Interpreting lipoproteins in nonalcoholic fatty liver disease

Lack of association between nonalcoholic fatty liver disease and intracerebral hemorrhage: A community-based cohort study

BACKGROUND

The association between nonalcoholic fatty liver disease (NAFLD) and intracerebral hemorrhage (ICH) remains unclear. This study aimed to investigate whether NAFLD and its severity predict incident ICH.

METHODS

Participants free of other liver diseases, prior stroke, myocardial infarction, cancer, or alcohol abuse in the Kailuan cohort were enrolled in this study. Abdominal ultrasonography was used to diagnose NAFLD and assess its severity. Participants were stratified into different groups including nonfatty liver, mild, moderate and severe NAFLD. Multivariable Cox proportional hazards regression models were used to evaluate the hazard ratios (HRs) and 95% CIs of ICH events in the 11-year follow-up.

RESULTS

A total of 77,461 participants were enrolled in our study. Among them, NAFLD was diagnosed in 23,890 (30.83 %) participants, including 15,581 (20.11 %) with mild NAFLD, 6839 (8.83 %) with moderate NAFLD and 1470 (1.90 %) with severe NAFLD. We documented 692 ICH events during 848,579 person years of follow-up. Patients with more severe NAFLD tended to be older, had higher levels of BMI, higher proportions of hypertension, diabetes and other known risk factors for cerebrovascular disease. However, there was no significant associations between NAFLD, its severity and incident ICH events. Relative to nonfatty liver participants, the HRs for participants with mild NAFLD, moderate and severe NAFLD were 0.98 (95 % CI, 0.80 to 1.20), 1.19 (95 % CI, 0.92 to 1.54) and 1.29 (95 % CI, 0.81 to 2.06), respectively.

CONCLUSIONS

NAFLD and its severity did not appear to be significantly associated with ICH after adjustment for potential risk factors.

Relationship between Uric Acid to High Density Lipoprotein Cholesterol Ratio and Nonalcoholic Fatty Liver Disease in Nonoverweight/Obese Patients with Type 2 Diabetes

AIMS

To investigate the relationship between uric acid to high-density lipoprotein cholesterol ratio (UHR) levels and nonalcoholic fatty liver disease (NAFLD) in nonoverweight/obese patients with type 2 diabetes.

METHODS

A retrospective study was designed including a total of 343 inpatients with type 2 diabetes whose BMI<24 kg/m2. The population was divided into three groups as the UHR tertiles. Logistic regression analysis was performed to estimate odds ratios (ORs) of UHR for NAFLD. ROC curve analysis was used to estimate the diagnostic value of UHR for NAFLD.

RESULTS

The prevalence rat of NAFLD enhanced progressively from the tertile 1 to tertile 3 of UHR (30.70% vs. 56.52% vs. 73.68%). Logistic regression analysis showed that participants in the higher UHR groups, compared with those in the first tertile group, had higher occurrence risks for NAFLD. The positive association between UHR and NAFLD was independent of age, BMI, blood pressure, hepatic enzymes, and other components of metabolic disorders. ROC curve analysis showed that the area under curve (AUC), sensitivity, and specificity for UHR were 0.697, 0.761, and 0.553, respectively.

CONCLUSIONS

In type 2 diabetic patients without overweight or obesity, UHR is significantly associated with NAFLD and can be used as a novel and useful predictor for NAFLD onset.

Network Pharmacological Analysis of a New Herbal Combination Targeting Hyperlipidemia and Efficacy Validation In Vitro

The network pharmacology (NP) approach is a valuable novel methodology for understanding the complex pharmacological mechanisms of medicinal herbs. In addition, various in silico analysis techniques combined with the NP can improve the understanding of various issues used in natural product research. This study assessed the therapeutic effects of Arum ternata (AT), Poria cocos (PC), and Zingiber officinale (ZO) on hyperlipidemia after network pharmacologic analysis. A protein-protein interaction (PPI) network of forty-one key targets was analyzed to discover core functional clusters of the herbal compounds. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene ontology (GO) term enrichment analysis identified significant categories of hypolipidemic mechanisms. The STITCH database indicated a high connection with several statin drugs, deduced by the similarity in targets. AT, PC, and ZO regulated the genes related to the energy metabolism and lipogenesis in HepG2 cells loaded with free fatty acids (FFAs). Furthermore, the mixture of three herbs had a combinational effect. The herbal combination exerted superior efficacy compared to a single herb, particularly in regulating acetyl-CoA carboxylase (ACC) and carnitine palmitoyltransferase 1 (CPT-1). In conclusion, the network pharmacologic approach was used to assess potential targets of the herbal combination for treatment. Experimental data from FFA-induced HepG2 cells suggested that the combination of AT, PC, and ZO might attenuate hyperlipidemia and its associated hepatic steatosis.

Alcohol consumption and metabolic syndrome: Clinical and epidemiological impact on liver disease

Alcohol use and metabolic syndrome are highly prevalent in the population and frequently co-exist. Both are implicated in a large range of health problems, including chronic liver disease, hepatocellular carcinoma, and liver-related outcomes (i.e. decompensation or liver transplantation). Studies have yielded mixed results regarding the effects of mild-moderate alcohol consumption on the risk of metabolic syndrome and fatty liver disease, possibly due to methodological differences. The few available prospective studies have indicated that mild-moderate alcohol use is associated with an increase in liver-related outcomes. This conclusion was substantiated by systems biology analyses suggesting that alcohol and metabolic syndrome may play a similar role in fatty liver disease, potentiating an already existing dysregulation of common vital homeostatic pathways. Alcohol and metabolic factors are independently and jointly associated with liver-related outcomes. Indeed, metabolic syndrome increases the risk of liver-related outcomes, regardless of alcohol intake. Moreover, the components of metabolic syndrome appear to have additive effects when it comes to the risk of liver-related outcomes. A number of population studies have implied that measures of central/abdominal obesity, such as the waist-to-hip ratio, can predict liver-related outcomes more accurately than BMI, including in individuals who consume harmful quantities of alcohol. Many studies even point to synergistic interactions between harmful alcohol use and many metabolic components. This accumulating evidence showing independent, combined, and modifying effects of alcohol and metabolic factors on the onset and progression of chronic liver disease highlights the multifactorial background of liver disease in the population. The available evidence suggests that more holistic approaches could be useful for risk prediction, diagnostics and treatment planning.

Risk for hepatic and extra-hepatic outcomes in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is defined by presence of steatosis in more than 5% of liver cells. The gold standard for diagnosis is liver biopsy, but this is seldom achieved due to costs and risk for side effects, and that is why the diagnosis is mostly made based on a combination of radiology and exclusion of other liver diseases. Disease severity staging can be noninvasively achieved with radiological exams such as elastography or blood-based markers that usually have lower sensitivity and specificity. NAFLD is today the most common chronic liver disease globally with a prevalence estimated to be 25%. Fortunately, for many persons NAFLD is an incidental finding with a good prognosis. Whilst a major focus has been on liver-related outcomes in NAFLD, there has recently been an increased interest in extrahepatic consequences of NAFLD. The most commonly studied outcomes include cardiovascular disease and cancer. The risk of adverse outcomes generally differs according to the baseline fibrosis stage. There is a five-time higher risk of liver-related events in NAFLD patients with fibrosis stage 3 as compared to those with no or little fibrosis. Meanwhile, the presence of nonalcoholic steatohepatitis (NASH) does not seem to influence prognosis in addition to fibrosis stage. Patients with NAFLD clearly have a higher risk for cardiovascular outcomes compared to the general population, with a recent meta-analysis indicating a 37% increased hazard for cardiovascular events as opposed to individuals without NAFLD. The risk of liver cancer is increased, which is mostly driven by presence of cirrhosis, but the increased risk is present also in patients without cirrhosis, and to a greater extent than for other chronic liver disease. Around one-third of patients with NAFLD and liver cancer do not have cirrhosis. Additionally, the risk of extrahepatic malignancies is thought to be moderately increased, with most evidence for a link between NAFLD and colorectal cancer where the risk is approximately 50% higher compared to patients without NAFLD. A particularly salient point is if NAFLD can be considered an independent risk factor for outcomes. Many studies have not been able to adjust for key confounders, or suffer from different forms of bias. The clinical problem is nevertheless to identify persons with an increased risk for adverse hepatic and extrahepatic outcomes. We here discuss the evidence linking NAFLD to severe hepatic and extrahepatic outcomes.

Increased Risk of Nonalcoholic Fatty Liver Disease in Individuals with High Weight Variability

BACKGROUND

Weight loss through lifestyle modification is recommended for patients with nonalcoholic fatty liver disease (NAFLD). Recent studies have suggested that repeated loss and gain of weight is associated with worse health outcomes. This study aimed to examine the association between weight variability and the risk of NAFLD in patients without diabetes.

METHODS

We examined the health-checkup data of 30,708 participants who had undergone serial examinations between 2010 and 2014. Weight variability was assessed using coefficient of variation and the average successive variability of weight (ASVW), which was defined as the sum of absolute weight changes between successive years over the 5-year period divided by 4. The participants were classified according to the baseline body mass index and weight difference over 4 years.

RESULTS

On dividing the participants into four groups according to ASVW quartile groups, those in the highest quartile showed a significantly increased risk of NAFLD compared to those in the lowest quartile (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.63 to 2.19). Among participants without obesity at baseline, individuals with high ASVW showed increased risk of NAFLD (OR, 1.80; 95% CI, 1.61 to 2.01). Participants with increased weight over 4 years and high ASVW demonstrated higher risk of NAFLD compared to those with stable weight and low ASVW (OR, 4.87; 95% CI, 4.29 to 5.53).

CONCLUSION

Regardless of participant baseline obesity status, high weight variability was associated with an increased risk of developing NAFLD. Our results suggest that further effort is required to minimize weight fluctuations after achieving a desirable body weight.

Mitochondrial Mutations and Genetic Factors Determining NAFLD Risk

NAFLD (non-alcoholic fatty liver disease) is a widespread liver disease that is often linked with other life-threatening ailments (metabolic syndrome, insulin resistance, diabetes, cardiovascular disease, atherosclerosis, obesity, and others) and canprogress to more severe forms, such as NASH (non-alcoholic steatohepatitis), cirrhosis, and HCC (hepatocellular carcinoma). In this review, we summarized and analyzed data about single nucleotide polymorphism sites, identified in genes related to NAFLD development and progression. Additionally, the causative role of mitochondrial mutations and mitophagy malfunctions in NAFLD is discussed. The role of mitochondria-related metabolites of the urea cycle as a new non-invasive NAFLD biomarker is discussed. While mitochondria DNA mutations and SNPs (single nucleotide polymorphisms) canbe used as effective diagnostic markers and target for treatments, age and ethnic specificity should be taken into account.

New insight and potential therapy for NAFLD: CYP2E1 and flavonoids

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

Serum proteome assessment in nonalcoholic fatty liver disease in children: a preliminary study

OBJECTIVES

Nonalcoholic fatty disease (NAFLD) affects 3-10% of the pediatric population, making it the most common chronic liver disease among children. The aim of the study is to identify potential biomarkers enabling the diagnosis of NAFLD and monitoring the course of the disease.

METHODS

Proteome analysis was performed in a group of 30 patients (19 boys and 11 girls) in total, of whom 16 children had previously diagnosed NAFLD based on the abdominal ultrasound after excluding other diseases of this organ.

RESULTS

A total of 297 proteins have been identified. Thirty-seven proteins (responsible for inflammation, stress response, and regulation of this process) differentiating both experimental groups were identified. Up-regulated proteins included afamin, retinol-binding protein-4, complement components, and hemopexin; while serum protease inhibitors, clusterin, immunoglobulin chains, and vitamin D binding protein were found in the down-regulated group. The correlation between selected proteins and indicators of noninvasive assessment of liver fibrosis (APRI, FIB-4) as well as differences between the serum proteome of patients with normal weight, overweight, and obesity were also assessed.

CONCLUSION

The plasma protein profile is significantly altered in nonalcoholic liver disease in children and may prove to be a valuable source of biomarkers to evaluate the extent of liver disease.

Review article: the impact of liver-directed therapies on the atherogenic risk profile in non-alcoholic steatohepatitis

BACKGROUND

Patients with non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, are at higher risk of cardiovascular disease (CVD) and associated mortality. Therefore, it is important to understand how new therapies for non-alcoholic steatohepatitis (NASH) may impact CVD risk factors in these patients.

AIMS

To summarise the effects of drug therapies on lipid and lipoprotein levels in patients with NASH and provide insight into the potential mechanisms for the observed changes.

METHODS

PubMed searches of the literature were performed and results were compiled.

RESULTS

Recent clinical trials have highlighted the safety and efficacy of drug candidates for the treatment of NASH. Several agents have shown improvements in the histological features of NASH and liver function. Pioglitazone, a drug that is currently available for type 2 diabetes and may be useful for NASH, exhibits beneficial effects on lipids. However, agents such as farnesoid X receptor agonists, which are in development for NASH, may adversely affect circulating lipids and lipoproteins.

CONCLUSIONS

NASH is a multi-system disease with a disproportionate CVD burden. Current and future drugs for NASH have had variable impact on the atherogenic risk profile. Potential co-administration of a statin may help mitigate the negative impact of some of these therapies on lipid and lipoprotein levels.

Lipoprotein A, combined with alanine aminotransferase and aspartate aminotransferase, contributes to predicting the occurrence of NASH: a cross-sectional study

Background

Nonalcoholic steatohepatitis (NASH) progresses from simple nonalcoholic fatty liver (NAFL) and has a poor prognosis. Abnormal lipid metabolism is closely related to the occurrence and development of nonalcoholic fatty liver disease (NAFLD). This study aimed to study the relationships between serum lipid metabolites and NASH, and to improve the early diagnosis of NASH.

Methods

This study included 86 NAFLD patients (23 NASH and 63 NAFL), and 81 unaffected individuals as controls from West China Hospital between October 2018 and May 2019. With lipid metabolites as the focus of the study, the differences in lipid metabolites were compared between the control group, NAFL patients, and NASH patients. Logistic regression analysis was used to examine the risk factors of NASH. Finally, receiver operating characteristic curve (ROC curve) was used to analyze the efficacy of the metabolites in NASH prediction.

Results

The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipoprotein A (LPA) increased with the severity of NAFLD. In NAFLD patients, LPA (OR:1.61; 95%CI: 1.03–2.52) was a potential risk factor for NASH, and ROC analysis showed that the combination of LPA, ALT, and AST had a greater predictive efficiency for NASH.

Conclusions

Abnormal apolipoprotein/lipoprotein is closely related to lipid metabolism disorder in patients with NAFLD. In NAFL, the combination of LPA, ALT, and AST contributes to predicting the occurrence of NASH. LPA may be a potential biomarker and therapeutic target for diagnosing and treating NASH.

Associations among liver disease, serum lipid profile, body mass index, ketonuria, meal skipping, and the alcohol dehydrogenase-1B and aldehyde dehydrogenase-2 genotypes in Japanese men with alcohol dependence

AIM

To elucidate associations among liver disease, lipid profile, body mass index (BMI), ketonuria, and meal skipping under the influence of alcohol dehydrogenase-1B (ADH1B; rs1229984) and aldehyde dehydrogenase-2 (ALDH2; rs671) genotypes in men with alcohol dependence.

METHODS

We investigated the associations among these variables in 1768 Japanese men with alcohol dependence. Serum lipid levels were followed up after abstinence.

RESULTS

The slow-metabolizing ADH1B Arg/Arg genotype and inactive ALDH2 Glu/Lys genotype increased the age- and drinking-adjusted odds ratio or regression coefficient for fatty liver, ketonuria, and serum high-density-lipoprotein cholesterol levels (HDL-C), and decreased these for cirrhosis and serum triglyceride levels (TG). The ADH1B Arg/Arg genotype increased the adjusted regression coefficient for BMI and non-HDL-C. In addition to the positive interlinkage among fatty liver, BMI, and atherogenic dyslipidemia, positive associations were observed of fatty liver with ketonuria and meal skipping, of cirrhosis with the BMI, and of ketonuria with non-HDL-C. Negative associations were observed of cirrhosis with fatty liver, TG, non-HDL-C, and HDL-C, and of ketonuria with BMI and TG. Overall, after admission for 4 or 6 weeks, the TG and HDL-C decreased, and the serum low-density lipoprotein cholesterol levels increased. However, there was no change of the serum low-density lipoprotein in the patients with cirrhosis or of the serum TG in those with fatty liver.

CONCLUSIONS

These associations and the alterations in lipid profile after abstinence serve as useful information for a better understanding of the clinical features of men with alcohol dependence.

Mutual interaction between endoplasmic reticulum and mitochondria in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common metabolic syndrome. Imbalances between liver lipid output and input are the direct causes of NAFLD, and hepatic steatosis is the pathological premise and basis for NAFLD progression. Mutual interaction between endoplasmic reticulum stress (ERS) and oxidative stress play important roles in NAFLD pathogenesis. Notably, mitochondria-associated membranes (MAMs) act as a structural bridges for functional clustering of molecules, particularly for Ca²⁺, lipids, and reactive oxygen species (ROS) exchange. Previous studies have examined the crucial roles of ERS and ROS in NAFLD and have shown that MAM structural and functional integrity determines normal ER- mitochondria communication. Upon disruption of MAM integrity, miscommunication directly or indirectly causes imbalances in Ca2+ homeostasis and increases ERS and oxidative stress. Here, we emphasize the involvement of MAMs in glucose and lipid metabolism, chronic inflammation and insulin resistance in NAFLD and summarize MAM-targeting drugs and compounds, most of which achieve their therapeutic or ameliorative effects on NAFLD by improving MAM integrity. Therefore, targeting MAMs may be a viable strategy for NAFLD treatment. This review provides new ideas and key points for basic NAFLD research and drug development centred on mitochondria and the endoplasmic reticulum.

Microvesicles and exosomes in metabolic diseases and inflammation

Metabolic diseases are based on a dysregulated crosstalk between various cells such as adipocytes, hepatocytes and immune cells. Generally, hormones and metabolites mediate this crosstalk that becomes alterated in metabolic syndrome including obesity and diabetes. Recently, Extracellular Vesicles (EVs) are emerging as a novel way of cell-to-cell communication and represent an attractive strategy to transfer fundamental informations between the cells through the transport of proteins and nucleic acids. EVs, released in the extracellular space, circulate via the various body fluids and modulate the cellular responses following their interaction with the near and far target cells. Clinical and experimental data support their role as biomarkers and bioeffectors in several diseases includimg also the metabolic syndrome. Despite numerous studies on the role of macrophages in the development of metabolic diseases, to date, there are little informations about the influence of metabolic stress on the EVs produced by macrophages and about the role of the released vesicles in the organism. Here, we review current understanding about the role of EVs in metabolic diseases, mainly in inflammation status burst. This knowledge may play a relevant role in health monitoring, medical diagnosis and personalized medicine.

Association between Serum Uric Acid to HDL-Cholesterol Ratio and Nonalcoholic Fatty Liver Disease in Lean Chinese Adults

METHODS

A cross-sectional study was performed among 6285 lean Chinese adults (body mass index < 24 kg/m²) who took their annual health checkups. NAFLD was diagnosed based on hepatic ultrasound examination, with exclusion of other etiologies.

RESULTS

Of 6285 lean participants enrolled, 654 NAFLD cases were diagnosed. The overall NAFLD prevalence was 10.41%, and the prevalence was 15.45% and 7.16% in men and women, respectively. UHR was significantly higher in NAFLD patients than in controls (14.25 ± 5.33% versus 10.09 ± 4.23%, P < 0.001). UHR quintiles were positively associated with NAFLD prevalence, which was 1.91% in the first UHR quintile and increased to 3.58%, 7.81%, 14.17%, and 24.54% in the second, third, fourth, and fifth quintile groups, respectively (P < 0.001 for trend). Multivariate logistic regression analysis showed that UHR was independently associated with an increased risk of NAFLD (odds ratio: 1.105; 95% CI: 1.076-1.134; P < 0.001). Sensitivity analysis showed that UHR remained significantly associated with NAFLD in lean participants with normal range of serum uric acid and HDL-cholesterol levels.

CONCLUSIONS

UHR was significantly associated with NAFLD and may serve as a novel and reliable marker for NAFLD in lean adults.

Atorvastatin and Vitamin E Accelerates NASH Resolution by Dietary Intervention in a Preclinical Guinea Pig Model

Despite affecting millions of patients worldwide, no pharmacological treatment has yet proved effective against non-alcoholic steatohepatitis (NASH) induced liver fibrosis. Current guidelines recommend lifestyle modifications including reductions in dietary energy intake. Recently, therapy with atorvastatin and vitamin E (vitE) has been recommended, although clinical studies on the resolution of hepatic fibrosis are inconclusive. Targeting NASH-induced hepatic end-points, this study evaluated the effects of atorvastatin and vitE alone or in combination with a dietary intervention in the guinea pig NASH model. Guinea pigs (n = 72) received 20 weeks of high fat feeding before allocating to four groups: continued HF feeding (HF), HF diet with atorvastatin and vitE (HF+), low-fat diet (LF) and low-fat with atorvastatin and vitE (LF+), for four or eight weeks of intervention. Both LF and LF+ decreased liver weight, cholesterol and plasma dyslipidemia. LF+ further improved hepatic histopathological hallmarks (p < 0.05), liver injury markers aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (p < 0.05) and reduced the expression of target genes of hepatic inflammation and fibrosis (p < 0.05), underlining an increased effect on NASH resolution in this group. Collectively, the data support an overall beneficial effect of diet change, and indicate that atorvastatin and vitE therapy combined with a diet change act synergistically in improving NASH-induced endpoints.

Combined obeticholic acid and elafibranor treatment promotes additive liver histological improvements in a diet-induced ob/ob mouse model of biopsy-confirmed NASH

Obeticholic acid (OCA) and elafibranor (ELA) are selective and potent agonists for the farnesoid X receptor (FXR) and dual peroxisome proliferator-activated receptor α/δ (PPAR-α/δ), respectively. Both agents have demonstrated clinical efficacy in nonalcoholic steatohepatitis (NASH). The present study used OCA and ELA to compare the effects of mono- and combination therapies on metabolic and histological endpoints in Lep^ob/ob mice with established diet-induced and biopsy-confirmed NASH (ob/ob-NASH). ob/ob-NASH mice were fed the AMLN diet high in trans-fat, fructose and cholesterol for 15 weeks, whereafter they received vehicle, OCA (30 mg/kg, PO, QD), ELA (3, 10 mg/kg, PO, QD), or combinations (OCA + ELA) for eight weeks. Within-subject comparisons were performed on histomorphometric changes, including fractional area of liver fat, galectin-3 and Col1a1. OCA and ELA monotherapies improved all quantitative histopathological parameters and OCA + ELA combinations exerted additive effects on metabolic and histological endpoints. In agreement with their different molecular mechanisms of action, OCA and ELA monotherapies elicited distinct hepatic gene expression profiles and their combination led to profound transcriptome changes associated with further improvements in lipid handling and insulin signaling, suppression of immune responses and reduced extracellular matrix formation. In conclusion, these findings provide preclinical proof-of-concept for combined FXR and PPAR-α/δ agonist-based therapies in NASH.

Vésicules extracellulaires, biomarqueurs et bioeffecteurs du syndrome métabolique

Les vésicules extracellulaires (VE) suscitent un intérêt croissant lié à leur capacité à transférer du contenu biologique entre cellules. Les VE, émises dans l’espace extracellulaire, circulent via les différents fluides de l’organisme et modulent localement ou à distance les réponses des cellules avec lesquelles elles ont interagi. Des données cliniques et expérimentales étayent leur rôle dans les maladies liées au syndrome métabolique. Les VE bousculent la vision traditionnelle de la communication intercellulaire et représentent ainsi un mode de communication alternatif et versatile, qui ouvre la porte à de nouveaux concepts et opportunités tant biologiques que thérapeutiques.

Apolipoprotein A5 gene polymorphisms are associated with non-alcoholic fatty liver disease

BACKGROUND

Several studies have reported that apolipoprotein A5 (APOA5) is involved in the development of non-alcoholic fatty liver disease (NAFLD). However, no research has been performed regarding the association between APOA5 polymorphisms and the risk of NAFLD. This study aimed to explore the association between APOA5 gene polymorphisms and NAFLD in a Chinese Han population.

METHODS

Genotypes of the SNPs (rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 in 232 NAFLD patients and 188 healthy controls were determined using polymerase chain reaction (PCR) analysis. Clinical characteristics were measured using biochemical methods.

RESULTS

The five single nucleotide polymorphisms (SNPs) (rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 showed no significant association with NAFLD (P > 0.05). The rs10750097 with G allele showed a higher serum level of alkaline phosphatase (ALP) compared with C allele in overall series and NAFLD patients (P < 0.05). The rs1263173(A/A) carriers showed a higher level of glucose compared to the non-carriers in overall series (P < 0.05). The rs17120035(T/T) carriers showed a lower plasma TG level in overall series and NAFLD patients (P < 0.05), and the rs662799(G/G) carriers showed higher levels of plasma triglyceride (TG), ALP, and lower level of high-density lipoprotein (HDL) compared to non-carriers in NAFLD patients (P < 0.05). No significant difference were observed on the clinic parameters of APOA5 rs3135507(T/T) carriers in both group of overall series and NAFLD patients (P > 0.05).

CONCLUSIONS

The five SNPs (rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 gene are not associated with the risk of NAFLD in the Chinese Han population. The genotypes of rs10750097(G/G), rs1263173(A/A), rs17120035(T/T), and rs662799(G/G) performed a significant effect on clinic characteristics in overall series and NAFLD patients, indicating that these polymorphisms may be associated with NAFLD.

Interaction between alcohol consumption and metabolic syndrome in predicting severe liver disease in the general population

The metabolic syndrome and alcohol risk use are both associated with a high prevalence of hepatic steatosis, but only a minority develop liver failure or liver cancer. Few general population studies have analyzed metabolic predictors of such severe liver complications. We studied which metabolic factors best predict severe liver complications, stratified by alcohol consumption, in 6732 individuals without baseline liver disease who participated in the Finnish population-based Health 2000 Study (2000-2001), a nationally representative cohort. Follow-up data from national registers until 2013 were analyzed for liver-related admissions, mortality, and liver cancer. Baseline alcohol use and metabolic factors were analyzed by backward stepwise Cox regression analysis. Eighty-four subjects experienced a severe liver event during follow-up. In the final multivariate model, factors predictive of liver events were age (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.004-1.04), sex (women: HR, 0.55; 95% CI, 0.34-0.91), alcohol use (HR, 1.002; 95% CI, 1.001-1.002), diabetes (HR, 2.73; 95% CI, 1.55-4.81), low-density lipoprotein (LDL) cholesterol (HR, 0.74; 95% CI, 0.58-0.93), and homeostasis model assessment of insulin resistance (HOMA-IR) (HR, 1.01; 95% CI, 1.004-1.02). Among alcohol risk users (≥210 g/week for men, ≥ 140 g/week for women), diabetes (HR, 6.79; 95% CI, 3.18-14.5) was the only significant predictor. Among nonrisk drinkers, age, alcohol use, smoking, waist circumference, low LDL cholesterol and HOMA-IR were significant independent predictors. The total-to-LDL cholesterol ratio and waist circumference-to-body mass index ratio emerged as additional independent predictors.

CONCLUSION

Multiple components of the metabolic syndrome independently affected the risk for severe liver disease. Alcohol was significant even when average alcohol consumption was within the limits currently defining nonalcoholic fatty liver disease. (Hepatology 2018;67:2141-2149).

Fructose Consumption, Lipogenesis, and Non-Alcoholic Fatty Liver Disease

Increased fructose consumption has been suggested to contribute to non-alcoholic fatty liver disease (NAFLD), dyslipidemia, and insulin resistance, but a causal role of fructose in these metabolic diseases remains debated. Mechanistically, hepatic fructose metabolism yields precursors that can be used for gluconeogenesis and de novo lipogenesis (DNL). Fructose-derived precursors also act as nutritional regulators of the transcription factors, including ChREBP and SREBP1c, that regulate the expression of hepatic gluconeogenesis and DNL genes. In support of these mechanisms, fructose intake increases hepatic gluconeogenesis and DNL and raises plasma glucose and triglyceride levels in humans. However, epidemiological and fructose-intervention studies have had inconclusive results with respect to liver fat, and there is currently no good human evidence that fructose, when consumed in isocaloric amounts, causes more liver fat accumulation than other energy-dense nutrients. In this review, we aim to provide an overview of the seemingly contradicting literature on fructose and NAFLD. We outline fructose physiology, the mechanisms that link fructose to NAFLD, and the available evidence from human studies. From this framework, we conclude that the cellular mechanisms underlying hepatic fructose metabolism will likely reveal novel targets for the treatment of NAFLD, dyslipidemia, and hepatic insulin resistance. Finally, fructose-containing sugars are a major source of excess calories, suggesting that a reduction of their intake has potential for the prevention of NAFLD and other obesity-related diseases.