Pediatric nonalcoholic fatty liver disease, metabolic syndrome and cardiovascular risk

Advances in metformin for the treatment of non-alcoholic fatty liver disease in children

INTRODUCTION

The increased economic and social burdens for NAFLD worldwide make treating such a disease a significant public health issue. Metformin, a kind of insulin sensitizer generally used to treat type 2 diabetes, has been recently found to have efficacy on children's NAFLD in various areas such as glucolipid metabolism, intestinal bacterial metabolism, oxidative stress, and anti-inflammatory response. This article aims to provide an overview of the possible mechanisms of NAFLD in children and the potential therapeutic application of metformin.

AREAS COVERED

The Cochrane Library, PubMed, Scopus, and EMBASE database was systematically searched on 12 April 2022, using the keywords metformin; non-alcoholic fatty liver disease; and children to identify similar studies. An additional search for recently published research was performed in June 2020.

EXPERT OPINION

Although metformin has been proved to have an excellent therapeutic effect on children's NAFLD; we can still explore its potential impacts and mechanisms from different angles, such as combined medication. At the same time, we should also pay attention to its side effects.

Chemokines in Primary Liver Cancer

The liver is responsible for extremely important functions in the human body. In the liver’s structure, we distinguish between connective tissue (stroma) and parenchyma, the latter of which is formed from the basic structural and functional units of the liver—hepatocytes. There are many factors, that negatively affect the liver cells, contributing to their damage. This may lead to fibrosis, liver failure and, in consequence, primary liver cancer, which is the sixth most commonly diagnosed malignancy and the fourth leading cause of cancer death worldwide. Chemokines are a large family of secreted proteins. Their main role is to direct the recruitment and migration of cells to sites of inflammation or injury. Some authors suggest that these proteins might play a potential role in the development of many malignancies, including primary liver cancer. The aim of this study was to evaluate and summarize the knowledge regarding liver diseases, especially primary liver cancer (HCC) and the participation of chemokines in the development of this malignancy. Chemokines involved in the initiation of this type of tumor belong mainly to the CC and CXC chemokines. Their significant role in the course of hepatocellular carcinoma proves their usefulness in detecting and monitoring the course and treatment in patients with this disease.

Gut microbiome is associated with metabolic syndrome accompanied by elevated gamma-glutamyl transpeptidase in men

It is predicted that by 2035, metabolic syndrome (MS) will be found in nearly more than half of our adult population, seriously affecting the health of our body. MS is usually accompanied by the occurrence of abnormal liver enzymes, such as elevated gamma-glutamyl transpeptidase (GGT). More and more studies have shown that the gut microbiota is involved in MS; however, the correlation between gut microbiota and MS with elevated GGT has not been studied comprehensively. Especially, there are few reports about its role in the physical examination of the population of men with MS and elevated GGT. By using the whole-genome shotgun sequencing technology, we conducted a genome-wide association study of the gut microbiome in 66 participants diagnosed as having MS accompanied by high levels of GGT (case group) and 66 participants with only MS and normal GGT level (control group). We found that the number of gut microbial species was reduced in participants in the case group compared to that of the control group. The overall microbial composition between the two groups is of significant difference. The gut microbiota in the case group is characterized by increased levels of “harmful bacteria” such as Megamonas hypermegale, Megamonas funiformis, Megamonas unclassified, Klebsiella pneumoniae, and Fusobacterium mortiferum and decreased levels of “beneficial bacteria” such as Faecalibacterium prausnitzii, Eubacterium eligens, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bacteroides dorei, and Alistipes putredinis. Moreover, the pathways of POLYAMSYN-PWY, ARG+POLYAMINE-SYN, PWY-6305, and GOLPDLCAT-PWY were also increased in the case group, which may play a role in the elevation of GGT by producing amine, polyamine, putrescine, and endogenous alcohol. Taken together, there are apparent changes in the composition of the gut microbiome in men with MS and abnormal GGT levels, and it is high time to discover specific gut microbiome as a potential therapeutic target in that population. More in-depth studies of relevant mechanism could offer some new methods for the treatment of MS with elevated GGT.

Nonalcoholic fatty liver disease in children with obesity- observations from one clinical centre in the Western Pomerania region

Nonalcoholic fatty liver disease (NAFLD) is a growing health problem in the pediatric population, due to the constantly increasing percentage of children with obesity. The objective of the study was to assess the occurrence of NAFLD based on ultrasound (USG) analysis and the use of alanine aminotransferase (ALT) in children with overweight and obesity depending on glucose tolerance. Medical records of 228 consecutive patients aged 2-18 years with overweight and obesity were reviewed retrospectively. Based on the oral glucose tolerance test children were divided into groups according to the severity of carbohydrate metabolism disorders. ALT, lipid parameters and insulin sensitivity indices HOMA, Matsuda and Quicki were analyzed. NAFLD was diagnosed (based on the USG) in 51 patients (23.61%) - the incidence in the impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) group was significantly higher when compared to ones without glucose intolerance. Because of extreme values of metabolic parameters in TDM2 children being outliers, they were not considered in the statistical analysis of the study. 22 (11.58%) patients had elevated ALT values, of which 12 (54.55%) had hepatic steatosis features on ultrasound. 72.73% (n=32) patients with fatty liver features on USG had ALT values considered normal with cut-off point 42 U/l accepted in this study. Almost every fourth obese child in the study group presents features of fatty liver in ultrasound examination. Although ultrasound is not recommended by North American Society For Pediatric Gastroenterology, Hepatology &Nutrition(NASPGHAN) for the diagnosis of NAFLD in children, it allows identifying a high percentage of children with features of fatty liver. This percentage increases significantly in children with glucose intolerance.

Relationship between non-alcoholic fatty liver disease and coronary heart disease

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease and considered a liver manifestation of metabolic syndrome. It is in close relationship with insulin resistance, obesity, diabetes mellitus, all of which increase risk of cardiovascular disease (CVD). Besides, many studies point out that NAFLD independently contributes to the development of atherosclerosis and CHD. On the other hand, CVDs are the leading cause of death in NAFLD patients. Many pathophysiological changes and molecular mechanisms play an important role in NAFLD for CVD formation. Atherosclerosis is common in NAFLD, which also mainly contributes to the CVD formation and CHD. Many studies linking atherosclerotic CHD and NAFLD are present in the literature. Subclinical CHD, mainly detected by coronary computed tomography views, have been detected more common in NAFLD patients. Presence of NAFLD has been found to be more common in patients with severe CHD and in stable CHD, NAFLD has been found to be associated with more diffuse disease. In acute coronary syndromes, especially in acute myocardial infarction, patients with NAFLD have been found to have poor prognosis when compared with NAFLD free patients. In this review, our aim is to evaluate the relationship between NAFLD and CHD in detail and go over the pathophysiological mechanisms underlying this relationship.

Non-alcoholic fatty liver disease is not independent risk factor for cardiovascular disease event: A cohort study

BACKGROUND

There are no consistent results between previous studies for an independent association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD) events.

AIM

To determine if there is an independent association between NAFLD and CVD events.

METHODS

In the present study, valid outcome data of 4808 subjects were available for phase 2 of our cohort study. These subjects had been followed up for seven years from phase 1, beginning in 2009-2010 to phase 2 during 2016-2017. Simple and multiple Cox proportional models were used to determine the association between NAFLD in the primary phase of the cohort and subsequent fatal and non-fatal CVD events during follow-up.

RESULTS

The incidence of non-fatal CVD events in males with NAFLD was significantly higher (P = 0.004) than in males without NAFLD. A positive association was demonstrated between NAFLD and non-fatal CVD events in males (Hazard ratio = 1.606; 95%CI: 1.166-2.212; P = 0.004) by the simple Cox proportional hazard model, but no independent association was detected between these in the multiple Cox models.

CONCLUSION

No independent association was detected between NAFLD and CVD. It is likely that diabetes mellitus and age may be the principle mediators in this regard.

The roles of triglyceride/high-density lipoprotein cholesterol ratio and uric acid as predisposing factors for metabolic syndrome in healthy children

PURPOSE

To estimate the roles of triglyceride/high-density lipoprotein cholesterol (TG/HDL) ratio and uric acid in predisposition for metabolic syndrome (MetS) and its components in healthy children.

METHODS

Anthropometric and biochemical analyses were performed on 110 children, aged 5 to 12 years, from the Greek county of Laconia. The children were studied as a whole population and in separate groups according to age and predisposition to MetS after taking into consideration International Diabetes Federation criteria, body mass index, and lipid profile.

RESULTS

Seventeen percent of children exhibited predisposition to MetS, while 39.1% had TG/HDL ratio >1, and 3.64% had high level of uric acid. According to a receiver operating characteristic curve analysis, the relative probability for MetS predisposition sextupled when TG/HDL ratio was ≥1 (odds ratio [OR], 5.986; 95% confidence interval [CI], 1.968-18.205). Children in the total population and those aged < 9 years had a greater probability for increased low-density lipoprotein (LDL) cholesterol (OR, 3.614; 95% CI, 1.561-8.365) when TG/HDL ratio was ≥ 1. The TG/HDL ratio was positively correlated with body mass index (BMI) (P=0.035) in children without MetS, cholesterol in the total population (P=0.06) and children ≥9 years old (P=0.026), and with LDL in the total population and both age groups (P=0.001). The TG/HDL ratio was also positively correlated with alanine aminotransferase in the total population (P=0.033) and gamma-glutamyl transferase in most studied groups (P<0.001). Uric acid was positively correlated with waist circumference in the total population (P=0.043) and in those without MetS (P=0.027). It was also positively correlated with BMI, TG, cholesterol, and TG/HDL ratio and negatively correlated with HDL in most studied groups (P<0.005).

CONCLUSION

The studied parameters correlated with MetS components and could be characterized as effective indexes for childhood MetS, regardless of age and predisposition to MetS.

Development of a Plasma Screening Panel for Pediatric Nonalcoholic Fatty Liver Disease Using Metabolomics

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children, but diagnosis is challenging due to limited availability of noninvasive biomarkers. Machine learning applied to high-resolution metabolomics and clinical phenotype data offers a novel framework for developing a NAFLD screening panel in youth. Here, untargeted metabolomics by liquid chromatography-mass spectrometry was performed on plasma samples from a combined cross-sectional sample of children and adolescents ages 2-25 years old with NAFLD (n = 222) and without NAFLD (n = 337), confirmed by liver biopsy or magnetic resonance imaging. Anthropometrics, blood lipids, liver enzymes, and glucose and insulin metabolism were also assessed. A machine learning approach was applied to the metabolomics and clinical phenotype data sets, which were split into training and test sets, and included dimension reduction, feature selection, and classification model development. The selected metabolite features were the amino acids serine, leucine/isoleucine, and tryptophan; three putatively annotated compounds (dihydrothymine and two phospholipids); and two unknowns. The selected clinical phenotype variables were waist circumference, whole-body insulin sensitivity index (WBISI) based on the oral glucose tolerance test, and blood triglycerides. The highest performing classification model was random forest, which had an area under the receiver operating characteristic curve (AUROC) of 0.94, sensitivity of 73%, and specificity of 97% for detecting NAFLD cases. A second classification model was developed using the homeostasis model assessment of insulin resistance substituted for the WBISI. Similarly, the highest performing classification model was random forest, which had an AUROC of 0.92, sensitivity of 73%, and specificity of 94%. Conclusion: The identified screening panel consisting of both metabolomics and clinical features has promising potential for screening for NAFLD in youth. Further development of this panel and independent validation testing in other cohorts are warranted.

A Systematic Review of NAFLD-Associated Extrahepatic Disorders in Youths

Background: There is growing evidence that non-alcoholic fatty liver disease (NAFLD) is a disease affecting not only the liver but also extrahepatic organs. Aim: To investigate whether in youths NAFLD is associated with extrahepatic complications such as subclinical atherosclerosis, cardiac abnormalities, hypertension, type 2 diabetes, decreased bone mineral density, renal dysfunction, obstructive sleep apnea, and polycystic ovary syndrome. Methods: We systematically reviewed PubMed; Scopus; Embase; and the Cochrane Library databases up to 28 February 2019 and assessed the quality of studies using the Newcastle-Ottawa Scale. Results: Thirty-five articles were selected for this systematic review: fifteen (4627 participants) evaluated the association of NAFLD with subclinical atherosclerosis; four (969 participants) with cardiac abnormalities; two (550 participants) with hypertension; four (1328 participants) with diabetes; six (523 participants) with low bone mineral density; two (865 participants) with renal dysfunction; one with obstructive sleep apnea; and one with polycystic ovary syndrome. Most studies found that youths with NAFLD have increased features of subclinical atherosclerosis; as well as of cardiac alterations. Limited data were available to endorse a solid estimate of the prevalence of diabetes; low mineral density and renal dysfunction in the pediatric NAFLD population. Conclusion: NAFLD-related intermediate CVD outcomes can occur and be detected early in young populations.

Clinically Actionable Hypercholesterolemia and Hypertriglyceridemia in Children with Nonalcoholic Fatty Liver Disease

OBJECTIVE

To determine the percentage of children with nonalcoholic fatty liver disease (NAFLD) in whom intervention for low-density lipoprotein cholesterol or triglycerides was indicated based on National Heart, Lung, and Blood Institute guidelines.

STUDY DESIGN

This multicenter, longitudinal cohort study included children with NAFLD enrolled in the National Institute of Diabetes and Digestive and Kidney Diseases Nonalcoholic Steatohepatitis Clinical Research Network. Fasting lipid profiles were obtained at diagnosis. Standardized dietary recommendations were provided. After 1 year, lipid profiles were repeated and interpreted according to National Heart, Lung, and Blood Institute Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction. Main outcomes were meeting criteria for clinically actionable dyslipidemia at baseline, and either achieving lipid goal at follow-up or meeting criteria for ongoing intervention.

RESULTS

There were 585 participants, with a mean age of 12.8 years. The prevalence of children warranting intervention for low-density lipoprotein cholesterol at baseline was 14%. After 1 year of recommended dietary changes, 51% achieved goal low-density lipoprotein cholesterol, 27% qualified for enhanced dietary and lifestyle modifications, and 22% met criteria for pharmacologic intervention. Elevated triglycerides were more prevalent, with 51% meeting criteria for intervention. At 1 year, 25% achieved goal triglycerides with diet and lifestyle changes, 38% met criteria for advanced dietary modifications, and 37% qualified for antihyperlipidemic medications.

CONCLUSIONS

More than one-half of children with NAFLD met intervention thresholds for dyslipidemia. Based on the burden of clinically relevant dyslipidemia, lipid screening in children with NAFLD is warranted. Clinicians caring for children with NAFLD should be familiar with lipid management.

Plasma trimethylamine-N-oxide and related metabolites are associated with type 2 diabetes risk in the Prevención con Dieta Mediterránea (PREDIMED) trial

Background

The role of trimethylamine-N-oxide (TMAO) in type 2 diabetes (T2D) is currently partially understood and controversial.

Objective

The aim of this study was to investigate associations between TMAO and related metabolites with T2D risk in subjects at high risk of cardiovascular disease.

Design

This is a case-cohort design study within the Prevención con Dieta Mediterránea (PREDIMED) study, with 251 incident T2D cases and a random sample of 694 participants (641 noncases and 53 overlapping cases) without T2D at baseline (median follow-up: 3.8 y). We used liquid chromatography-tandem mass spectrometry to measure plasma TMAO, l-carnitine, betaine, lyso-phosphatidylcholine (LPC) and lyso-phosphatidylethanolamine (LPE) species, phosphocholine, α-glycerophosphocholine, and choline at baseline and after 1 y. We examined associations with the use of weighted Cox proportional hazard models, accounting for the weighted case-cohort design by the Barlow method.

Results

After adjustment for recognized T2D risk factors and multiple testing, individuals in the highest quartile of baseline TMAO and α-glycerophosphocholine had a lower risk of T2D [HR (95% CI): 0.52 (0.29, 0.89) and 0.46 (0.24, 0.89), respectively]. The HR (95% CI) comparing the extreme quartiles of betaine was 0.41 (0.23, 0.74). Similar trends were observed for C16:0 LPC, C18:1 LPC, C18:0 LPC, C20:4 LPC, C22:6 LPC, C18:1 LPC plasmalogen, and C16:0 LPE. After correcting for multiple comparisons, participants in the highest quartile of 1-y changes in oleic acid LPC plasmalogen concentrations had a lower T2D risk than the reference quartile.

Conclusion

Whether the associations between plasma TMAO and certain metabolite concentrations with T2D risk reflect its pathophysiology or represent an epiphenomenon needs to be elucidated. This trial is registered at http://www.controlled-trials.com as ISRCTN35739639.

Correlation of blood glucose, serum chemerin and insulin resistance with NAFLD in patients with type 2 diabetes mellitus

Non-alcoholic fatty liver disease (NAFLD) is a form of clinical syndrome characterized by the fatty degeneration in liver histology and should be further investigated. The aim of the study was to investigate the effects of blood glucose, serum chemerin and insulin resistance on non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus to provide a basis for the prevention and treatment thereof. In total, 300 patients with type 2 diabetes mellitus treated and admitted into the Endocrinology Department of our hospital from June 2015 to June 2017 were enrolled and divided into the simple type 2 diabetes mellitus (group A) and concurrent NAFLD (group B) groups. The sex, age, body mass index (BMI), blood pressure, blood biochemical indexes and chemerin level were compared between the two groups. The patients in group B were further divided into the mild fatty liver (group B1), moderate fatty liver (group B2) and severe fatty liver (group B3) groups. The sex, age, BMI blood pressure, blood biochemical indexes and chemerin level were also compared among the three groups. Finally, the risk factors of type 2 diabetes mellitus complicated by NAFLD were analyzed via logistic regression. The BMI, fasting plasma glucose (FPG), 2 h post-prandial plasma glucose (2hPG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), alanine aminotransferase (ALT), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA-β indexes and serum chemerin level in group B were significantly higher than those in group A (P<0.05 or P<0.01). Notably, the aggravation of NAFLD, the aforementioned indexes were obviously increased (P<0.05 or P<0.01). The regression analysis revealed that BMI, FPG, TC, LDL-c, FINS, HOMA-IR and chemerin were risk factors of concurrent NAFLD. Thus, type 2 diabetes mellitus complicated by NAFLD is closely associated with severe glucose-lipid metabolism disorder and insulin resistance, and BMI, FPG, TC, LDL-c, FINS, HOMA-IR and chemerin constitute risk factors of concurrent NAFLD.

Can Fetuin-A Be a Marker for Insulin Resistance and Poor Glycemic Control in Children with Type 1 Diabetes Mellitus?

OBJECTIVE

Metabolic impairment in type 1 diabetes mellitus (T1DM) with poor glycemic control causes insulin resistance, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, and increased carotid intima-media thickness (CIMT). Fetuin-A has a protective effect in cardiovascular disorders and is increased in hepatosteatosis. We aimed to investigate the reliability of fetuin-A levels in early detection of diabetic complications in children with T1DM and to identify a cut-off value that may show poor metabolic control.

METHODS

The study included 80 patients who had T1DM for at least 5 years and who had no chronic complications or an auto-immune disorder. Blood samples were drawn to measure hemoglobin A1c (HbA1c), biochemical parameters, and fetuin-A levels. Anthropometric parameters were also measured. Percent body fat was calculated. Hepatosteatosis and CIMT were assessed by sonography.

RESULTS

Mean age of the patients was 13.5 years. Grade 1 hepatosteatosis was detected in 10%. Patients were stratified into 2 groups based on presence of NAFLD. Fetuin-A level was increased in patients with NAFLD. We identified a fetuin-A cut-off value (514.28 ng/mL; sensitivity: 47.34; specificity: 96.72) that may predict NAFLD. HbA1c and total cholesterol levels were found to be higher in patients with fetuin-A levels above higher the cut-off value.

CONCLUSION

Fetuin-A is a reliable parameter in the prediction of complications and poor glycemic control in patients with T1DM.

Non-alcoholic fatty liver disease and its associations among adolescents in an urban, Sri Lankan community

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common problem across the world. We aimed to determine the prevalence of NAFLD and its associations in Sri Lankan adolescents living in an urban Sri Lankan community.

METHOD

The study population consisted of the birth cohort of the year 2000, residing in the Ragama Medical Officer of Health area. Socio-demographic and anthropometric data [anthropometric measurements, blood pressure and total body fat distribution] of these adolescents were collected by trained data collectors. Fasting blood sugar, serum insulin, fasting serum lipids and serum alanine aminotransferase (ALT) levels were measured and an abdominal ultrasound was performed. NAFLD was diagnosed on established ultrasound criteria for fatty liver and absent alcohol consumption.

RESULTS

The study sample consisted of 499 adolescents [263 (51.8%) girls]. Forty two (8.4%) had NAFLD. NAFLD was significantly associated with being breast fed for less than 4 months (33.3% vs. 17.1 in controls, p = 0.02), higher waist circumference (prevalence risk ratio 83.3/20.3, 4.1, p < 0.0001), higher body mass index (prevalence risk ratio 40.5/4.8, 8.4, p < 0/0001),higher HOMA-IR (3.7 vs. 1.9, p < 0.0001) and high triglycerides (prevalence risk ratio 14.3/5.8, 2.5, p = 0.033). Adolescents with NAFLD also had a higher amount of total body fat (p < 0.001) and subcutaneous fat (p < 0.001) than those without NAFLD. The number of children with metabolic derangements was higher among adolescents with NAFLD than those without (85.8 vs 26.3 in controls, p < 0.0001), but a family history of hypertension, diabetes, myocardial infarction or dyslipidaemia were not.

CONCLUSION

Prevalence of NAFLD was high in Sri Lankan adolescents, and was associated with metabolic derangements, especially obesity, insulin resistance and early cessation of breast feeding.

Association of MTTP gene variants with pediatric NAFLD: A candidate-gene-based analysis of single nucleotide variations in obese children

Objective

We used targeted next-generation sequencing to investigate whether genetic variants of lipid metabolism-related genes are associated with increased susceptibility to nonalcoholic fatty liver disease (NAFLD) in obese children.

Methods

A cohort of 100 obese children aged 6 to 18 years were divided into NAFLD and non-NAFLD groups and subjected to hepatic ultrasound, anthropometric, and biochemical analyses. We evaluated the association of genetic variants with NAFLD susceptibility by investigating the single nucleotide polymorphisms in each of 36 lipid-metabolism-related genes. The panel genes were assembled for target region sequencing. Correlations between single nucleotide variations, biochemical markers, and clinical phenotypes were analyzed.

Results

97 variants in the 36 target genes per child were uncovered. Twenty-six variants in 16 genes were more prevalent in NAFLD subjects than in in-house controls. The mutation rate of MTTP rs2306986 and SLC6A2 rs3743788 was significantly higher in NAFLD subjects than in non-NAFLD subjects (OR: 3.879; P = 0.004; OR: 6.667, P = 0.005). Logistic regression analysis indicated the MTTP variant rs2306986 was an independent risk factor for NAFLD (OR: 23.468, P = 0.044).

Conclusions

The results of this study, examining a cohort of obese children, suggest that the genetic variation at MTTP rs2306986 was associated with higher susceptibility to NAFLD. This may contribute to the altered lipid metabolism by disruption of assembly and secretion of lipoprotein, leading to reducing fat export from the involved hepatocytes.

Cardiometabolic risk factors in children with celiac disease on a gluten-free diet

Celiac disease (CD) is an immune-mediated systemic condition evoked by gluten and related prolamines in genetically predisposed subjects. It is characterised by a variable combination of gluten-dependent clinical symptoms, CD-specific antibodies, HLA-DQ2 and HLA-DQ8 haplotypes, and enteropathy. The only therapy of CD consists of a life-long gluten free diet (GFD). Strict GFD adherence results in full clinical, serological and histological remission, avoiding long-term complications in CD patients. However, this diet is not without problems. Gluten free products have high levels of lipids, sugar and salt to improve food palatability and consistency, and subjects with CD show an excessive consumption of hypercaloric and hyperlipidic foods to compensate dietetic restriction. GFD may therefore have a negative impact on cardiometabolic risk factors such as obesity, serum lipid levels, insulin resistance, metabolic syndrome, and atherosclerosis. In adults, some studies have suggested that GFD have a beneficial effect on cardiovascular profile, whereas others have shown an atherogenic effect of GFD. In children, very few studies are available on the issue. Thus, the aim of the present narrative review was to analyze the current clinical evidence on the impact of GFD on cardiometabolic risk factors in children with CD.

The Association between Non-Alcoholic Fatty Liver Disease and Cardiovascular Risk in Children

The rising prevalence of childhood obesity in the past decades has made Non-Alcoholic Fatty Liver Disease (NAFLD) the most common cause of pediatric chronic liver disease worldwide. Currently, a growing body of evidence links NAFLD with cardiovascular disease (CVD) even at an early age. Data on the pediatric population have shown that NAFLD could represent an independent risk factor not only for cardiovascular events but also for early subclinical abnormalities in myocardial structure and function. Briefly, we review the current knowledge regarding the relationship between pediatric NAFLD and cardiovascular risk in an attempt to clarify our understanding of NAFLD as a possible cardiovascular risk factor in childhood.

Pediatric Non-Alcoholic Fatty Liver Disease

With the increase in the prevalence of obesity, non-alcoholic fatty liver disease (NAFLD) has become among the leading causes of chronic liver disease in the pediatric age group. Once believed to be a “two-hit process”, it is now clear that the actual pathophysiology of NAFLD is complex and involves multiple pathways. Moreover, NAFLD is not always benign, and patients with non-alcoholic steatohepatitis (NASH) are at increased risk of developing advanced stages of liver disease. It has also been shown that NAFLD is not only a liver disease, but is also associated with multiple extrahepatic manifestations, including cardiovascular diseases, type 2 diabetes, and low bone mineral density. Although the data is scarce in the pediatric population, some studies have suggested that long-term mortality and the requirement of liver transplantation will continue to increase in patients with NAFLD. More studies are needed to better understand the natural history of NAFLD, especially in the pediatric age group.

The Role of Lipid and Lipoprotein Metabolism in Non-Alcoholic Fatty Liver Disease

Due to the epidemic of obesity across the world, nonalcoholic fatty liver disease (NAFLD) has become one of the most prevalent chronic liver disorders in children and adolescents. NAFLD comprises a spectrum of fat-associated liver conditions that can result in end-stage liver disease and the need for liver transplantation. Simple steatosis, or fatty liver, occurs early in NAFLD and may progress to nonalcoholic steatohepatitis, fibrosis and cirrhosis with increased risk of hepatocellular carcinoma. The mechanism of the liver injury in NAFLD is currently thought to be a “multiple-hit process” where the first “hit” is an increase in liver fat, followed by multiple additional factors that trigger the inflammatory activity. At the onset of disease, NAFLD is characterized by hepatic triglyceride accumulation and insulin resistance. Liver fat accumulation is associated with increased lipotoxicity from high levels of free fatty acids, free cholesterol and other lipid metabolites. As a consequence, mitochondrial dysfunction with oxidative stress and production of reactive oxygen species and endoplasmic reticulum stress-associated mechanisms, are activated. The present review focuses on the relationship between intra-cellular lipid accumulation and insulin resistance, as well as on lipid and lipoprotein metabolism in NAFLD.

Using controlled attenuation parameter combined with ultrasound to survey non-alcoholic fatty liver disease in hemodialysis patients: A prospective cohort study

BACKGROUND AND AIMS

Controlled attenuation parameter (CAP) is a non-invasive method for measuring hepatic steatosis (HS). Non-alcoholic fatty liver disease (NAFLD) is closely related to cardiovascular diseases (CVDs). CVDs are the leading cause of morbidity and mortality in hemodialysis patients. The aim of this study was to investigate the prevalence of NAFLD in hemodialysis patients.

METHOD

We prospectively enrolled patients undergoing chronic hemodialysis, as well as patients with normal renal function who served as controls. The control group patients were referred by an endocrinologist to be tested for NAFLD; most of these patients had diabetes, hypertension, or dyslipidemia. We excluded those with excess alcohol intake, use of drugs known to induce HS, chronic viral hepatitis, or CAP failure. CAP ≥ 238 dB/m was used as a cutoff suggesting HS. An increased liver kidney contrast, as defined by ultrasound, was used to make the diagnosis of HS.

RESULTS

Three hundred and forty-three hemodialysis patients and 252 control group patients were enrolled. Among the hemodialysis patients, 192 (56.0%) had CAP- or ultrasound-identified HS compared with 91 (26.5%) who only had ultrasound-identified HS (P<0.001). Among the control group patients, 212 (84.1%) had CAP- or ultrasound-identified HS compared with 180 (71.4%) who only had ultrasound-identified HS (P<0.001).

CONCLUSIONS

The prevalence of NAFLD in the hemodialysis patients was 56%. The number of diagnoses of NAFLD made by using CAP combined with ultrasound was more than 2 times the number made with ultrasound alone in the hemodialysis patients. Therefore, we suggest the use of CAP combined with ultrasound to screen for NAFLD in hemodialysis patients.

The Prevalence of Metabolic Syndrome In Non-alcoholic Fatty Liver Disease; A Population-Based Study

BACKGROUND

Some evidence, not in large study populations, suggests that nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) share common interactions. We aimed to determine the prevalence of NAFLD and MetS in a large population registered to Kavar Cohort Study center. We also assessed the role of each component of MetS in NAFLD existence.

METHODS

Data were obtained from 3415 volunteers who called and refereed to our center. Complete anthropometric and laboratory measurement and abdominal ultrasonography was done for these individuals to screen NAFLD and its grade. A questionnaire was also used to obtain information on demographical and medical history and alcohol consumption. MetS was defined in all participants based on the National Cholesterol Education Program Adult Treatment Panel III (2001) (NCEP/ATP-III) and criteria for clinical diagnosis of metabolic syndrome in Iranian adults (CCDMIA).

RESULTS

Among the refereed individuals, 2980 peoples were aged ≥18 years with male to women ratio of 1:2.45. NAFLD was diagnosed by ultrasound in 32.9% and 27.4% of men and women, respectively. MetS was detected in 65.9 and 64.6 of the patients with NAFLD (based on NCEP/ATP-III) and in 30.1% and 73.7% (based on CCDMIA) of men and women, respectively. There were no significant differences between two gender in none of the components (p>0.05). Although, OR for hyperglycemia and abdominal obesity were approximately high in CCDMIA criteria (0.9613 and 1.2082, respectively), the differences were not statistically significant.

CONCLUSION

NAFLD was associated with MetS. However, it was not possible to determine whether NAFLD predating the development of MetS

Effects of dietary milk- and soya-phospholipids on lipid-parameters and other risk indicators for cardiovascular diseases in overweight or obese men - two double-blind, randomised, controlled, clinical trials

The present study examined the effect of milk phospholipids (milk-PL) on lipid metabolism and on other risk factors for CVD, in comparison with milk fat (control) or soya phospholipids (soya-PL), respectively. Two double-blind parallel-group intervention trials were conducted in overweight or obese male subjects. In the first trial (trial 1), sixty-two men consumed milk enriched with either 2 g milk-PL or 2 g milk fat (control) for 8 weeks. In trial 2, fifty-seven men consumed milk enriched with either 3 g milk-PL or 2·8 g soya-PL for 7 weeks. In trial 1, milk-PL as compared with control reduced waist circumference but did not affect plasma lipids (total, HDL- and LDL-cholesterol, total cholesterol:HDL-cholesterol ratio, TAG, phospholipids), apoB, apoA1, glucose, insulin, insulin sensitivity index, C-reactive protein, IL-6, soluble intracellular adhesion molecule and total homocysteine (tHcy). Serum activities of alanine transaminase and aspartate transaminase were not changed. Activity of γ-glutamyl transferase (GGT), a marker of fatty liver, increased in the control but not in the milk-PL group, with a significant intervention effect. In trial 2, milk-PL as compared with soya-PL did not affect the above-mentioned parameters, but decreased GGT. Subjects with the methylenetetrahydrofolate reductase mutations CT and TT had 11 % (P < 0·05) higher baseline tHcy concentrations than those with the wild-type CC. However, genotype did not modulate the phospholipid intervention effect on tHcy. In conclusion, supplementation with milk-PL as compared with control fat reduced waist circumference and, as compared with both control fat and soya-PL, GGT activity.

Evaluation of Periaortic Adiposity and Metabolic Disorders in Obese Children

OBJECTIVE

To evaluate the relationship between periaortic fat thickness (PAFT) and parameters involved in the development of metabolic complications of the cardiovascular system in obese children and to assess the usefulness of echocardiographic measurements of PAFT in correlation with cardiovascular risk factors.

METHODS

The study was conducted with 263 obese and 100 healthy children and adolescents. PAFT was measured with echocardiography method which was recently performed in obese children and adolescents.

RESULTS

PAFT was significantly higher in the obese group (0.258±0.031 mm) than in the control group (0.137±0.032 mm) (p<0.001). In multivariable regression analysis, body mass index-standard deviation score and total body fat were predictors of PAFT. The area under the receiver operating characteristic curve was 0.989 and was quite significant at p<0.001. PAFT above 0.179 mm was determined as the cut-off value in obese children and adolescents (sensitivity=1, specificity=0.97).

CONCLUSION

The measurement of PAFT in obese children and adolescents may be a good method to reveal the presence of early cardiovascular risk.

Detection of carcinogenic etheno-DNA adducts in children and adolescents with non-alcoholic steatohepatitis (NASH)

BACKGROUND

Carcinogenic exocyclic-DNA adducts like 1,N(6)-etheno-2'-deoxyadenosine (εdA) are formed through reactive intermediates of 4-hydroxynonenal (4-HNE) or other lipid peroxidation (LPO) products with the DNA bases A, C, methyl-C and G. High levels of hepatic etheno-DNA adducts have been detected in cancer prone liver diseases including alcoholic liver disease (ALD). In ALD εdA levels correlated significantly with cytochrome P-450 2E1 (CYP2E1) expression which is also induced in non-alcoholic steatohepatitis (NASH). We investigated the occurrence of εdA adducts in children with NASH as a DNA damage marker.

METHODS

Liver biopsies from 21 children/adolescents with histologically proven NASH were analysed for hepatic fat content, inflammation, and fibrosis. εdA levels in DNA, CYP2E1-expression and protein bound 4-hydroxynonenal (HNE) were semi-quantitatively evaluated by immunohistochemistry.

RESULTS

Among 21 NASH children, εdA levels in the liver were high in 3, moderate in 5, weak in 9 and not elevated in 4 patients. There was a positive correlation between CYP2E1 and protein-bound 4-HNE (r=0.60; P=0.008) and a trend for a positive relationship for CYP2E1 vs. staining intensity of εdA (r=0.45; P=0.06). Inflammatory activity and fibrosis correlated significantly (r=0.49, P=0.023).

CONCLUSIONS

Our results demonstrate for the first time the presence of elevated carcinogenic etheno-DNA lesions (εdA) in the majority (17/21) of liver biopsies from young NASH patients. Our data suggest that LPO-derived etheno-adducts are implicated in NASH. Whether these adducts may serve as predictive risk markers in NASH children to develop hepatocellular cancer later in life remains to be investigated.

Tobacco Smoke-Induced Brain White Matter Myelin Dysfunction: Potential Co-Factor Role of Smoking in Neurodegeneration

BACKGROUND

Meta-analysis studies showed that smokers have increased risk for developing Alzheimer's disease (AD) compared with non-smokers, and neuroimaging studies revealed that smoking damages white matter structural integrity.

OBJECTIVE

The present study characterizes the effects of side-stream (second hand) cigarette smoke (CS) exposures on the expression of genes that regulate oligodendrocyte myelin-synthesis, maturation, and maintenance and neuroglial functions.

METHODS

Adult male A/J mice were exposed to air (8 weeks; A8), CS (4 or 8 weeks; CS4, CS8), or CS8 followed by 2 weeks recovery (CS8 + R). The frontal lobes were used for histology and qRT-PCR analysis.

RESULTS

Luxol fast blue, Hematoxylin and Eosin stained histological sections revealed CS-associated reductions in myelin staining intensity and narrowing of the corpus callosum. CS exposures broadly decreased mRNA levels of immature and mature oligodendrocyte myelin-associated, neuroglial, and oligodendrocyte-related transcription factors. These effects were more prominent in the CS8 compared with CS4 group, suggesting that molecular abnormalities linked to white matter atrophy and myelin loss worsen with duration of CS exposure. Recovery normalized or upregulated less than 25% of the suppressed genes; in most cases, inhibition of gene expression was either sustained or exacerbated.

CONCLUSION

CS exposures broadly inhibit expression of genes needed for myelin synthesis and maintenance. These adverse effects often were not reversed by short-term CS withdrawal. The results support the hypothesis that smoking contributes to white matter degeneration, and therefore could be a key risk factor for a number of neurodegenerative diseases, including AD.

[Waist circumference as a marker for screening nonalcoholic fatty liver disease in obese adolescents]

OBJECTIVE

To assess the relationship between the degree of waist circumference (WC) and nonalcoholic fatty liver disease (NAFLD) in obese adolescents of both genders, analyzed according to quartiles of WC.

METHODS

Cross-sectional study that involved 247 obese adolescents aged 12-19 years. Mean values of the nutritional parameters and serum analyses were compared with the groups using the independent t-test. Pearson correlation coefficient was used to determine the relationship of the parameters studied. Chi-square test for trend was used to determine the relationship between the prevalence of the NAFLD and WC quartile by gender.

RESULTS

NAFLD were presented in 60% of the study participants. Obese adolescents in the 3rd and 4th quartiles of WC presented higher prevalence of NAFLD when compared with that in the 1st quartile in both genders. The NAFLD patients had significantly higher values for body weight, BMI (body mass index), BAZ-score (BMI-for-age z-scores), total fat (% and kg), WC, visceral fat, insulin, insulin resistance index (HOMA-IR), aspartate aminotransferase and alanine aminotransferase, when compared with non-NAFLD obese adolescents.

CONCLUSIONS

The results presented here suggest that an increase in WC can reliably predict the risk of NAFLD in obese adolescents. This is a low cost and easy-to-use tool that can help in screening in adolescents.

Association between the corrected QT interval, carotid artery intima-media thickness, and hepatic steatosis in obese children

Objective:

Childhood obesity is related to subclinical atherosclerosis. Carotid intima-media thickness (CIMT) and hepatosteatosis are parameters that reflect subclinical atherosclerosis and are shown to be associated with obesity. However, their relation with the corrected QT interval (QTc) has not been thoroughly studied in children. Here, we aimed to research the relation between QTc, hepatic steatosis, and CIMT among obese children.

Methods:

Fifty-three obese and 53 age- and sex-matched non-obese children aged 6–16 years were included in this prospective cross-sectional study. The QTc of each subject was accordingly obtained from lead II on a 12-lead resting electrocardiogram. Thus, CIMT measurement and abdominal ultrasonographic examination were performed. The data for obese and non-obese children were analyzed and compared.

Result:

The age and gender distribution of the subjects were statistically similar. The CIMT value of the obese group was higher than that of the non-obese group (p<0.001). The obese group had a higher frequency of hepatosteatosis at grade 1 or 2 than the non-obese group (p<0.001). The QTc values were also found to be more prolonged in the obese group than in the other group (p<0.001). With Student’s t-test and Mann-Whitey U test accordingly.

Conclusion:

We demonstrated that obese children had higher CIMT and QTc values as well as more frequent hepatosteatosis, and that the presence of hepatosteatosis or increased CIMT had an association with prolonged QTc values in obese children. Therefore, with the aim of detecting cardiovascular effects of obesity, it may be beneficial to perform the measurements of QTc in the presence of hepatosteatosis and/or increased CIMT among obese children.

Assessment of Cardiovascular Parameters in Obese Children and Adolescents with Non-Alcoholic Fatty Liver Disease

OBJECTIVE

The aim of this study was to evaluate the periaortic fat thickness (PAFT) using conventional echocardiography in obese children and adolescents with non-alcoholic fatty liver disease (NAFLD).

METHODS

Two hundred and ninety-seven obese children and adolescents were included in the study. Anthropometric measurements were made in all subjects, and fasting venous blood samples were taken for determination of glucose, insulin, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Ultrasonography of the liver was used for assessment of NAFLD and the subjects were grouped as NAFLD and non-NAFLD. Echocardiography was performed in all subjects.

RESULTS

PAFT was higher in patients with NAFLD compared with the non-NAFLD group. In patients with NAFLD, PAFT was positively correlated with waist circumference and with total cholesterol levels. In multiple regression analysis, waist circumference (β=0.28, p=<0.001) was found to be the best predictor of PAFT.

CONCLUSION

Conventional echocardiography may be used to determine increased PAFT at an early stage in obese children and adolescents with NAFLD for careful monitoring of cardiovascular risk.

Low Serum Potassium Levels Associated with Disease Severity in Children with Nonalcoholic Fatty Liver Disease

PURPOSE

Recent studies have suggested that decreased serum potassium level may contribute to various metabolic disorders in adult patients including nonalcoholic fatty liver disease (NAFLD). We aimed to study the correlation between serum potassium levels and the histologic severity of NAFLD in children.

METHODS

Pediatric patients with biopsy-proven NAFLD were included in this study. Demographic, clinical, and histopathological data were obtained. Multivariable logistic regression analysis was used to assess whether potassium levels are associated with the presence of nonalcoholic steatohepatitis (NASH) or fibrosis after adjusting for possible confounders. A p-value <0.05 was considered statistically significant.

RESULTS

Among 125 biopsies, 49.6% (62) had evidence of NASH while 66.4% (83) had some degree of fibrosis (stage 1-3). Mean serum potassium was significantly lower in NASH group as compared to non-NASH group (4.4±0.42 mmoL/L vs. 4.8±0.21, p<0.001). Higher potassium level had negative correlation with presence of steatosis, ballooning, lobular inflammation, fibrosis and NAFLD activity score (p<0.05). On multivariable analysis and after adjusting for the metabolic syndrome and insulin resistance, higher potassium level was significantly associated with lower likelihood of having a histological diagnosis of NASH on biopsy (odds ratio [OR], 0.12; 95% confidence interval [95% CI], 0.05-0.28; p<0.001). Similarly, the likelihood of having fibrosis decreases by 76% for every 0.5 mmoL/L increase in potassium (OR ,0.24; 95% CI, 0.11-0.54; p<0.001).

CONCLUSION

Our study shows an inverse relationship between serum potassium levels and the presence of aggressive disease (NASH and fibrosis) in children with NAFLD.

The association between retinal microvascular changes, metabolic risk factors, and liver histology in pediatric patients with non-alcoholic fatty liver disease (NAFLD)

BACKGROUND

The prevalence of childhood obesity is increasing worldwide. Studies in adult populations show that retinal microvascular changes are associated with obesity and components of the metabolic syndrome. In our study we have assessed the effect of body mass index (BMI), metabolic parameters, and adiposity on the retinal microvasculature in children.

METHODS

Fifty-four consecutive children with biopsy-proven NAFLD were enrolled in this study. Anthropometric and laboratory parameters were obtained using standardized protocols. Retinal caliber was quantified from digital retinal images using well-known computer-based programs. Twenty-four-hour ambulatory blood pressure monitoring was measured using a standard protocol.

RESULTS

In our population, the prevalence of retinopathy was of 53 % (13 males). The 29 patients with retinopathy (mean age 10.91 ± 3.10) showed significantly higher values of triglycerides (mg/day) (105.57 vs. 90.20, p = 0.04), basal insulin (mUI/ml) (17.20 vs. 12.97, p = 0.02), and HOMA-IR (3.37 vs. 2.76, p = 0.04). The patients with a HOMA-IR >2.5 (OR = 3.34, p = 0.02; 95 % IC, 1.07-10.39), and systolic non-dipping (OR 4.16, p = 0.028, 95 % IC, 1.11-13.67), have an increased risk of retinopathy. Moreover, the study of correlation between all stages of liver biopsy (CRN criteria) and the grade of retinopathy showed a positive correlation with fibrosis (r = 0.31) and an NAS score (r = 0.28).

CONCLUSIONS

We found an association between metabolic parameters and nocturnal blood pressure on the retinal microvasculature among the obese children with NAFLD. Furthermore, for the first time, we report the positive relationship between hepatic fibrosis in pediatric NAFLD patients and the degree of retinopathy signs.

Association of Nonalcoholic Fatty Liver Disease with Subclinical Cardiovascular Changes: A Systematic Review and Meta-Analysis

In the last 20 years, nonalcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease worldwide, primarily as a result of the epidemic of obesity. NAFLD is strongly associated with insulin resistance, glucose intolerance, and dyslipidemia and is currently regarded as the liver manifestation of the metabolic syndrome, a highly atherogenic condition even at a very early age. Patients with NAFLD including pediatric subjects have a higher prevalence of subclinical atherosclerosis, as shown by impaired flow-mediated vasodilation, increased carotid artery intima-media thickness, and arterial stiffness, which are independent of obesity and other established risk factors. More recent work has identified NAFLD as a risk factor not only for premature coronary heart disease and cardiovascular events, but also for early subclinical abnormalities in myocardial structure and function. Thus, we conducted a systematic review and meta-analysis to test the hypothesis that NAFLD is associated with evidence of subclinical cardiac structural and functional abnormalities.

Metabolic syndrome is common and persistent in youth-onset type 2 diabetes: Results from the TODAY clinical trial

OBJECTIVE

To examine the prevalence of metabolic syndrome (MetS) in youth-onset type 2 diabetes in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study.

METHODS

Prevalence of MetS (ATP III definition) was compared at baseline (n = 679) and at 6 (n = 625) and 24 months (n = 545) using chi-square tests. Laboratory data were examined between MetS classifications at each time point using ANOVA.

RESULTS

Baseline prevalence of MetS was 75.8% and did not differ by treatment group or change over time. MetS was more common in females (83.1%) than males (62.3%; P < 0.0001) at baseline; this difference persisted over 24 months. Prevalence of MetS was similar between ethnic groups at baseline but greater in Hispanics (82.7%) vs. non-Hispanic Whites (67.5%; P = 0.0017) and non-Hispanic Blacks (72.7%; P = 0.0164) at 24 months. Although MetS was common in participants with hemoglobin A1c < 7.0% (74.4% at baseline; no significant change over 24 months), it was more common in those who did not maintain glycemic control at 6 months (80.3%; P = 0.0081). Elevated C-reactive protein, ALT, IL-6, and PAI-1 levels were more frequent with MetS.

CONCLUSIONS

Persistent high prevalence of MetS in youth-onset diabetes, even with excellent glycemic control, is of concern given the associated increased cardiovascular risk.

Proton density fat-fraction is an accurate biomarker of hepatic steatosis in adolescent girls and young women

OBJECTIVES

To compare complex quantitative magnetic resonance imaging (MRI) with MR spectroscopy (MRS) for quantification of hepatic steatosis (HS) and determine clinically significant MRI-based thresholds of HS in female youths.

METHODS

This prospective, cross-sectional study was conducted in 132 healthy females (11-22 years, mean 13.3 ± 2). Proton density fat-fraction (PDFF) was measured using complex quantitative MRI and MRS. Body mass index (BMI), fasting labs [glucose, insulin, alanine aminotransferase (ALT), and other metabolic markers] were obtained. Outcomes were measured using regression analysis, Spearman-rank correlation, and receiver operator characteristics (ROC) analysis. HS was defined as MRI-PDFF >5.6%.

RESULTS

HS was detected by MRI-PDFF in 15% of all subjects. Linear regression demonstrated excellent correlation and agreement [r(2) = 0.96, slope = 0.97 (95 %CI: 0.94-1.00), intercept = 0.78% (95 %CI: 0.58-0.98%)] between MRI-PDFF and MRS-PDFF. MRI-PDFF had a sensitivity of 100% (95 %CI: 0.79-1.00), specificity of 96.6% (95 %CI: 0.91-0.99), and a kappa index of 87% (95 %CI: 0.75-0.99) for identifying HS. In overweight subjects with HS, MRI-PDFF correlated with ALT (r = 0.84, p < 0.0001) and insulin (r = 0.833, p < 0.001), but not with BMI or WC. ROC analysis ascertained an optimal MRI-PDFF threshold of 3.5% for predicting metabolic syndrome (sensitivity = 76 %, specificity = 83 %).

CONCLUSION

Complex quantitative MRI demonstrates strong correlation and agreement with MRS to quantify hepatic triglyceride content in adolescent girls and young women. A low PDFF threshold is predictive of metabolic syndrome in this population.

KEY POINTS

• Confounder-corrected quantitative MRI (ccqMRI) effectively measures hepatic triglyceride content in adolescent girls. • MRS and ccqMRI strongly correlate in liver proton density fat-fraction (PDFF) detection. • A PDFF threshold of 3.5% may be predictive of paediatric metabolic syndrome.

Metabolomics profiling to investigate the pharmacologic mechanisms of berberine for the treatment of high-fat diet-induced nonalcoholic steatohepatitis

Objective. Berberine has been used to treat nonalcoholic steatohepatitis (NASH), which has been addressed in many studies. In this study, we investigated the molecular pharmacology mechanisms of berberine using metabolomic techniques. Methods. Sprague-Dawley rats were randomly divided into three groups (10 rats in each group): (i) normal control group; (ii) high-fat diet- (HFD-) induced NASH model group; and (iii) HFD berberine-treated group (i.d. 200 mg/kg). The handling procedure lasted eight weeks. Then, UPLC-Q-TOF/MS techniques coupled with histopathology and biochemical analyses were adopted to explore the mechanisms of berberine on the protective effects against NASH. Key Findings. (i) According to conventional test results, berberine treatment plays a fighting role in HFD-induced NASH due to its beneficial effects against insulin resistance, inflammation, and lipid metabolism. (ii) Based on UPLC-Q-TOF/MS techniques, metabolic profiles that involved sphingomyelin (SM), phosphatidylcholine (PC), lysophosphatidylcholine (LysoPC), 13-hydroperoxy-9, 11-octadecadienoic acid (13-HpODE), eicosatrienoic acid, docosatrienoic acid, and eicosenoic acid could provide potential metabolic biomarkers to address the pharmacological mechanisms of berberine. Conclusions. The parts of molecular pharmacological mechanisms of berberine for NASH treatment are related to the regulation of metabolic disruption involving phospholipid and unsaturated fatty acids in rats with NASH.

Pancreatic fat and β-cell function in overweight/obese children with nonalcoholic fatty liver disease

AIM: To analyze the associations of pancreatic fat with other fat depots and β-cell function in pediatric nonalcoholic fatty liver disease (NAFLD).

METHODS: We examined 158 overweight/obese children and adolescents, 80 with NAFLD [hepatic fat fraction (HFF) ≥ 5%] and 78 without fatty liver. Visceral adipose tissue (VAT), pancreatic fat fraction (PFF) and HFF were determined by magnetic resonance imaging. Estimates of insulin sensitivity were calculated using the homeostasis model assessment of insulin resistance (HOMA-IR), defined by fasting insulin and fasting glucose and whole-body insulin sensitivity index (WBISI), based on mean values of insulin and glucose obtained from oral glucose tolerance test and the corresponding fasting values. Patients were considered to have prediabetes if they had either: (1) impaired fasting glucose, defined as a fasting glucose level ≥ 100 mg/dL to < 126 mg/dL; (2) impaired glucose tolerance, defined as a 2 h glucose concentration between ≥ 140 mg/dL and < 200 mg/dL; or (3) hemoglobin A1c value of ≥ 5.7% to < 6.5%.

RESULTS: PFF was significantly higher in NAFLD patients compared with subjects without liver involvement. PFF was significantly associated with HFF and VAT, as well as fasting insulin, C peptide, HOMA-IR, and WBISI. The association between PFF and HFF was no longer significant after adjusting for age, gender, Tanner stage, body mass index (BMI)-SD score, and VAT. In multiple regression analysis with WBISI or HOMA-IR as the dependent variables, against the covariates age, gender, Tanner stage, BMI-SD score, VAT, PFF, and HFF, the only variable significantly associated with WBISI (standardized coefficient B, -0.398; P = 0.001) as well as HOMA-IR (0.353; P = 0.003) was HFF. Children with prediabetes had higher PFF and HFF than those without. PFF and HFF were significantly associated with prediabetes after adjustment for clinical variables. When all fat depots where included in the same model, only HFF remained significantly associated with prediabetes (OR = 3.38; 95%CI: 1.10-10.4; P = 0.034).

CONCLUSION: In overweight/obese children with NAFLD, pancreatic fat is increased compared with those without liver involvement. However, only liver fat is independently related to prediabetes.

Antioxidant vitamins in the context of nonalcoholic fatty liver disease in obese children and adolescents

OBJECTIVE:

To review the literature on the importance of antioxidant vitamins, analyzed in the context of dietary intake, its plasma levels, and its current use as a supplementation treatment in obese children and adolescents with nonalcoholic fatty liver disease.

DATA SOURCES:

The articles were identified in Lilacs, Ibecs, SciELO, PubMed/Medline, and Scopus databases. To conduct the survey, the "fatty liver" descriptor was associated to the following words: "children", "antioxidants" and "vitamins". The search was limited to articles written in Portuguese, Spanish and English, with publication date until December, 2012.

DATA SYNTHESIS:

Six studies were selected. The survey revealed a low dietary intake and low antioxidant vitamins serum levels in this population. The changes in lifestyle, with adequate dietary intake of vitamins, and the increase in physical activity were associated with a significant improvement in liver histology and in laboratory tests. Vitamin supplementation also improved the disease progression markers, as the alanine aminotransferase serum levels and the histological characteristics of lobular inflammation and hepatocellular damage. However, these improvements were not statistically significant in all studies.

CONCLUSIONS:

There is insufficient evidence to recommend or to refute antioxidant supplementation in patients with simple steatosis or steatohepatitis. The changes in lifestyle seem to be, at the present time, the more advisable therapy.

Association of Tumor Necrosis Factor-alpha Polymorphisms and Risk of Coronary Artery Disease in Patients With Non-alcoholic Fatty Liver Disease

BACKGROUND

Cardiovascular events account for the main cause of death in patients with non-alcoholic fatty liver disease (NAFLD), and are largely influenced by genetic factors. Although multiple studies showed that tumor necrosis factor-alpha (TNF-α) polymorphisms are risk factors in the progression of NAFLD, few papers on the association of the polymorphisms and the developing coronary artery disease (CAD) in NAFLD patients have been reported.

OBJECTIVES

The present study was designed to evaluate the association of TNF-α polymorphisms at residues -238 and -308, with the risk of developing CAD in Chinese patients with NAFLD.

PATIENTS AND METHODS

The TNF-α polymorphisms at residues 238 and 308 were genotyped in B-type ultrasonography proven NAFLD patients with (n = 246), without (n = 247) CAD and healthy controls (n = 304), using polymerase chain reaction (PCR). Serum lipid profiles were determined using biochemical methods. Statistical analyses were performed using SPSS statistical software, version 20.0 for Mac.

RESULTS

We found a significant association between TNF-α-238 guanine to alanine (GA) polymorphism and carriers of variant allele A between NAFLD patients with and without CAD (P < 0.05). Carriers of the A allele of TNF-α-238 had higher serum triglycerides (TG) and low density lipoprotein (LDL) levels in NAFLD patients with CAD (P = 0.025 and 0.001, respectively) and a higher TG level in NAFLD patients without CAD (P = 0.017), than their non-carrier counterparts.

CONCLUSIONS

In the Chinese Han population that we studied, NAFLD patients who carry the TNF-α-238 GA polymorphism have an increased risk of developing CAD. Mechanisms underlying this potentially important association require further investigation.

PNPLA3 I148M variant in nonalcoholic fatty liver disease: Demographic and ethnic characteristics and the role of the variant in nonalcoholic fatty liver fibrosis

Patatin-like phospholipase domain-containing 3 (PNPLA3 or adiponutrin) displays anabolic and catabolic activities in lipid metabolism, and has been reported to be significantly associated with liver fat content. Various studies have established a strong link between the 148 isoleucine to methionine protein variant (I148M) of PNPLA3 and liver diseases, including nonalcoholic fatty liver disease (NAFLD). However, detailed demographic and ethnic characteristics of the I148M variant and its role in the development of nonalcoholic fatty liver fibrosis have not been fully elucidated. The present review summarizes the current knowledge on the association between the PNPLA3 I148M variant and NAFLD, and especially its role in the development of nonalcoholic fatty liver fibrosis. First, we analyze the impact of demographic and ethnic characteristics of the PNPLA3 I148M variant and the presence of metabolic syndrome on the association between PNPLA3 I148M and NAFLD. Then, we explore the role of the PNPLA3 I148M in the development of nonalcoholic fatty liver fibrosis, and hypothesize the underlying mechanisms by speculating a pro-fibrogenic network. Finally, we briefly highlight future research that may elucidate the specific mechanisms of the PNPLA3 I148M variant in fibrogenesis, which, in turn, provides a theoretical foundation and valuable experimental data for the clinical management of nonalcoholic fatty liver fibrosis.

Which metabolic syndrome criteria best predict non-alcoholic fatty liver disease in children?

OBJECTIVE

The aim of this study was to identify which metabolic syndrome criteria (WHO or IDF) better reflect the presence of non-alcoholic fatty liver disease (NAFLD) and to determine the prevalence of metabolic syndrome (MS) and NAFLD.

METHODS

Two hundred and seventeen obese children and adolescents, 8-15 years of age (body mass index >95 p), were included in the study. Anthropometric measurements, blood pressure measurements, an oral glucose tolerance test and lipid profile were measured. MS was diagnosed according to WHO and IDF criteria. NAFLD risk ratio was assessed according to the two MS criteria.

RESULTS

The prevalence of MS according to the IDF criteria was 43.3 %, and according to WHO criteria it was 55.2 %. NAFLD prevalence in the metabolic syndrome group according to IDF criteria was 25.5 % and this was statistically significant (p = 0.007). The prevalence of NAFLD was 20.8 % in the group with MS according to WHO criteria and this was not a statistically significant difference (p = 0.15). NAFLD hazard ratios were 7.06 (95 % CI 1.29-5.50) in the MS group according to IDF criteria and 2.02 (95 % CI 0.81-3.53) in the group with metabolic syndrome according to WHO criteria. IDF criteria were found to have a higher odds ratio.

CONCLUSION

The prevalence of MS depends on the diagnostic criteria used. IDF criteria give the best measure for the presence of NAFLD. NAFLD might be important as diagnostic criterion for MS.

Chemerin as a novel non-invasive serum marker of intrahepatic lipid content in obese children

BACKGROUND

Ectopic hepatic lipid accumulation is closely related to the development of insulin resistance, which is regarded as one of the most significant risk factors of non-alcoholic fatty liver disease (NAFLD). The current study has shown that fat tissue constitutes an important endocrine organ with its own production and metabolism of many biologically active substances, among which adipokines play an important role. Classic adipokines (e.g. leptin, adiponectin, resistin) are fat-derived hormones which serum level is altered in patients with NAFLD. The role of novel adipokines in the pathomechanism of this disease is not clear. Therefore, the aim of our study was to evaluate the serum concentrations of chemerin, omentin and vaspin in obese children with NAFLD.

METHODS

Forty-five obese children, aged 7-17 years old, were admitted to our Department with suspected liver disease (hepatomegaly, and/or ultrasonographic liver brightness, and/or increased ALT activity). Viral hepatitides, as well as autoimmune and metabolic liver diseases were excluded. Fasting serum levels of chemerin, omentin and vaspin were determined. The grade of liver steatosis in ultrasound was graded according to Saverymuttu. (1)HMR spectroscopy was performed with a 1.5 T scanner and with PRESS sequencing.

RESULTS

Fatty liver was confirmed in 39 children by ultrasound and in 33 patients by (1)HMRS (19 of them also had increased ALT activity /NAFLD/). Chemerin and vaspin levels were significantly higher in children with NAFLD compared to the control group (n = 30). The concentration of chemerin was significantly higher in children with advanced liver steatosis compared to non-hepatopathic patients (p = 0,02). Significant positive correlations were found between the total liver lipids in (1)HMRS and chemerin (r = 0,33; p = 0,02) and vaspin (r = 0,4; p = 0,006). The ability of serum chemerin (cut-off = 190 ng/ml, Se = 75%, Sp = 58%) to differentiate children with fatty liver in (1)HMRS from those without steatosis was significant (AUC = 0,7, p = 0,04). Omentin and vaspin did not allow a useful prediction to be made.

CONCLUSION

Chemerin seems to be the most suitable non-invasive biomarker in predicting both intrahepatic lipid content in obese children and advanced liver steatosis in children with NAFLD.

Systems biology approaches for studying the pathogenesis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease of increasing public health concern. In western populations the disease has an estimated prevalence of 20%-40%, rising to 70%-90% in obese and type II diabetic individuals. Simplistically, NAFLD is the macroscopic accumulation of lipid in the liver, and is viewed as the hepatic manifestation of the metabolic syndrome. However, the molecular mechanisms mediating both the initial development of steatosis and its progression through non-alcoholic steatohepatitis to debilitating and potentially fatal fibrosis and cirrhosis are only partially understood. Despite increased research in this field, the development of non-invasive clinical diagnostic tools and the discovery of novel therapeutic targets has been frustratingly slow. We note that, to date, NAFLD research has been dominated by in vivo experiments in animal models and human clinical studies. Systems biology tools and novel computational simulation techniques allow the study of large-scale metabolic networks and the impact of their dysregulation on health. Here we review current systems biology tools and discuss the benefits to their application to the study of NAFLD. We propose that a systems approach utilising novel in silico modelling and simulation techniques is key to a more comprehensive, better targeted NAFLD research strategy. Such an approach will accelerate the progress of research and vital translation into clinic.

Nonalcoholic fatty liver disease and vascular disease: State-of-the-art

Nonalcoholic fatty liver disease (NAFLD), the most common of chronic liver disease in Western Country, is closely related to insulin resistance and oxidative stress and includes a wide spectrum of liver diseases ranging from steatosis alone, usually a benign and non-progressive condition, to nonalcoholic steatohepatitis (NASH), which may progress to liver fibrosis and cirrhosis. NAFLD is considered the hepatic manifestation of the metabolic syndrome with which shares several characteristics, however recent data suggest that NAFLD is linked to increased cardiovascular risk independently of the broad spectrum of risk factors of metabolic syndrome. Accumulating evidence suggests that the clinical burden of NAFLD is not restricted to liver-related morbidity and mortality, with the majority of deaths in NAFLD patients related to cardiovascular disease and cancer and not to the progression of liver disease. Retrospective and prospective studies provide evidence of a strong association between NAFLD and subclinical manifestation of atherosclerosis (increased intima-media thickness, endothelial dysfunction, arterial stiffness, impaired left ventricular function and coronary calcification). A general agreement emerging from these studies indicates that patients with NASH are at higher risk of cardiovascular diseases than those with simple steatosis, emphasizing the role of chronic inflammation in the pathogenesis of atherosclerosis of these patients. It is very likely that the different mechanisms involved in the pathogenesis of atherosclerosis in patients with NAFLD have a different relevance in the patients according to individual genetic background. In conclusion, in the presence of NAFLD patients should undergo a complete cardiovascular evaluation to prevent future atherosclerotic complications. Specific life-style modification and aggressive pharmaceutical modification will not only reduce the progression of liver disease, but also reduce morbidity for cardiovascular disease improving overall prognosis and survival.

Dietary fructose reduction improves markers of cardiovascular disease risk in Hispanic-American adolescents with NAFLD

Nonalcoholic fatty liver disease (NAFLD) is now thought to be the most common liver disease worldwide. Cardiovascular complications are a leading cause of mortality in NAFLD. Fructose, a common nutrient in the westernized diet, has been reported to be associated with increased cardiovascular risk, but its impact on adolescents with NAFLD is not well understood. We designed a 4-week randomized, controlled, double-blinded beverage intervention study. Twenty-four overweight Hispanic-American adolescents who had hepatic fat >8% on imaging and who were regular consumers of sweet beverages were enrolled and randomized to calorie-matched study-provided fructose only or glucose only beverages. After 4 weeks, there was no significant change in hepatic fat or body weight in either group. In the glucose beverage group there was significantly improved adipose insulin sensitivity, high sensitivity C-reactive protein (hs-CRP), and low-density lipoprotein (LDL) oxidation. These findings demonstrate that reduction of fructose improves several important factors related to cardiovascular disease despite a lack of measurable improvement in hepatic steatosis. Reducing dietary fructose may be an effective intervention to blunt atherosclerosis progression among NAFLD patients and should be evaluated in longer term clinical trials.

Nonalcoholic fatty liver disease and the heart in children and adolescents

Over the last two decades, the rise in the prevalence rates of overweight and obesity explains the emergence of nonalcoholic fatty liver disease (NAFLD) as the leading cause of chronic liver disease worldwide. As described in adults, children and adolescents with fatty liver display insulin resistance, glucose intolerance, and dyslipidemia. Thus NAFLD has emerged as the hepatic component of the metabolic syndrome (MetS) and a strong cardiovascular risk factor even at a very early age. Several studies, including pediatric populations, have reported independent associations between NAFLD and markers of subclinical atherosclerosis including impaired flow-mediated vasodilation, increased carotid artery intima-media thickness, and arterial stiffness, after adjusting for cardiovascular risk factors and MetS. Also, it has been shown that NAFLD is associated with cardiac alterations, including abnormal left ventricular structure and impaired diastolic function. The duration of these subclinical abnormalities may be important, because treatment to reverse the process is most likely to be effective earlier in the disease. In the present review, we examine the current evidence on the association between NAFLD and atherosclerosis as well as between NAFLD and cardiac dysfunction in the pediatric population, and discuss briefly the possible biological mechanisms linking NAFLD and cardiovascular changes. We also address the approach to treatment for this increasingly prevalent disease, which is likely to have an important future global impact on the burden of ill health, to prevent not only end-stage liver disease but also cardiovascular disease.

Serum choline plasmalogens, particularly those with oleic acid in sn-2, are associated with proatherogenic state

Serum plasmalogens (Pls) (1-O-alk-1'-enyl-2-acyl glycerophospholipids) are of particular interest for studies on metabolic disorders associated with oxidative stress and chronic inflammation. Serum levels of Pls are known to correlate positively with HDL-cholesterol (HDL-C); however, few studies have examined serum Pls molecular species in association with pathophysiological conditions and their clinical significance. To clarify these, we determined serum levels of individual ether glycerophospholipids in Japanese asymptomatic cohorts (n = 428; 362 male and 66 female subjects) by LC/MS/MS, and examined their correlations with clinical parameters. We found that the proportion of choline Pls (PlsCho) among total serum phospholipids was significantly lower in the male group over 40 years old and was associated with multiple risk parameters more strongly than HDL-C. The abundance of serum PlsCho with oleic acid (18:1) in sn-2 exhibited the strongest positive correlation with serum concentrations of adiponectin and HDL-C, while being inversely associated with waist circumference and the serum levels of TG and small dense LDL-cholesterol. The characterization of serum ether glycerophospholipids verified the specificity of PlsCho, particularly the ones with 18:1 in sn-2, as a sensitive biomarker for the atherogenic state.

Cardiovascular disorders in the context of non-alcoholic Fatty liver disease: a literature review

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in the United States and other industrialized countries, and the reported prevalence in the developing countries is also rather high. This disease is associated with a high rate of morbidity and mortality and damage to the other organs. The cardiovascular system is, perhaps, the most vulnerable organ to NAFLD adverse effects to the extent that most mortality associated with this disease is reportedly from the cardiovascular system rather than from the liver itself. In this article, we review the significant aspects of cardiovascular disorders associated with NAFLD, including the epidemiology of cardiovascular diseases in NAFLD patients, factors that interfere in this relationship like hypertension, severity of NAFLD, and age of the patients, and finally preventive strategies whose employment could significantly improve the outcome.

Pediatric non-alcoholic fatty liver disease: an increasing public health issue

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial condition that encompasses a wide spectrum of liver abnormalities ranging from simple liver steatosis to steatohepatitis (non-alcoholic steatohepatitis), which may be associated with fibrosis and progress to cirrhosis and end-stage liver disease. NAFLD has recently become the most common cause of chronic liver disease in children and adolescents. NAFLD prevalence, alongside obesity, continues to increase among pediatric patients. Obesity is believed to represent a major risk factor for NAFLD, which is considered to be the liver presentation of the metabolic syndrome. Although the pathogenesis of NAFLD is not fully understood, the notion that multiple factors affect disease development and progression is widely accepted. Both genetic background and environmental factors contribute to NAFLD development. A more complete understanding of the pathogenesis may aid in developing non-invasive diagnostic tools and identifying new therapeutic targets. Liver biopsy currently remains the gold standard for NAFLD diagnosis and staging. Although lifestyle and diet modifications are key in NAFLD treatment, the development of new pharmacological therapies is crucial for patients who are unresponsive to first-line therapy.

CONCLUSION

Pediatric NAFLD is an increasing public health issue that remains underdiagnosed. A large-scale screening in the high-risk population, especially among the overweight pediatric patients, should be considered, including measurement of serum transaminases and liver ultrasound. It is crucial to treat this condition as soon as possible in order to avoid the progression to end-stage liver disease.

Development of nonalcoholic hepatopathy: contributions of oxidative stress and advanced glycation end products

Advanced glycation end products (AGEs) are generated spontaneously in cells; however, under conditions of hyperglycemia and lipid peroxidation, their levels are higher than usual, which contribute to the development of diseases such as the nonalcoholic fatty liver disease (NAFLD). NAFLD is associated with oxidative stress (OS), which is linked to the transition of steatosis to steatohepatitis due to lipid peroxidation. The AGE-receptor interaction in hepatic stellate cells leads to an increase in reactive oxygen species and enhances the proliferation and activation of these cells, worsening liver fibrosis and disease progression. In this vicious cycle, there is production of (carboxymethyl)lysine, a biomarker for products of advanced glycation and lipid peroxidation, being a shared component between the two pathways. In this review, we aim to compile evidence to support the basic molecular mechanisms of AGEs and OS generation and their influence, independently or combined, on the evolution of NAFLD. The deeper understanding of the interrelations of AGEs + OS may help to elucidate the pathogenic pathways of NAFLD and to devise rational therapeutic interventions for this disease, with an expected positive impact on quality of life of patients.

Association between Serum Atypical Fibroblast Growth Factors 21 and 19 and Pediatric Nonalcoholic Fatty Liver Disease

Atypical fibroblast growth factors (FGF) 21 and 19 play a central role in energy metabolism through the mediation of Klotho coreceptor. Contradictory findings are available about the association of FGF21 and FGF19 with nonalcoholic fatty liver disease (NAFLD) in humans. We investigated the association of serum FGF21, FGF19 and liver Klotho coreceptor with non-alcoholic steatohepatitis (NASH) and fibrosis in children with NAFLD. Serum FGF21 and FGF19 were measured in 84 children with biopsy-proven NAFLD and 23 controls (CTRL). The hepatic expression of Klotho coreceptor was measured in 7 CTRL, 9 patients with NASH (NASH+) and 11 patients without NASH (NASH−). FGF21 and FGF19 showed a tendency to decrease from CTRL (median FGF21 = 196 pg/mL; median FGF19 = 201 pg/mL) to NASH− (FGF21 = 89 pg/mL; FGF19 = 81 pg/mL) to NASH+ patients (FGF21 = 54 pg/mL; FGF19 = 41 pg/mL) (p<0.001 for all comparisons) and were inversely associated with the probability of NASH and fibrosis in children with NAFLD. The hepatic expression of Klotho coreceptor was inversely associated with NASH (R² = 0.87, p<0.0001) and directly associated with serum FGF21 (R² = 0.57, p<0.0001) and FGF19 (R² = 0.67, p<0.0001). In conclusion, serum FGF19 and FGF21 and hepatic Klotho expression are inversely associated with hepatic damage in children with NAFLD and these findings may have important implications for understanding the mechanisms of NAFLD progression.