Nonalcoholic Fatty Liver Disease in Children

Nutritional Approaches in Children with Overweight or Obesity and Hepatic Steatosis

Childhood obesity is a global public health problem. Worldwide, 41 million children under 5 years and 340 million children and adolescents between 5 and 19 years are overweight. In addition, the recent COVID-19 epidemic has further amplified this social phenomenon. Obesity is a condition associated with various comorbidities, such as nonalcoholic fatty liver disease (NAFLD). The pathophysiology of NAFLD in obesity is intricate and involves the interaction and dysregulation of several mechanisms, such as insulin resistance, cytokine signaling, and alteration of the gut microbiota. NAFLD is defined as the presence of hepatic steatosis in more than 5% of hepatocytes, evaluated by histological analysis. It can evolve from hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, hepatocellular carcinoma, and end-stage liver failure. Body weight reduction through lifestyle modification remains the first-line intervention for the management of pediatric NAFLD. Indeed, studies suggest that diets low in fat and sugar and conversely rich in dietary fibers promote the improvement of metabolic parameters. This review aims to evaluate the existing relationship between obesity and NAFLD in the pediatric population and to assess the dietary patterns and nutritional supplementations that can be recommended to prevent and manage obesity and its comorbidities.

Uric acid versus metabolic syndrome as markers of fatty liver disease in young people with overweight/obesity

AIMS

To compare the association of high serum uric acid (HUA) or metabolic syndrome (MetS) with fatty liver disease (FLD) in youths with overweight/obesity (OW/OB).

MATERIALS AND METHODS

Cross-sectional study of anthropometrics, biochemical variables, and liver ultrasound of 3104 individuals with OW/OB (age 5-17 years). Metabolic syndrome was defined by ≥ 3 criteria among (1) high waist circumference; (2) high triglycerides; (3) low high-density lipoproteins; (4) fasting glucose ≥100 mg/dl; (5) blood pressure ≥95^th percentile in children, and ≥130/80 mmHg in adolescents. High serum uric acid was defined as serum UA value ≥ 75^th percentile adjusted for sex. Fatty liver disease was determined by echography.

RESULTS

The sample was stratified in four categories: (1) no HUA, no MetS (reference category); (2) MetS; (3) HUA; (4) HUA and MetS (HUA + MetS). The prevalence of FLD increased across the four categories from 29.9%, 44.0%, 52.2%, to 67.1%, respectively (p < 0.0001). The ORs for the categorical variables were 1.33 (1.06-1.68) for MetS (p = 0.02), 3.19 (2.51-4.05) for HUA (p < 0.0001) and 3.72 (2.65-5.21) for HUA + MetS (p < 0.0001), versus the reference category regardless of the body mass index.

CONCLUSIONS

HUA represents a useful marker of FLD in youths with OW/OB, given its greater ability to identify those at increased risk of the disease compared to MetS. The ability of both to predict incident FLD must be investigated in longitudinal study.

Higher BMI predicts liver fibrosis among obese children and adolescents with NAFLD - an interventional pilot study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) can range from simple steatosis to steatohepatitis with or without fibrosis. The predictors for liver fibrosis and the effect of nutritional intervention on hepatic fibrosis in pediatric population are not well established. We aimed to investigate the predictors for liver fibrosis and the effects of short-term nutritional intervention on steatosis and fibrosis among obese adolescents with NAFLD.

METHODS

Cross-sectional study among obese adolescents. Sociodemographic and clinical data were collected. Liver fibrosis was estimated by Shearwave elastography. All participants were recommended to consume a low carbohydrate diet and were followed biweekly. Blood tests and elastography were performed upon admission and repeated after 3 months.

RESULTS

Fifty-seven pediatric patients were recruited (35 males, mean age 13.5±2.9 years, mean body mass index [BMI] 38.8±9.7). Liver fibrosis was diagnosed in 34 (60%) subjects, which was moderate/severe (F≥2) in 24 (70%). A higher BMI Z score and moderate/severe steatosis correlated with moderate/severe fibrosis (P < 0.05). Seventeen patients completed 3 months of follow-up and displayed a decrease in BMI Z score (from BMI Z score 2.6±0.5 before intervention to 2.4±0.5 after intervention), with a significant decrease in liver fibrosis (P = 0.001).

CONCLUSION

Pediatric patients with high BMIs and severe liver steatosis are at risk for severe liver fibrosis. Nutritional intervention with minimal weight loss may improves hepatic fibrosis among the pediatric population.

TRIAL REGISTRATION

TRN NCT04561804 (9/17/2020).

Germination Improves the Polyphenolic Profile and Functional Value of Mung Bean (Vigna radiata L.)

The use of legumes as functional foods has gained increasing attention for the prevention and treatment of the so called non-communicable diseases that are highly prevalent worldwide. In this regard, biotechnological approaches for the enhancement of legumes' nutritional and functional value have been extensively employed. In the present study, the process of germination increased several parameters of mung bean (Vigna radiata L.) functionality, including extract yield, total phenolic content and in vitro antioxidant capacity. In addition, 3-day-germinated mung bean proved to be an interesting source of dietary essential minerals and exhibited a greater variety of polyphenolic compounds compared to raw mung bean. These properties resulted in enhanced cytoprotective features of the 3-day mung bean extracts against radical oxygen species in human colorectal (HT29) and monocyte (U937) cell lines. Moreover, the antiproliferative effects were tested in different colon cancer cell lines, T84 and drug-resistant HCT-18, as well as in a non-tumor colon CCD-18 line. Altogether, our results demonstrate that the germination process improves the mung bean's nutritional value and its potential as a functional food.

Hepatocyte Injury and Hepatic Stem Cell Niche in the Progression of Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by lipid accumulation in hepatocytes in the absence of excessive alcohol consumption. The global prevalence of NAFLD is constantly increasing. NAFLD is a disease spectrum comprising distinct stages with different prognoses. Non-alcoholic steatohepatitis (NASH) is a progressive condition, characterized by liver inflammation and hepatocyte ballooning, with or without fibrosis. The natural history of NAFLD is negatively influenced by NASH onset and by the progression towards advanced fibrosis. Pathogenetic mechanisms and cellular interactions leading to NASH and fibrosis involve hepatocytes, liver macrophages, myofibroblast cell subpopulations, and the resident progenitor cell niche. These cells are implied in the regenerative trajectories following liver injury, and impairment or perturbation of these mechanisms could lead to NASH and fibrosis. Recent evidence underlines the contribution of extra-hepatic organs/tissues (e.g., gut, adipose tissue) in influencing NASH development by interacting with hepatic cells through various molecular pathways. The present review aims to summarize the role of hepatic parenchymal and non-parenchymal cells, their mutual influence, and the possible interactions with extra-hepatic tissues and organs in the pathogenesis of NAFLD.

The Contribution of the Adipose Tissue-Liver Axis in Pediatric Patients with Nonalcoholic Fatty Liver Disease after Laparoscopic Sleeve Gastrectomy

OBJECTIVE

To evaluate the histopathologic modifications in liver and visceral adipose tissue (VAT), and to correlate these changes with clinical measures, adipokine production, and proinflammatory cytokines in a population of adolescents with obesity with nonalcoholic fatty liver disease (NAFLD) who underwent laparoscopic sleeve gastrectomy (LSG).

STUDY DESIGN

Twenty adolescents with obesity who underwent LSG and with biopsy-proven NAFLD were included. Patients underwent clinical evaluation and blood tests at baseline and 1 year after the surgical procedure. Liver and VAT specimens were processed for routine histology, immunohistochemistry, and immunofluorescence.

RESULTS

In adolescents with obesity and NAFLD, hepatic histologic alterations were uncorrelated with VAT inflammation. LSG induced in both liver and VAT tissue histopathology amelioration and macrophage profile modification that were correlated with body mass index and improvement in insulin resistance. The adipokine profile in liver and VAT was associated with weight loss and histologic improvement after LSG. Serum proinflammatory cytokines were correlated with liver and VAT histopathology and IL-1β and IL-6 levels were independently predicted by liver necroinflammatory grade.

CONCLUSIONS

This study suggests a unique adipose tissue/fatty liver crosstalk in pediatric patients. LSG induces a similar pattern of histologic improvement in the liver and in VAT. Besides VAT, our results strengthen the role of the liver in adipocytokine production and its contribution to systemic inflammation in pediatric patients with NAFLD.

Higher D-lactate levels are associated with higher prevalence of small dense low-density lipoprotein in obese adolescents

BACKGROUND

Childhood obesity is associated with insulin resistance (IR), increased levels of small dense low-density lipoprotein (sd-LDL) as well as with augmented hepatic de novo lipogenesis, which implies increased triose phosphate fluxes that may lead to increased methylglyoxal (MG) and its catabolic end product D-lactate. We hypothesized that obese adolescents have increased D-lactate serum levels associated with high incidence of sd-LDL.

METHODS

This is a cross-sectional study where the anthropometric characteristics, atherogenic dyslipidemia complex, sd-LDL (Lipoprint, Quantimetrix) and D-lactate (kinetic enzymatic analysis) were explored in 30 lean vs. 30 obese adolescents (16 females and 14 males per group) without metabolic syndrome (MetS). Endothelial function by flow-mediated dilation (FMD, by ultrasound) and arterial lesion by carotid intima media thickness (CIMT, by ultrasound) were also measured.

RESULTS

The mean age of participants was 16.8 ± 1.4 years. Obese adolescents had a body mass index of 32.7 ± 3.8 vs. 21.8 ± 2.1 in lean participants. The obesity group showed higher D-lactate levels: 6.2 ± 3.0 vs. 4.5 ± 2.5 μmol/L, higher levels of insulin: 15 (9.6-23.5) vs. 7.9 (6.5-10.5) μIU/mL; triglyceride (TG): 1.46 (1.1-1.8) vs. 0.84 (0.6-1.2) mmol/L; non-high-density lipoprotein-cholesterol (NON-HDL-C): 2.8 ± 0.9 vs. 2.3 ± 0.7 mmol/L; total cholesterol (TC)/HDL-C) index: 2.9 ± 0.7 vs. 2.4 ± 0.5; TG/HDL-C index: 2.2 (1.5-2.8) vs. 1.1 (0.8-1.8); %LDL-3: 4.2 ± 4.07 vs. 1.9 ± 2.7; smaller LDL size: 270.6 ± 3 vs. 272.2 ± 1.1 Å. D-lactate correlated positively with LDL-2: r = 0.44 and LDL-3 (sd-LDL): r = 0.49 and negatively with large LDL-1: r = -0.48 and LDL size: r = -0.46; (p<0.05, p<0.01, p<0.001 and p<0.0001, respectively). Obese adolescents showed higher CIMT: 0.51 ± 0.08 vs. 0.46 ± 0.08 mm and lower FMD: 20.3% ± 6.7% vs. 26.0% ± 9.3%.

CONCLUSIONS

Obese adolescents display subclinical signs of IR and endothelial dysfunction. Higher serum sd-LDL levels correlated positively with D-lactate levels. These findings suggest an association between atherogenic dyslipoproteinemia and whole body MG fluxes already detectable in apparently healthy obese adolescents.

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.

Associations between Liver Enzyme Levels and Parameters of the Metabolic Syndrome in Obese Children

BACKGROUND

Obesity is strongly associated with insulin resistance, hypertension, dyslipidemia, and therefore risk for metabolic syndrome (MetS), which is an increasing problem in youth. The potential role of elevated liver enzyme levels in this context needs to be further investigated.

METHODS

This paper provides a post hoc analysis of a cross-sectional study of 77 obese nondiabetic children (51% female; median age 11.7 years; BMI >97th percentile) enrolled at the University of Bonn, Bonn, Germany. Anthropometric parameters, lipid profiles, glycemic control, and liver enzyme levels were evaluated. Glucose and insulin levels were determined during an oral glucose tolerance test (OGTT). Gender- and age-specific cutoff values were used to assess MetS.

RESULTS

A high prevalence of hypertension (51%), dyslipidemia (52%), elevated liver enzyme levels (51%), and hyperglycemia (24%) was found. There was considerable overlap between the presence of different MetS risk factors in individuals, and 40% of the participants had ≥3 of a maximum of 5 MetS risk factors. Elevated liver enzyme levels were significantly associated with reduced insulin sensitivity, as the OGTT-insulin response was significantly higher in participants with elevated transaminases (p = 0.01). This association was independent of hyperglycemia and dyslipidemia (p = 0.03).

CONCLUSIONS

We conclude that liver enzyme levels are related to insulin sensitivity in obese children and could therefore be an indirect indicator for MetS. Testing for disturbed glucose metabolism should be considered for obese children with elevated liver enzymes.

Laparoscopic Sleeve Gastrectomy Improves Nonalcoholic Fatty Liver Disease-Related Liver Damage in Adolescents by Reshaping Cellular Interactions and Hepatic Adipocytokine Production

OBJECTIVES

To investigate whether the modulation of local cellular cross-talks and the modification of hepatic adipocytokine expression could mechanistically explain the improvement of liver histopathology after laparoscopic sleeve gastrectomy (LSG) in adolescents with nonalcoholic fatty liver disease (NAFLD).

STUDY DESIGN

Twenty obese (body mass index of ≥35 kg/m²) adolescents who underwent LSG and with biopsy-proven NAFLD were included. At baseline (T0) and 1 year after treatment, patients underwent clinical evaluation, blood tests, and liver biopsy. Hepatic progenitor cells, hepatic stellate cells (HSCs), macrophages, and adipocytokines were evaluated by immunohistochemistry and immunofluorescence.

RESULTS

Liver biopsy samples after LSG demonstrated a significant improvement of NAFLD Activity Score and fibrosis. Immunohistochemistry indicated a significant reduction of hepatocyte cell cycle arrest, ductular reaction, activated HSC, and macrophage number after LSG compared with T0. The activation state of HSC was accompanied by modification in the expression of the autophagy marker LC3. Hepatocyte expression of adiponectin was significant higher after LSG than into T0. Moreover, LSG caused decreased resistin expression in Sox9⁺ hepatic progenitor cells compared with T0. The number of S100A9⁺ macrophages was also reduced by LSG correlating with resistin expression. Finally, serum levels of proinflammatory cytokines significantly correlated with macrophages and activated HSC numbers.

CONCLUSIONS

The histologic improvement induced by LSG is associated with the reduced activation of local cellular compartments (hepatic progenitor cells, HSCs, and macrophages), thus, strengthening the role of cellular interactions and hepatic adipocytokine production in the pathogenesis of NAFLD.

Prevalence and Correlates of Suspected Nonalcoholic Fatty Liver Disease in Chinese Children

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health problem worldwide; however, the availability of information on the prevalence of NAFLD in the general pediatric population is still limited. The primary aim of this study was to reveal the prevalence and correlates of suspected NAFLD in Chinese children at the national level. Data from the China Health and Nutrition Surveys (CHNS) was used. Weight, height, waist circumference (WC), blood pressure (BP) were measured for children aged 7–18 years. Blood samples were collected and analyzed. Children were classified as having suspected NAFLD if common causes of liver disease were excluded, and serum alanine aminotransferase (ALT) values were above the established thresholds (>22.1 IU/L for girls and >25.8 IU/L for boys). A percentage of 9.03% (75 out of 831) of Chinese children was found to have suspected NAFLD. Overweight and obesity according to BMI percentiles, abdominal obesity, hyperuricemia (uric acid (UA) > 327 μmol/L), and elevated total cholesterol (TC) were all detected as the correlates of childhood suspected NAFLD when adjusting for other factors. Our study revealed the prevalence of suspected NAFLD in general Chinese children at the national level for the first time. Our findings indicate that suspected NAFLD in children is associated with increasing childhood morbidities, further studies are needed to better understand the prevalence of childhood NAFLD and its correlates, and large-scale programs should be launched to screen NAFLD in the pediatric population in China.

The Benefit of Sleeve Gastrectomy in Obese Adolescents on Nonalcoholic Steatohepatitis and Hepatic Fibrosis

OBJECTIVE

To determine whether bariatric surgery is effective for the treatment of nonalcoholic steatohepatitis (NASH) in adolescence, we compared the efficacy of laparoscopic sleeve gastrectomy (LSG) with that of lifestyle intervention (nonsurgical weight loss [NSWL]) for NASH reversal in obese adolescents.

STUDY DESIGN

Obese (body mass index ≥ 35 kg/m²) adolescents (13-17 years of age) with biopsy-proven NAFLD underwent LSG, lifestyle intervention plus intragastric weight loss devices (IGWLD), or only NSWL. At baseline and 1 year after treatment, patients underwent clinical and psychosocial evaluation, blood tests, liver biopsy, polysomnography, and 24-hour ambulatory blood pressure estimation.

RESULTS

Twenty patients (21%) underwent LSG, 20 (21%) underwent IGWLD, and 53 (58%) received lifestyle intervention alone (NSWL). One year after treatment, patients who underwent LSG lost 21.5% of their baseline body weight, whereas patients who underwent IGWLD lost 3.4%, and patients who underwent NSWL increase 1.7%. In patients who underwent LSG, NASH reverted completely in all patients and hepatic fibrosis stage 2 disappeared in 18 patients (90%). After IGWLD, NASH reverted in 6 patients (24%) and fibrosis in 7 (37%). Patients who received the NSWL intervention did not improve significantly. Hypertension resolved in all patients who underwent LSG with preoperative hypertension (12/12) versus 50% (4/8) of the patients who underwent IGWLD (P = .02). The cohort-specific changes in impaired glucose metabolism were similar: 100% (9/9) of affected patients who underwent LSG versus 50% (1/2) of patients who underwent IGWLD (P = .02). LSG was also more affective in resolving dyslipidemia (55% [7/12] vs 26% [10/19]; P = .05) and sleep apnea (78% [2/9] vs 30% [11/20]; P = .001).

CONCLUSION

LSG was more effective than lifestyle intervention, even when combined with intragastric devices, for reducing NASH and liver fibrosis in obese adolescents after 1 year of treatment.

Beneficial effects of legumes on parameters of the metabolic syndrome: a systematic review of trials in animal models

Legume consumption plays a pivotal role in the prevention and treatment of the metabolic syndrome (MetS). This systematic review aimed to highlight the beneficial effects of legume interventions for the prevention and/or improvement of parameters related to the MetS and the implicated metabolic pathways so far reported. The methodology involved a search in four electronic databases (Medline, Web of Science, Scopus, Cochrane Library) from January 2007 to December 2014, considering as descriptors ‘Metabolic Syndrome’ and ‘Fabaceae’ and adequately adjusting the equation in each one of them. In total, forty-one studies were finally included. The majority of the studies described a regulating effect on glucose and lipid metabolism due to legume administration, whereas effects on blood pressure and renal parameters are not fully described. Regarding the metabolic pathways involved, they include the up-regulation of genes related to β-oxidation and acetyl-CoA degradation and the down-regulation of glycolytic and lipogenesis genes, as well as those associated with the acetyl-CoA synthesis. The ameliorating effects of legume consumption on the alterations associated with the MetS are clearly reported and coincide with changes in the expression of protein and genes involved in lipid and glucose metabolism. More research needs to be conducted including more legume species that are highly consumed as part of a healthy dietary pattern.

The CBS/CSE system: a potential therapeutic target in NAFLD?

Non-alcoholic fatty liver disease (NAFLD) is a broad spectrum liver disorder diagnosed in patients without a history of alcohol abuse. NAFLD is growing at alarming rates worldwide. Its pathogenesis is complex and incompletely understood. The cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) system regulates homocysteine and cysteine metabolism and contributes to endogenous hydrogen sulfide (H2S) biosynthesis. This review summarizes our current understanding of the hepatic CBS/CSE system, and for the first time, positions this system as a potential therapeutic target in NAFLD. As will be discussed, the CBS/CSE system is highly expressed and active in the liver. Its dysregulation, presenting as alterations in circulating homocysteine and (or) H2S levels, has been reported in NAFLD patients and in NAFLD-associated co-morbidities such as obesity and type 2 diabetes. Intricate links between the CBS/CSE system and a number of metabolic and stress related molecular mediators have also emerged. Various dysfunctions in the hepatic CBS/CSE system have been reported in animal models representative of each NAFLD spectrum. It is anticipated that a newfound appreciation for the hepatic CBS/CSE system will emerge that will improve our understanding of NAFLD pathogenesis, and give rise to new prospective targets for management of this disorder.

Low-grade chronic inflammation induces behavioral stereotypy in rats

Schizophrenia is known to be associated with metabolic disturbances including diabetes mellitus, obesity and cardiovascular diseases. A growing body of evidence has suggested abnormal cytokine levels in schizophrenia. In the present study, we explored the effects of low-grade chronic inflammation on behavioral stereotypy in a rat model of non-alcoholic fatty liver disease (NAFLD). In order to induce NAFLD, rats were fed with either water enriched with 30 % fructose or plain tap water for 8 weeks. Following feeding period, behavioral stereotypy was evaluated with apomorphine-induced stereotypy test. Also, levels of tumor necrosis factor alpha (TNF-α), interleukin 2 (IL-2) and nuclear factor kappa B (NF-κB) in the liver and brain tissues were assessed biochemically. Brain homovanilic acid (HVA) was measured to evaluate the dopamine turnover. NAFLD rats showed significantly higher stereotypy score compared to controls (p = 0.016). TNF-α, IL-2, and NF-κB levels were significantly increased in NAFLD rats compared to control group. Brain HVA levels were elevated in NAFLD rats as well (p = 0.008). Moreover, NAFLD group prompted a considerable increase in brain IL-2 immunoexpression (p = 0.005). In conclusion, the present study demonstrates that low-grade chronic inflammation such as NAFLD may enhance apomorphine-induced stereotypic behavior via increasing dopaminergic activity in rats.

The evaluation of hepatic fibrosis scores in children with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in children and can progress to liver cirrhosis during childhood. Patients with more advanced fibrosis on biopsy tend to have more liver complications. Noninvasive hepatic fibrosis scores have been developed for adult patients with NAFLD; however, these scores have not been validated in children. The aim of our study was to evaluate some of these scores in assessing the presence of fibrosis in children with biopsy-proven NAFLD.

METHODS

Our study consisted of 92 biopsy-proven NAFLD children from five major US centers. Fibrosis was determined by an experienced pathologist (F0-4). Clinically significant fibrosis was defined as fibrosis stage ≥ 2, and advanced fibrosis was defined as F3-4. The following fibrosis scores were calculated for each child: AST/ALT ratio, AST/platelet ratio index (APRI), NAFLD fibrosis score (NFS), and FIB-4 index. ROC was performed to assess the performance of different scores for prediction of presence of any, significant, or advanced fibrosis. A p value < 0.05 was considered statistically significant.

RESULTS

Mean age was 13.3 ± 3 years, and 33 % were females. Eleven (12 %) subjects had no fibrosis, 35 (38 %) had fibrosis score of 1, 26 (28 %) had fibrosis score of 2, and 20 (22 %) had a score of 3. APRI had a fair diagnostic accuracy for the presence of any fibrosis (AUC of 0.80) and poor diagnostic accuracy for significant or advanced fibrosis. AST/ALT, NFS, and FIB-4 index all either had poor diagnostic accuracy or failed to diagnose the presence of any, significant, or advanced fibrosis.

CONCLUSION

Noninvasive hepatic fibrosis scores developed in adults had poor performance in diagnosing significant fibrosis in children with NAFLD. Our results highlight the urgent need to develop a reliable pediatric fibrosis score.

Comparison between a pediatric health promotion center and a pediatric obesity clinic in detecting metabolic syndrome and non-alcoholic fatty liver disease in children

This study was done to evaluate the efficacy of health check-ups in children in detecting metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) by comparing the pediatric health promotion center with the pediatric obesity clinic. Children who visited a pediatric health promotion center (n=218) or a pediatric obesity clinic (n=178) were included. Anthropometric data, blood pressure, laboratory tests, and abdominal ultrasonography were evaluated. Two different criteria were applied to diagnose metabolic syndrome. The prevalence of metabolic syndrome in the 2 units was 3.2%-3.7% in a pediatric health promotion center and 23%-33.2% in a pediatric obesity clinic. Significant differences were observed in the prevalence of each component of metabolic syndrome between the 2 units including abdominal adiposity, blood pressure, serum triglycerides, and fasting blood glucose (P<0.05). The prevalence of NAFLD was 8.7% and 71.9% in the 2 units according to liver enzymes and 5.9% and 61.8% according to ultrasonography (P<0.05). The prevalence of metabolic syndrome and NAFLD was higher among patients visiting the obesity clinic targeting obese children than that among patients visiting the health promotion center offering routine check-ups. An obesity-oriented approach is required to prevent obesity-related health problems in children.

Recently discovered adipokines and cardio-metabolic comorbidities in childhood obesity

White adipose tissue (WAT) asset, in terms of cell number, fat storage capacity and endocrine function, is largely determined in early stages of life and is pivotal for shaping the WAT pro-inflammatory behavior. WAT derived adipokines have been shown to play a main role in several cardio-metabolic abnormalities of obesity. This review focuses on the most recently identified adipokines, namely adipocyte-fatty acid-binding protein, chemerin, fibroblast growth factor-21, lipocalin-2, omentin-1 and vaspin; their role in the pathogenesis of obesity and associated cardio-metabolic abnormalities; and on their adaptive response to body weight change. Evidence consistently suggests a pathogenic role for A-FABP, chemerin and FGF-21. Nevertheless, large population studies are needed to verify whether they can be useful to predict the risk of cardio-metabolic abnormalities in adulthood and/or monitor the clinical response to therapeutic interventions.

Non-alcoholic Fatty liver disease in children

In the last years, there has been extremely much information which reveals an alarming increase of obesity in children and, at the same time, an increase of the incidence of non-alcoholic fatty liver disease (NAFLD). NAFLD implies a wide range of affections starting from simple hepatic steatosis to non-alcoholic steatohepatitis (NASH); the latter can evolve to cirrhosis and hepatic carcinoma. All these affections were noticed in children, too. The article presents data on the epidemiology, pathogeny, clinical and paraclinical findings, and treatment of NAFLD in children.

[Non-alcoholic fatty liver in children and adolescents with excess weight and obesity]

BASIS AND OBJECTIVE

Hepatic steatosis, also known as non-alcoholic fatty liver (NAFL), is the most frequent liver disease in obese children. Due to an increase in infantile obesity, it is experiencing a significant increment in incidence. Our objetives are: Estimate the prevalence of NAFL in children with excess weight and obesity using the glutamate pyruvate transaminase (GPT) value as a biochemical test and an abdominal ultrasound, and correlate the presence of hepatic steatosis with various anthropometric and biochemical parameters.

PATIENTS AND METHOD

Cross-sectional prevalence study which includes children with excess weight and obesity between the ages of 5 and 15 years, between the years 2004-2012. The independent variables included were: age, sex, weight, size, body mass index (BMI), waist circumference (WC), waist size index (WSI), insulinemia, Homeostasis model assessment-insulin resistance (HOMA-R), total cholesterol, triglycerides (TG), high density lipoproteins (HDL), low density lipoproteins (LDL), glutamic-oxaloacetic transaminase (GOT), GPT and gamma-glutamyl transpeptidase (GGT).

RESULTS

One hundred and twenty-six patients, with an average age of 11.94 (3.12) years were recruited. A percentage of 19.66 of the patients presented elevated GPT pathology. Of the 126 abdominal ultrasounds performed, 38 patients presented hepatic steatosis (30.15%). The levels of insulinemia, HOMA-R and LDL were significantly higher in patients with altered GPT, compared to those with normal GPT values (P=.015, P=.008 and P=.002, respectively). The patients with an objective HGNA in ultrasound, also showed greater levels of insulinemia, WC, WSI, total cholesterol, TG, LDL, GLT, GPT and GGT than the patients with normal ultrasounds, thereby achieving statistical significance in insulinemia, HOMA-R, LDL and GPT values.

CONCLUSIONS

NAFL is a relatively frequent disorder in obese children and adolescents. In our study, 2 of 10 children -using GPT- and 3 of every 10 -using abdominal ultrasound- present the same. The biochemical marker which best defines it is an elevation in GPT. A modification in lifestyle which includes weight loss as a principal means of avoiding complications in adult life, is essential and necessary.

Assessment of atherosclerosis in obese adolescents: positive correlation of mean platelet volume and carotid intima media thickness

AIMS

This study aims to assess the correlation of mean platelet volume (MPV) and common carotid artery (CCA) thickness in a population of obese adolescents.

METHODS

Sixty-eight patients and 23 controls were enrolled. Anthropometric measurements, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, hemoglobin, white blood cell count, platelet count, MPV and insulin resistance by homeostasis model of assessment of insulin resistance were investigated. Furthermore, CCA thickness was measured by high-resolution ultrasound.

RESULTS

MPV and the left CCA thickness were significantly higher in obese adolescents than the healthy controls. The association between MPV and left CCA was checked by linear regression analysis. MPV explained 19% of the variation in left CCA (P < 0.001). At multiple regression analysis, MPV maintained a positive association with the left CCA thickness (P = 0.002) independently of fatty liver grade, relative weight, total cholesterol and homeostasis model of assessment of insulin resistance.

CONCLUSION

MPV is significantly correlated with CCA thickness in obese adolescents.

Imaging of non alcoholic fatty liver disease: A road less travelled

Non alcoholic fatty liver disease (NAFLD) is a spectrum that includes simple steatosis, nonalcoholic steatohepatitis and cirrhosis. It is increasingly emerging as a cause of elevated liver enzymes, cryptogenic cirrhosis and hepatocellular carcinoma. The morbidity and mortality related to NAFLD is expected to rise with the upsurge of obesity and type 2 diabetes mellitus. The need of the hour is to devise techniques to estimate and then accurately follow-up hepatic fat content in patients with NAFLD. There are lots of imaging modalities in the radiological armamentarium, namely, ultrasonography with the extra edge of elastography, computed tomography, and magnetic resonance imaging with chemical shift imaging and spectroscopy to provide an estimation of hepatic fat content.

Role of physical activity in the treatment of nonalcoholic fatty liver disease in children and adolescents

Currently, nonalcoholic fatty liver disease (NAFLD) is the most frequent liver abnormality observed in obese children and adolescents. A strong body of evidence suggests that increased liver fat is significantly associated with visceral adiposity, metabolic syndrome, and insulin resistance in obese children and adolescents. Diet and exercise are generally recommended to treat obese youth with NAFLD as they do not carry side effects and confer multiple cardiometabolic benefits. Studies in adult populations report a beneficial effect of regular physical activity on reducing liver fat. In children and adolescents, available data show that weight loss induced by increasing physical activity and calorie restriction is beneficial to reduce liver fat and associated health risk factors such as insulin resistance and dyslipidemia. Currently, evidence regarding the independent effects of regular exercise alone (e.g., without calorie restriction) on NAFLD are unclear. Additionally, there is no data regarding the optimal exercise regimen (e.g., type, dose, intensity) that should be prescribed for reducing NAFLD in children and adolescents. The purpose of this review is to examine the role of physical activity on NAFLD in children and adolescents.

Subclinical hypothyroidism as a risk factor for the development of cardiovascular disease in obese adolescents with nonalcoholic fatty liver disease

No data are available on the relationship between subclinical hypothyroidism and risk factors for the development of cardiovascular disease in obese adolescents with nonalcoholic fatty liver disease (NAFLD). This study aimed to determine whether an association exists between subclinical hypothyroidism and risk factors for the development of cardiovascular disease in obese adolescents with NAFLD. The study enrolled 111 obese adolescents and 42 lean subjects. The obese subjects were divided into two subgroups based on the presence or absence of fatty liver with high transaminases: a NAFLD group and a non-NAFLD group. Subclinical hypothyroidism was defined as a thyroid-stimulating hormone (TSH) level higher than 4 mIU/l and a normal free-thyroxine level (0.6-1.8 ng/dl). Insulin resistance was calculated by the homeostasis model assessment (HOMA-IR). Left ventricular mass (LVM), LVM index measurements, carotid intima media thickness (IMT), and HOMA-IR values were higher in the NAFLD obese group with TSH levels higher than 4 mIU/l than in the NAFLD obese group with TSH levels lower than 4 mIU/l. Elevated TSH values in the NAFLD obese group were positively correlated with most of the metabolic and cardiovascular risk parameters such as total cholesterol (r = 0.606, p = 0.001), triglycerides (r = 0.476, p = 0.016), low-density lipoprotein cholesterol (r = 0.461, p = 0.004), insulin (r = 0.607, p = 0.001), HOMA-IR (r = 0.596, p = 0.002), carotid IMT (r = 0.894, p < 0.0001), and LVM (r = 0.563, p = 0.003). The findings demonstrated that the obese adolescents with NAFLD and subclinical hypothyroidism had a more adverse cardiovascular risk profile and a higher carotid IMT and LVM.

Pediatric Obesity and the Liver

The obesity epidemic affects both the adult and pediatric populations. Obese children are at risk for comorbidities such as cardiovascular disease and nonalcoholic fatty liver disease (NAFLD). NAFLD is the most common cause of pediatric liver disease and prevalence rates are increasing in parallel to obesity rates. Pediatric NAFLD is a difficult diagnostic entity complicated by lack of accurate noninvasive screening tools. Currently, microscopic liver examination biopsy is the gold standard for diagnosis. Histologically, NAFLD can range from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Pediatric NASH is histologically distinct from typical adult NASH. Type 2 NASH, originally described as the most common pattern of pediatric NASH, is characterized by macrovesicular steatosis, portal tract inflammation, and variable fibrosis without ballooning degeneration or perisinusoidal fibrosis. Type 1 NASH, or adult NASH, is characterized by macrovesicular steatosis, ballooning degeneration, lobular inflammation, and variable fibrosis. Recent studies have shown that overlap patterns between NASH type 1 and 2 are more frequently encountered in the pediatric population. We address the association between pediatric obesity and nonalcoholic fatty liver disease (NAFLD) with discussion of disease demographics, histopathology, and the role of autopsy.

Potential clinical translation of juvenile rodent inactivity models to study the onset of childhood obesity

According to the latest data from the Center for Disease Control and Prevention 17%, or 12.5 million, of children and adolescents aged 2-19 years in the United States are obese. Physical inactivity is designated as one of the actual causes of US deaths and undoubtedly contributes to the obesity epidemic in children and adults. Examining the effects of inactivity on physiological homeostasis during youth is crucial given that 58% of children between the ages 6-11 yr old fail to obtain the recommended 60 min/day of physical activity and 92% of adolescents fail to achieve this goal [Troiano et al. Med Sci Sports Exerc. 40, 2008]. Nonetheless, invasive mechanistic studies in children linking diminished physical activity with metabolic maladies are lacking for obvious ethical reasons. The rodent wheel lock (WL) model was adopted by our laboratory and others to study how different organ systems of juvenile rats respond to a cessation of daily physical activity. Our WL model houses rats in cages equipped with voluntary running wheels starting at 28 days of age. After a certain period of voluntary running (3 to 6 wk), the wheels are locked, thus preventing the rats' primary source of physical activity. The studies discussed herein suggest that obesity-associated maladies including skeletal muscle insulin resistance, hypothalamic leptin resistance, fatty acid oxidation impairments in skeletal muscle and adipose tissue, nonalcoholic fatty liver disease, and endothelial dysfunction are initiated in juvenile animals that are restrained from voluntary exercise via WL. The use of the juvenile rodent WL or other inactivity models will continue to provide a powerful clinical translational tool that can be used for primordial prevention of human childhood obesity.

Diagnosis of nonalcoholic fatty liver disease in children and adolescents: position paper of the ESPGHAN Hepatology Committee

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children and adolescents in the United States, and most probably also in the rest of the industrialized world.As the prevalence of NAFLD in childhood increases with the worldwide obesity epidemic, there is an urgent need for diagnostic standards that can be commonly used by pediatricians and hepatologists. To this end, we performed a PubMed search of the adult and pediatric literature on NAFLD diagnosis through May 2011 using Topics and/or relevant Authors as search words. According to the present literature, NAFLD is suspected based on the association of fatty liver combined with risk factors (mainly obesity), after the exclusion of other causes of liver disease. The reference but imperfect standard for confirming NAFLD is liver histology. The following surrogate markers are presently used to estimate degree of steatosis and liver fibrosis and risk of progression to end-stage liver disease: imaging by ultrasonography or magnetic resonance imaging, liver function tests, and serum markers of liver fibrosis.NAFLD should be suspected in all of the overweight or obese children and adolescents older than 3 years with increased waist circumference especially if there is a NAFLD history in relatives. The typical presentation, however, is in children ages 10 years and older. The first diagnostic step in these children should be abdominal ultrasound and liver function tests, followed by exclusion of other liver diseases. Overweight/obese children with normal ultrasonographic imaging and normal liver function tests should still be monitored due to the poor sensitivity of these tests at a single assessment.Indications for liver biopsy include the following: to rule out other treatable diseases, in cases of clinically suspected advanced liver disease, before pharmacological/surgical treatment, and as part of a structured intervention protocol or clinical research trial.

Metabolic syndrome in childhood from impaired carbohydrate metabolism to nonalcoholic fatty liver disease

Compelling evidence supports the concept that nonalcoholic fatty liver disease (NAFLD) represents the hepatic component of metabolic syndrome (MetS). Intrahepatic fat seems to predict more strongly than does visceral adiposity an individual's cardiovascular risk and the likelihood that metabolic abnormalities are present in youth. Young individuals with fatty liver are more insulin resistant and present with a higher prevalence of metabolic abnormalities than do individuals without intrahepatic fat accumulation. They also present with a certain endothelial dysfunction and greater carotid intima-media thickness. Conversely, youth with MetS seem to have an increased risk of developing liver inflammation, a condition termed nonalcoholic steatohepatitis (NASH), and fibrosis. In the context of MetS, the liver is central in that it can drive both hepatic and systemic insulin resistance, trigger low-grade inflammation, and promote atherogenic processes. In the context of MetS, NAFLD and altered carbohydrate metabolism track from childhood to adulthood. Thus, prevention, recognition, and effective treatment of these two abnormalities may limit the burden of morbidity and mortality associated with obesity and may delay onset of cardiovascular disease in early adulthood. The present review aims at systematically presenting evidence of the critical interplay of fatty liver and altered glucose metabolism in youth. It attempts to provide pathogenetic explanations for such an association and the rationale for its treatment, with particular regard to nutritional interventions. Key teaching points: Overweight and obese youth should be screened for fatty liver disease once after puberty by liver function tests and ultrasonography. Screening for fatty liver should be accurately performed in young patients with features of metabolic syndrome. Obese patients with fatty liver are at increased risk for altered glucose metabolism, thus they should undergo an oral glucose tolerance test. A nutritional and behavioral intervention aimed at achieving a permanent change of the lifestyle in patients and their parents is recommended.

Role of cytokines and chemokines in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) includes a variety of histological conditions (ranging from liver steatosis and steatohepatitis, to fibrosis and hepatocarcinoma) that are characterized by an increased fat content within the liver. The accumulation/deposition of fat within the liver is essential for diagnosis of NAFLD and might be associated with alterations in the hepatic and systemic inflammatory state. Although it is still unclear if each histological entity represents a different disease or rather steps of the same disease, inflammatory processes in NAFLD might influence its pathophysiology and prognosis. In particular, non-alcoholic steatohepatitis (the most inflamed condition in NAFLDs, which more frequently evolves towards chronic and serious liver diseases) is characterized by a marked activation of inflammatory cells and the upregulation of several soluble inflammatory mediators. Among several mediators, cytokines and chemokines might play a pivotal active role in NAFLD and are considered as potential therapeutic targets. In this review, we will update evidence from both basic research and clinical studies on the potential role of cytokines and chemokines in the pathophysiology of NAFLD.

Adverse metabolic effects of a hypercaloric, high-fat diet in rodents precede observable changes in body weight

Although a high-fat diet (HFD) is recognized as an important contributor to obesity, human research is limited by confounders such as income, whereas animal research has typically examined diet during specific developmental periods rather than throughout the lifespan. We hypothesized that the use of an HFD in short-term studies as has been commonly done in animals does not adequately reflect the lifelong dietary patterns seen frequently in humans with consequent metabolic disturbances. We examined the impact of HFD from weaning until 39 weeks (middle age) on the metabolism of male rats. At 7, 26, and 39 weeks, glucose tolerance tests were performed, a subset of animals was euthanized, and serum and tissues were collected. After 4 weeks, preceding increased body weight, HFD animals had increased intra-abdominal fat, triglycerides, and hyperglycemia. Hyperinsulinemia was insufficient to maintain normoglycemia, and beta cell mass and glucagon-like peptide 1 decreased over time in HFD and control animals. Despite lacking significant lipid abnormalities, nonalcoholic fatty liver disease was evident by 39 weeks. Our HFD model demonstrated that significant metabolic abnormalities may go undetected by current standard screening such as weighing and biochemistry.

Relationship between fatty liver and glucose metabolism: a cross-sectional study in 571 obese children

BACKGROUND AND AIMS

Early onset type 2 diabetes mellitus (T2DM) is associated with obesity, insulin resistance and impaired beta-cell function. Non-alcoholic fatty liver disease (NAFLD) may be an independent risk factor for T2DM. We investigated the relationship between NAFLD and glucose metabolism in a large sample of obese children.

METHODS AND RESULTS

A total of 571 obese children (57% males and 43% females) aged 8-18 years were consecutively studied at a tertiary care centre specialised in paediatric obesity. Liver ultrasonography was used to diagnose NAFLD after exclusion of hepatitis B and C and alcohol consumption. Oral-glucose tolerance testing (OGTT) was performed; insulin sensitivity was evaluated by using the insulin sensitivity index (ISI) and beta-cell function by using the ratio between the incremental areas under the curve (AUC) of insulin and glucose (incAUCins/incAUCglu). A total of 41% of the obese children had NAFLD. Impaired glucose tolerance or T2DM was present in 25% of the children with NAFLD versus 8% of those without it (p<0.001). Children with NAFLD had higher body mass index (BMI), fasting glucose, 120-min OGTT glucose, incAUCins/incAUCglu and lower ISI as compared with children without NAFLD (p≤0.002). At bootstrapped multivariable median regression analysis controlling for gender, age, pubertal status and BMI, NAFLD was an independent predictor of 120-min OGTT glucose and ISI, but not of incAUCins/incAUCglu. Similar findings were obtained using continuous liver steatosis as the predictor, instead of dichotomous NAFLD.

CONCLUSION

NAFLD was present in 41% of our obese children and was associated with higher insulin resistance, but not with impaired beta-cell function.

Early interplay of intra-hepatic iron and insulin resistance in children with non-alcoholic fatty liver disease

BACKGROUND & AIMS

The liver is a crucial organ at the crossroads of iron and glucose metabolism. The aim of the study was to assess intra-hepatic iron in young patients with non-alcoholic fatty liver disease (NAFLD) and its association with insulin resistance and severity of liver damage.

METHODS

Intrahepatic iron content was assessed (Pearl's stain grade) in 66 patients (41 males, age 3.3-17.6years) with biopsy-proven NAFLD. Mutations of the Hereditary Hemochromatosis (HFE) gene were determined by sequence allele-specific polymerase chain reaction. Insulin resistance was estimated by means of the Oral Glucose Tolerance Test and the Insulin Sensitivity Index (ISI); the Insulino-Genic Index was also calculated. Tumor necrosis factor-alpha and interleukin-6 were measured.

RESULTS

Low-mild intra-hepatic iron deposition was observed in one out of five children (n=15, 22%), and it was not associated with HFE mutations, carried by 17 patients (26%). Among carriers of HFE mutations, four had siderosis. No abnormalities were observed in systemic indices of iron balance. Serum ferritin was within normal adult ranges in all patients (33.6±7.6ng/ml), but it was correlated with ISI (r(o)=-0.361; p=0.003). No significant difference was observed in insulin sensitivity, iron balance, inflammatory milieu, and liver histology between patients with and without hepatic siderosis.

CONCLUSIONS

In young obese individuals with NAFLD, despite normal peripheral iron parameters, mild intra-hepatic iron deposition is a frequent finding, but it is not associated with insulin resistance or severity of liver damage. Longitudinal studies are required to define the long-term relevance of these findings.

Gut microbiota, lipopolysaccharides, and innate immunity in the pathogenesis of obesity and cardiovascular risk

Compelling evidence supports the concepts that gut microbiota actively promotes weight gain and fat accumulation and sustains, indirectly, a condition of low-grade inflammation, thus enhancing the cardiovascular risk. Fewer Bacteroidetes and more Firmicutes seem to characterize the gut microbiota of obese people as compared with that of lean individuals. This difference translates into an increased efficiency of microbiota of obese individuals in harvesting energy from otherwise indigestible carbohydrates. Furthermore, the microbiota also seems able to favor fat accumulation. Indeed, studies performed in germ-free animals have demonstrated that conventionalization of sterile intestine with gut microbiota is associated with an enhanced expression of various lipogenic genes in different tissues, i.e., hepatic, adipose, and muscle tissues. Finally, the microbiota favors systemic exposure to the lipopolysaccharides (LPSs), large glycolipids derived from the outer membrane of Gram-negative bacteria. LPSs can cause a condition of "metabolic endotoxemia" characterized by low-grade inflammation, insulin resistance, and augmented cardiovascular risk. LPSs are a powerful trigger for the innate immune system response. Upon binding to the Toll-like receptor 4 and its coreceptors, LPSs trigger a cascade of responses ultimately resulting in the release of proinflammatory molecules that interfere with modulation of glucose and insulin metabolism, promote development and rupture of the atherosclerotic plaque, and favor progression of fatty liver disease to steatohepatitis. This review gives a comprehensive breakdown of the interaction among gut microbiota, LPSs, and the innate immune system in the development of obesity and promotion of an individual's cardiovascular risk.

Pediatric nonalcoholic fatty liver disease: Overview with emphasis on histology

Nonalcoholic fatty liver disease (NAFLD) is a disease in which excessive fat accumulates in the liver of a patient without a history of alcohol abuse. This disease includes simple steatosis and nonalcoholic steatohepatitis (NASH). NAFLD/NASH is recognized as a hepatic manifestation of metabolic syndrome. In recent years, pediatric NAFLD has increased in line with the increased prevalence of pediatric obesity. The estimated prevalence of pediatric NAFLD is 2.6%-9.6%, and it is associated with sex, age, and ethnicity. With regard to the pathogenesis of NAFLD, the “two-hit” hypothesis is widely accepted and oxidative stress is thought to play an important role in the second hit. Although clinical symptoms, laboratory data, and imaging findings are important, liver biopsy is regarded as the gold standard for the diagnosis of NAFLD/NASH. In addition, liver biopsy is essential for assessing the degree of necro-inflammatory change and fibrosis in NASH. Two different types of steatohepatitis (type 1 and type 2 NASH) have been reported, with type 2 NASH being present in as many as 51% of pediatric NAFLD patients. However, we and others have observed that type 1 and 2 patterns commonly overlap. Although pharmacotherapy has been studied in clinical trials, lifestyle modification by diet and exercise remains the mainstay of treatment for NAFLD/NASH.

Mean platelet volume in obese adolescents with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the accumulation of excess fat in the liver in the absence of alcohol consumption, which commonly coexists with obesity. NAFLD is associated with increased risk of atherosclerosis and insulin resistance. Mean platelet volume (MPV) is a marker of platelet activation, which is a determinant of atherosclerosis.

AIMS

The first aim of the present study was to investigate the MPV levels in obese adolescents and compare the MPV levels in patients with and without NAFLD and also with healthy controls. The second aim of this study was to evaluate the relationship between IR and MPV.

PATIENTS AND METHODS

Case records of 128 exogenous obese adolescents were retrospectively evaluated. Laboratory parameters were collected by using a computerized patient database. Insulin resistance was calculated by a homeostasis model assessment (HOMA-IR) index. Patients were divided into two groups: patients with NAFLD (Group 1) and patients without NAFLD (Group 2). Forty-seven healthy children constituted the control group.

RESULTS

MPV was significantly higher in obese adolescents than their healthy peers. Group 1 had significantly higher MPV than group 2. HOMA-IR was significantly higher in group 1 than group 2. MPV was significantly higher in patients with IR than patients without IR. There was a positive correlation between MPV and HOMA-IR. MPV was inversely correlated with HDL cholesterol and platelet count.

CONCLUSION

MPV may be used as a follow-up marker in patients with NAFLD at the point of atherosclerosis.

Hepatic gene expression of Caucasian and African-American patients with obesity-related non-alcoholic fatty liver disease

BACKGROUND/AIM

There is increasing data suggesting that African Americans with NAFLD tend to have less progressive liver disease. The aim of this study is to assess differences in the hepatic gene expression of African-American and Caucasian patients with NAFLD who had undergone bariatric surgery.

METHODS

A total of 94 patients (81 NAFLD and 13 weight-matched controls with normal liver biopsy) were included. Of the entire cohort, 73 were Caucasians and 21 were African Americans. All patients were undergoing bariatric surgery. Two liver biopsies were obtained at the time of surgery. One biopsy was snap-frozen for gene expression and the other biopsy was stained for pathologic assessment. Liver biopsy confirmed that 24 patients from our cohort had NASH while 57 had only simple steatosis. Snap-frozen liver biopsy specimens of these patients were then used for the RNA extraction. cDNA probes were hybridized with customized microarray gene chips containing 5,220 relevant genes. Gene expression profiles were compared between groups using significance analysis of microarrays algorithm.

RESULTS

In comparison to all Caucasian patients, African-American patients had over-expression of EPB41L1, IGF2, FAH, ACSL4, FUT4, CYP3A (q values < 10(-4)). In comparison to Caucasian NAFLD patients, African-American NAFLD patients showed over-expression of EPB41L1 and ACSL4 genes. Finally, in comparison to Caucasian NASH patients, African-American NASH patients showed over-expression of GSTM 2, GSTM4 and GSTM5 as well as FH and ASCL4 genes. Some genes highlighted by this analysis, particularly cytochrome CYP3A and glutathione transferases GSTM2, 4, 5, were previously implicated in the pathogenesis of NASH.

CONCLUSION

African-American patients with biopsy-proven obesity-related NAFLD and NASH have a specific hepatic gene expression pattern that may explain their differences from Caucasian patients with NAFLD in developing progressive liver disease.

Pediatric non-alcoholic fatty liver disease: Preventive and therapeutic value of lifestyle intervention

Nonalcoholic fatty liver disease (NAFLD), ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), and eventually cirrhosis and liver failure, is seen to be increasing amongst Western children. NAFLD rates are rising in parallel with the epidemic of childhood obesity, and in particular, fatty liver evolves more easily in NASH when poor dietary habits and sedentary lifestyle are combined. In fact, its general prevalence in the child population varies between 2.6% and 10%, but increases up to 80% in obese children. Since NASH is expected to become the most common cause of pediatric chronic liver disease in the near future, there is broad interest amongst clinical researchers to move forward, both in diagnosis and treatment. Unfortunately, to date, the expensive and invasive procedure of liver biopsy is seen as the gold standard for NASH diagnosis and few noninvasive diagnostic methods can be applied successfully. Moreover, there are still no approved pharmacological interventions for NAFLD/NASH. Therefore, current management paradigms are based upon the presence of associated risk factors and aims to improve an individual’s quality of life, thus reducing NAFLD-associated morbidity and mortality. Today, lifestyle intervention (diet and exercise) is the treatment of choice for NAFLD/NASH. Thus far, no study has evaluated the potential preventive effect of lifestyle intervention on children at risk of NAFLD/NASH. Future studies will be required in this area with the perspective of developing a national program to promote nutrition education and increase physical activity as means of preventing the disease in individuals at risk. Here, we outline the clinical course, pathogenesis and management of NAFLD in children, highlighting the preventive and therapeutic value of lifestyle intervention.

Intima-media thickness and liver histology in obese children and adolescents with non-alcoholic fatty liver disease

OBJECTIVE

To evaluate the relationship between biopsy-proven non-alcoholic fatty liver disease (NAFLD) and carotid artery intima-media thickness (CIMT) in children and adolescents.

METHODS

A case-control study was performed. Cases were 31 mostly obese children and adolescents, with NAFLD detected at ultrasonography, and confirmed by liver biopsy. Controls were 49 mostly obese children matched for gender, age and BMI without NAFLD at ultrasonography and with normal levels of aminotransferases. Besides standard laboratory measurements, subjects underwent an oral glucose tolerance test to evaluate glucose tolerance and to estimate whole body insulin sensitivity (ISI).

RESULTS

CIMT was similar in cases and controls on the right side but higher in cases on the left side. Although statistically significant, this difference is unlikely to be clinically relevant because of substantial overlap of CIMT values between cases and controls. Moreover, there was no association between CIMT and the severity of steatosis, ballooning, fibrosis, and the non-alcoholic steato-hepatitis score in cases. At multivariable analysis in the pooled sample (n=80), age and the z-score of BMI but not NAFLD, gender, blood pressure and triglycerides, were associated with CIMT.

CONCLUSIONS

We found no association between CIMT and NAFLD in children and adolescents. More importantly, there was no association between histological severity and CIMT in children with NAFLD.

Practical approach to childhood craniopharyngioma: a role of an endocrinologist and a general paediatrician

OBJECTIVES

The objectives of this study are to evaluate co-morbidities in patients with craniopharyngioma and to elaborate an interdisciplinary protocol of the follow-up.

PATIENTS AND METHODS

The group comprised 15 children (median age at the diagnosis, 10.1; mean follow-up period, 4 years). All patients had surgical resection of the tumour: gross total in seven, subtotal or partial removal in eight cases. Surgery was followed by radiotherapy in ten cases for tumour residue or progression. Sexual development and auxology were evaluated at diagnosis and during follow-up. Hormones were determined by chemiluminescent immunometric assays. Antidiuretic hormone dysfunction was diagnosed on the grounds of clinical symptoms, water-electrolyte balance, urine specific gravity, and serum osmolality. Metabolic control was monitored by levels of glucose, insulin, lipids, and transaminases; insulin resistance was expressed by homeostatic model assessment (HOMA) index.

RESULTS

At diagnosis, median height standard deviation score (hSDS) was -1.6 (five children being short-statured). Median change hSDS for the whole follow-up was 1.2 (four children decelerating growth). Diabetes insipidus was diagnosed in eight (within 0-1.8 years of the follow-up), hypocorticolism in eight, and hypothyroidism in 12 subjects (within 0-3.75 years for both endocrinopathies). Four patients required sex hormone replacement therapy. At diagnosis, five children were overweight; during follow-up, only four children sustained normal body mass index. Hypertransaminasaemia was found in three, dyslipidaemia in 11, and hyperinsulinaemia in seven patients (with elevated HOMA in four cases).

CONCLUSIONS

On the grounds of these observations, the management of craniopharyngioma in our institution includes repeated hormonal and metabolic assays in chosen time intervals. Early detection of co-morbidities and their management involves interdisciplinary team.

Identification and treatment of metabolic complications in pediatric obesity

Metabolic consequences of obesity including insulin resistance, type 2 diabetes mellitus, hyperlipidemia, hypertension, polycystic ovarian syndrome, and non-alcoholic fatty liver infiltration are rapidly emerging in the pediatric population. Identifying effective strategies for identifying and treating these obesity related comorbidities in children are crucial to the prevention of future cardiovascular disease and poor health outcomes.This review discusses the pathophysiologic connections between obesity, metabolic disease and cardiovascular risk. Current evidence and recommendations for screening and treatment for the metabolic consequences of pediatric obesity are reviewed.