assess this relationship among this population.

Methods

We studied a cross-sectional analytical design of 140 [male/female, 77/63; age in years (ranges), 45 (25–68)] prediabetic subjects after confirming with 75 g oral glucose tolerance test. The diagnosis of NAFLD was made by ultrasonic examination of the liver and divided into groups of without NAFLD (n = 63) and NAFLD (n = 77). All individuals underwent anthropometric and clinical examinations. Among laboratory investigations, serum glucose was estimated by glucose oxidase method, serum lipid profile and liver enzymes were measured by the enzymatic colorimetric method and glycated hemoglobin was measured by high performance liquid chromatography technique. Serum insulin and high sensitivity C reactive protein (hsCRP) were measured by enzyme immunoassay technique. Insulin resistance (HOMA-IR) was calculated by homeostasis model assessment (HOMA).

Results

There was significantly higher levels of hsCRP (2.82 ± 1.60 vs. 1.39 ± 0.66 mg/l, P < 0.001) and HOMA-IR (4.03 ± 1.39 vs. 1.98 ± 1.04, P < 0.001) in NAFLD subjects compared to their without NAFLD counterparts. hsCRP [odds ratio (OR) = 5.888, 95 % confidence interval (CI) 2.673–12.970, P < 0.001] and HOMA-IR (OR = 4.618, 95 % CI 2.657–8.024, P < 0.001) showed significant determinants of NAFLD after potential confounders of body mass index and triglyceride were adjusted.

Conclusions

Subclinical chronic inflammation and insulin resistance seem to be independent mediators of the association between NAFLD and prediabetes. The data also indicate that the inflammatory condition and insulin resistance are associated with each other and these, in turn, are affected by adiposity and dyslipidemia in prediabetic subjects.

Epidemiology of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis in the United States and the Rest of the World

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease with increasing prevalence, which can progress to cirrhosis and liver failure. Because of the obesity epidemic and increasing prevalence of metabolic syndrome, NAFLD and its progressive form, nonalcoholic steatohepatitis, are seen more commonly in different parts of the world. This article reviews the worldwide epidemiology of NAFLD and nonalcoholic steatohepatitis. The PubMed database was used to identify studies related to epidemiology of NAFLD in the adult population. It is estimated that the epidemic of obesity will continue to fuel the burden of NAFLD and its long-term complications.

The Prevalence and Pathobiology of Nonalcoholic Fatty Liver Disease in Patients of Different Races or Ethnicities

Nonalcoholic fatty liver disease (NAFLD) is emerging as the most common cause of liver disease in the United States. The prevalence varies dramatically when comparing individuals of different races and ethnicities. Rates are highest in Hispanic patient populations compared with non-Hispanic whites and African Americans, despite similar rates of the metabolic syndrome and risk factors. This observation remains poorly characterized; variations in genes that effect lipid metabolism may play a role. This article describes the prevalence of NAFLD in patients of different races or ethnicities, and discusses pathophysiologic mechanisms that may explain why these differences exist.

Metformin Changes the Relationship between Blood Monocyte Toll-Like Receptor 4 Levels and Nonalcoholic Fatty Liver Disease-Ex Vivo Studies

BACKGROUND

Toll-like receptor 4 (TLR4) contributes to the development of NAFLD (nonalcoholic fatty liver disease) and MetS (metabolic syndrome). It is unclear whether anti-diabetic metformin affects TLR4 expression on blood monocytes, thereby protecting or improving inflammatory parameters. Therefore, we investigated TLR4 in patients with NAFLD meeting different sets of MetS criteria and linked the results with the disease burden.

METHODS

70 subjects were characterized and divided into three groups: (I) healthy individuals, (II) nonobese with NAFLD and without MetS, and (III) prediabetic, obese with NAFLD and MetS. We determined the concentrations of IL-1β, IL-6, TNFα, and monocyte TLR4 levels in fresh blood as well as in blood cultures with or without metformin supplementation.

RESULTS

The characteristics of the study groups revealed a significant association between NAFLD and BMI, MetS and inflammatory parameters, and TLR4. In ex vivo studies, 100 μM of metformin decreased the TLR4 level by 19.9% (II group) or by 35% (III group) as well as IL-1β and TNFα production. A stepwise multiple regression analysis highlighted a strong effect of metformin on attenuation of the link between TLR4 and NAFLD, and TNFα.

CONCLUSION

We concluded that, by attenuation of the blood monocyte TLR4 level, metformin reduced their inflammatory potential-critical after recruitment these cells into liver. However, this finding should be confirmed after in vivo metformin administration.

Relationship between non-alcoholic fatty liver disease and inflammation in patients with non-alcoholic fatty liver

Background:

Non-alcoholic fatty liver is the most chronic liver disease that eventually can become cirrhosis. One of the underlying assumptions for the fatty liver created by inflammation of the hepatocytes. We aimed to assess the association between non-alcoholic fatty liver disease (NAFLD) and sub-clinical inflammation.

Materials and Methods:

This is a cross-sectional study which was conducted on 55 patients over 30 years, with NAFLD. Fatty liver grade was assessed using liver ultrasound. Liver enzymes (alanine aminotransferase, aspartate aminotransferase), anthropometric characteristics and inflammatory marker C-reactive protein (CRP) were measured. Qualitative variables (sex and fatty liver grade) and quantitative variables such as were compared with independent t-test and Chi-square test. Relationship between fatty liver grade and inflammatory index was assessed with SPSS software (version 20; SPSS, Inc. Chicago, IL, USA).

Results:

Non-alcoholic fatty liver grades were associated with CRP level and this relationship remains in statistically significant level even after adjusting the effects of confounding variables such as age, sex and body mass index of participants (P = 0.016).

Conclusion:

In this cross-sectional study, presentation of NAFLD showed a significant correlation with sub-clinical systemic inflammation and CRP level.

Nonalcoholic fatty liver disease in patients with coronary disease from a Brazil northeast area

Background Nonalcoholic fatty liver disease (NAFLD) is the most frequent chronic liver injury around the world. It is associated with metabolic syndrome and cardiovascular diseases. Objective To evaluate the frequency and relevance of NAFLD in patients with coronary artery disease (CAD). Methods Patients from a Brazil Northeast area, who underwent elective coronary angiography (CAG) from 2009 to 2010 were included. All of them had suspicion of CAD. Criteria to CAD: presence of obstructive lesions in the epicardial coronary arteries, or in their major branches. NAFLD criteria: presence of hepatic steatosis on ultrasound; exclusion of other liver diseases; ethanol intake ≤ 20g/day. Statistics analysis included Independent t-test, Mann-Whitney and Pearson's chi-squared test. Multivariate regression analysis measured the relationship between the risk factors and the concomitant presence of CAD and NAFLD. Results A total of 244 patients were evaluated: 63.5% had CAD and 42.2% had NAFLD. NAFLD was observed in 43.9% of the CAD patients. The regression analysis showed that the relationship between CAD and NAFLD was positively correlated with HOMA-IR ≥3.0 or insulin resistance and overweight/obesity. Conclusion NAFLD was frequent among CAD patients; insulin resistance and overweight/obesity were the most relevant risk factors related to the association NAFLD and CAD. The results suggest that patients with CAD should be evaluated for NAFLD.