Increasing prevalence of nonalcoholic fatty liver disease among United States adolescents, 1988-1994 to 2007-2010

Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline

COSPONSORING ASSOCIATIONS

The European Society of Endocrinology and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society.

OBJECTIVE

To formulate clinical practice guidelines for the assessment, treatment, and prevention of pediatric obesity.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of 6 experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The Task Force commissioned 2 systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and co-sponsoring organizations reviewed and commented on preliminary drafts of this guideline.

CONCLUSION

Pediatric obesity remains an ongoing serious international health concern affecting ∼17% of US children and adolescents, threatening their adult health and longevity. Pediatric obesity has its basis in genetic susceptibilities influenced by a permissive environment starting in utero and extending through childhood and adolescence. Endocrine etiologies for obesity are rare and usually are accompanied by attenuated growth patterns. Pediatric comorbidities are common and long-term health complications often result; screening for comorbidities of obesity should be applied in a hierarchal, logical manner for early identification before more serious complications result. Genetic screening for rare syndromes is indicated only in the presence of specific historical or physical features. The psychological toll of pediatric obesity on the individual and family necessitates screening for mental health issues and counseling as indicated. The prevention of pediatric obesity by promoting healthful diet, activity, and environment should be a primary goal, as achieving effective, long-lasting results with lifestyle modification once obesity occurs is difficult. Although some behavioral and pharmacotherapy studies report modest success, additional research into accessible and effective methods for preventing and treating pediatric obesity is needed. The use of weight loss medications during childhood and adolescence should be restricted to clinical trials. Increasing evidence demonstrates the effectiveness of bariatric surgery in the most seriously affected mature teenagers who have failed lifestyle modification, but the use of surgery requires experienced teams with resources for long-term follow-up. Adolescents undergoing lifestyle therapy, medication regimens, or bariatric surgery for obesity will need cohesive planning to help them effectively transition to adult care, with continued necessary monitoring, support, and intervention. Transition programs for obesity are an uncharted area requiring further research for efficacy. Despite a significant increase in research on pediatric obesity since the initial publication of these guidelines 8 years ago, further study is needed of the genetic and biological factors that increase the risk of weight gain and influence the response to therapeutic interventions. Also needed are more studies to better understand the genetic and biological factors that cause an obese individual to manifest one comorbidity vs another or to be free of comorbidities. Furthermore, continued investigation into the most effective methods of preventing and treating obesity and into methods for changing environmental and economic factors that will lead to worldwide cultural changes in diet and activity should be priorities. Particular attention to determining ways to effect systemic changes in food environments and total daily mobility, as well as methods for sustaining healthy body mass index changes, is of importance.

Liver transplantation for nonalcoholic steatohepatitis in young patients

Nonalcoholic steatohepatitis (NASH) is the hepatic manifestation of obesity and insulin resistance. The aim of this study was to determine the frequency of NASH as an indication for liver transplantation (LT) in children and young adults and to characterize patient and graft survival. The study included all children and young adult patients (up to the age of 40 years) who underwent LT in the United States for NASH cirrhosis from the 1987 to 2012 United Network for Organ Sharing (UNOS) database. Kaplan-Meier analysis was used to assess patient and graft survival. A total of 330 patients were included, 68% were Caucasian, and the mean BMI was 33.6 ± 6.3. Age at time of LT ranged between 4 and 40 years (mean 33.9 ± 6.6 years). Fourteen subjects were <18 years of age at time of LT and 20 were between the ages of 18 and 25 years. Median follow-up after 1st LT was 45.8 months [10.7, 97.3]. During this time, 30% of subjects (n = 100) died and 11.5% (n = 38) were retransplanted including 13 for NASH recurrence. In conclusion, NASH can progress to end-stage liver disease requiring LT in childhood and early adulthood. A significant number of young patients transplanted for NASH cirrhosis required retransplantation.

Developmental origins of NAFLD: a womb with a clue

Changes in the maternal environment leading to an altered intrauterine milieu can result in subtle insults to the fetus, promoting increased lifetime disease risk and/or disease acceleration in childhood and later in life. Particularly worrisome is that the prevalence of NAFLD is rapidly increasing among children and adults, and is being diagnosed at increasingly younger ages, pointing towards an early-life origin. A wealth of evidence, in humans and non-human primates, suggests that maternal nutrition affects the placenta and fetal tissues, leading to persistent changes in hepatic metabolism, mitochondrial function, the intestinal microbiota, liver macrophage activation and susceptibility to NASH postnatally. Deleterious exposures in utero include fetal hypoxia, increased nutrient supply, inflammation and altered gut microbiota that might produce metabolic clues, including fatty acids, metabolites, endotoxins, bile acids and cytokines, which prime the infant liver for NAFLD in a persistent manner and increase susceptibility to NASH. Mechanistic links to early disease pathways might involve shifts in lipid metabolism, mitochondrial dysfunction, pioneering gut microorganisms, macrophage programming and epigenetic changes that alter the liver microenvironment, favouring liver injury. In this Review, we discuss how maternal, fetal, neonatal and infant exposures provide developmental clues and mechanisms to help explain NAFLD acceleration and increased disease prevalence. Mechanisms identified in clinical and preclinical models suggest important opportunities for prevention and intervention that could slow down the growing epidemic of NAFLD in the next generation.

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.

Fatty acid and non-alcoholic fatty liver disease: Meta-analyses of case-control and randomized controlled trials

BACKGROUND AND AIMS

Blood and/or liver fatty acid contents of healthy subjects and non-alcoholic fatty liver disease (NAFLD) patients have shown inconsistent associations. In addition, the results of randomized controlled trials (RCTs) in relation to the effects of n-3 polyunsaturated fatty acid (PUFA) supplementation on alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver fat, triglyceride (TAG) and fasting glucose levels are inconsistent. The present study aimed to investigate the differences of fatty acid content in the blood and/or liver tissue between healthy subjects and NAFLD patients, and to quantify the benefits of n-3 PUFA therapy in NAFLD patients.

METHODS

A systematic literature search was performed up to November 2016 using PubMed and Scopus databases. The differences of fatty acid content between cases and controls were calculated as weighted mean differences (WMD) by using a random-effects model. The intervention effects of RCTs were calculated as WMD for net changes in ALT, AST, liver fat, TAG and fasting glucose levels, respectively. Meta-regression with restricted maximum likelihood estimation was used to evaluate a potential linear relationship between confounding factors and effect sizes. Generalized least square was performed for dose-response analysis.

RESULTS

Ten eligible case-control studies and 11 RCTs were included. The pooled estimates of case-control studies showed that blood and/or liver docosahexaenoic acid (DHA) content was significantly higher in the controls compared with cases. The pooled estimates of RCTs showed that n-3 PUFA supplementation significantly reduced the ALT (-7.53 U/L; 95% CI: -9.98, -5.08 U/L), ASL (-7.10 U/L, 95% CI: -11.67, -2.52 U/L) and TAG (-36.16 mg/dL, 95% CI: -49.15, -23.18 mg/dL) concentrations, and marginally reduced the liver fat content (-5.11%, 95% CI: -10.24, 0.02%, P = 0.051), but not fasting glucose. Dose-response analysis of RCTs showed that 1 g per day increment of eicosapentaenoic acid (EPA)+DHA was associated with a 3.14 U/L, 2.43 U/L, 2.74% and 9.97 mg/dL reduction in ALT (95% CI: -5.25, -1.02 U/L), AST (95% CI: -3.90, -0.90 U/L), liver fat (95% CI: -4.32, -1.16%) and TAG (95% CI: -14.47, -5.48 mg/dL) levels, respectively.

CONCLUSIONS

The present meta-analysis provides substantial evidence that n-3 PUFA supplementation, especially DHA, has a favorable effect in treatment of NAFLD.

What is the appropriate upper limit for added sugars consumption?

Dramatic increases in obesity and diabetes have occurred worldwide over the past 30 years. Some investigators have suggested that these increases may be due, in part, to increased added sugars consumption. Several scientific organizations, including the World Health Organization, the Scientific Advisory Council on Nutrition, the Dietary Guidelines Advisory Committee 2015, and the American Heart Association, have recommended significant restrictions on upper limits of sugars consumption. In this review, the scientific evidence related to sugars consumption and its putative link to various chronic conditions such as obesity, diabetes, heart disease, nonalcoholic fatty liver disease, and the metabolic syndrome is examined. While it appears prudent to avoid excessive calories from sugars, the scientific basis for restrictive guidelines is far from settled.

Elevated transaminase levels among overweight adolescents in eastern China

AIM

We aim to investigate the prevalence and correlates of suspected nonalcoholic fatty liver disease (NAFLD) among adolescents in eastern China.

METHODS

The study uses data from the annual health examination among all students finishing high school who applied for university entrance in Changzhou City between 2012 and 2014 (n = 19 162). Suspected NAFLD was defined as overweight plus elevated alanine aminotransferase levels (males >25.8 U/L; females >22.1 U/L).

RESULTS

The prevalence of suspected NAFLD was 6.9% (11.1% in males and 2.6% in females). Students from medium and high socio-economic status (SES) schools had a higher prevalence of suspected NAFLD than those from low SES schools. Prehypertension had similar odds ratios (ORs, above four) for suspected NAFLD in both genders. The positive association between impaired fasting glucose/diabetes and suspected NAFLD was stronger in females than males. Compared with those born in autumn, these born in spring (OR 1.39; 95% CI, 1.16-1.67) and winter (OR 1.24; 95% CI, 1.04-1.49) had increased odds to have suspected NAFLD in males but not in females.

CONCLUSION

Suspected NAFLD was prevalent among urban university applicants especially in males and those of high SES. Prehypertension was positively related to suspected NAFLD. Season of birth was related to suspected NAFLD in males but not in females.

Hepatic rhythmicity of endoplasmic reticulum stress is disrupted in perinatal and adult mice models of high-fat diet-induced obesity

We investigated the regulation of hepatic ER stress in healthy liver and adult or perinatally programmed diet-induced non-alcoholic fatty liver disease (NAFLD). Female mice were fed either obesogenic or control diet before mating, during pregnancy and lactation. Post-weaning, offspring from each maternal group were divided into either obesogenic or control diet. At six months, offspring were sacrificed at 4-h intervals over 24 h. Offspring fed obesogenic diets developed NAFLD phenotype, and the combination of maternal and offspring obesogenic diets exacerbated this phenotype. UPR signalling pathways (IREα, PERK, ATF6) and their downstream regulators showed different basal rhythmicity, which was modified in offspring exposed to obesogenic diet and maternal programming. The double obesogenic hit increased liver apoptosis measured by TUNEL staining, active caspase-3 and phospho-JNK and GRP78 promoter methylation levels. This study demonstrates that hepatic UPR is rhythmically activated. The combination of maternal obesity (MO) and obesogenic diets in offspring triggered altered UPR rhythmicity, DNA methylation and cellular apoptosis.

Immune Imbalances in Non-Alcoholic Fatty Liver Disease: From General Biomarkers and Neutrophils to Interleukin-17 Axis Activation and New Therapeutic Targets

Non-alcoholic fatty liver disease (NAFLD) is an increasing problem worldwide and is associated with negative outcomes such as cirrhosis, hepatocellular carcinoma, insulin resistance, diabetes, and cardiovascular events. Current evidence shows that the immune response has an important participation driving the initiation, maintenance, and progression of the disease. So, various immune imbalances, from cellular to cytokines levels, have been studied, either for better compression of the disease pathophysiology or as biomarkers for severity assessment and outcome prediction. In this article, we performed a thorough review of studies that evaluated the role of inflammatory/immune imbalances in the NAFLD. At the cellular level, we gave special focus on the imbalance between neutrophils and lymphocytes counts (the neutrophil-to-lymphocyte ratio), and that which occurs between T helper 17 (Th17) and regulatory T cells as emerging biomarkers. By extension, we reviewed the reflection of these imbalances at the molecular level through pro-inflammatory cytokines including those involved in Th17 differentiation (IL-6, IL-21, IL-23, and transforming growth factor-beta), and those released by Th17 cells (IL-17A, IL-17F, IL-21, and IL-22). We gave particular attention to the role of IL-17, either produced by Th17 cells or neutrophils, in fibrogenesis and steatohepatitis. Finally, we reviewed the potential of these pathways as new therapeutic targets in NAFLD.

Obese Mice Fed a Diet Supplemented with Enzyme-Treated Wheat Bran Display Marked Shifts in the Liver Metabolome Concurrent with Altered Gut Bacteria

BACKGROUND

Enzyme-treated wheat bran (ETWB) contains a fermentable dietary fiber previously shown to decrease liver triglycerides (TGs) and modify the gut microbiome in mice. It is not clear which mechanisms explain how ETWB feeding affects hepatic metabolism, but factors (i.e., xenometabolites) associated with specific microbes may be involved.

OBJECTIVE

The objective of this study was to characterize ETWB-driven shifts in the cecal microbiome and to identify correlates between microbial changes and diet-related differences in liver metabolism in diet-induced obese mice that typically display steatosis.

METHODS

Five-week-old male C57BL/6J mice fed a 45%-lard-based fat diet supplemented with ETWB (20% wt:wt) or rapidly digestible starch (control) (n = 15/group) for 10 wk were characterized by using a multi-omics approach. Multivariate statistical analysis was used to identify variables that were strong discriminators between the ETWB and control groups.

RESULTS

Body weight and liver TGs were decreased by ETWB feeding (by 10% and 25%, respectively; P < 0.001), and an index of liver reactive oxygen species was increased (by 29%; P < 0.01). The cecal microbiome showed an increase in Bacteroidetes (by 42%; P < 0.05) and a decrease in Firmicutes (by 16%; P < 0.05). Metabolites that were strong discriminators between the ETWB and control groups included decreased liver antioxidants (glutathione and α-tocopherol); decreased liver carbohydrate metabolites, including glucose; lower hepatic arachidonic acid; and increased liver and plasma β-hydroxybutyrate. Liver transcriptomics revealed key metabolic pathways affected by ETWB, especially those related to lipid metabolism and some fed- or fasting-regulated genes.

CONCLUSIONS

Together, these changes indicate that dietary fibers such as ETWB regulate hepatic metabolism concurrently with specific gut bacteria community shifts in C57BL/6J mice. It is proposed that these changes may elicit gut-derived signals that reach the liver via enterohepatic circulation, ultimately affecting host liver metabolism in a manner that mimics, in part, the fasting state.

Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) has become a major cause of cirrhosis and liver-related deaths worldwide. NASH is strongly associated with obesity and the metabolic syndrome, conditions that cause lipid accumulation in hepatocytes (hepatic steatosis). It is not well understood why some, but not other, individuals with hepatic steatosis develop NASH. The factors that determine whether or not NASH progresses to cirrhosis are also unclear. This review summarizes key components of NASH pathogenesis and discusses how inherent and acquired variations in regulation of these processes impact the risk for NASH and NASH cirrhosis.

Stereological Analysis of Liver Biopsy Histology Sections as a Reference Standard for Validating Non-Invasive Liver Fat Fraction Measurements by MRI

Background and Aims

Validation of non-invasive methods of liver fat quantification requires a reference standard. However, using standard histopathology assessment of liver biopsies is problematical because of poor repeatability. We aimed to assess a stereological method of measuring volumetric liver fat fraction (VLFF) in liver biopsies and to use the method to validate a magnetic resonance imaging method for measurement of VLFF.

Methods

VLFFs were measured in 59 subjects (1) by three independent analysts using a stereological point counting technique combined with the Delesse principle on liver biopsy histological sections and (2) by three independent analysts using the HepaFat-Scan^® technique on magnetic resonance images of the liver. Bland Altman statistics and intraclass correlation (IC) were used to assess the repeatability of each method and the bias between the methods of liver fat fraction measurement.

Results

Inter-analyst repeatability coefficients for the stereology and HepaFat-Scan^® methods were 8.2 (95% CI 7.7–8.8)% and 2.4 (95% CI 2.2–2.5)% VLFF respectively. IC coefficients were 0.86 (95% CI 0.69–0.93) and 0.990 (95% CI 0.985–0.994) respectively. Small biases (≤3.4%) were observable between two pairs of analysts using stereology while no significant biases were observable between any of the three pairs of analysts using HepaFat-Scan^®. A bias of 1.4±0.5% VLFF was observed between the HepaFat-Scan^® method and the stereological method.

Conclusions

Repeatability of the stereological method is superior to the previously reported performance of assessment of hepatic steatosis by histopathologists and is a suitable reference standard for validating non-invasive methods of measurement of VLFF.

Similarities and differences between pediatric and adult nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is highly common and potentially serious in children and adolescents. The term NAFLD refers to a spectrum of diseases ranging from accumulation of fat in the liver (simple steatosis or nonalcoholic fatty liver "NAFL") to the potentially progressive form of nonalcoholic steatohepatitis (NASH) characterized by hepatocyte ballooning, inflammation, and often associated with fibrosis. While large prospective longitudinal studies in pediatric NAFLD are still lacking, growing evidence suggests that children with NAFL are at increased risk for cardiometabolic complications, while those with NASH and advance fibrosis are also at risk for significant liver-related morbidity including cirrhosis and its complications. Pediatric NAFLD shares features of adult NAFLD but also shows many different characteristics in terms of prevalence, histology, diagnosis and management. Translational studies suggest that NAFLD is a highly heritable disease in which genetic variations and environment closely interact to determine the disease phenotype and the progression to the more advanced forms of the disease. Changes in lifestyle, targeting gradual weight reduction, and physical exercise continue to be the mainstay of treatment for NAFLD in children. Recent advances in development of noninvasive diagnostic modalities and the potential for identifying effective pharmacological interventions may result in significant progress in the management of NAFLD in the pediatric population.

The effects of low carbohydrate diets on liver function tests in nonalcoholic fatty liver disease: A systematic review and meta-analysis of clinical trials

Background:

Although several observational and experimental studies have examined the effects of low carbohydrate diets (LCDs) on nonalcoholic fatty liver disease (NAFLD), there are considerable inconsistencies among studies. We summarized the effect of LCDs on liver function tests, including intrahepatic lipid content (IHLC), alanine transaminase (ALT), aspartate aminotransferases (AST), and gamma-glutamyl transferase (GGT) in patients with NAFLD.

Materials and Methods:

PubMed, ISI Web of Science, Scopus, and Google Scholar databases were searched for relevant publications until July 2014, resulting in ten relevant papers that were included in meta-analysis. Related articles were found by searching Medical Subject Heading terms of “NAFLD” in combination with “low carbohydrate”. For this meta-analysis, we used mean differences and standard errors of liver function biomarkers. Summary effect and corresponding confidence interval (CI) were estimated using random effect models. Heterogeneity between studies was assessed using Cochran's Q- and I-squared tests.

Results:

Our search led to ten eligible papers that evaluated serum ALT levels (n = 238), nine reported serum AST levels (n = 216), five reported serum GGT concentrations (n = 91), and four assessed IHLC (n = 50). LCD decreased IHLC by −11.53% (95% CI: −18.10, −4.96; I² = 83.2%). However, the effect of LCD on liver enzymes was not significant. Mean differences for the effects of LCDs on ALT, AST, and GGT were −4.35 IU/L (95% CI: −12.91, 4.20; I² = 87.9%), −1.44 IU/L (95% CI: −4.98, 2.10; I² = 61.4%), and −7.85 IU/L (95% CI: −29.65, 13.96; I² = 99.4%), respectively.

Conclusion:

LCD consumption in subjects with NAFLD led to a significant reduction in IHLC, but did not significantly affect the concentration of liver enzymes.

Hepatic immunophenotyping for streptozotocin-induced hyperglycemia in mice

Emerging evidence revealed that diabetes induces abnormal immune responses that result in serious complications in organs. However, the effect of hyperglycemia on hepatic immunity remains obscure. We evaluated the population and function of hepatic immune cells in streptozotocin (STZ)-induced hyperglycemic mice. CC chemokine receptor 2 (CCR2)-knockout mice and mice with a depletion of regulatory T cells (DEREG) were used to investigate the migration and role of regulatory T cells (Tregs) in hyperglycemic mice. The inflammatory cytokines and hepatic transaminase levels were significantly increased in the hyperglycemic mice. The population and number of infiltrating monocytes, granulocytes, and Tregs were enhanced in the livers of the hyperglycemic mice. Hepatic monocytes other than macrophages showed the increased expression of inflammatory cytokines and chemokines in the hyperglycemic mice. The CCR2 knockout and DEREG chimeric mice exhibited increased populations of activated T cells and neutrophils compared to the WT chimeric mice, which promoted hepatic inflammation in the hyperglycemic mice. The migration of CCR2 knockout Tregs into the liver was significantly reduced compared to the WT Tregs. We demonstrated that hyperglycemia contributes to increase in infiltrating monocytes and Tregs, which are associated with hepatic immune dysfunction in mice. CCR2-mediated migration of Tregs regulates hyperglycemia-induced hepatic inflammation.

Resting Energy Expenditure of Children and Adolescents With Nonalcoholic Fatty Liver Disease

BACKGROUND

The mainstay of treatment for pediatric nonalcoholic fatty liver disease (NAFLD) is lifestyle modification, which includes dietary changes that lead to slow but sustained weight loss or weight stabilization in growing children. Accurate estimation of energy requirements is necessary to achieve this goal. The objective of this study was to assess the accuracy of the most commonly used equations in predicting the resting energy expenditure (REE) of children with NAFLD.

METHODS

This was a retrospective study performed in a single institution. The predictive accuracy of various equations was assessed by comparing their estimates against the measured REE obtained with indirect calorimetry. Accuracy was defined as an estimate within 10% of measured REE.

RESULTS

Fifty-six children (70% male; 52% white and 36% Asian) with a median age of 13 years were included. The median measured REE was 1829 kcal/d. Of the equations studied, the Schofield had the smallest average bias (-32 kcal/d; confidence interval, -121 to 56). The Schofield and Molnar equations were the most accurate, providing REE estimates within 10% of measured in 59% of cases. The remaining equations had lower and variable predictive accuracy. The use of adjusted body weight in predictive equations did not improve the predictive accuracy.

CONCLUSION

In a cohort of children and adolescents with NAFLD, the Schofield and Molnar equations performed best in predicting energy expenditure. However, predictive equations were often inaccurate, suggesting that clinicians should interpret their results with caution and consider using indirect calorimetry when available.

Inflammation-associated upregulation of the sulfated steroid transporter Slc10a6 in mouse liver and macrophage cell lines

AIM

Slc10a6, an incompletely characterized member of the SLC10A bile acid transporter family, was one of the most highly induced RNA transcripts identified in a screen for inflammation-responsive genes in mouse liver. This study aimed to elucidate a role for Slc10a6 in hepatic inflammation.

METHODS

Mice were treated with lipopolysaccharide (LPS; 2 mg/kg) or interleukin (IL)-1β (5 mg/kg) for various time points. Cells were treated with LPS (1 μg/mL) at various time points, with cell signaling inhibitors, nuclear receptor ligands and Slc10a6 substrates. All mRNA levels were determined by quantitative polymerase chain reaction.

RESULTS

Slc10a6 mRNA levels were upregulated in mouse liver at 2 h (7-fold), 4 h (100-fold) and 16 h (50-fold) after LPS treatment, and 35-fold by the cytokine IL-1β (4 h). Both absence of the nuclear receptor Fxr and pretreating mice with the synthetic retinoid X receptor-α ligand LG268 attenuated the LPS upregulation of Slc10a6 mRNA by 60-75%. In vitro, Slc10a6 mRNA was induced 30-fold by LPS in mouse RAW264.7 macrophages in a time-dependent manner (maximum at 8 h). The Slc10a6 substrate dehydroepiandrosterone sulfate (DHEAS) enhanced LPS induction of CCL5 mRNA, a pro-inflammatory chemokine, by 50% in RAW264.7 cells. This effect was abrogated in the presence of anti-inflammatory nuclear receptor ligands 9-cis-retinoic acid and dexamethasone.

CONCLUSION

Dramatic upregulation of Slc10a6 mRNA by LPS combined with enhanced LPS stimulation of CCL5 expression by the Slc10a6 substrate DHEAS in macrophages suggests that Slc10a6 function contributes to the hepatic inflammatory response.

Role of hemostatic factors in hepatic injury and disease: animal models de-liver

Chronic liver damage is associated with unique changes in the hemostatic system. Patients with liver disease often show a precariously rebalanced hemostatic system, which is easily tipped towards bleeding or thrombotic complications by otherwise benign stimuli. In addition, some clinical studies have shown that hemostatic system components contribute to the progression of liver disease. There is a strong basic science foundation for clinical studies with this particular focus. Chronic and acute liver disease can be modeled in rodents and large animals with a variety of approaches, which span chronic exposure to toxic xenobiotics, diet-induced obesity, and surgical intervention. These experimental approaches have now provided strong evidence that, in addition to perturbations in hemostasis caused by liver disease, elements of the hemostatic system have powerful effects on the progression of experimental liver toxicity and disease. In this review, we cover the basis of the animal models that are most often utilized to assess the impact of the hemostatic system on liver disease, and highlight the role that coagulation proteases and their targets play in experimental liver toxicity and disease, emphasizing key similarities and differences between models. The need to characterize hemostatic changes in existing animal models and to develop novel animal models recapitulating the coagulopathy of chronic liver disease is highlighted. Finally, we emphasize the continued need to translate knowledge derived from highly applicable animal models to improve our understanding of the reciprocal interaction between liver disease and the hemostatic system in patients.

Liver-related mortality in countries of the developed world: an ecological study approach to explain the variability

BACKGROUND

Liver-related mortality varies across developed nations.

AIM

To assess the relative role of various risk factors in relation to liver-related mortality in an ecological study approach.

METHODS

Data for liver-related mortality, prevalence data for hepatitis B and C, human immunodeficiency virus (HIV), alcohol consumption per capita, Type 2 Diabetes mellitus (T2DM), overweight and obesity were extracted from peer-reviewed publications or WHO databases for different developed countries. As potential other risk-modifying factors, purchase power parity (PPP)-adjusted gross domestic product (GDP) per capita and health expenditure per capita were assessed. As an environmental 'hygiene factor', we also assessed the effect of the prevalence of Helicobacter pylori. Only countries with a PPP-adjusted GDP greater than $20 000 and valid information for at least 8 risk modifiers were included. Univariate and multivariate analyses were utilised to quantify the contribution to the variability in liver-related mortality.

RESULTS

The proportion of chronic liver diseases (CLD)-related mortality ranged from 0.73-2.40% [mean 1.56%, 95% CI (1.43-1.69)] of all deaths. Univariately, CLD-related mortality was significantly associated with Hepatitis B prevalence, alcohol consumption, PPP-adjusted GDP (all P < 0.05) and potentially H. pylori prevalence (P = 0.055). Other investigated factors, including hepatitis C, did not yield significance. Backward elimination suggested hepatitis B, alcohol consumption and PPP-adjusted GDP as risk factors (explaining 66.3% of the variability).

CONCLUSION

Hepatitis B infection, alcohol consumption and GDP, but not hepatitis C or other factors, explain most of the variance of liver-related mortality.

Studying Associations in Health Care Research

This article discusses some of the types of relationships observed in healthcare research and depicts them in graphic form. The article begins by explaining two basic associations observed in chemistry and physics (Boyles' Law and Charles' Law), and illustrates how these associations are similar to curvilinear and linear associations, respectively, found in healthcare. Graphs of curvilinear associations include morbidity curves and survival and mortality curves. Several examples of linear relationships are given and methods of testing linear relationships with interval and ratio data are introduced (i.e., correlation and ordinary least-squares regression). In addition, 2 × 2 contingency tables for testing the association between categorical (or nominal) data are described. Finally, Sir Austin Bradford Hill's eight criteria for assessing causality from research on associations between variables are presented and explained. Three appendices provide interested readers with opportunities to practice interpreting selected curvilinear and linear relationships.

Comparison of the Phenotype and Approach to Pediatric vs Adult Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the main chronic noncommunicable diseases in Westernized societies; its worldwide prevalence has doubled during the last 20 years. NAFLD has serious health implications not only for adults, but also for children. However, pediatric NAFLD is not only an important global problem in itself, but it is likely to be associated with increases in comorbidities, such as metabolic syndrome and cardiovascular diseases. There are several differences between NAFLD in children and adults, and it is not clear whether the disease observed in children is the initial phase of a process that progresses with age. The increasing prevalence of pediatric NAFLD has serious implications for the future adult population requiring appropriate action. Studies of NAFLD progression, pathogenesis, and management should evaluate disease phenotypes in children and follow these over the patient's lifetime. We review the similarities and differences of NAFLD between children and adults.

Behavioral Weight Loss Treatment in Antipsychotic Treated Youth

BACKGROUND

Antipsychotic-treated youth have increased risk for the development of obesity and type 2 diabetes. Behavioral weight loss treatments show promise in reducing obesity and diabetes risk in antipsychotic treated adults, but have received no study in antipsychotic treated youth.

OBJECTIVE

We describe a rationale for behavioral weight loss interventions in high-weight antipsychotic treated youth, and report behavioral, anthropomorphic, and metabolic findings from a case series of obese antipsychotic-treated adolescents participating in a short-term, family-based behavioral weight loss intervention.

METHODS

We adapted the Traffic Light Plan, a 16-week family-based weight loss intervention that promotes healthy energy balance using the colors of the traffic light to categorize the nutritional value of foods and intensity of physical activity, adapting a social ecological framework to address health behavior change in multiple social contexts. The intervention was administered to three obese adolescents with long-term antipsychotic medication exposure. Efficacy of the intervention was evaluated with a battery of anthropomorphic and metabolic assessments including weight, body mass index percentile, whole body adiposity, liver fat content, and fasting plasma glucose and lipids. Participants and their parents also filled out a treatment satisfaction questionnaire upon study completion.

RESULTS

Two males and 1 female (all aged 14 years) participated. All 3 participants attended all 16 sessions, and experienced beneficial changes in adiposity, fasting lipids and liver fat content associated with weight stabilization or weight loss. Adolescents and their parents all reported a high level of satisfaction with the treatment.

CONCLUSIONS

Family-based behavioral weight loss treatment can be feasibly delivered and is acceptable to antipsychotic-treated youth and their families. Randomized controlled trials are needed to fully evaluate the effectiveness and acceptability of behavioral weight loss interventions in antipsychotic treated youth and their families.

Gut Microbiota of Nonalcoholic Fatty Liver Disease

The prevalence of nonalcoholic fatty liver disease has been rapidly increasing worldwide. It has become a leading cause of liver transplantation. Accumulating evidence suggests a significant role for gut microbiota in its development and progression. Here we review the effect of gut microbiota on developing hepatic fatty infiltration and its progression. Current literature supports a possible role for gut microbiota in the development of liver steatosis, inflammation and fibrosis. We also review the literature on possible interventions for NAFLD that target the gut microbiota.

Amino Acid Metabolism is Altered in Adolescents with Nonalcoholic Fatty Liver Disease-An Untargeted, High Resolution Metabolomics Study

OBJECTIVE

To conduct an untargeted, high resolution exploration of metabolic pathways that was altered in association with hepatic steatosis in adolescents.

STUDY DESIGN

This prospective, case-control study included 39 Hispanic-American, obese adolescents aged 11-17 years evaluated for hepatic steatosis using magnetic resonance spectroscopy. Of these 39 individuals, 30 had hepatic steatosis ≥5% and 9 were matched controls with hepatic steatosis <5%. Fasting plasma samples were analyzed in triplicate using ultra-high resolution metabolomics on a Thermo Fisher Q Exactive mass spectrometry system, coupled with C18 reverse phase liquid chromatography. Differences in plasma metabolites between adolescents with and without nonalcoholic fatty liver disease (NAFLD) were determined by independent t tests and visualized using Manhattan plots. Untargeted pathway analyses using Mummichog were performed among the significant metabolites to identify pathways that were most dysregulated in NAFLD.

RESULTS

The metabolomics analysis yielded 9583 metabolites, and 7711 with 80% presence across all samples remained for statistical testing. Of these, 478 metabolites were associated with the presence of NAFLD compared with the matched controls. Pathway analysis revealed that along with lipid metabolism, several major amino acid pathways were dysregulated in NAFLD, with tyrosine metabolism being the most affected.

CONCLUSIONS

Metabolic pathways of several amino acids are significantly disturbed in adolescents with elevated hepatic steatosis. This is a novel finding and suggests that these pathways may be integral in the mechanisms of NAFLD.

Global Epidemiology of Nonalcoholic Fatty Liver Disease and Perspectives on US Minority Populations

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome predicted to be the next global epidemic affecting millions of people worldwide. The natural course of this disease including its subtype, non-alcoholic steatohepatitis (NASH), is not clearly defined especially in the African-American segment of the US population.

AIMS

To conduct a review of the global epidemiology of NAFLD with emphasis on US minority populations.

METHODS

A thorough search of evidence-based literature was conducted using the Pubmed database and commercial web sources such as Medscape and Google Scholar.

RESULTS

NAFLD and its subtype NASH are becoming the principal cause of chronic liver disease across the world. In the US, Hispanics are the most disproportionately affected ethnic group with hepatic steatosis, and elevated aminotransferase levels, whereas African-Americans are the least affected. Genetic disparities involved in lipid metabolism seem to be the leading explanation for the lowest incidence and prevalence of both NAFLD and NASH in African-Americans.

CONCLUSIONS

The unprecedented rise in the prevalence of NAFLD globally requires an initiation of population cohort studies with long-term follow-up to determine the incidence and natural history of NAFLD and its underrepresentation in African-Americans. Future studies should also focus on the delineation of the interplay between genetic and environmental factors that trigger the development of NAFLD and NASH.

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.

Global Epidemiology of Nonalcoholic Fatty Liver Disease and Perspectives on US Minority Populations

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome predicted to be the next global epidemic affecting millions of people worldwide. The natural course of this disease including its subtype, non-alcoholic steatohepatitis (NASH), is not clearly defined especially in the African-American segment of the US population.

AIMS

To conduct a review of the global epidemiology of NAFLD with emphasis on US minority populations.

METHODS

A thorough search of evidence-based literature was conducted using the Pubmed database and commercial web sources such as Medscape and Google Scholar.

RESULTS

NAFLD and its subtype NASH are becoming the principal cause of chronic liver disease across the world. In the US, Hispanics are the most disproportionately affected ethnic group with hepatic steatosis, and elevated aminotransferase levels, whereas African-Americans are the least affected. Genetic disparities involved in lipid metabolism seem to be the leading explanation for the lowest incidence and prevalence of both NAFLD and NASH in African-Americans.

CONCLUSIONS

The unprecedented rise in the prevalence of NAFLD globally requires an initiation of population cohort studies with long-term follow-up to determine the incidence and natural history of NAFLD and its underrepresentation in African-Americans. Future studies should also focus on the delineation of the interplay between genetic and environmental factors that trigger the development of NAFLD and NASH.

Increased apolipoprotein A5 expression in human and rat non-alcoholic fatty livers

Apolipoprotein A5 (apoA5) is a potent regulator of triglyceride (TG) metabolism and therefore may contribute to the pathogenesis of non-alcoholic fatty liver disease (NAFLD), a disease characterised by excessive TG-rich lipid droplets in hepatocytes. To test this hypothesis, we examined the mRNA expression of apoA5 in paediatric NAFLD livers in comparison to healthy controls. According to microarray and quantitative real-time PCR, human NAFLD livers exhibited elevated apoA5 expression compared to healthy controls. The apoA5 expression levels were positively correlated with hepatic TG storage and a marker for lipid droplets (perilipin), but were not correlated with plasma TG levels. These observations were confirmed with a NAFLD rat model. Interestingly, apoA5 expression was not altered in cultured fat-laden HepG2 cells, demonstrating that fat storage does not induce apoA5 in NAFLD livers. Therefore, the correlation between apoA5 and intracellular fat storage is likely explained by the potent effect of apoA5 in promoting intracellular fat storage. Our NAFLD patients and rats had elevated insulin resistance, which may have a role in elevating apoA5 expression in NAFLD livers. Our data support the hypothesis that apoA5 promotes hepatic TG storage and therefore contributes to the pathogenesis of NAFLD, and may represent a potential target for therapeutic intervention.

TM6SF2 Glu167Lys polymorphism is associated with low levels of LDL-cholesterol and increased liver injury in obese children

BACKGROUND

The Glu167Lys (E167K) transmembrane 6 superfamily member 2 (TM6SF2) variant has been associated with liver steatosis, high alanine transaminase (ALT) levels and reduced plasma levels of liver-derived triglyceride-rich lipoproteins.

OBJECTIVES

The objectives of this study were to investigate in a group of obese children the association among the 167K allele of TM6SF2 gene and ALT, cholesterol and triglycerides levels, and hepatic steatosis, and to evaluate the potential interaction between this variant and the I148M patatin like phospholipase 3 gene (PNPLA3) polymorphism on liver enzymes.

METHODS

We genotyped 1010 obese children for TM6SF2 E167K and PNPLA3 I148M polymorphisms. Anthropometrical and biochemical data were collected. Ultrasound imaging of the liver was performed.

RESULTS

The 167K allele showed an association with steatosis (P < 0.0001), higher ALT levels (P < 0.001) and lower total cholesterol (P < 0.00001), low-density lipoprotein cholesterol (P < 0.0001), triglycerides (P = 0.02) and non-high-density lipoprotein cholesterol levels (P < 0.000001). The subjects homozygous for the PNPLA3 148M allele carrying the rare variant of TM6SF2 showed an odds ratio of 12.2 (confidence interval 3.8-39.6, P = 0.000001) to present hypertransaminasaemia compared with the remaining patients.

CONCLUSION

Although the TMS6SF2 E167K variant predisposes the obese children to non-alcoholic fatty liver disease, there is an association between this variant and lower levels of cardiovascular risk factors. Overall, the data suggest differential effects of TMS6SF2 E167K variant on liver and heart health.

Laboratory screening in overweight/obese adolescents: do the results change the management?

Due to the growth of the epidemic of obesity and the association of obesity with both short-term and long-term medical complications, many professional organizations have recommended performing laboratory testing as part of the initial evaluation of overweight and obese children and adolescents. We report on the results of laboratory testing performed on 110 patients (mean age 14.0 years, range 8-20 years) referred to our weight management program between 2011 and 2013. Our results showed mild abnormalities in levels of cholesterol, glucose, liver enzymes, and thyroid stimulating hormone (TSH) in fewer than 5% of patients for each test and no changes in management based on these results for any of the patients. We call for re-consideration of the recommendations for laboratory testing in children and adolescents being evaluated and treated for overweight and obesity.

Added sugar intake and metabolic syndrome in US adolescents: cross-sectional analysis of the National Health and Nutrition Examination Survey 2005–2012

Objective

To examine the association between added sugar intake and metabolic syndrome among adolescents.

Design

Dietary, serum biomarker, anthropometric and physical activity data from the US National Health and Nutrition Examination Survey cycles between 2005 and 2012 were analysed using multivariate logistic regression models. Added sugar intake in grams per day was estimated from two 24 h standardized dietary recalls and then separated into quintiles from lowest to highest consumption. Multivariate logistic regression analyses were adjusted for physical activity, age, BMI Z-score and energy intake, and their interactions with race were included.

Setting

Nationally representative sample, USA.

Subjects

US adolescents aged 12–19 years (n 1623).

Results

Added sugar was significantly associated with metabolic syndrome. The adjusted prevalence odds ratios for having metabolic syndrome comparing adolescents in the third, fourth and fifth quintiles v. those in the lowest quintile of added sugar were 5·3 (95 % CI 1·4, 20·6), 9·9 (95 % CI 1·9, 50·9) and 8·7 (95 % CI 1·4, 54·9), respectively.

Conclusions

Our findings suggest that higher added sugar intake, independent of total energy intake, physical activity or BMI Z-score, is associated with increased prevalence of metabolic syndrome in US adolescents. Further studies are needed to determine if reducing intake of added sugar may help US adolescents prevent or reverse metabolic syndrome.

Relationships Between Alanine Aminotransferase, Serum Triglycerides, Body Mass Index and Nonalcoholic Fatty Liver Disease in an Outpatient Pediatric Clinic Population

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease in children and adolescents. The goal of this study was to describe the demographic, anthropometric and biochemical data of children and adolescents diagnosed with NAFLD during a seven-year period in an outpatient pediatric clinic in the Southwest region of the US and to evaluate relationships between race, BMI, ALT, triglyceride levels, age and gender with a diagnosis of NAFLD. A retrospective medical record review of patients who attended an outpatient pediatric clinic with a billing diagnosis ICD-9 code of 571.8 was conducted. Forty-one patients met these criteria. The majority was male (74%) Hispanic (32%), Hispanic/Latino (68%) and obese. The small number of patients diagnosed with NAFLD in our study is consistent with previously reported results. Our results indicate that the population of this culturally diverse, high-risk population has significant clinical markers that are indicative of NAFLD.

Nonalcoholic Fatty Liver Disease in Pediatrics

A 16-year-old Hispanic girl with an elevated body mass index in an otherwise normal state of health presented for her well-child examination. She had signs of metabolic syndrome and insulin resistance including increased waist circumference and acanthosis nigricans. Laboratory results revealed elevated transaminases with otherwise normal hepatic function. Based on the physical examination and laboratory results, she was diagnosed with nonalcoholic fatty liver disease (NAFLD). After further evaluation, she eventually underwent a liver biopsy. The biopsy revealed nonalcoholic steatohepatitis (NASH) with stage 2 fibrosis. This article reviews the definition of NAFLD and NASH, an increasingly prevalent cause of pediatric chronic liver disease associated with obesity and metabolic syndrome. The article also outlines the epidemiology, risk factors, and natural history of NAFLD, which may help identify and prevent high-risk pediatric patients from progressing to irreversible liver disease. Understanding the diagnostic and treatment options offers the best chance at preventing and reversing the early stages of this disease.

Is Western Diet-Induced Nonalcoholic Steatohepatitis in Ldlr-/- Mice Reversible?

Background

Nonalcoholic fatty liver disease (NAFLD) is a major public health burden in western societies. The progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), is characterized by hepatosteatosis, inflammation, oxidative stress, and hepatic damage that can progress to fibrosis and cirrhosis; risk factors for hepatocellular carcinoma. Given the scope of NASH, validating treatment protocols (i.e., low fat diets and weight loss) is imperative.

Methods

We evaluated the efficacy of two diets, a non-purified chow (NP) and purified (low-fat low-cholesterol, LFLC) diet to reverse western diet (WD)-induced NASH and fibrosis in Ldlr^-/- mice.

Results

Mice fed WD for 22–24 weeks developed robust hepatosteatosis with mild fibrosis, while mice maintained on the WD an additional 7–8 weeks developed NASH with moderate fibrosis. Returning WD-fed mice to the NP or LFLC diets significantly reduced body weight and plasma markers of metabolic syndrome (dyslipidemia, hyperglycemia) and hepatic gene expression markers of inflammation (Mcp1), oxidative stress (Nox2), fibrosis (Col1A, LoxL2, Timp1) and collagen crosslinking (hydroxyproline). Time course analyses established that plasma triglycerides and hepatic Col1A1 mRNA were rapidly reduced following the switch from the WD to the LFLC diet. However, hepatic triglyceride content and fibrosis did not return to normal levels 8 weeks after the change to the LFLC diet. Time course studies further revealed a strong association (r² ≥ 0.52) between plasma markers of inflammation (TLR2 activators) and hepatic fibrosis markers (Col1A, Timp1, LoxL2). Inflammation and fibrosis markers were inversely associated (r² ≥ 0.32) with diet-induced changes in hepatic ω3 and ω6 polyunsaturated fatty acids (PUFA) content.

Conclusion

These studies establish a temporal link between plasma markers of inflammation and hepatic PUFA and fibrosis. Low-fat low-cholesterol diets promote reversal of many, but not all, features associated with WD-induced NASH and fibrosis in Ldlr^-/- mice.

Magnetic resonance elastography of abdomen

Many diseases cause substantial changes in the mechanical properties of tissue, and this provides motivation for developing methods to noninvasively assess the stiffness of tissue using imaging technology. Magnetic resonance elastography (MRE) has emerged as a versatile MRI-based technique, based on direct visualization of propagating shear waves in the tissues. The most established clinical application of MRE in the abdomen is in chronic liver disease. MRE is currently regarded as the most accurate noninvasive technique for detection and staging of liver fibrosis. Increasing experience and ongoing research is leading to exploration of applications in other abdominal organs. In this review article, the current use of MRE in liver disease and the potential future applications of this technology in other parts of the abdomen are surveyed.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a disorder characterized by excess accumulation of fat in hepatocytes (nonalcoholic fatty liver (NAFL)); in up to 40% of individuals, there are additional findings of portal and lobular inflammation and hepatocyte injury (which characterize nonalcoholic steatohepatitis (NASH)). A subset of patients will develop progressive fibrosis, which can progress to cirrhosis. Hepatocellular carcinoma and cardiovascular complications are life-threatening co-morbidities of both NAFL and NASH. NAFLD is closely associated with insulin resistance; obesity and metabolic syndrome are common underlying factors. As a consequence, the prevalence of NAFLD is estimated to be 10-40% in adults worldwide, and it is the most common liver disease in children and adolescents in developed countries. Mechanistic insights into fat accumulation, subsequent hepatocyte injury, the role of the immune system and fibrosis as well as the role of the gut microbiota are unfolding. Furthermore, genetic and epigenetic factors might explain the considerable interindividual variation in disease phenotype, severity and progression. To date, no effective medical interventions exist that completely reverse the disease other than lifestyle changes, dietary alterations and, possibly, bariatric surgery. However, several strategies that target pathophysiological processes such as an oversupply of fatty acids to the liver, cell injury and inflammation are currently under investigation. Diagnosis of NAFLD can be established by imaging, but detection of the lesions of NASH still depend on the gold-standard but invasive liver biopsy. Several non-invasive strategies are being evaluated to replace or complement biopsies, especially for follow-up monitoring.

Yield of diagnostic tests in obese children with an elevated alanine aminotransferase

AIM

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and affects roughly 10% of children. However, NAFLD is often diagnosed by exclusion - that is, obese children with an elevated alanine aminotransferase (ALT) are screened for other liver diseases in the absence of a biopsy. This testing is nonstandardized, and professional society recommendations differ. This study examines the yield of testing for disorders other than NAFLD in this patient population.

METHODS

A retrospective study was performed in 120 obese, asymptomatic, noncholestatic children with an ALT ≥40 U/L and additional diagnostic testing.

RESULTS

No patients were found to have Wilson's, hepatitis A, hepatitis B, hepatitis C, cytomegalovirus, alpha-1 antitrypsin deficiency, autoimmune hepatitis, celiac disease or Epstein-Barr virus. Only one patient (1/120) was identified with definite disease other than NAFLD, which was muscular dystrophy. The positive predictive value of a screening test was 5%, and the specificity was 97%. Of 70 children with an abdominal ultrasound, no significant abnormalities were identified.

CONCLUSION

Extensive testing in asymptomatic, noncholestatic, obese children with an elevated ALT may be of limited diagnostic value and false-positive tests are likely. Large, prospective studies are needed to help focus the work up in this patient population.

A clinically relevant method to screen for hepatic steatosis in overweight adolescents: a cross sectional study

Background

To develop a screening algorithm to detect hepatic steatosis in overweight and obese adolescents.

Methods

We performed a cross sectional study of 129 overweight adolescents 13–18 yrs. The primary outcome, hepatic steatosis was defined as an intracellular triglyceride content > 5.5 mg/g and quantified using ¹H-magenetic resonance spectroscopy. Primary predictor variables included, alanine and aspartate transaminases (ALT/AST) and features of the metabolic syndrome.

Results

Hepatic steatosis was present in 33 % of overweight and obese adolescents. Adolescents with hepatic steatosis were more likely to be boys (adjusted OR: 4.8; 95 % CI: 2.5–10.5), display a higher waist circumference (111 ± 12 vs 100 ± 13 cm, p < 0.001) and have metabolic syndrome (adjusted OR: 5.1; 95 % CI: 1.6–16.4). Serum ALT predicted hepatic steatosis in boys (AUC: 0.82; 95 % CI: 0.70–0.95; p < 0.001) but not girls (AUC = 0.63; 95 % CI: 0.46–0.75, p = 0.16). An ALT >20 U/L, combined with the presence of metabolic syndrome, male gender and an elevated waist circumference provided the best model (AUC 0.85) with high sensitivity (72 %) and specificity (82 %) and positive and negative predictive values of 61 % and 89 % respectively.

Conclusions

Serum transaminases provide modest predictive value for hepatic steatosis in youth. The ALT threshold for predicting hepatic steatosis is significantly lower than current clinical thresholds for predicting non-alcoholic fatty liver disease. The addition of ALT, presence of the metabolic syndrome and male gender significant improve the ability to predict hepatic steatosis.

Nonalcoholic Fatty Liver Disease and Fibrosis in Youth Taking Psychotropic Medications: Literature Review, Case Reports, and Management

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide epidemic because of the greater prevalence of obesity. Despite implications for youth with severe mental disorders, little has been published in the psychiatric literature about this increasingly common medical comorbidity. The goals of this article are to: 1) provide an overview of the epidemiology and pathophysiology of NAFLD, including progression to nonalcoholic steatohepatitis (NASH); 2) describe two clinical cases illustrating difficulties faced in management; and 3) review screening recommendations, differential diagnosis, and monitoring and intervention approaches.

METHODS

A literature review was conducted, including guidelines and recommendations, with case presentations including case and control liver histology biopsy photographs.

RESULTS

NAFLD in childhood and adolescence, as a precursor to NASH, progresses to fibrosis in a small percentage of youth, leading to risk for early onset cirrhosis and the need for transplantation. The cases presented raise concern that youth with severe mental health disorders, already at greater risk for obesity and its sequelae, may be at higher risk for progression to NASH, potentially because of greater rates of weight gain on top of overweight or obese status, and to liver metabolism changes from psychotropic medications favoring fat deposition.

CONCLUSIONS

Patients with rapid weight gain into the overweight or obese categories, or who develop elevated liver transaminases that persist across 3-6 months, should be screened or referred for screening by their psychotropic-providing clinicians for early detection, diagnosis, and co-management by a pediatric gastroenterologist, to decrease risk of progression to NASH, which is reversible if early and sufficient lifestyle change results in significant weight loss. There is urgent need for controlled research on the relationships among weight gain, psychotropic medications, ultrasound and biopsy findings, and rates of progression to NAFLD and NASH in youth taking weight-gain-inducing psychotropic medications.

Plateaued national utilization of adolescent bariatric surgery despite increasing prevalence of obesity-associated co-morbidities

BACKGROUND

The number of adolescent bariatric surgeries (ABS) performed from 2003 to 2009 has been stable despite reports of an increase in adolescent morbid obesity.

OBJECTIVES

We sought to determine the trend in national ABS volume and the changes in obesity-associated co-morbidities (OACM) from 2004 to 2011.

SETTING

The Healthcare Cost and Utilization Project National Inpatient Sample database.

METHODS

The National Inpatient Sample database was queried for adolescents undergoing Roux-en-Y gastric bypass, adjustable gastric banding, or sleeve gastrectomy from 2004 to 2011. Twelve OACM categories were created by ICD-9 code.

RESULTS

From 2004 to 2011, an estimated 968 ABS cases per year were performed with no significant change in yearly volumes. There was a significant decrease in the annual volume of Roux-en-Y gastric bypasses (85.7%-54.4%, P<.001) with a significant increase in the number of adjustable gastric bandings (13.6%-18.9%, P = .002) and sleeve gastrectomies (.7%-26.7%, P<.001). The mean patient age was 18.0±1.3 years, and 76% of patients were female. The average number of OACMs per adolescent increased significantly, from 1.44±1.3 in 2004-2005 to 1.85±1.5 in 2010-2011 (P<.001). There was a significant increase over time in the prevalence of preoperative obstructive sleep apnea (15.6%-26.8%, P<.001), hypertension (16.6%-24.2%, P = .006), hyperlipidemia (10.2%-15.4%, P = .021), and fatty liver disease (5.2%-10.5%, P = .004).

CONCLUSIONS

There was a significant increase in OACMs for patients undergoing ABS. Despite the increase in OACMs, there has not been a concomitant increase in the number of ABS performed as of 2011. Given the increase in OACMs, these data support efforts to address barriers to adolescent bariatric surgical evaluation and treatment.

Hb and dyslipidaemia as predicting markers of serum alanine aminotransferase elevation in Chinese adolescents

OBJECTIVE

Fe is an essential element for erythropoiesis and Hb synthesis. High Hb levels affect the blood's viscosity and are associated with cardiovascular dysfunction. The aim of the present study was to examine relationships of Hb and cardiometabolic abnormalities with the risk of alanine aminotransferase (ALT) elevation in adolescents.

DESIGN

A population-based, cross-sectional study.

SETTING

National Nutrition and Health Survey in Taiwan (2010-2011, adolescents).

SUBJECTS

Healthy adolescents aged 13-18 years.

RESULTS

In total, 1941 adolescents (963 boys and 978 girls) were entered in the study. The mean age was 15·3 (sd 0·1) years (boys, 15·3 (sd 0·1) years; girls, 15·2 (sd 0·1) years). ALT tertile cut-off points for boys were 11 and 16 U/l, and for girls were 9 and 12 U/l. Girls without dyslipidaemia and presenting in the highest quartile (Q1) of Hb (>13·6 g/dl) were 1·89 and 3·76 times more likely to have raised serum ALT (9 and >12 U/l, respectively) than the reference (lowest quartile of Hb (Q1), 12 U/l) than the reference (Q1 of Hb, 15·4 g/dl), who were 7·40 times more likely to have elevated serum ALT of >16 U/l than the reference (Q1 of Hb, <14·1 g/dl).

CONCLUSIONS

Our findings suggest that an increased Hb level is a predictor of elevated serum ALT in adolescent girls with dyslipidaemia. Our study also highlights the importance of further research to establish cut-off points for Hb and its utility in diagnosing and preventing the onset of dyslipidaemia in adolescents.