Non-alcoholic fatty liver disease and cardiovascular disease: epidemiological, clinical and pathophysiological evidences

Cardiometabolic risk factors and coronary atherosclerosis progression in patients with metabolic dysfunction-associated steatotic liver disease: the influential role of quantity over type

BACKGROUND AND AIM

Individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) who are at an increased risk of cardiovascular disease (CVD) are critical to identify and manage. We aimed to assess whether the risk of CVD in patients with MASLD differed according to the type or number of cardiometabolic risk factors.

METHODS

This longitudinal cohort study involved 5674 adults who underwent at least two health checkups between 2004 and 2021. Steatotic liver disease (SLD) was assessed using ultrasonography and participants with SLD were classified as having either non-MASLD or MASLD. CVD risk was evaluated using coronary artery calcium (CAC) progression as measured using multidetector computed tomography scans.

RESULTS

Over an average 5.8-year follow-up period, patients with MASLD exhibited faster CAC progression than those with non-MASLD (18% vs 11%, P < 0.01). MASLD with any cardiometabolic risk factor exacerbated CAC progression; however, the degree of CAC progression was similar among the different risk components. The adjusted ratios (95% CI) of CAC progression rates comparing non-MASLD with MASLD with one, two, three, four, and five cardiometabolic risk factors were 1.02 (0.99, 1.06), 1.04 (1.01, 1.08), 1.07 (1.03, 1.10), 1.08 (1.05, 1.11), and 1.11 (1.07, 1.15), respectively.

CONCLUSIONS

In individuals with MASLD, all cardiometabolic risk factors contributed to the deterioration of coronary atherosclerosis, with no specific factor exerting a dominant influence. Coronary atherosclerosis progression is directly associated with the cumulative number of cardiometabolic risk factors. Therefore, identifying and managing an increasing number of these factors is imperative in clinical practice, even when MASLD is diagnosed based on only one risk factor.

The association of metabolic dysfunction-associated steatotic liver disease (MASLD) with the risk of myocardial infarction: a systematic review and meta-analysis

Objective While studies have documented how metabolic dysfunction-associated steatotic liver disease (MASLD) can contribute to cardiovascular disease (CVD), whether MASLD is associated with myocardial infarction (MI) remains debateable. Herein, we systematically reviewed published articles and performed a meta-analysis to determine the relationship between MASLD and MI risk.Methods PubMed, MEDLINE, Embase, Web of Science, CNKI, CBM, VIP, and WanFang databases were searched, and the DerSimonian Laird method was used to obtain hazard ratios (HRs) for binary variables to assess the correlation between MASLD and MI risk. Subgroup analyses for the study region, MASLD diagnosis, quality score, study design, and follow-up time were conducted simultaneously for the selected studies retrieved from the time of database establishment to March 2022. All study procedures were independently conducted by two investigators.Results The final analysis included seven articles, including eight prospective and two retrospective cohort studies. The MI risk was higher among MASLD patients than among non-MASLD patients (HR = 1.26; 95% CI: 1.08-1.47, p = 0.003). The results of the subgroup analysis of the study region revealed an association of MASLD with MI risk among Americans and Asians, but not in Europeans. Subgroup analyses of MASLD diagnosis showed that ultrasonography and other (fatty liver index[FLI] and computed tomography [CT)]) diagnostic methods, but not international classification of disease (ICD), increased the risk of MI. Subgroup analysis of the study design demonstrated a stronger relationship between MASLD and MI in retrospective studies but not in prospective studies. Subgroup analysis based on the follow-up duration revealed the association of MASLD with MI risk in cases with < 3 years of follow-up but not with ≥3 years of follow-up.Conclusion MASLD increases the risk of MI, independent of traditional risk factors.

Liver magnetic resonance imaging, non-alcoholic fatty liver disease and metabolic syndrome risk in pre-pubertal Mexican boys

Rising global pediatric obesity rates, increase non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) prevalence, with MetS being a NAFLD risk factor. NAFLD can be asymptomatic, with liver function tests insensitive to mild disease, and liver biopsy, risking complications. Thus, we investigated multiparametric MRI (mpMRI) metrics of liver fat (proton density fat fraction, PDFF) and disease activity (fibro-inflammation; iron-corrected T1, cT1), in a Hispanic pre-pubertal pediatric cohort, with increased risk of NAFLD. Pre-pubertal boys (n = 81) of varying Body-Mass Index (BMI) were recruited in Mexico City. Most children (81%) had normal liver transaminase levels, 38% had high BMI, and 14% had ≥ 3 MetS risk factors. Applying mpMRI thresholds, 12%, 7% and 4% of the cohort had NAFLD, NASH and high-risk NASH respectively. Participants with ≥ 3 MetS risk factors had higher cT1 (834 ms vs. 737 ms, p = 0.004) and PDFF (8.7% vs. 2.2%, p < 0.001) compared to those without risk factors. Those with elevated cT1 tended to have high BMI and high insulin (p = 0.005), HOMA-IR (p = 0.005) and leptin (p < 0.001). The significant association of increased risk of MetS with abnormal mpMRI, particularly cT1, proposes the potential of using mpMRI for routine pediatric NAFLD screening of high-risk (high BMI, high MetS risk score) populations.

Nonalcoholic Fatty Liver Disease and the Kidney: A Review

Nonalcoholic fatty liver disease (NAFLD) is associated with several extrahepatic manifestations such as cardiovascular disease and sleep apnea. Furthermore, NAFLD is reported to be associated with an increased risk of incident chronic kidney disease (CKD). Inflammation and oxidative stress are suggested to be the key factors involved in the inflammatory mechanisms and pathways linking NAFLD to CKD and are responsible for both the pathogenesis and the progression of CKD in NAFLD patients. This review aims to provide a more comprehensive overview of the association between CKD and NAFLD, also considering the effect of increasing severity of NAFLD. A PubMed search was conducted using the terms "non-alcoholic fatty liver disease AND kidney". In total, 537 articles were retrieved in the last five years and 12 articles were included in the qualitative analysis. Our results showed that CKD developed more frequently in NAFLD patients compared to those without NAFLD. This association persisted after adjustment for traditional risk factors and according to the severity of NAFLD. Therefore, patients with NAFLD should be considered at high risk of CKD. Intensive multidisciplinary surveillance over time is needed, where hepatologists and nephrologists must act together for better and earlier treatment of NAFLD patients.

A Review of Research Progress on Agathis dammara and its Application Prospects for Cardiovascular Diseases and Fatty Liver Disease

Cardiovascular diseases and fatty liver disease have become the leading causes of death in modern society. However, the currently existing drugs do not solve all issues related to these diseases; thus, it is expected that more potential drugs for clinical use will be developed. Undeniably, natural products have attracted increasing attention. It is of great significance to identify effective active monomer components for drug discovery and disease prevention. As a pure natural product, Agathis dammara (AD) has antioxidant, hypolipidemic, hypoglycemic, antitumor, and anti-inflammatory activities. However, at present, there are few reports regarding the effects of AD on chronic inflammatory cardiovascular diseases, such as aneurysm, atherosclerosis, myocardial ischemia-reperfusion injury, and cardiac hypertrophy and liver diseases such as fatty liver disease. AD and products derived from it have a very broad application prospect for cardiovascular diseases and fatty liver disease.

Evaluation of the Impact of Ranolazine Treatment on Liver Function Tests in Patients With Coronary Heart Disease and Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver pathology in the developed world. Nonalcoholic fatty liver disease is associated with a higher risk of cardiovascular disease. We investigated the impact of ranolazine on liver tests in patients with NAFLD and coronary artery disease (CAD). Patients who had established CAD and NAFLD (as assessed by raised serum transaminase activity, sonographic criteria, and the absence of any other obvious liver disease) were allocated to "on ranolazine" (n = 40) or "not on ranolazine" (n = 35) groups. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured in all patients at baseline and at the end of the study. After 6 months of ranolazine treatment, both ALT and AST activities were significantly lower in patients in the "on ranolazine" group compared with "not on ranolazine" patients (change from baseline: ALT, -11.0 ± 1.7 IU/L, P < .001; AST, -5.2 ± 1.9 IU/L, P =.009). In conclusion, the present study showed that treatment with ranolazine for 6 months led to a significant reduction in the activities of both serum aminotransferases in patients with stable CAD and NAFLD.

New Insights into the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Gut-Derived Lipopolysaccharides and Oxidative Stress

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The intricate NAFLD pathogenesis is summarized by the multiple-hits hypothesis, which combines all the environmental and genetic factors that promote the development of NAFLD into a single scenario. Among these, bacterial lipopolysaccharides (LPS) are derived from the overgrowth of Gram-negative bacteria and translocated mainly as a consequence of enhanced intestinal permeability. Furthermore, oxidative stress is increased in NAFLD as a consequence of reactive oxygen species (ROS) overproduction and a shortage of endogenous antioxidant molecules, and it is promoted by the interaction between LPS and the Toll-like receptor 4 system. Interestingly, oxidative stress, which has previously been described as being overexpressed in cardiovascular disease, could represent the link between LPS and the increased cardiovascular risk in NAFLD subjects. To date, the only effective strategy for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH) is the loss of at least 5% body weight in overweight and/or obese subjects. However, the dose-dependent effects of multispecies probiotic supplementation on the serum LPS level and cardiometabolic profile in obese postmenopausal women were demonstrated. In addition, many antibiotics have regulatory effects on intestinal microbiota and were able to reduce serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor alpha (TNF-α) in NASH animal models. Regarding the oxidant status, a Mediterranean diet has been reported to reduce oxidant stress, while vitamin E at high daily dosages induced the resolution of NASH in 36% of treated patients. Silymarin had the positive effect of reducing transaminase levels in NAFLD patients and long-term treatment may also decrease fibrosis and slow liver disease progression in NASH. Finally, the influence of nutraceuticals on gut microbiota and oxidant stress in NAFLD patients has not yet been well elucidated and there are insufficient data either to support or refuse their use in these subjects.

Nonalcoholic Fatty Liver Disease and Fibrosis Associated With Increased Risk of Cardiovascular Events in a Prospective Study

BACKGROUND & AIMS

Patients with non-alcoholic fatty liver disease (NAFLD) are at increased chance for cardiovascular events (CVEs). Severity of liver fibrosis is used to determine prognoses for patients with NAFLD, but little is known about the relationship between liver fibrosis and CVEs in the real world.

METHODS

We analyzed data from the prospective observational progression of liver damage and cardiometabolic disorders in non-alcoholic fatty liver disease study, comprising 898 consecutive outpatients (mean age, 56.4 ± 12.7 years; 37.5% women) screened for liver steatosis by ultrasound according to Hamagughi criteria. Liver fibrosis was defined as FIB-4 score greater than 2.67 and NAFLD fibrosis score greater than 0.676. After enrolment, patients were interviewed by phone every 6 months and examined every 12 months in the outpatient clinic, and CVEs were recorded (fatal or nonfatal ischemic stroke and myocardial infarction, cardiac or peripheral revascularization, new-onset arterial fibrillation and cardiovascular death). The primary outcomes were incidence rate of CVEs in patients with vs without NAFLD and factors associated with CVEs in patients with NAFLD.

RESULTS

Over a median follow-up time of 41.4 months (3044.4 patient-years), 58 CVEs (1.9%/year) were registered. The rate of CVEs was higher in patients with (n = 643, 2.1%/year) vs without NAFLD (n = 255, 1.0%/year) (P = .066). In multivariable Cox proportional regression analysis, NAFLD increased risk for CVEs (hazard ratio [HR], 2.41; 95% CI, 1.06-5.47; P = .036), after adjustment for metabolic syndrome. Among patients with NAFLD, male sex, previous CVEs, metabolic syndrome and FIB-4 scores greater than 2.67 (HR, 4.02; 95% CI, 1.21-13.38; P = .023) were independently associated with risk of incident CVEs. NFS scores greater than 0.676 were also independently associated with risk of incident CVEs (HR, 2.35; 95% CI, 1.05-5.27; P = .038).

CONCLUSIONS

In an analysis of data from a study of patients screened for NAFLD and followed, individuals with NAFLD had more than a 2-fold increase in risk of CVEs, and those with liver fibrosis had a 4-fold increase in risk. In patients with NAFLD, liver fibrosis indexes were independently associated with risk of incident CVEs. ClinicalTrials.gov no:NCT04036357.

Association between non-alcoholic fatty liver disease and obstructive sleep apnea

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging liver disease and currently the most common cause of incidental abnormal liver tests. The pathogenesis of NAFLD is multifactorial and many mechanisms that cause fatty liver infiltration, inflammation, oxidative stress and progressive fibrosis have been proposed. Obstructive sleep apnea (OSA) may be linked with the pathogenesis and the severity of NAFLD.

AIM

To study the association between NAFLD and OSA considering also the efficacy of continuous positive airway pressure (CPAP) treatment.

METHODS

A PubMed search was conducted using the terms "non-alcoholic fatty liver disease AND (obstructive sleep apnea OR obstructive sleep disorders OR sleep apnea)". Research was limited to title/abstract of articles published in English in the last 5 years; animal and child studies, case reports, commentaries, letters, editorials and meeting abstracts were not considered. Data were extracted on a standardized data collection table which included: First author, publication year, country, study design, number of patients involved, diagnosis and severity of OSA, diagnosis of NAFLD, patient characteristics, results of the study.

RESULTS

In total, 132 articles were initially retrieved on PubMed search and 77 in the last five years. After removal of irrelevant studies, 13 articles were included in the qualitative analysis. There was a total of 2753 participants across all the studies with a mean age between 42 and 58 years. The proportion of males ranged from 21% to 87.9% and the mean body mass index ranged from 24.0 to 49.9 kg/m2. The results of this review showed an increased prevalence of NAFLD in patients with diagnosis of OSA, even in the absence of coexisting comorbidities such as obesity or metabolic syndrome. Furthermore, the severity of NAFLD is associated with the increase in OSA severity. Effective CPAP treatment, although not always decisive, may stabilize or slow NAFLD progression with benefits on metabolic and cardiovascular functions.

CONCLUSION

In NAFLD patients, although asymptomatic, it is recommended to systematically perform polysomnography in order to early and better treat them before the development of potentially life threatening systemic dysfunctions.

Redox Regulation of Metabolic Syndrome: Recent Developments in Skeletal Muscle Insulin Resistance and Non-alcoholic Fatty Liver Disease (NAFLD)

Several new discoveries over the past decade have shown that metabolic syndrome, a cluster of metabolic disorders, including increased visceral obesity, hyperglycemia, hypertension, dyslipidemia and low HDL-cholesterol, is commonly associated with skeletal muscle insulin resistance. More recently, non-alcoholic fatty liver disease (NAFLD) was recognized as an additional condition that is strongly associated with features of metabolic syndrome. While the pathogenesis of skeletal muscle insulin resistance and fatty liver is multifactorial, the role of dysregulated redox signaling has been clearly demonstrated in the regulation of skeletal muscle insulin resistance and NAFLD. In this review, we aim to provide recent updates on redox regulation with respect to (a) pro-oxidant enzymes (e.g. NAPDH oxidase and xanthine oxidase); (b) mitochondrial dysfunction; (c) endoplasmic reticulum (ER) stress; (d) iron metabolism derangements; and (e) gut-skeletal muscle or gut-liver connection in the development of skeletal muscle insulin resistance and NAFLD. Furthermore, we discuss promising new therapeutic strategies targeting redox regulation currently under investigation for the treatment of skeletal muscle insulin resistance and NAFLD.

A fatty acid analogue targeting mitochondria exerts a plasma triacylglycerol lowering effect in rats with impaired carnitine biosynthesis

L-carnitine is important for the catabolism of long-chain fatty acids in the mitochondria. We investigated how the triacylglycerol (TAG)-lowering drug 2-(tridec-12-yn-1-ylthio)acetic acid (1-triple TTA) influenced lipid metabolism in carnitine-depleted, 3-(2,2,2-trimethylhydrazinium)propionate dehydrate (Mildronate; meldonium)-treated male Wistar rats. As indicated, carnitine biosynthesis was impaired by Mildronate. However, TAG levels of both plasma and liver were decreased by 1-triple TTA in Mildronate-treated animals. This was accompanied by increased gene expression of proteins involved in mitochondrial activity and proliferation and reduced mRNA levels of Dgat2, ApoB and ApoCIII in liver. The hepatic energy state was reduced in the group of Mildronate and 1-triple TTA as reflected by increased AMP/ATP ratio, reduced energy charge and induced gene expression of uncoupling proteins 2 and 3. The increase in mitochondrial fatty acid oxidation was observed despite low plasma carnitine levels, and was linked to strongly induced gene expression of carnitine acetyltransferase, translocase and carnitine transporter, suggesting an efficient carnitine turnover. The present data suggest that the plasma TAG-lowering effect of 1-triple TTA in Mildronate-treated rats is not only due to increased mitochondrial fatty acid oxidation reflected by increased mitochondrial biogenesis, but also to changes in plasma clearance and reduced TAG biosynthesis.

Oxidative Stress as a Critical Factor in Nonalcoholic Fatty Liver Disease Pathogenesis

SIGNIFICANCE

Nonalcoholic fatty liver disease (NAFLD), characterized by liver triacylglycerol build-up, has been growing in the global world in concert with the raised prevalence of cardiometabolic disorders, including obesity, diabetes, and hyperlipemia. Redox imbalance has been suggested to be highly relevant to NAFLD pathogenesis. Recent Advances: As a major health problem, NAFLD progresses to the more severe nonalcoholic steatohepatitis (NASH) condition and predisposes susceptible individuals to liver and cardiovascular disease. Although NAFLD represents the predominant cause of chronic liver disorders, the mechanisms of its development and progression remain incompletely understood, even if various scientific groups ascribed them to the occurrence of insulin resistance, dyslipidemia, inflammation, and apoptosis. Nevertheless, oxidative stress (OxS) more and more appears as the most important pathological event during NAFLD development and the hallmark between simple steatosis and NASH manifestation.

CRITICAL ISSUES

The purpose of this article is to summarize recent developments in the understanding of NAFLD, essentially focusing on OxS as a major pathogenetic mechanism. Various attempts to translate reactive oxygen species (ROS) scavenging by antioxidants into experimental and clinical studies have yielded mostly encouraging results.

FUTURE DIRECTIONS

Although augmented concentrations of ROS and faulty antioxidant defense have been associated to NAFLD and related complications, mechanisms of action and proofs of principle should be highlighted to support the causative role of OxS and to translate its concept into the clinic. Antioxid. Redox Signal. 26, 519-541.

Under-prescription of statins in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is a common disease associated with high cardiovascular risk. Management of dyslipidaemia plays a pivotal role in the prevention of CV events and statins have proved to be safe in these patients. However, in everyday clinical practice statin prescription is sometimes limited because of the concern of physicians about side-effects. The aim of the study was to investigate if the presence of NAFLD affects the prescription of lipid-lowering treatment in a large series of patients with cardio-metabolic disorders.

METHODS AND RESULTS

Cardiovascular risk and LDL-C targets were defined according to ESC/EAS Guidelines in 605 consecutive adult subjects referred for screening of suspected metabolic diseases. Liver steatosis was assessed by ultrasound Hamaguchi criteria. In the whole cohort, 442 patients had indication for cholesterol-lowering treatment. Lack of statin prescription was present in 230 (52.0%) patients. Of these, 77 (33.5%) were very high-risk, 48 (20.8%) high-risk, and 105 (45.6%) moderate risk patients. Only 44% of the NAFLD patients with indication for statin treatment were on therapy. NAFLD patients on statin treatment had significantly lower ALT values as compared to those not on treatment (p < 0.05).

CONCLUSIONS

Our findings show that about 50% of patients with indication to statin treatment do not receive any cholesterol-lowering medication. Statin under-use was particularly high in subjects with NAFLD. Use of statin treatment should be encouraged in the context of NAFLD, as it may improve lipid profile and reduce the cardiovascular risk in this setting.

Does Lysosomial Acid Lipase Reduction Play a Role in Adult Non-Alcoholic Fatty Liver Disease?

Lysosomal Acid Lipase (LAL) is a key enzyme involved in lipid metabolism, responsible for hydrolysing the cholesteryl esters and triglycerides. Wolman Disease represents the early onset phenotype of LAL deficiency rapidly leading to death. Cholesterol Ester Storage Disease is a late onset phenotype that occurs with fatty liver, elevated aminotransferase levels, hepatomegaly and dyslipidaemia, the latter characterized by elevated LDL-C and low HDL-C. The natural history and the clinical manifestations of the LAL deficiency in adults are not well defined, and the diagnosis is often incidental. LAL deficiency has been suggested as an under-recognized cause of dyslipidaemia and fatty liver. Therefore, LAL activity may be reduced also in non-obese patients presenting non-alcoholic fatty liver disease (NAFLD), unexplained persistently elevated liver transaminases or with elevation in LDL cholesterol. In these patients, it could be indicated to test LAL activity. So far, very few studies have been performed to assess LAL activity in representative samples of normal subjects or patients with NAFLD. Moreover, no large study has been carried out in adult subjects with NAFLD or cryptogenic cirrhosis.

Oxidative stress: New insights on the association of non-alcoholic fatty liver disease and atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) represents the most common and emerging chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and more severe liver complications such as cirrhosis, hepatocellular carcinoma and liver mortality. NAFLD is strongly associated with obesity, insulin resistance, hypertension, and dyslipidaemia, and is now regarded as the liver manifestation of the metabolic syndrome. The increased mortality of patients with NAFLD is primarily a result of cardiovascular disease and, to a lesser extent, to liver related diseases. Increased oxidative stress has been reported in both patients with NAFLD and patient with cardiovascular risk factors. Thus, oxidative stress represents a shared pathophysiological disorder between the two conditions. Several therapeutic strategies targeting oxidative stress reduction in patients with NAFLD have been proposed, with conflicting results. In particular, vitamin E supplementation has been suggested for the treatment of non-diabetic, non-cirrhotic adults with active NASH, although this recommendation is based only on the results of a single randomized controlled trial. Other antioxidant treatments suggested are resveratrol, silybin, L-carnitine and pentoxiphylline. No trial so far, has evaluated the cardiovascular effects of antioxidant treatment in patients with NAFLD. New, large-scale studies including as end-point also the assessment of the atherosclerosis markers are needed.

A concise review of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and the incidence of which is rising rapidly due to the increasing epidemic of obesity in both adults and children. The initial accumulation of fat followed by subsequent inflammation is central to the development of liver damage, and is critically influenced by host factors including age, gender, presence of diabetes, genetic polymorphisms and more recently by the gut microbiome. An increasing body of data suggest that NAFLD is also an independent risk factor of cardiovascular disease, which remains the commonest cause of mortality in such patients. This review focusses on the pathogenesis of NAFLD, and the evolution of new approaches to the management and treatment of NAFLD.

The efficacy and safety of statins for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is an emerging liver disease in Western countries and the most frequent cause of incidental elevation of serum liver enzymes. Dyslipidaemia is frequently observed in patients with non-alcoholic fatty liver disease, and treatment of dyslipidaemia plays a critical role in the overall management of these patients. Moreover, coronary artery disease remains the most common cause of death. Statins are effective lipid-lowering agents, associated with a lowering the risk of cardiovascular events in several interventional randomized clinical trials. However, statins are often underused in patients with non-alcoholic fatty liver disease and many physicians are concerned about the prescription of statins to patients with unexplained persistent elevation of liver enzymes or active liver disease. Based on currently available data, statin therapy, at low-to-moderate doses, seems to be safe and has low liver toxicity. Treatment of dyslipidaemia in patients with non-alcoholic fatty liver disease is recommended and may also improve liver function tests. In these patients, the risks of not taking statins could outweigh the risks of taking the drug. Conversely, the usefulness of statins for the treatment of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis is still a matter of debate and randomized clinical trials of adequate size and duration are required.

Non-alcoholic fatty liver disease, metabolic syndrome and patatin-like phospholipase domain-containing protein3 gene variants

BACKGROUND & AIMS

Non-alcoholic fatty liver disease was traditionally interpreted as a condition which may progress to liver-related complications. However, the increased mortality is primarily a result of cardiovascular diseases. It has been suggested that fatty liver can be considered as the hepatic consequence of the metabolic syndrome. The aim was to describe the different clinical presentations of non-alcoholic fatty liver disease on the basis of the patatin-like phospholipase domain-containing protein3 (PNPLA3) rs738409 gene variant.

METHODS

Fatty liver was defined by ultrasonographic Hamaguchi's criteria in 211 consecutive subjects with non-alcoholic fatty liver disease. The rs738409 polymorphism was determined by TaqMan assays. Metabolic syndrome was defined according to ATPIII modified criteria.

RESULTS

Prevalence of PNPLA3-148II, PNPLA3-148IM, and PNPLA3-148MM genotypes was 45.0%, 40.7%, and 14.3% respectively. Prevalence of metabolic syndrome progressively increased with the severity of liver steatosis (from 52.5% to 65.2%, and 82.3% respectively, p<0.01). The PNPLA3-148MM group had significantly lower mean serum triglycerides (p<0.001), Framingham cardiovascular risk score (p<0.01) and lower prevalence of metabolic syndrome (p<0.05) and its components. Age and HOMA-IR were positive independent predictors of metabolic syndrome, while a negative independent association was found between metabolic syndrome and the homozygotes PNPLA3 I148M variant.

CONCLUSIONS

We suggest a lower prevalence of MetS and reduced cardiovascular risk in NAFLD patients with PNPLA3MM genotype.

NOX2-generated oxidative stress is associated with severity of ultrasound liver steatosis in patients with non-alcoholic fatty liver disease

BACKGROUND

Chronic oxidative stress is one of the key mechanisms responsible for disease progression in non-alcoholic fatty liver disease. However, so far, few studies reported increased circulating levels of oxidative stress markers in patients with non-alcoholic fatty liver and no study has been performed with newer markers of systemic oxidative stress. The aim was to assess the relationship between urinary 8-iso-prostaglandin F2α and serum soluble NOX2-derived peptide and the severity of liver steatosis in subjects with non-alcoholic fatty liver.

METHODS

The study was performed in 264 consecutive patients referred for suspected metabolic disease. Steatosis was defined according to Hamaguchi ultrasonographic criteria. Oxidative stress was assessed by urinary 8-iso- prostaglandin F2α and serum soluble NOX2-derived peptide levels.

RESULTS

Patients with non-alcoholic fatty liver had higher (p < 0.001) mean values of urinary 8-iso-PGF2α and of serum soluble NOX2-derived peptide, alanine aminotransferase, Cytokeratin-18 and homeostasis model of insulin resistance and lower values of serum adiponectin as compared to those without. Prevalence of metabolic syndrome and of its clinical features was significantly higher in patients with non-alcoholic fatty liver. Same findings were also observed after the exclusion of obese subjects, or subjects with diabetes or with metabolic syndrome and in those not taking statin medication. In addition, the levels of urinary 8-iso-PGF2α were independent predictors of non-alcoholic fatty liver and a strong association of urinary 8-iso-PGF2α and of serum soluble NOX2-derived peptide with the severity of steatosis at ultrasound was also observed.

CONCLUSIONS

We demonstrated increased markers of oxidative stress in subjects with non-alcoholic fatty liver. Urinary 8-iso-PGF2α and serum soluble NOX2-derived peptide levels were independent from obesity, diabetes and metabolic syndrome and increased with the severity of liver steatosis at ultrasound.

Modest alcohol consumption and carotid plaques or carotid artery stenosis in men with non-alcoholic fatty liver disease

BACKGROUND

Favorable association between modest alcohol consumption and cardiovascular disease had been reported in general population, however, whether observed benefit extend to men with established fatty liver disease remains unknown.

METHODS

Cross-sectional study of 10,581 consecutive male participants aged 30 years or older undergoing abdominal ultrasonography and carotid artery ultrasonography were screened. Non-alcoholic fatty liver disease (NAFLD) was diagnosed with ultrasonography and exclusion of secondary causes for fat accumulation or other causes of chronic liver disease. Modest alcohol use was defined as consumption of less than 20 g of alcohol per day.

RESULTS

There were total 2280 men diagnosed with fatty liver, and the mean age was 51.8 years old. Among them, 1797 were modest alcohol drinkers. The prevalence of carotid plaques (55.3% vs. 43.4%, p < 0.001) and carotid artery stenosis (11.0% vs. 5.5%, p < 0.001) was higher in non-drinkers than modest drinkers. Modest alcohol consumption had the independent inverse association with carotid plaques [odd ratio (OR): 0.74, 95% confidence interval (CI): 0.60-0.92] and carotid artery stenosis (OR: 0.62, 95% CI: 0.43-0.90), adjusted for age, smoking and metabolic syndrome.

CONCLUSIONS

Modest alcohol consumption had a favorable association with carotid plaque or CAS in men with NAFLD.

Effects of rhaponticum carthamoides versus glycyrrhiza glabra and punica granatum extracts on metabolic syndrome signs in rats

Background

Rhaponticum cathamoides (RC) is an endemic wild Siberian herb with marked medicinal properties that are still poorly understood. The aim of this study is to investigate the therapeutic potential of RC extract (ERC) compared to the effects of Glycyrrhiza glabra (EGG) and Punica granatum extracts (EPG) in a rat model with high-fat diet-(HFD)-induced signs of metabolic syndrome; therefore, this study addresses a significant global public health problem.

Methods

Six-month-old male Wistar Albino Glaxo rats were subjected to eight weeks of a standard diet (SD), HFD, or HFD in which ERC, EGG, or EPG powders were incorporated at 300 mg/kg/day. The serum lipid profile, corticosterone and cytokine concentrations, glucose tolerance, systolic blood pressure, triacylglycerol accumulation, and PPARα DNA-binding activities in the liver samples were determined.

Results

In contrast to EGG and EPG, an ERC supplement significantly reduced the weight of epididymal tissue (19.0%, p < 0.01) and basal serum glucose level (19.4%, p < 0.05). ERC improved glucose intolerance as well as dyslipidemia more efficiently than EGG and EPG. EGG but not ERC or EPG supplementation decreased systolic blood pressure by 12.0% (p < 0.05). All of the tested extracts reduced serum IL6 and corticosterone levels induced by HFD. However, the lowering effects of ERC consumption on the serum TNF-α level and its restoring effect on the adrenal corticosterone level significantly exceeded the improvements induced by EGG and EPG. ERC intake also reduced triacylglycerol accumulation and increased the PPARα DNA-binding activity in the liver more significantly than EGG and EPG.

Conclusions

ERC powder supplementation improved glucose and lipid metabolism more significantly than EGG and EPG in rats fed on HFD, supporting the strategy of R. carthamoides use for safe relief of metabolic syndrome and its related disturbances such as inflammation, stress, and hepatic steatosis.

Physical activity for the prevention and treatment of metabolic disorders

Metabolic syndrome and its various features (obesity, hypertension, dyslipidemia, diabetes, and nonalcoholic fatty liver disease) are increasing worldwide and constitute a severe risk for the sustainability of the present universal Italian health care system. Lifestyle interventions should be the first therapeutic strategy to prevent/treat metabolic diseases, far before pharmacologic treatment. The role of diet and weight loss has been fully ascertained, whereas the role of physical activity is frequently overlooked both by physicians and by patients. Physical activity has favorable effects on all components of the metabolic syndrome and on the resulting cardiovascular risk, the cornerstone in the development of cardiometabolic diseases. The quantity and the frequency of physical activity necessary to produce beneficial effects has not been defined as yet, but brisk walking is considered particularly appropriate, as it can be practiced by a large number of individuals, without any additional cost, and has a low rate of injury. The effects of exercise and leisure time physical activity extend from prevention to treatment of the various components of the metabolic syndrome, as well as to mood and quality of life. Any effort should be done to favor adherence to protocols of physical activity in the community.