Nonalcoholic fatty liver disease and carotid atherosclerosis in children

Helicobacter pylori components increase the severity of metabolic syndrome and its hepatic manifestations induced by a high fat diet

The metabolic syndrome, often accompanied by hepatic manifestations, is a high-risk factor for developing cardiovascular disease. Patients with metabolic dysfunction associated with steatohepatic disease (MASDL) are at significant risk of developing coronary artery disease. Atherosclerosis is a systemic inflammatory disorder in which several factors, including dietary or infectious factors, can cause an inflammatory response. Helicobacter pylori (HP) bacteria have been implicated in the progression of proatherogenic vascular endothelial lesions, moreover, our previous study in an experimental in vivo model of Cavia porcellus showed that HP components and high-fat substances acted synergistically in promoting vascular endothelial inflammation, leading to an early onset of a proatherogenic environment. In the present study, our goal was to determine the contribution of HP components to the development of hepatic manifestations of metabolic syndrome in an experimental model. Our results showed that HP infection in animals exposed to a high-fat diet increased oxidative stress and lipid peroxidation, followed by endothelial lipid deposition, impaired endothelial apoptosis, cell lysis, and increased vascular stiffness. Finally, histopathological analysis of liver tissue showed signs of MASLD development in HP-infected animals fed a high-fat diet.

Atherogenic Index of Plasma (AIP) and Its Association with Fatty Liver in Obese Adolescents

BACKGROUND

The atherogenic index of plasma (AIP) is the base-10 logarithmic conversion of the triglyceride to high-density lipoprotein cholesterol ratio [AIP = log10 (triglyceride/HDL cholesterol)]. Some studies have found a link between low serum vitamin D levels, AIP, and fatty liver. This study was conducted to evaluate the relationship between AIP levels, fatty liver, and vitamin D levels in obese adolescents aged 10-17 years.

METHODS

This study included 136 adolescents, including 83 obese and 53 healthy controls, in the age range of 10-17 years. Thirty-nine of the obese adolescents had fatty livers. Those with ultrasonography grades 2 or 3 of fat were in the fatty liver group. The AIP value was calculated as the logarithmic conversion of the ratio (triglyceride/HDL cholesterol) at the base of 10. Vitamin D and other laboratory tests were analyzed biochemically. Statistical evaluations were made with the SPSS program.

RESULTS

The AIP, body mass index (BMI), homeostatic model assessment for insulin resistance (HOMA-IR), and insulin averages of obese adolescents with fatty liver were significantly higher than those of obese adolescents without fatty liver and the healthy control group (p < 0.05). Again, the mean AIP of obese patients without fatty liver was pointedly higher than that of the healthy control group (p < 0.05). There was a positive, moderate relationship between AIP and BMI, AIP and HOMA-IR, and AIP and insulin levels (p < 0.05), whereas there was a negative, moderate (37.3%) relationship between AIP and vitamin D (p = 0.019).

CONCLUSION

AIP levels were higher in obese adolescents, and this increase was higher in obese adolescents with fatty liver in this study. Moreover, we detected a negative correlation between AIP and vitamin D levels and a positive correlation with BMI, insulin resistance, and insulin levels. Based on our data, we concluded that AIP can be a useful predictor of fatty liver in obese adolescents.

Current applications for measuring pediatric intima-media thickness

Intima-media thickness is a known subclinical radiologic marker of the early manifestations of atherosclerotic disease. It is the thickness of the vessel wall, most often the carotid artery. Intima-media thickness is measured on conventional US manually or automatically. Other measurement techniques include radiofrequency US. Because there is variation in its measurement, especially in children, several recommendations have been set to increase the measurement's validity and comparability among studies. Despite these recommendations, several pitfalls should be avoided, and quality control should be performed to avoid erroneous interpretation. This article summarizes current literature in relation to the clinical applications for intima-media thickness measurement in children with known risk factors such as obesity, liver steatosis, hypercholesterolemia, diabetes, hypertension, systemic inflammatory diseases, cancer survival, kidney and liver transplant, and sickle cell disease or beta thalassemia major. Most potential indications for intima-media thickness measurement remain in the research domain and should be interpreted combined with other markers. The objective of diagnosing an increased intima-media thickness is to start a multidisciplinary treatment approach to prevent disease progression and its sequelae in adulthood.

Dietary sugar restriction reduces hepatic de novo lipogenesis in adolescent boys with fatty liver disease

BACKGROUNDHepatic de novo lipogenesis (DNL) is elevated in nonalcoholic fatty liver disease (NAFLD). Improvements in hepatic fat by dietary sugar reduction may be mediated by reduced DNL, but data are limited, especially in children. We examined the effects of 8 weeks of dietary sugar restriction on hepatic DNL in adolescents with NAFLD and correlations between DNL and other metabolic outcomes.METHODSAdolescent boys with NAFLD (n = 29) participated in an 8-week, randomized controlled trial comparing a diet low in free sugars versus their usual diet. Hepatic DNL was measured as percentage contribution to plasma triglyceride palmitate using a 7-day metabolic labeling protocol with heavy water. Hepatic fat was measured by magnetic resonance imaging-proton density fat fraction.RESULTSHepatic DNL was significantly decreased in the treatment group (from 34.6% to 24.1%) versus the control group (33.9% to 34.6%) (adjusted week 8 mean difference: -10.6% [95% CI: -19.1%, -2.0%]), which was paralleled by greater decreases in hepatic fat (25.5% to 17.9% vs. 19.5% to 18.8%) and fasting insulin (44.3 to 34.7 vs. 35.5 to 37.0 μIU/mL). Percentage change in DNL during the intervention correlated significantly with changes in free-sugar intake (r = 0.48, P = 0.011), insulin (r = 0.40, P = 0.047), and alanine aminotransferase (ALT) (r = 0.39, P = 0.049), but not hepatic fat (r = 0.13, P = 0.532).CONCLUSIONOur results suggest that dietary sugar restriction reduces hepatic DNL and fasting insulin, in addition to reductions in hepatic fat and ALT, among adolescents with NAFLD. These results are consistent with the hypothesis that hepatic DNL is a critical metabolic abnormality linking dietary sugar and NAFLD.TRIAL REGISTRYClinicalTrials.gov NCT02513121.FUNDINGThe Nutrition Science Initiative (made possible by gifts from the Laura and John Arnold Foundation, Ambrose Monell Foundation, and individual donors), the UCSD Altman Clinical and Translational Research Institute, the NIH, Children's Healthcare of Atlanta and Emory University's Children's Clinical and Translational Discovery Core, Children's Healthcare of Atlanta and Emory University Pediatric Biostatistical Core, the Georgia Clinical and Translational Science Alliance, and the NIH National Institute of Diabetes, Digestive, and Kidney Disease.

Upregulated monocyte expression of PLIN2 is associated with early arterial injury in children with overweight/obesity

BACKGROUND AND AIMS

Perilipin 2 (PLIN2) regulates intracellular lipid metabolism in macrophages, and thus, plays a role in atherosclerosis. Aim of the study was to evaluate whether PLIN2 dysregulation is involved in the onset of preclinical atherosclerosis in children with overweight/obesity and to explore dysregulation mechanisms.

METHODS

Sixty-three children with overweight/obesity and 21 normal weight children (controls) of the same age and sex were enrolled. Carotid intima media thickness (cIMT) was evaluated; mRNA expression of PLIN2 and proteasome subunits (PSMD3, PSMC4) was determined by Real Time PCR, and protein expression of PLIN2, LAMP2A and Hsc70 by Western blot analysis; fluorimetric assay was used to measure proteasome chymotrypsin like activity. We performed transient LAMP2A downregulation by siRNA and quantified intracellular lipids in monocytes by Nile Red staining and flow cytometry analysis.

RESULTS

PLIN2 protein levels were significantly higher in children with overweight/obesity and correlated with cIMT after adjusting for confounders. Accordingly, monocytes of children with overweight/obesity showed a higher intracellular amount of lipids compared with controls. mRNA expression of the regulatory subunits PSMC4 and PSMD3 and proteasome activity were lower in children with overweight/obesity, while expression of LAMP2A and Hsc70 proteins, which belong to the chaperone-mediated autophagy (CMA) pathway, was not different, suggesting that PLIN2 dysregulation in monocytes was due to an impairment of proteasome efficiency and was not CMA related.

CONCLUSION

PLIN2 was overexpressed in monocytes of children with overweight/obesity and could contribute to the onset of arteropathy. Our data suggest that proteasome impairment could contribute to PLIN2 overexpression.

Lack of change in serum sCD36 concentration in children with non-alcoholic fatty liver disease - A preliminary study

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is increasingly being recognized in the pediatric population, therefore, the search for non-invasive parameters to predict progression of NAFLD is of great interest. The aim of this study was to assess serum concentration of sCD36 in children with obesity and to determine its diagnostic value in pediatric NAFLD.

PATIENTS AND METHODS

The study group consisted of 50 children with obesity aged 8-17.5 years, admitted to our Department because of suspected liver pathology. Selected liver diseases were excluded in the examined group. Anthropometry, laboratory tests (including the concentration of sCD36) and liver ultrasound, were performed in all subjects.

RESULTS

NAFLD was confirmed in 16 out of 50 patients with obesity. There was significantly higher activity of ALT, AST, GGT, and increased waist-hip ratio WHR in individuals with NAFLD in comparison to non-hepatopathic children with obesity. We did not find a significant difference between sCD36 concentration in patients with obesity and NAFLD and non-hepathopathic patients with obesity. We also did not find a significant difference between sCD36 concentration in children with obesity in comparison to the control group and between mild (grade 1) vs. advanced (grade ≥2) steatosis. Correlation of sCD36 concentration with anthropometric, biochemical, and bioimpedance parameters in children with obesity was confirmed only with body fat percentage.

CONCLUSIONS

sCD36 is not a suitable parameter to differentiate children with NAFLD from non-hepatopathic children with obesity and controls without obesity. Further studies on a larger pediatric population are needed to confirm these findings.

Vascular diameter and intima-media thickness to diameter ratio values of the carotid artery in 642 healthy children

In children, arterial alterations occur with increased intima-media thickness as well as vascular diameter enlargement. Both conditions correlate with higher cardiovascular risk in adults, and both the array and proportion of these alterations are important hemodynamic parameters. In terms of functional adaptation processes, they influence several arterial wall properties as for example the shear and tensile stress of the vessel. There are no reference values for the vascular diameter and intima-media thickness/diameter ratio of the carotid artery in children. Therefore, this study aimed to assess vascular diameter, intima-media thickness/diameter ratio and related tensile stress values in children and to further investigate the influence of sex, age, body mass index, and blood pressure. The parameters were measured with high-resolution semi-automated ultrasound. Sex- and age-dependent values were calculated with the LMS method for a cross-sectional sample of 642 healthy, non-obese children aged 8-17 years. The mean vascular diameter was 5.45 ± 0.46 mm; the median intima-media thickness/diameter ratio was 0.085 (0.079-0.092); the median tensile stress was 105.4 (95.2-116.4) kPa. The vascular diameter and the tensile stress were higher, and the intima-media thickness/diameter ratio was lower in boys than in girls. In comparison to the normal weight study population the excludedobese children had a significantly higher diameter, a lower intima-media thickness/diameter ratio, and a higher tensile stress. In multiple regression analyses of diameter, intima-media thickness/diameter ratio, and tensile stress, all parameters were influenced by sex and body mass index. Furthermore, systolic and diastolic blood pressure significantly influenced the vascular diameter, and systolic blood pressure significantly influenced the intima-media thickness/diameter ratio. Conclusion: This study is the first to report values for the diameter, the intima-media thickness/diameter ratio of the carotid artery, and the related tensile stress allowing a more differentiated view of cardiovascular adaptations as it combines structural and functional vascular parameters. What is known: • Intima-media thickness and vascular diameter are related to a higher cardiovascular risk in adults • The intima-media thickness/diameter ratio gives information about hemodynamic and functional vessel adaptation What is new: • Values for vascular diameter, intima-media thickness/diameter ratio, and tensile stress of the carotid artery in children are presented in this study • Intima-media thickness as a surrogate marker for arterial health in children should be complemented by intima-media thickness/diameter ratio measurement.

Osteocalcin and osteoprotegerin levels and their relationship with adipokines and proinflammatory cytokines in children with nonalcoholic fatty liver disease

OBJECTIVES

To investigate the relationship between osteocalcin and osteoprotegerin as bone markers and inflammatory biomarkers such as adiponectin, leptin, tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) in children with nonalcoholic fatty liver disease (NAFLD).

METHODS

This study included 40 obese children with NAFLD as the patient group and 40 healthy obese children of matched age, sex and BMI as the control group. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting blood glucose, fasting insulin, Homeostatic model assessment method of insulin resistance (HOMA-IR), lipid profile, osteocalcin, osteoprotegerin, adiponectin, leptin, TNF-α, and IL-6 were measured in all participants.

RESULTS

Children with NAFLD had a significant decrease in osteocalcin, osteoprotegerin and adiponectin level with a significant increase in TNF-α and IL-6 levels. We also found a significant positive correlation between osteocalcin level and adiponectin levels but a significant negative correlation of osteocalcin with each of leptin and TNF-α. However, there was a significant negative correlation between osteoprotegerin levels and both TNF-α and IL-6 levels. Moreover, adiponectin and TNF-α were significant predictors for osteocalcin, and IL-6 was a significant predictor for osteoprotegerin.

CONCLUSION

Adiponectin, leptin, TNF-α, and IL-6 have potential association with the changes of osteocalcin and osteoprotegerin levels in children with NAFLD.

Perspectives on youth-onset nonalcoholic fatty liver disease

BACKGROUND

The prevalence and incidence of youth-onset nonalcoholic fatty liver disease (NAFLD) far exceeds other paediatric chronic liver diseases and represents a considerable public health issue globally.

METHODS

Here, we performed a narrative review of current knowledge regarding the epidemiology of paediatric NAFLD, selected concepts in pathogenesis, comorbidities, diagnosis, and management, and issues related to the transition to adulthood.

RESULTS

Paediatric NAFLD has become increasingly more prevalent, especially in certain subgroups, such as children with obesity and certain races/ethnicities. The pathophysiology of paediatric NAFLD is complex and multifactorial, driven by an interaction of environmental and genetic factors. Once developed, NAFLD in childhood is associated with type 2 diabetes, hypertension, increased cardiovascular disease risk, and end-stage liver disease. This predicts an increased burden of morbidity and mortality in adolescents and young adults. Early screening and diagnosis are therefore crucial, and the development of noninvasive biomarkers remains an active area of investigation. Currently, treatment strategies are focused on lifestyle changes, but there is also research interest in pharmacological and surgical options. In the transition from paediatric to adult care, there are several potential challenges/barriers to treatment and research is needed to understand how best to support patients during this time.

CONCLUSIONS

Our understanding of the epidemiology and pathophysiology of paediatric NAFLD has increased considerably over recent decades, but several critical knowledge gaps remain and must be addressed in order to better mitigate the short-term and long-term risks of youth-onset NAFLD.

Carotid Extra-Media Thickness in Children: Relationships With Cardiometabolic Risk Factors and Endothelial Function

Background: Emerging evidence suggests that structural adventitial modifications and perivascular adipose tissue (PAT) may have a role in early atherogenesis. In a cohort of children and adolescents, we explored (1) the association of carotid extra-media thickness (cEMT), an ultrasound measure whose main determinants are arterial adventitia and PAT, with obesity and its cardiometabolic complications; and (2) the interplay between cEMT and endothelial function. Methods: The study participants included 286 youths (age, 6-16 years; 154 boys, and 132 girls). Anthropometric and laboratory parameters, liver ultrasound, vascular structure measures [cEMT and carotid intima-media thickness (cIMT)], endothelial function [brachial artery flow-mediated dilation (FMD)] were obtained in all subjects. Non-alcoholic fatty liver disease (NAFLD) was diagnosed in the presence of hepatic fat on ultrasonography, in the absence of other causes of liver disease. Diagnosis of metabolic syndrome (MetS) was established on the basis of three or more of the following cardiovascular disease (CVD) risk variables: abdominal obesity, high triglycerides, low high-density lipoprotein cholesterol, elevated blood pressure (BP), and impaired fasting glucose. Results: cEMT demonstrated significant associations with body-mass index (BMI) and waist circumference (WC), BP, insulin resistance, NAFLD, and inflammation. No association was found between cEMT and lipid values, and between cEMT and MetS. A stepwise multivariate linear regression analysis indicated that WC (β coefficient, 0.35; P < 0.0001) was the only determinant of cEMT, independently of other major cardiometabolic risk factors. Further adjustment for cIMT did not significantly alter this association. FMD was correlated to age, Tanner stage, total and abdominal obesity, BP, NAFLD, and cEMT. The association between FMD and cEMT was independent of age, sex, Tanner stage, WC, and BMI (β coefficient, -0.14; P = 0.027). After controlling for CVD risk factors and basal brachial artery diameter, cEMT remained associated with FMD (β coefficient, -0.11; P = 0.049). Conclusions: In youths, cEMT is associated with abdominal fat, a well-established body fat depot with important implications for cardiovascular diseases. Furthermore, cEMT is related to FMD, suggesting that arterial adventitia and PAT may be involved in the early changes in endothelial function.

Semi-Quantitative Ultrasonographic Evaluation of NAFLD

Nonalcoholic fatty liver disease (NAFLD) embraces histopathological entities ranging from the relatively benign simple steatosis to the progressive form nonalcoholic steatohepatitis (NASH), which is associated with fibrosis and an increased risk of progression to cirrhosis and hepatocellular carcinoma. NAFLD is the most common liver disease and is associated with extrahepatic comorbidities including a major cardiovascular disease burden. The non-invasive diagnosis of NAFLD and the identification of subjects at risk of progressive liver disease and cardio-metabolic complications are key in implementing personalized treatment schedules and follow-up strategies. In this review, we highlight the potential role of ultrasound semiquantitative scores for detecting and assessing steatosis severity, progression of NAFLD, and cardio-metabolic risk. Ultrasonographic scores of fatty liver severity act as sensors of cardio-metabolic health and may assist in selecting patients to submit to second-line non-invasive imaging techniques and/or liver biopsy.

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.

Obesity genetics and cardiometabolic health: Potential for risk prediction

The increasing burden of obesity worldwide and its effect on cardiovascular disease (CVD) risk is an opportunity for evaluation of preventive approaches. Both obesity and CVD have a genetic background and polymorphisms within genes which enhance expression of variant proteins that influence CVD in obesity. Genome-based prediction may therefore be a feasible strategy, but the identification of genetically driven risk factors for CVD manifesting as clinically recognized phenotypes is a major challenge. Clusters of such risk factors include hyperglycaemia, hypertension, ectopic liver fat, and inflammation. All involve multiple genetic pathways having complex interactions with variable environmental influences. The factors that make significant contributions to CVD risk include altered carbohydrate homeostasis, ectopic deposition of fat in muscle and liver, and inflammation, with contributions from the gut microbiome. A futuristic model depends on harnessing the predictive power of plausible genetic variants, phenotype reversibility, and effective therapeutic choices based on genotype-phenotype interactions. Inverting disease phenotypes into ideal cardiovascular health metrics could improve genetic and epigenetic assessment, and form the basis of a future model for risk detection and early intervention.

Association of OPG-RANKL ratio with left ventricular hypertrophy and geometric remodeling in male overweight/obese youths

PURPOSE

Receptor activator of nuclear factor kappa B ligand/receptor activator of nuclear factor kappa B/osteoprotegerin (RANKL/RANK/OPG) axis has been hypothesized as a potential mediator of left ventricular hypertrophy (LVH). The aim of the study was to assess whether circulating concentrations of RANKL, RANK, and OPG were associated with early signs of morphological cardiac changes in overweight/obese youths.

METHODS

We determined serum levels of RANKL, RANK and OPG by enzyme-linked immunosorbent assays in 188 overweight/obese children and adolescents. LV mass index (LVMI) and relative wall thickness (RWT) were estimated using M-mode echocardiography.

RESULTS

OPG and RANKL levels were higher among girls than among boys [1.73 (1.64-1.86) and 3.28 (1.90-6.37) pmol/L, respectively, vs. 1.69 (1.59-1.82) and 2.12 (1.52-3.80) pmol/L; p = 0.02 and p = 0.0001, respectively], but the OPG/RANKL ratio was lower [0.52 (0.26-0.88) vs 0.77 (0.44-1.11); p = 0.001]. In gender-specific multivariate linear regression, OPG/RANKL ratio was associated with LVMI and RWT in boys but not in girls. In multiple logistic regression, after adjustment for clinical variables, OPG/RANKL ratio was associated with concentric remodeling, eccentric and concentric LVH in boys but not in girls.

CONCLUSION

OPG/RANKL ratio is independently associated with LVH and patterns of LV structural remodeling in male overweight/obese children and adolescents.

Is There an Association of Vascular Disease and Atherosclerosis in Children and Adolescents With Obesity and Non-alcoholic Fatty Liver Disease?

Carotid intima media thickness (cIMT) and brachial flow-mediated dilation (FMD) evaluated by ultrasound are non-invasive markers of atherosclerosis. Increased cIMT in adults has been correlated to early vascular damage. Several studies show similar correlations of elevated cIMT in children with obesity, hyperlipidemia, and metabolic syndrome. Additionally, several articles have correlated non-alcoholic fatty liver disease (NAFLD) with elevated cIMT, indicating early atherosclerosis. It is alarming that these vascular changes may be seen in children as young as 10 years of age. Children with NAFLD may also have an increased pulse wave velocity that correlates to increased arterial stiffness and increased left ventricular dimension, mass, and diastolic dysfunction. These articles are persuasive, indicating a correlation of Pediatric NAFLD and early vascular disease. However, study limitations include the use of elevated alanine aminotransferase (ALT) and echogenic changes on ultrasound that may have low accuracy to identify NAFLD. Ultrasound has low sensitivities and specificities for detection of NAFLD and therefore is not recommended for diagnosis. In comparison, studies that used liver biopsy or proton magnetic resonance spectroscopy to identify NAFLD did not find a correlation with elevated cIMT or reduction in FMD. Due to these conflicting findings, more studies looking at cIMT and FMD changes in children with NAFLD are needed with more accurate diagnostic methods for steatosis to identify if there truly is a correlation of increased liver steatosis to early atherosclerosis.

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.

Dyslipidemia is associated with pediatric nonalcoholic fatty liver disease

BACKGROUND

With the increasing prevalence of childhood obesity, nonalcoholic fatty liver disease (NAFLD) has emerged as the most common cause of pediatric chronic liver disorder. Factors underlying the pathophysiology of NAFLD remain poorly defined.

OBJECTIVE

This study aimed to describe the metabolic characteristics of children with NAFLD differing in race/ethnicity and to test associations between dyslipidemia and NAFLD.

METHODS

A retrospective chart review was conducted at a tertiary referral university hospital among 309 children with a diagnosis of NAFLD.

RESULTS

Participants (mean age 12.5 ± 3.4 years) were 64% male, 63% white, 23% Hispanic, and 14% black. Hispanic children were diagnosed with NAFLD at a significantly younger age (10.6 ± 3.1 years, P < .0001) and lower body mass index (31.5 ± 6.8 kg/m², P < .0001) than their white and black counterparts. For the entire cohort, prevalence of systolic hypertension was 41%, diabetes 14%, elevated cholesterol 42%, elevated non-high-density lipoprotein cholesterol (non-HDL-C) 58%, elevated low-density lipoprotein cholesterol 36%, elevated triglycerides (TG) 88%, and low high-density lipoprotein cholesterol 77%. Whites had elevated non-HDL-C, low-density lipoprotein cholesterol, and TG compared to blacks or Hispanics. Serum TG and non-HDL-C were significantly correlated to alanine aminotransferase (r = 0.18, P = .01; r = 0.16, P = .02), respectively, and persisted after adjusting for age and body mass index.

CONCLUSION

Cardiometabolic derangements, especially dyslipidemia, are highly prevalent in children with NAFLD and differ based on race/ethnicity. Serum TG and non-HDL-C may play an important role in the pathophysiology of pediatric NAFLD.

Use and Importance of Nonhuman Primates in Metabolic Disease Research: Current State of the Field

Obesity and its multiple metabolic sequelae, including type 2 diabetes, cardiovascular disease, and fatty liver disease, are becoming increasingly widespread in both the developed and developing world. There is an urgent need to identify new approaches for the prevention and treatment of these costly and prevalent metabolic conditions. Accomplishing this will require the use of appropriate animal models for preclinical and translational investigations in metabolic disease research. Although studies in rodent models are often useful for target/pathway identification and testing hypotheses, there are important differences in metabolic physiology between rodents and primates, and experimental findings in rodent models have often failed to be successfully translated into new, clinically useful therapeutic modalities in humans. Nonhuman primates represent a valuable and physiologically relevant model that serve as a critical translational bridge between basic studies performed in rodent models and clinical studies in humans. The purpose of this review is to evaluate the evidence, including a number of specific examples, in support of the use of nonhuman primate models in metabolic disease research, as well as some of the disadvantages and limitations involved in the use of nonhuman primates. The evidence taken as a whole indicates that nonhuman primates are and will remain an indispensable resource for evaluating the efficacy and safety of novel therapeutic strategies targeting clinically important metabolic diseases, including dyslipidemia and atherosclerosis, type 2 diabetes, hepatic steatosis, steatohepatitis, and hepatic fibrosis, and potentially the cognitive decline and dementia associated with metabolic dysfunction, prior to taking these therapies into clinical trials in humans.

Insulin resistance and the metabolic syndrome are related to the severity of steatosis in the pediatric population with obesity

BACKGROUND

To determine the factors associated with an increased risk for severe steatosis (SS) and establish the Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) as a screening tool.

METHODS

A cross-sectional study was performed in obese children to assess the relationship between the metabolic syndrome (MetS) and glucose metabolism alterations (GMA) and the risk for severe steatosis.

RESULTS

A total of 94 children (51 males) aged from six to 14 years were included. Thirteen children (14.8%) had severe steatosis (SS). The anthropometric variables associated with SS included body mass index (BMI) (SS 34.1 vs non-SS 29.7, p = 0.005), waist circumference (cm) (100 vs 92.5, p = 0.015) and hip circumference (cm) (108 vs 100, p = 0.018). The blood parameters included alanine aminotransferase (ALT) (UI/dl) (27 vs 21, p = 0.002), gamma-glutamil transpeptidase (GGT) (UI/dl) (16 vs 15, p = 0.017), fasting glycemia (mg/dl) (96 vs 88, p = 0.006), fasting insulin (UI/dl) (25 vs 15.3, p < 0.001) and HOMA-IR score (7.1 vs 3.7, p < 0.001). Eighteen children with MetS were found to be at an increased risk for severe steatosis (odds ratio [OR] 11.36, p < 0.001). After receiver operating characteristic (ROC) curve analysis, the best area under the curve (AUC) was obtained for HOMA-R of 0.862. The HOMA-R 4.9 cut-off value had a 100% sensitivity (CI 95%: 96.2-100) and 67.9% specificity (CI 95%: 57.1-78.7) for severe steatosis.

CONCLUSIONS

The presence of MetS and glucose metabolism alterations are risk factors for severe steatosis. The 4.9 cut-off value for HOMA-IR may be a risk factor for severe steatosis in obese children.

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.

Nonalcoholic Fatty Liver Disease in Children: Hepatic and Extrahepatic Complications

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome and has become the most common form of chronic liver disease in children and adolescents. The histologic spectrum of NAFLD is broad ranging, from the relatively benign form of simple steatosis to the aggressive form of nonalcoholic steatohepatitis, eventually leading to fibrosis and cirrhosis. NAFLD has also been recognized as an independent risk factor for extrahepatic complications, such as cardiovascular disease, type 2 diabetes mellitus, sleep disorders, and osteoporosis. In this review, we discuss both the hepatic and extrahepatic complications of NAFLD in children.

Nonalcoholic fatty liver disease: implications for cardiovascular risk

Nonalcoholic fatty liver disease (NAFLD) is a growing epidemic in the USA affecting ∼30% of the population. It has been closely linked to metabolic syndrome and type 2 diabetes, with strong implications for cardiovascular disease (CVD). This review focuses on the relationship between NAFLD and CVD and the proposed interactions interlinking these two diseases. This appraisal also discusses treatments targeting NAFLD in the context of CVD. NAFLD is a multisystem disease and ultimately the goals of therapy are to ameliorate CVD and prevent coronary artery disease morbidity and mortality.

NASPGHAN Clinical Practice Guideline for the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease in Children: Recommendations from the Expert Committee on NAFLD (ECON) and the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN)

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that occurs in the setting of insulin resistance and increased adiposity. It has rapidly evolved into the most common liver disease seen in the pediatric population and is a management challenge for general pediatric practitioners, subspecialists, and for health systems. In this guideline, the expert committee on NAFLD reviewed and summarized the available literature, formulating recommendations to guide screening and clinical care of children with NAFLD.

Arterial Stiffness, Thickness and Association to Suitable Novel Markers of Risk at the Origin of Cardiovascular Disease in Obese Children

Atherosclerosis origins early in childhood. Aim of the study was to investigate vascular signature and phenotypes of cardiovascular disease in obese children and adolescents identifying novel potential circulating markers of risk. Cross-sectional study of intima-media-thickness (IMT), pulse wave velocity (PWV), augmentation index (AIX@75), circulating markers (E-selectin, soluble-intercellular-adhesion-molecule1_ICAM1, chemerin, fatty-acid-binding protein 4, sCD36, lipopolysaccharides_LPS, oxLDL, fetuin) in 123 obese (body mass index, BMI z-score >1.645 SD) children (N=55, age ≤10 years-old) and adolescents (N=68, age >10 years-old). Adolescents had significantly higher uric acid (p=0.002), non-HDL-cholesterol (p=0.02), fasting glucose (p=0.04), systolic blood pressure (p=0.005) and PWV (p=0.02) than children. Obese adolescent patients with metabolic syndrome (MetS) abnormalities had higher PWV (p<0.05) than peers without. No differences were observed in circulating biomarkers in relationship to age and MetS status. oxLDL, sCD36 and LPS were correlated to AIX@75 and/or IMT_M in children and adolescents (p ranging from <0.05 to <0.0001). Total cholesterol, non-HDL-cholesterol, TG/HDL ratio, oxLDL, sCD36, ICAM1, LPS were significantly different across AIX@75 tertiles (p between 0.03 and 0.001). Early phenotypes of cardiovascular alterations in young severely obese patients encompass increased IMT, stiffness of intermediate size and resistance vasculature. Novel biomarkers investigated in the present study were associated to estimates of stiffness and thickness not differently from traditional risk factor such as non-HDL-cholesterol and TG/HDL ratio.

Nonalcoholic fatty liver disease as an independent risk factor for carotid atherosclerosis

PURPOSE:

Nonalcoholic fatty liver disease (NAFLD) is a frequently encountered clinical condition in clinical practice, particularly in obese and diabetic patients. Carotid atherosclerosis is regarded as surrogate marker of coronary atherosclerosis. We aimed to know whether evaluation for carotid atherosclerosis should be done in all patients of NAFLD.

MATERIALS AND METHODS:

A total of 200 NAFLD patients and 100 age- and sex-matched controls were enrolled into the study. Ultrasound was done to document fatty liver and carotid intimal thickness, and relation between these two was observed.

RESULTS:

Grade 1 fatty liver was seen in 36% patients while Grade 2 fatty liver was found in 39% and Grade 3 fatty liver in 25%. Patients with Grade 1 fatty liver had left intima-media thickness (IMT) in the range of 0.4–0.6 mm (mean IMT - 0.69 mm) and had right IMT in the range of 0.5–0.8 mm (mean IMT - 0.71 mm). In patients with Grade 2 fatty liver, left IMT was in the range of 0.6–1.0 mm (mean IMT - 0.80 mm) and right IMT in the range of 0.7–1.0 mm (mean IMT - 0.84 mm), while in patients with Grade 3 fatty liver, left IMT was in the range of 0.8–1.2 mm (mean IMT - 0.93 mm) and right IMT in the range of 0.9–1.4 mm (mean IMT - 0.99 mm). Among controls, the mean left IMT was 0.579 mm and mean right IMT was 0.575 mm.

CONCLUSION:

The level of carotid intimomedial thickness was more in cases than in controls and progressively increased with the grade of fatty liver which was statistically significant.

Association of Osteoprotegerin with Obesity, Insulin Resistance and Non-Alcoholic Fatty Liver Disease in Children

BACKGROUND

Osteoprotegerin (OPG) is a member of the tumor necrosis factor superfamily. Reduced OPG levels are related to obesity, insulin resistance, and non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

The aim of this study was to evaluate the relationship between OPG levels, obesity, insulin resistance, and NAFLD in pediatric patients.

METHODS

This was a prospective, cross-sectional, controlled study that was conducted in the department of pediatrics at Bagcilar training and research hospital in Istanbul, Turkey, between April and August 2015. The study was performed on 107 children with obesity and 37 controls aged 5 - 17 years. In the obese subset, 62 patients had NAFLD. Homeostatic model assessment-insulin resistance (HOMA-IR) was used to calculate insulin resistance. Insulin resistance was defined as a HOMA-IR value greater than 2.5. Plasma OPG levels were measured using enzyme-linked immunosorbent assays. NAFLD was diagnosed by hepatic ultrasound.

RESULTS

The mean age was 11.25 ± 3.38 years in the patient group and 10.41 ± 3.15 years in the control group. The OPG level in the obese group with the mean of 55.20 ± 24.55 pg/mL (median = 48.81 pg/mL) was significantly lower than that in the control group with the mean of 70.78 ± 33.41 pg/mL (median = 64.57 pg/mL) (P = 0.0001). The optimal cut-off point (sensitivity, specificity) of the OPG level for the diagnosis of obesity was ≤ 46, 19 pg/mL. According to logistic regression analysis, fasting insulin (P = 0.036) and OPG (P = 0.01) levels were most affected by obesity. In the obese patients, who had HOMA-IR < 2.5, the mean level of OPG was 58.91 ± 6.88729 pg/mL (median = 49.55). In the obese patients, who had HOMA-IR ≥ 2.5, the mean level of OPG was 54.19 ± 22.21 pg/mL (median = 48.47). No significant correlations were found between OPG and HOMA-IR (P = 0.791). No statistically significant difference was observed in the mean OPG between patients with hepatosteatosis (mean = 54.55 ± 25.01 pg/mL) (median = 49.46) and those without the disease (56.30 ± 24.02 pg/mL) (mean = 48.34) (P = 0.089).

CONCLUSIONS

We confirmed that serum OPG concentrations reduce in obese children. However, no correlation was identified between OPG and insulin resistance. OPG levels are not meaningful in the diagnosis of NAFLD in children with obesity.

Relationship between Abdominal Aortic Intima Media Thickness and Central Obesity in Children

BACKGROUND

Childhood obesity is one of the important risk factors for early atherosclerosis. We aimed to evaluate the effect of obesity on abdominal aortic intima media thickness (aaIMT) in children.

METHODS

We consecutively recruited 60 obese and 28 healthy children from the outpatient clinic of pediatrics. In all patients, BMI, waist circumference (WC) and hip circumference (HC) were measured, and fasting serum lipid profile, plasma glucose and plasma insulin were studied. Homeostasis model assessment-estimated insulin resistance (HOMA-IR) was calculated for the obese group. All children underwent ultrasonography to evaluate hepatosteatosis and to measure aaIMT.

RESULTS

There was a significant difference between the groups in terms of aaIMT, insulin, glucose, HOMA-IR, total cholesterol, low-density lipoprotein, triglyceride and hepatosteatosis. aaIMT was 1.12 ± 0.25 and 0.61 ± 0.18 mm in the obese and nonobese groups, respectively (p < 0.001). In the obese group, there was a positive correlation between aaIMT and WC, WC/height ratio, BMI, HC and hepatosteatosis (p < 0.05 for all), with the highest significance for WC.

CONCLUSIONS

This study showed that aaIMT was significantly higher in obese children than in nonobese children, and that WC was a strong predictor for aaIMT. Early detection of an increased aaIMT in obese children may guide the follow-up of these patients in terms of developing atherosclerosis and its complications.

Low 25-hydroxyvitamin D level is not an independent risk factor for hepatosteatosis in obese children

BACKGROUND

Obesity is an important risk factor for non-alcoholic fatty liver disease. Few studies have evaluated the association between vitamin D and non-alcoholic fatty liver disease in obese children. Therefore, we conducted a study to examine the relationship of vitamin D levels and hepatosteatosis in obese children.

METHODS

One hundred and eleven children with obesity participated in this study. Hepatosteatosis was diagnosed and graded using ultrasonography in all patients. Study participants were divided based on the presence of hepatosteatosis into two subgroups (hepatosteatosis and non-hepatosteatosis). Serum levels of 25-hydroxyvitamin D, calcium, phosphate, alkaline phosphatase, parathormone, and lipids were measured and compared.

RESULTS

Hepatosteatosis existed in 52% of obese children without chronic diseases. There was no statistically significant difference in the vitamin D level between the hepatosteatosis and non-hepatosteatosis groups. Alanine aminotransferase levels and the triglycerides-to-high density lipoprotein ratio were significantly higher, and the high density lipoprotein levels were significantly lower in the hepatosteatosis group compared to the non-hepatosteatosis group.

CONCLUSIONS

Vitamin D deficiency is not directly related with hepatosteatosis. A high ALT level and a high triglycerides-to-HDL ratio and low HDL levels are more significant in hepatic steatosis in obese children.

The Progression and Natural History of Pediatric Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the United States. Childhood NAFLD is associated with hepatic and nonhepatic morbidity and mortality. Nonhepatic associations include cardiovascular, metabolic, pulmonary, and psychological disorders. Cardiovascular conditions observed in childhood include left ventricular dysfunction. Furthermore, childhood obesity is associated with greater odds of having hepatocellular carcinoma as an adult. Evidence suggests that NAFLD may begin in utero in children of diabetic mothers. Thus rigorous efforts for structured diagnosis and follow-up are a priority to better develop the understanding of outcomes in pediatric NAFLD.

The evaluation of carotid intima-media thickness and mean platelet volume values and correlation with cardiac functions in obese children

BACKGROUND

Obesity is associated with many risk factors, such as hyperlipidemia, hyperinsulinemia, hypertension and leads to early atherosclerosis. The aim of this study was to investigate the relation of the mean platelet volume (MPV) and the carotid intima media thickness (CIMT) on cardiac functions among obese children.

MATERIALS AND METHODS

Sixty obese children, with body mass index percentile were >95% and forty eight healthy controls were enrolled in the study. Triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), thyroid function tests, hemoglobin, white blood cell, MPV and insulin resistance were evaluated. CIMT was measured by using high-resolution ultrasound and echocardiography was performed to all individuals.

RESULTS

MPV and CIMT values were found significantly higher in obese children than controls. There was positive correlation between CIMT and age, body surface area (BSA), systolic and diastolic blood pressure, left ventricular meridional end-systolic wall stress (ESWSm), myocardial fiber stress (MFS), stroke volume (SV) and insulin and negative correlation with left ventricle end-systolic elastance by single beat technique (Ees(sb)) and arterial elastance (Ea). There was no correlation between LVM, cardiac risk profiles and CIMT. Multiple stepwise regression analyses revealed that ESWSm (β=0.337, P=0.049) was only independent factor on CIMT. MPV values showed negative correlation with ALT, AST, Free T4, thyroid stimulating hormone and positive correlation with age and BSA.

CONCLUSION

Current study showed that obesity has an independent impact on CIMT and MPV values in children. Increased CIMT in obese children leads significant increase in ESWSm and decrease in Ea and Ees(sb).

Caring for children with NAFLD and navigating their care into adulthood

NAFLD is the most common chronic liver disease in children and adults, with its prevalence closely associated with obesity and other features of the metabolic syndrome. As young adults with NAFLD transition from the paediatric care environment to adult services, establishing a coordinated model of transition to ensure ongoing and appropriate care is critical. Enabling a smooth transfer begins with an understanding of the key differences between paediatric and adult NAFLD as well as the psychosocial factors that affect older adolescents. This Review summarizes the literature on paediatric NAFLD from the past two decades with a focus on the differences in epidemiology, pathology, pathophysiology and treatment that are relevant to clinicians who transition paediatric patients to adult care. An integrated model, which employs a team of adult and paediatric providers who can address the psychosocial, cognitive and logistical challenges of transition, provides the best opportunity for a seamless and coordinated transfer to adult care.

Nonalcoholic fatty liver disease and carotid artery atherosclerosis in children and adults: a meta-analysis

Observational studies suggest that nonalcoholic fatty liver disease (NAFLD) is associated with increased carotid intimal medial thickness (C-IMT) and carotid plaques in both children and adults. We carried out a meta-analysis to evaluate the relationship between NAFLD and carotid atherosclerosis measured as C-IMT and carotid plaque prevalence. Medline (Ovid), PubMed, Web of Science, and CINAHL databases were searched from 1946 to September 2014, complemented with a manual review of references of the published articles for studies that compared C-IMT or carotid plaque prevalence in adults and children. Results were pooled using both fixed and random effects models. Of the studies identified, 20 were suitable for testing the effect of NAFLD on C-IMT in adults, 13 for testing the effect of NAFLD on carotid plaque prevalence in adults, and five for testing the effect of NAFLD on C-IMT in the pediatric population. The pooled data from 20 studies (19,274 adult participants: NAFLD=8652, controls=10,622) showed significantly increased C-IMT in patients with NAFLD, compared with controls without NAFLD, according to both fixed [standardized mean difference (SMD)=0.251, 95% confidence interval (CI): 0.220-0.282, P<0.001] and random effects models (SMD=0.944, 95% CI: 0.728-1.160, P<0.001). NAFLD was also found to be associated with a higher carotid artery plaque prevalence when compared with controls, according to both fixed (OR=1.273, 95% CI=1.162-1.394, P<0.001) and random effects models (OR=1.769, 95% CI: 1.213-2.581, P=0.003), on pooling of 13 studies (14,445 adult participants: NAFLD=5399 and controls=9046). Analysis of pooled data from five studies in the pediatric population (1121 pediatric participants: NAFLD=312 and controls=809) also found NAFLD to be associated with significantly increased C-IMT according to fixed (SMD=0.995, 95% CI: 0.840-1.150, P<0.001) and random effects models (1.083, 95% CI: 0.457-1.709, P=0.001). NAFLD is associated with increased C-IMT in both children and adults, and with increased carotid plaque prevalence in adults. Individuals identified with carotid disease should be evaluated for NAFLD and vice versa.

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.

Obesity and Gestational Diabetes Mellitus Pathways for Programming in Mouse, Monkey, and Man—Where Do We Go Next? The 2014 Norbert Freinkel Award Lecture

Obesity and gestational diabetes mellitus continue to increase worldwide and span the spectrum of age, race, ethnicity, and socioeconomic status. Alarmingly, 1 in 10 infants and toddlers is obese, and 1 in 5 youths is both obese and at risk for metabolic syndrome prior to puberty. The mechanisms underlying how poor maternal health imparts risk for future metabolic disease in the offspring are beginning to emerge in deeply phenotyped human and nonhuman primate models. Maternal diet and obesity impact fuels, hormones, and inflammation with powerful effects on fetal metabolic systems. These are accompanied by persistent changes in the infant microbiome and epigenome and in offspring behavior. These results suggest that gestational and lactational dietary exposures are driving health risks in the next generation. Whether maternal diet can prevent changes in the womb to alter infant life-course disease risk is still unknown. Controlled, mechanistic studies to identify interventions are sorely needed for a healthier next generation.

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.

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.

Nonalcoholic fatty liver disease and cardiovascular risk in children with obesity

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has been recognized as an independent risk factor for cardiovascular disease in adults. It has not been established whether NAFLD is related to early atherosclerotic changes in children.

METHODS

In a cross-sectional study, 78 non diabetic, non smoking children with severe obesity were evaluated for NAFLD. Proton magnetic resonance spectroscopy was used to detect liver steatosis and serum ALT was used as a surrogate marker for steatohepatitis. Carotid intima-media thickness (CIMT) and arterial wall stiffness were measured using ultrasound.

RESULTS

Steatosis was present in 41 (53%) of subjects. Of these children, 26 out of 41 (63%) had elevated ALT levels. No differences in CIMT and arterial wall stiffness were observed between those without and with steatosis and those with steatosis plus elevated ALT levels [CIMT = 0.47 (±0.06), 0.48 (±0.06) and 0.48 (±0.07) mm, respectively; stiffness = 2.78 (±0.50), 3.00 (±0.81), and 2.90 (±0.78), respectively]. Steatosis and ALT were not correlated to CIMT (r = -0.02 and -0.14, respectively) or arterial wall stiffness (r = 0.13 and -0.11, respectively).

CONCLUSIONS

In this study, no relationship between NAFLD and early atherosclerotic changes in children was observed. An atherogenic effect of steatohepatitis (NASH) on pediatric age and long-term atherogenic consequences of simple steatosis cannot be excluded based on this study.

Amount of hepatic fat predicts cardiovascular risk independent of insulin resistance among Hispanic-American adolescents

Background

Nonalcoholic fatty liver disease (NAFLD) has emerged as the major pediatric chronic liver disease, and it is estimated to affect more than one third of obese children in the U.S. Cardiovascular complications are a leading cause of increased mortality in adults with NAFLD and many adolescents with NAFLD already manifest signs of subclinical atherosclerosis including increased carotid intima-media thickness.

Methods

Volume of intrahepatic fat was assessed in 50 Hispanic-American, overweight adolescents, using Magnetic Resonance Spectroscopy. Lipoprotein compositions were measured using Nuclear Magnetic Resonance.

Results

Plasma triglycerides (TG) (p = 0.003), TG/HDL ratio (p = 0.006), TG/apoB ratio (p = 0.011), large VLDL concentration (p = 0.019), VLDL particle size (p = 0.012), as well as small dense LDL concentration (p = 0.026) progressively increased across higher levels of hepatic fat severity, while large HDL concentration progressively declined (p = 0.043). This pattern of associations remained even after controlling for gender, BMI, visceral fat, and insulin resistance.

Conclusions

Our findings suggest that increased hepatic fat is strongly associated with peripheral dyslipidemia and the amount of fat in the liver may influence cardiovascular risk. Further studies are needed to longitudinally monitor dyslipidemia in children with NAFLD and to examine whether the reduction of hepatic fat would attenuate their long-term CVD risk.

Association between cardiovascular risk factors and carotid intima-media thickness in prepubertal Brazilian children

BACKGROUND

Early exposure to cardiovascular risk factors creates a chronic inflammatory state that could damage the endothelium followed by thickening of the carotid intima-media.

OBJECTIVE

To investigate the association of cardiovascular risk factors and thickening of the carotid intima.

SUBJECTS/METHODS

Media in prepubertal children. In this cross-sectional study, carotid intima-media thickness (cIMT) and cardiovascular risk factors were assessed in 129 prepubertal children aged from 5 to 10 year. Association was assessed by simple and multivariate logistic regression analyses.

RESULTS

In simple logistic regression analyses, body mass index (BMI) z-score, waist circumference, and systolic blood pressure (SBP) were positively associated with increased left, right, and average cIMT, whereas diastolic blood pressure was positively associated only with increased left and average cIMT (p<0.05). In multivariate logistic regression analyses increased left cIMT was positively associated to BMI z-score and SBP, and increased average cIMT was only positively associated to SBP (p<0.05).

CONCLUSIONS

BMI z-score and SBP were the strongest risk factors for increased cIMT.

Role of ultrasound in the diagnosis and treatment of nonalcoholic fatty liver disease and its complications

We review the role of liver ultrasonography (US) and related techniques as non-invasive tools in predicting metabolic derangements, liver histology, portal hypertension and cardiovascular risk as well as allowing early diagnosis and management of hepatocellular carcinoma in patients with nonalcoholic fatty liver disease. In this setting, US detects fatty changes as low as ≥20% and hepatic steatosis identified ultrasonographically, in its turn, closely mirrors coronary and carotid atherosclerosis burden. Semi-quantitative US indices (to exclude nonalcoholic steatohepatitis) and sonoelastography (to quantify fibrosis) help in predicting liver histology and selecting patients to submit to liver biopsy. Surveillance for hepatocellular carcinoma conducted through biannual US is mandatory and US has a role in guiding locoregional treatment and in evaluating the efficacy of treatment. High-intensity focused ultrasound can be delivered with precision resulting in coagulative necrosis of hepatocellular carcinoma without puncturing the liver. Costs and inconveniences have so far hampered its diffusion.

Improvement in liver histology is associated with reduction in dyslipidemia in children with nonalcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD), the most common cause of liver disease among US children, may be associated with cardiovascular disease (CVD) risk. The present study sought to determine the prevalence of dyslipidemia in children with NAFLD and assess dyslipidemia by liver histology and histologic changes.

METHODS

Individuals in the Treatment of NAFLD in Children (TONIC) trial were included (N = 173). In the TONIC trial, children with NAFLD were randomized to vitamin E, metformin, or placebo for 96 weeks. Nonalcoholic steatohepatitis (NASH) improved in 56 children. Change in lipid levels from baseline and 96 weeks was compared between patients with and without histologic improvement and with and without NASH.

RESULTS

Dyslipidemia was frequent, with low high-density lipoprotein (HDL) (< 40 mg/dL) in 61.8%, hypertriglyceridemia (≥ 130 mg/dL) in 50.3%, hypercholesterolemia (≥ 200 mg/dL) in 23.7%, elevated low-density lipoprotein (LDL) (≥ 130 mg/dL) in 21.5%, elevated non-HDL cholesterol (non-HDL-C) (≥ 145 mg/dL) in 35.2%, and triglycerides/HDL > 3.0 in 57.2% of patients. Histologic improvement was associated with significant decreases in cholesterol (-11.4 mg/dL vs -1.9 mg/dL, P = 0.04), LDL (-11.2 mg/dL vs -2.1 mg/dL, P = 0.04), and non-HDL-C (-8.8 mg/dL vs 0.5 mg/dL, P = 0.03) compared with those without improvement. Children with NASH resolution had significant decreases in cholesterol (-10.0 mg/dL vs -0.9 mg/dL, P = 0.02) and non-HDL-C (-7.3 mg/dL vs 1.1 mg/dL, P = 0.01) compared with those without NASH resolution. There was no improvement in triglycerides, HDL level, or triglycerides/HDL ratio in either group.

CONCLUSIONS

Dyslipidemia is frequent in children with NAFLD. NASH resolution and histologic improvement are associated with improvements in some forms of dyslipidemia.

Nonalcoholic fatty liver disease as a potential risk factor of cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic component of the metabolic syndrome. The aim of this review is to summarize the available data linking NAFLD with cardiovascular disease (CVD). The following topics are reviewed: (a) the clinical evidence linking NAFLD to increased prevalence of CVD; (b) the relationship between NAFLD (which is diagnosed by liver biopsy, serum liver enzymes, or ultrasonography) and incidence of CVD; (c) the mechanism linking NAFLD to CVD and clinical implication; and (d) the potential impact of NAFLD treatment on cardiac complications. CVD dictates the outcome (or outcomes) in patients with NAFLD more frequently and to a greater extent than does the progression of liver disease. NAFLD patients have a higher risk of all-cause death than the general population, mainly because of CVD or liver-related causes. The biologic mechanism linking NAFLD and CVD might be associated with various factors, involving a complex interaction among insulin resistance, oxidative stress, abnormal adipocytokine profile, endothelial dysfunction, lipid abnormalities, and activation of inflammatory cascade. Lifestyle modifications and pharmacotherapy are helpful to treat patients with NAFLD. NAFLD is likely to be associated with an increased risk of CVD, and raises the possibility that NAFLD may not only be a marker but also an early mediator of CVD.

Atherogenic dyslipidemia and cardiovascular risk factors in obese children

Childhood obesity when associated with serum lipoprotein changes triggers atherosclerosis. Evidences suggest that the atherosclerotic process begins in childhood and that the extent of early atherosclerosis of the aorta and coronary arteries can be associated with lipoprotein levels and obesity. Furthermore, many studies in childhood demonstrate an important relationship between parameters of insulin sensitivity, body fat distribution, and the development of lipid abnormalities. This review focuses on the most recent findings on the relationship between obesity, dyslipidemia, and cardiovascular risk in children.

Longitudinal assessment of high blood pressure in children with nonalcoholic fatty liver disease

Objective

Nonalcoholic fatty liver disease (NAFLD) affects 9.6% of children and may put these children at elevated risk of high blood pressure and subsequent cardiovascular morbidity and mortality. Therefore, we sought to determine the prevalence of and risk factors for high blood pressure in children with NAFLD.

Methods

Cohort study performed by the NIDDK NASH Clinical Research Network. There were 484 children with NAFLD ages 2 to 17 at enrollment; 382 children were assessed both at enrollment and 48 weeks afterwards. The main outcomes were high blood pressure at baseline and persistent high blood pressure at both baseline and 48 weeks.

Results

Prevalence of high blood pressure at baseline was 35.8% and prevalence of persistent high blood pressure was 21.4%. Children with high blood pressure were significantly more likely to have worse steatosis than children without high blood pressure (mild 19.8% vs. 34.2%, moderate 35.0% vs. 30.7%, severe 45.2% vs. 35.1%; P = 0.003). Higher body mass index, low-density lipoprotein, and uric acid were independent risk factors for high blood pressure (Odds Ratios: 1.10 per kg/m², 1.09 per 10 mg/dL, 1.25 per mg/dL, respectively). Compared to boys, girls with NAFLD were significantly more likely to have persistent high blood pressure (28.4% vs.18.9%; P = 0.05).

Conclusions

In conclusion, NAFLD is a common clinical problem that places children at substantial risk for high blood pressure, which may often go undiagnosed. Thus blood pressure evaluation, control, and monitoring should be an integral component of the clinical management of children with NAFLD.

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.

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.

Association of serum triglyceride-to-HDL cholesterol ratio with carotid artery intima-media thickness, insulin resistance and nonalcoholic fatty liver disease in children and adolescents

BACKGROUND AND AIMS

The triglyceride (TG)/high-density lipoprotein-cholesterol (HDL-C) ratio has been reported as a useful marker of atherogenic lipid abnormalities, insulin resistance, and cardiovascular disease. We evaluated in a large sample of children and adolescents the association of TG/HDL-C ratio with early signs of morphological vascular changes and cardiometabolic risk factors including nonalcoholic fatty liver disease (NAFLD).

METHODS AND RESULTS

The study population, including 548 children (aged 6-16 years), of whom 157 were normal-weight, 118 overweight, and 273 obese, had anthropometric, laboratory, liver and carotid ultrasonography (carotid artery intima-media thickness-cIMT) data collected. Subjects were stratified into tertiles of TG/HDL-C. There was a progressive increase in body mass index (BMI), BMI-SD score (SDS), waist circumference, blood pressure (BP), liver enzymes, glucose, insulin, homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein (hsCRP), and cIMT values across TG/HDL-C tertiles. The odds ratios for central obesity, insulin resistance, high hsCRP, NAFLD, metabolic syndrome, and elevated cIMT increased significantly with the increasing tertile of TG/HDL-C ratio, after adjustment for age, gender, pubertal status, and BMI-SDS. In a stepwise multivariate logistic regression analysis, increased cIMT was associated with high TG/HDL-C ratio [OR, 1.81 (95% CI, 1.08-3.04); P < 0.05], elevated BP [5.13 (95% CI, 1.03-15.08); P < 0.05], insulin resistance [2.16 (95% CI, 1.30-3.39); P < 0.01], and NAFLD [2.70 (95% CI, 1.62-4.56); P < 0.01].

CONCLUSION

TG/HDL-C ratio may help identify children and adolescents at high risk for structural vascular changes and metabolic derangement.

Alanine aminotransferase elevation in obese infants and children: a marker of early onset non alcoholic Fatty liver disease

BACKGROUND

Elevated aminotransferases serve as surrogate markers of non-alcoholic fatty liver disease, a feature commonly associated with the metabolic syndrome. Studies on the prevalence of fatty liver disease in obese children comprise small patient samples or focus on those patients with liver enzyme elevation.

OBJECTIVES

We have prospectively analyzed liver enzymes in all overweight and obese children coming to our tertiary care centre.

PATIENTS AND METHODS

In a prospective study 224 healthy, overweight or obese children aged 1 - 12 years were examined. Body Mass Index-Standard Deviation Score, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl-transpeptidase were measured.

RESULTS

Elevated alanine aminotransferase was observed in 29% of children. 26 % of obese and 30 % of overweight children had liver enzyme elevations. Obese children had significantly higher alanine aminotransferase levels than overweight children (0.9 vs. 0.7 times the Upper Limit of Normal; P = 0.04).

CONCLUSIONS

Elevation of liver enzymes appears in 29 % obese children in a tertiary care centre. Absolute alanine aminotransferase levels are significantly higher in obese than in overweight children. Even obese children with normal liver enzymes show signs of fatty liver disease as demonstrated by liver enzymes at the upper limit of normal.

Serum fetuin A concentration is elevated in children with non-alcoholic fatty liver disease

PURPOSE

To assess the serum fetuin A concentration as a potential marker of subclinical atherosclerosis in obese children with NAFLD.

MATERIAL/METHODS

A prospective analysis of 45 obese children initially diagnosed with liver pathology (elevated serum ALT activity and/or ultrasonographic liver brightness and/or hepatomegaly) was conducted. The diagnosis of NAFLD was established in the children with elevated serum ALT activity and liver steatosis on ultrasound examination. Viral hepatitis, autoimmune, metabolic liver diseases (Wilson disease, alpha-1-antitrypsin deficiency, cystic fibrosis) and drug and toxin-induced liver injury were excluded in all children. The degree of liver steatosis was graded according to Saverymuttu scale and the total liver lipids concentration was assessed using proton magnetic resonance spectroscopy ((1)H MRS).

RESULTS

Serum fetuin A concentration was significantly higher in examined children compared to the control group (n=30) (p=0.00002). Higher serum fetuin A concentration was also observed in children with NAFLD (n=19) in comparison to the controls (p=0.000026). Additionally, higher BMI values, waist circumferences, ALT and GGT activity, intensity of liver steatosis on ultrasound and total concentration of lipids in the liver in (1)H MRS were found in children with NAFLD compared to the rest of the examined obese patients (n=26). There was not found any correlation of the investigated glycoprotein with any other assessed parameters both in children with NAFLD and obese children without NAFLD.

CONCLUSION

Higher serum fetuin A concentration found in children with NAFLD compared to the control group support the hypothesis that atherosclerotic processes may develop faster in hepatopatic obese patients.