Advances in pediatric nonalcoholic fatty liver disease

Which obesity index is the most useful marker for predicting hepatic steatosis in children and adolescents with obesity? A cross-sectional study using quantitative magnetic resonance imaging

INTRODUCTION

We aimed to evaluate the relationships between hepatic steatosis and various indices of obesity, and to identify the most useful index for the prediction of hepatic steatosis in children and adolescents with obesity.

METHODS

A total of 226 children and adolescents with a mean body mass index (BMI) z-score of 2.65 and a mean age of 11.4 years were subjected to anthropometric and body composition measurements, laboratory testing, abdominal fat mass assessment, and hepatic fat accumulation by magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF). The participants were divided into quartiles according to the severity of their hepatic steatosis, and the presence of hepatic steatosis was defined using an MRI-PDFF ≥ 5%.

RESULTS

The multivariate ordinal regression analysis showed that the severity of hepatic steatosis was positively associated with BMI, waist circumference, waist-to-hip ratio, waist-to-height ratio, fat mass, fat-free mass, visceral adiposity, and abdominal subcutaneous adiposity. Higher activities of liver enzymes and higher concentrations of triglyceride, C-reactive protein, fasting insulin, and leptin were associated with more severe hepatic steatosis, whereas high-density lipoprotein-cholesterol and adiponectin were negatively associated with hepatic steatosis. The indices of obesity with areas under the receiver operating characteristic curves (AUCs) > 0.8 for the prediction of hepatic steatosis were liver enzymes, visceral adipose tissue area, waist-to-hip ratio, and waist-to-height ratio.

CONCLUSION

The severity of hepatic steatosis significantly correlated with various indices of obesity and cardiometabolic markers in children and adolescents with obesity. The indices of abdominal obesity would be the most useful for the prediction of hepatic steatosis.

Analysis of clinical findings and serum micronutrients in pediatric patients with nonalcoholic fatty liver disease

Aim: Serum micronutrient levels play an important role in liver metabolism. This study examines risk factors and diagnostic methods for patients on follow-up due to nonalcoholic fatty liver disease (NAFLD). NAFLD and the control groups were compared for clinical findings, serum ferritin, B12, and vitamin D levels, and their relationship with NAFLD was examined. Material and Method: Included in the study were 60 NAFLD patients and 66 other children that formed the control group. The two groups were compared in serum lipid profile, aminotransferase, insulin, glucose, and HOMA-IR. Ultrasonography (USG) and Shear wave elastography (SWE) were performed on all patients. Both groups were then analyzed in terms of serum ferritin, B12, and vitamin D levels. Results: NAFLD and control groups were compared in terms of USG and SWE results. 35% (n=21)of the patients in the NAFLD group had grade 1, 55% (n=33) had grade 2 and 10% (n=6) had grade 3 adiposity. HOMA-IR and insulin levels were higher in the NAFLD group (p=0.02; p=0.001). While the serum ferritin level of the patients in the NAFLD group was higher than the control group (p=0.001); the B12 level was lower (p=0.006). In terms of vitamin D, there was no difference (p=0.368). Conclusion: It is essential to identify risk factors in children on follow-up due to NAFLD. USG and liver function tests remain the first option in the diagnosis and screening of NAFLD in children. Serum ferritin, B12, and vitamin D levels of children on follow-up due to NAFLD should be analyzed in consideration of liver fattening.

Successful telehealth transformation of a pediatric outpatient obesity teaching program due to the COVID-19 pandemic - the "Video KiCK" program

OBJECTIVES

To investigate if digital approaches can ameliorate the known consequences of social-distancing restrictions in the context of the global COVID-19 pandemic for adolescent participants originally registered for a face-to-face outpatient weight regulation program and whether video-based multiprofessional outpatient obesity therapy is successful for a group of adolescents with preexisting obesity.

METHODS

The certified KiCK outpatient training program for children and adolescents with overweight and obesity was remodeled as a consequence of the lockdown traditional face-to-face program to a completely digital and video-based format on short notice. The virtual approach was compared with the results of the conventional program regarding metabolic parameters, body mass index standard deviation score (BMI SDS), well-being, and physical fitness.

RESULTS

Sixty-nine of 77 enrolled participants for KiCK (age 8 to 17 years, BMI z score >2.0) were able and willing to participate virtually. After the first lockdown significant improvements of BMI SDS (mean 0.18; p=0.02), homeostasis model assessment (HOMA) index (mean 1.4; p=0.016), triglycerides (mean 0.18 mmol/dL; p=0.021), 6 minute-walk-test (mean 97.0 m; p=0.030, and well-being according to the World Health Organization 5 (WHO-5) questionnaire (mean 2.5; p=0.002) were found after the virtual intervention, which was comparable to the results observed previously in matched pairs data from the program during the pre-COVID period. After the end of the second lockdown weight SDS, BMI SDS, HOMA INDEX, and cholesterol were also measured reduced compared to baseline parameters measured before program initiation. Walking distance in the 6 MWT and improvement in general well-being in the WHO-5 questionnaire also persisted.

CONCLUSIONS

These results indicate good acceptance and efficacy of the video-intervention for youth with overweight and obesity during the lockdown, supporting the use of virtual modules in future programs after the pandemic.

The Role of Aspartate Transaminase to Platelet Ratio Index (APRI) for the Prediction of Non-Alcoholic Fatty Liver Disease (NAFLD) in Severely Obese Children and Adolescents

The aspartate transaminase to platelet ratio index (APRI) has been proposed as an easy-to-use biochemical marker in obese adults with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatotic hepatitis (NASH). The objective of the present study was to evaluate the clinical and predictive value of APRI in a paediatric obese population. Seven hundred fifty-seven obese children and adolescents (BMI standard deviation score, SDS: >2.0; age range: 10–18.5 years), not consuming alcohol and without hepatitis B or C, were recruited after having been screened for NAFLD by ultrasonography. A series of demographic, biochemical and clinical parameters was compared between the two subgroups (with or without NAFLD); the same parameters were correlated with APRI; and finally, univariable and multivariable logistic regression was used to evaluate the predictors of NAFLD. NAFLD was diagnosed in about 39% of the entire paediatric population, predominantly in males and in subjects suffering from metabolic syndrome. APRI was correlated with the waist circumference (WC), high-density lipoprotein cholesterol (HDL-C), uric acid, total bilirubin, C reactive protein (CRP) and systolic blood pressure (SBP). Furthermore, APRI was higher in males than females, but independent from steatosis severity and metabolic syndrome. With the univariable analysis, the BMI SDS, triglycerides (TG), insulin, homeostatic model assessment for insulin resistance (HOMA-IR), APRI, uric acid and metabolic syndrome were positive predictors of NAFLD, with female sex being negative predictor. At multivariable analysis; however, only BMI SDS, TG, HOMA-IR and APRI were positive predictors of NAFLD, with female sex being a negative predictor. The accuracy of APRI as a biochemical marker of NAFLD was about 60%.In conclusion, in a large (Italian) paediatric obese population, parameters, such as BMI SDS, TG, HOMA-IR and APRI, were positive predictors of NAFLD, with female sex being a negative predictor and most of the prediction explained by APRI. Nevertheless, APRI appears to be a simple biochemical marker of liver injury rather than of NAFLD/NASH and, moreover, is endowed with a limited accuracy for the prediction/diagnosis of NAFLD.

Single Point Insulin Sensitivity Estimator in Pediatric Non-Alcoholic Fatty Liver Disease

BACKGROUND

Attenuated insulin-sensitivity (IS) is a central feature of pediatric non-alcoholic fatty liver disease (NAFLD). We recently developed a new index, single point insulin sensitivity estimator (SPISE), based on triglycerides, high-density-lipoprotein and body-mass-index (BMI), and validated by euglycemic-hyperinsulinemic clamp-test (EHCT) in adolescents. This study aims to assess the performance of SPISE as an estimation of hepatic insulin (in-)sensitivity. Our results introduce SPISE as a novel and inexpensive index of hepatic insulin resistance, superior to established indices in children and adolescents with obesity.

MATERIALS AND METHODS

Ninety-nine pubertal subjects with obesity (13.5 ± 2.0 years, 59.6% males, overall mean BMI-SDS + 2.8 ± 0.6) were stratified by MRI (magnetic resonance imaging) into a NAFLD (>5% liver-fat-content; male n=41, female n=16) and non-NAFLD (≤5%; male n=18, female n=24) group. Obesity was defined according to WHO criteria (> 2 BMI-SDS). EHCT were used to determine IS in a subgroup (n=17). Receiver-operating-characteristic (ROC)-curve was performed for diagnostic ability of SPISE, HOMA-IR (homeostatic model assessment for insulin resistance), and HIRI (hepatic insulin resistance index), assuming null hypothesis of no difference in area-under-the-curve (AUC) at 0.5.

RESULTS

SPISE was lower in NAFLD (male: 4.8 ± 1.2, female: 4.5 ± 1.1) than in non-NAFLD group (male 6.0 ± 1.6, female 5.6 ± 1.5; P< 0.05 {95% confidence interval [CI]: male NAFLD 4.5, 5.2; male non-NAFLD 5.2, 6.8; female NAFLD 4.0, 5.1, female non-NAFLD 5.0, 6.2}). In males, ROC-AUC was 0.71 for SPISE (P=0.006, 95% CI: 0.54, 0.87), 0.68 for HOMA-IR (P=0.038, 95% CI: 0.48, 0.88), and 0.50 for HIRI (P=0.543, 95% CI: 0.27, 0.74). In females, ROC-AUC was 0.74 for SPISE (P=0.006), 0.59 for HOMA-IR (P=0.214), and 0.68 for HIRI (P=0.072). The optimal cutoff-level for SPISE between NAFLD and non-NAFLD patients was 5.18 overall (Youden-index: 0.35; sensitivity 0.68%, specificity 0.67%).

CONCLUSION

SPISE is significantly lower in juvenile patients with obesity-associated NAFLD. Our results suggest that SPISE indicates hepatic IR in pediatric NAFLD patients with sensitivity and specificity superior to established indices of hepatic IR.

Association between ectopic pancreatic and hepatic fat and metabolic risk factors in children with non-alcoholic fatty liver disease

BACKGROUND

Few studies have reported an association between ectopic pancreatic and hepatic fat and metabolic factors in children with non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

We investigated this association and also the factors associated with pancreatic and hepatic fat deposition in children with NAFLD.

METHODS

This cross-sectional study investigated 65 children with NAFLD (49 boys, 13.0 ± 3.2 years, mean body mass index z-score 2.5 ± 1.2), who underwent liver biopsy and magnetic resonance imaging-based proton density fat fraction, as well as anthropometry, laboratory tests, body composition analysis, and hepatic fat fraction (HFF) and pancreatic fat fraction (PFF) measurements.

RESULTS

HFF and PFF were 4.2%-49.9% (median 24.3) and 0.4%-26.9% (median 3.8), respectively. HFF was not significantly correlated with PFF. HFF was correlated with total body fat% (r = 0.329, p = 0.010) and γ-glutamyl transpeptidase (GGT) (r = 0.260, p = 0.040), while PFF was correlated with the diastolic blood pressure (r = 0.253, p = 0.045), GGT (r = 0.335, p = 0.007) and fasting plasma glucose (r = 0.417, p = 0.001). Multiple linear regression analysis showed that HFF was significantly associated with sex, age, body fat% and GGT, whereas PFF was associated with hypertension and fasting plasma glucose levels but not insulin resistance.

CONCLUSIONS

HFF was associated with sex, age and body fat in children with NAFLD, while PFF was associated with hypertension and increased fasting plasma glucose, which suggests that the pathophysiology of ectopic fat accumulation varies across organs in children with NAFLD.

Evaluation of clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a common obesity-related comorbidity in childhood. In this study, we aimed to evaluate predictors of NAFLD by comparing clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis.

METHODS

Two hundred and eight obese children aged 6-18 years were included. The patients were divided into group 1 (patients with NAFLD, n=94) and group 2 (patients without NAFLD, n=114). Anthropometric measurements, pubertal stage, lipid profiles, fasting glucose and insulin, homeostatic model of assessment for insulin resistance (HOMA-IR), uric acid, total bilirubin, alanine aminotransferase (ALT), blood urea nitrogen, thyroid-stimulating hormone and free thyroxine parameters were compared retrospectively.

RESULTS

The mean body weight, body mass index (BMI), height, tri-ponderal mass index (TMI), insulin, HOMA-IR, triglyceride, ALT and uric acid values were significantly higher, while high-density lipoprotein-cholesterol (HDL-C) values were significantly lower in group 1. The 70.7% of obese children with hepatosteatosis and 83.9% of those without hepatosteatosis were correctly estimated by parameters including age, gender, ALT, HDL-C, fasting insulin and uric acid values.

CONCLUSIONS

Since obesity-associated hepatosteatosis induces various long-term metabolic impacts in children, early detection is of critical importance. Age, gender, TMI, BMI, ALT, HDL-C, fasting insulin and uric acid values may help to predict the risk of hepatosteatosis. Besides, we assessed whether TMI compared to BMI does not have a better utility in estimating obesity-induced hepatosteatosis in children. This is the first study to show the association between TMI and hepatosteatosis in children.

The Evaluation of Drug Delivery Nanocarrier Development and Pharmacological Briefing for Metabolic-Associated Fatty Liver Disease (MAFLD): An Update

Current research indicates that the next silent epidemic will be linked to chronic liver diseases, specifically non-alcoholic fatty liver disease (NAFLD), which was renamed as metabolic-associated fatty liver disease (MAFLD) in 2020. Globally, MAFLD mortality is on the rise. The etiology of MAFLD is multifactorial and still incompletely understood, but includes the accumulation of intrahepatic lipids, alterations in energy metabolism, insulin resistance, and inflammatory processes. The available MAFLD treatment, therefore, relies on improving the patient's lifestyle and multidisciplinary pharmacotherapeutic options, whereas the option of surgery is useless without managing the comorbidities of the MAFLD. Nanotechnology is an emerging approach addressing MAFLD, where nanoformulations are suggested to improve the safety and physicochemical properties of conventional drugs/herbal medicines, physical, chemical, and physiological stability, and liver-targeting properties. A wide variety of liver nanosystems were constructed and delivered to the liver, only those that addressed the MAFLD were discussed in this review in terms of the nanocarrier classes, particle size, shape, zeta potential and offered dissolution rate(s), the suitable preparation method(s), excipients (with synergistic effects), and the suitable drug/compound for loading. The advantages and challenges of each nanocarrier and the focus on potential promising perspectives in the production of MAFLD nanomedicine were also highlighted.

Effectiveness of a Primary Care-Based Pediatric Weight Management Program

BACKGROUND

Childhood obesity is a growing epidemic of great concern for our nation, including pediatric populations treated at military treatment facilities.

OBJECTIVE

This study aims to retrospectively evaluate the effectiveness of a primary care-based structured weight management program in a sample of pediatric patients with obesity at a military treatment facility.

METHODS

This study was a retrospective chart review of patients enrolled in the All About Me Program (AAMP) from August 1, 2011, through July 10, 2012. Baseline demographics, 5-2-1-0 behavioral targets, and anthropometric measures were obtained from 54 enrollees. Pre- and post-program weight, body mass index (BMI) percentile, and 5-2-1-0 behavioral targets were compared for 20 patients who completed the program which consisted of a total of five visits over 3 months.

RESULTS

Participants showed a significant reduction in their BMI, improvement in daily servings of fruits and vegetables, reduction in recreational screen time from baseline, improvement in daily physical activity, and reduction in consumption of sugary beverages.

CONCLUSIONS

These preliminary findings are a promising indicator that primary care-based obesity interventions may be effective for the management and treatment of pediatric obesity.

IMPLICATIONS FOR NURSING

This evidence-based toolkit provides a practical point-of-care guidance on the prevention, assessment, and treatment of childhood obesity and can be easily implemented in other primary care settings.

Curcumin Ameliorates Nonalcoholic Fatty Liver Disease through Inhibition of O-GlcNAcylation

The cause of progression to non-alcoholic fatty liver disease (NAFLD) is not fully understood. In the present study, we aimed to investigate how curcumin, a natural phytopolyphenol pigment, ameliorates NAFLD. Initially, we demonstrated that curcumin dramatically suppresses fat accumulation and hepatic injury induced in methionine and choline-deficient (MCD) diet mice. The severity of hepatic inflammation was alleviated by curcumin treatment. To identify the proteins involved in the pathogenesis of NAFLD, we also characterized the hepatic proteome in MCD diet mice. As a result of two-dimensional proteomic analysis, it was confirmed that thirteen proteins including antioxidant protein were differentially expressed in hepatic steatosis. However, the difference in expression was markedly improved by curcumin treatment. Interestingly, eight of the identified proteins are known to undergo O-GlcNAcylation modification. Thus, we further focused on elucidating how the regulation of O-linked β-N-acetylglucosamine (O-GlcNAc) modification is associated with the progression of hepatic steatosis leading to hepatitis in MCD diet mice. In parallel with lipid accumulation and inflammation, the MCD diet significantly up-regulated hexosamine biosynthetic pathway (HBP) and O-GlcNAc transferase (OGT) via ER stress. Curcumin treatment alleviates the severity of hepatic steatosis by relieving the dependence of O-GlcNAcylation on nuclear factor-κB (NF-κB) in inflammation signaling. Conversely, the expressions of superoxide dismutase 1 (SOD1) and SIRT1 were significantly upregulated by curcumin treatment. In conclusion, curcumin inhibits O-GlcNAcylation pathway, leading to antioxidant responses in non-alcoholic steatohepatitis (NASH) mice. Therefore, curcumin will be a promising therapeutic agent for diseases involving hyper-O-GlcNAcylation, including cancer.

NAFLD in children: new genes, new diagnostic modalities and new drugs

Nonalcoholic fatty liver disease (NAFLD) has rapidly become the most common form of chronic liver disease in children and adolescents. Over the past 5 years, developments have revolutionized our understanding of the genetic factors, natural history, diagnostic modalities and therapeutic targets for this disease. New polymorphisms, such as those in PNPLA3, TM6SF2, MBOAT7 and GCKR, have been identified and used to predict the development and severity of NAFLD in both adults and children, and their interaction with environmental factors has been elucidated. Studies have demonstrated the true burden of paediatric NAFLD and its progression to end-stage liver disease in adulthood. In particular, nonalcoholic steatohepatitis can progress to advanced fibrosis and cirrhosis, emphasizing the importance of early diagnosis. Non-invasive imaging tests, such as transient elastography, will probably replace liver biopsy for the diagnosis of nonalcoholic steatohepatitis and the assessment of fibrosis severity in the near future. The therapeutic landscape is also expanding rapidly with the development of drugs that can modify liver steatosis, inflammation and fibrosis, indicating that pharmacotherapy for NAFLD will become available in the future. In this Review, we summarize current knowledge and new advances related to the pathogenesis and management of paediatric NAFLD.

Triplet Male Lambs Are More Susceptible than Twins to Dietary Soybean Oil-Induced Fatty Liver

BACKGROUND

Litter size affects fetal development but its relation to diet-induced fatty liver later in life is unknown.

OBJECTIVES

This aim of this study was to test the hypothesis that litter size influences postweaning fatty liver development in response to soybean oil-supplemented diet.

METHODS

Weanling twin (TW) or triplet (TP) male lambs (n = 16) were fed a control diet or 2% soybean oil-supplemented diet (SO) for 90 d. Liver tissue morphology, biochemical parameters, and lipid metabolic enzymes were determined. Hepatic gene expression was analyzed by RNA sequencing (n = 3), followed by enrichment analysis according to Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes. Differentially expressed genes involved in lipid metabolism were further verified by quantitative reverse transcriptase-polymerase chain reaction (n = 4). All data were analyzed by a 2-factor ANOVA, apart from differentially expressed genes, which were identified by the Benjamini-Hochberg approach (q value ≤0.05).

RESULTS

SO increased liver triglyceride (by 55%) and nonesterified fatty acid (by 54%) concentrations in TPs (P ≤ 0.05) but not in TWs (P > 0.05). SO also induced a 2.3- and 2.1-fold increase in the liver steatosis score of TPs and TWs, respectively (P ≤ 0.05). Moreover, SO reduced the activity of lipolytic enzymes including hepatic lipase and total lipase in TPs by 47% and 25%, respectively (P ≤ 0.05). In contrast, activities of lipogenic enzymes, including malic enzyme and acetyl coenzyme A carboxylase, were significantly higher in TPs (P ≤ 0.05). Moreover, TPs had higher expression of lipogenic genes, such as FASN (by 45%) and APOB (by 72%), and lower expression of lipolytic genes, such as PRKAA2 (by 28%) and CPT1A (by 43%), compared with TWs (P ≤ 0.05).

CONCLUSIONS

TPs have a gene expression profile that is more susceptible to SO-induced fatty liver than that of TWs, which indicates that insufficient maternal nutrient supply at fetal and neonatal stages may increase the risk of nonalcoholic fatty liver disease.

Pediatric NAFLD: an overview and recent developments in diagnostics and treatment

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adults in industrialized countries. Besides liver-related morbidity, NAFLD is also associated with an increased risk of cardiovascular disease, type 2 diabetes and mortality at adult age. However, despite the high prevalence and serious complications, diagnosing and staging of disease remains complicated due to a lack of accurate screening tools and non-invasive methods to detect fibrosis. Areas covered: Recent insights in epidemiology, pathogenesis, diagnostic evaluation and treatment options in pediatric NAFLD are being reviewed, with a particular focus on new developments in diagnostic tools. Expert opinion: Due to their long life span, children with NAFLD are particularly at risk of complications in their lifetime. Therefore, an effective screening strategy for children to identify those with NAFLD at risk of complications is urgently needed. This is further underscored by new pharmacological therapies that are expected to become available in the next 5 years. Momentarily no accurate non-invasive method for diagnosing pediatric NAFLD is available. New promising biomarkers and imaging tools could hopefully provide better screening tools and could contribute to the development of a successful management plan to identify children with NAFLD.

Role of Nutrition in the Pathogenesis and Prevention of Non-alcoholic Fatty Liver Disease: Recent Updates

Non-alcoholic fatty liver disease (NAFLD) is an acquired metabolic disease characterized by triglycerides (TGs) deposition in liver induced by other factors rather than alcohol consumption. NAFLD significantly contributes to liver diseases in children and adults. NAFLD pathogenesis is associated with age, gender, race and ethnicity. Insulin resistance, hyperinsulinemia, elevated plasma free fatty acids (FFAs), fatty liver, hepatocyte injury, liver inflammation, oxidative stress, mitochondrial dysfunction, imbalanced pro-inflammatory cytokines, and fibrosis are the characteristics of NAFLD. Factors including genetic and epigenetic pathways, sedentary lifestyle, sleep, and diet composition affect NAFLD pathogenesis. In this review, we discuss the aetiology, risk factors and pathogenesis of NAFLD. Special focus is given to macro and micro nutrition as causing factors and their role in the prevention of NAFLD pathogenesis.

Genetic and metabolic predictors of hepatic fat content in a cohort of Italian children with obesity

OBJECTIVES

To comprehensively explore metabolic and genetic contributors to liver fat accumulation in overweight/obese children.

METHODS

Two hundred thirty Italian children with obesity were investigated for metabolic parameters and genotyped for PNPLA3, TM6SF2, GCKR, and MBOAT7 gene variants. Percentage hepatic fat content (HFF%) was measured by nuclear magnetic resonance.

RESULTS

HFF% was positively related with BMI, HOMA_IR, metabolic syndrome, ALT, AST, γGT, and albumin. Carriers of [G] allele in PNPLA3, [T] allele in GCKR and [T] allele in TM6SF2 genes had significantly higher hepatic fat content than wild-type carriers. HFF% was explained for 8.7% by metabolic and for 16.1% by genetic factors and, a model including age, gender, BMI, HOMA_IR, PNPLA3, GCKR, and TM6SF2 variants was the best predictor of HFF%, explaining 24.8% of its variation (P < 0.001). A weighted-genetic risk score combining PNPLA3, GCKR, and TM6SF2 risk alleles was associated with almost eightfold higher risk of NAFLD.

CONCLUSIONS

Our data highlighted the predominant role of genetic factors in determining the amount of liver fat content in children with obesity.

Dietitian-led lifestyle modification programme for obese Chinese adolescents with non-alcoholic fatty liver disease: a randomized controlled study

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children is increasing. This study evaluated the efficacy of a dietitian-led lifestyle modification programme (D-LMP) to reduce NAFLD in obese adolescents.

METHODS

Subjects with intra-hepatic triglyceride content (IHTC) equal to or greater than 5% diagnosed by proton-magnetic resonance spectroscopy (¹H-MRS) were enroled and randomly assigned to either the D-LMP intervention or conventional paediatrician-led consultation (P-CON) group. Subjects in the P-CON group received usual care consisting of a consultation by a paediatrician with the child and parents every 16 weeks. Intention-to-treat analysis was used for data analysis.

RESULTS

Fifty-two subjects were recruited, with 26 in each group. After the initiation phase (at week-16), there was a greater difference in the change in the IHTC and BMI z-score in the D-LMP group (P = 0.029 and <0.001, respectively) and there was a decrease in dietary intake of fat content (P = 0.019). After 52 weeks of the maintenance phase, both groups had reductions of IHTC to 2-3% and there was no intergroup difference in the rate of reduction. During the maintenance phase, parents' involvement was minimal in the D-LMP group, with only three parents accompanying their children to attend the dietitian sessions. In contrast, over 90% of the parents in the P-CON group regularly accompanied their children to attend the consultations suggesting the possibility that regular parental and paediatrician involvement may contribute to increasing awareness on fatty liver complications. Multivariate analysis showed that only reduction in body fat remained as an independent factor associated with remission of NAFLD at the end of both study phases.

CONCLUSIONS

A dietitian-led lifestyle modification intervention reduced IHTC, BMI z-score and body fat in obese Chinese adolescents with NAFLD. To sustain the effect of this intervention, regular parental and paediatrician involvement may be important.

Assessment of Fatty Liver in Models of Disease Programming

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease worldwide and is present in a third of the general population and the majority of individuals with obesity and type 2 diabetes. Importantly, NAFLD can progress to severe nonalcoholic steatohepatitis (NASH), associated with liver failure and hepatocellular carcinoma. Recent research efforts have extensively focused on identifying factors contributing to the additional "hit" required to promote NALFD disease progression. The maternal diet, and in particular a high-fat diet (HFD), may be one such hit "priming" the development of severe fatty liver disease, a notion supported by the increasing incidence of NAFLD among children and adolescents in Westernized countries. In recent years, a plethora of key studies have used murine models of maternal obesity to identify fundamental mechanisms such as lipogenesis, mitochondrial function, inflammation, and fibrosis that may underlie the developmental priming of NAFLD. In this chapter, we will address key considerations for constructing experimental models and both conventional and advanced methods of quantifying NAFLD disease status.

Serum high mobility group box 1 protein levels are not associated with either histological severity or treatment response in children and adults with nonalcoholic fatty liver disease

Aim

Serum high mobility group box 1 protein (HMGB1) is a proinflammatory molecule that could potentially serve as a biomarker for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) due to its correlation with degree of liver fibrosis. The aim of the current study was to examine the cross-sectional and longitudinal relationships between serum HMGB1 levels and liver histology in adults and children with NAFLD participating in two large randomized controlled trials.

Methods

Serum HMGB1 levels were measured at various time points in adults and children with NAFLD, who participated in PIVENS and TONIC clinical trials respectively. PIVENS trial compared vitamin E or pioglitazone to placebo in adults whereas TONIC trial compared vitamin E or metformin to placebo in children. Participants had liver biopsies at baseline and the end of treatment (96 weeks), and liver histology was reviewed by a central committee of study pathologists.

Results

In the cross-sectional analyses (n = 205 for PIVENS and 109 for TONIC), there was no significant relationship between serum HMGB1 levels and histological features such as steatosis, ballooning, inflammation, fibrosis, or presence of steatohepatitis in either adults or children. Serum HMGB1 levels did not change significantly during treatment either with placebo, vitamin E therapy (P = 0.81) or pioglitazone (P = 0.09) in the PIVENS trial. Similarly, serum HMGB1 levels did not change significantly during treatment either with placebo, metformin (P = 0.15) or vitamin E (P = 0.23) in the TONIC trial. In the longitudinal analyses (n = 105 for PIVENS and 109 for TONIC), changes in serum HMGB1 levels did not correlate with histologic improvement or resolution of NASH in either adults or children. There was no relationship between serum HMGB1 and ALT levels in either adults or children with NAFLD.

Conclusion

Serum HMGB1 levels were not associated with histological severity or treatment response in either children or adults with NAFLD.

A Branched-Chain Amino Acid-Related Metabolic Signature Characterizes Obese Adolescents with Non-Alcoholic Fatty Liver Disease

Dysregulation of several metabolite pathways, including branched-chain amino acids (BCAAs), are associated with Non-Alcoholic Fatty Liver Disease (NAFLD) and insulin resistance in adults, while studies in youth reported conflicting results. We explored whether, independently of obesity and insulin resistance, obese adolescents with NAFLD display a metabolomic signature consistent with disturbances in amino acid and lipid metabolism. A total of 180 plasma metabolites were measured by a targeted metabolomic approach in 78 obese adolescents with (n = 30) or without (n = 48) NAFLD assessed by magnetic resonance imaging (MRI). All subjects underwent an oral glucose tolerance test and subsets of patients underwent a two-step hyperinsulinemic-euglycemic clamp and/or a second MRI after a 2.2 ± 0.8-year follow-up. Adolescents with NAFLD had higher plasma levels of valine (p = 0.02), isoleucine (p = 0.03), tryptophan (p = 0.02), and lysine (p = 0.02) after adjustment for confounding factors. Circulating BCAAs were negatively correlated with peripheral and hepatic insulin sensitivity. Furthermore, higher baseline valine levels predicted an increase in hepatic fat content (HFF) at follow-up (p = 0.01). These results indicate that a dysregulation of BCAA metabolism characterizes obese adolescents with NAFLD independently of obesity and insulin resistance and predict an increase in hepatic fat content over time.

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

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

A Guide to Non-Alcoholic Fatty Liver Disease in Childhood and Adolescence

Non-Alcoholic Fatty Liver Disease (NAFLD) is now the most prevalent form of chronic liver disease, affecting 10%–20% of the general paediatric population. Within the next 10 years it is expected to become the leading cause of liver pathology, liver failure and indication for liver transplantation in childhood and adolescence in the Western world. While our understanding of the pathophysiological mechanisms underlying this disease remains limited, it is thought to be the hepatic manifestation of more widespread metabolic dysfunction and is strongly associated with a number of metabolic risk factors, including insulin resistance, dyslipidaemia, cardiovascular disease and, most significantly, obesity. Despite this, ”paediatric” NAFLD remains under-studied, under-recognised and, potentially, undermanaged. This article will explore and evaluate our current understanding of NAFLD in childhood and adolescence and how it differs from adult NAFLD, in terms of its epidemiology, pathophysiology, natural history, diagnosis and clinical management. Given the current absence of definitive radiological and histopathological diagnostic tests, maintenance of a high clinical suspicion by all members of the multidisciplinary team in primary and specialist care settings remains the most potent of diagnostic tools, enabling early diagnosis and appropriate therapeutic intervention.

Meta-analysis of the influence of TM6SF2 E167K variant on Plasma Concentration of Aminotransferases across different Populations and Diverse Liver Phenotypes

A nonsynonymous E167K (rs58542926 C/T) variant in TM6SF2 gene was recently associated with nonalcoholic fatty liver disease (NAFLD). We explored the association between E167K and plasma concentrations of alanine (ALT) and aspartate (AST) aminotransferases through a meta-analysis. We also estimated the strength of the effect across diverse liver phenotypes, including NAFLD and chronic viral hepatitis; fourteen studies were included. We found that ALT (p = 3.2 × 10⁻⁶, n = 94,414) and AST (p = 0007, n = 93,809) levels were significantly associated with rs58542926 in NAFLD. By contrast, rs58542926 was not associated with either ALT (p = 0.24, n = 4187) or AST (p = 0.17, n = 2678) levels in four studies on chronic hepatitis. In conclusion, the results of the pooled estimates in patients with NAFLD showed that carriers of the T allele (EK + KK), when compared with homozygous subjects for the C allele (EE genotype) have increased levels of aminotransferases; however, this increase represents –2.5 (9.8%) and 1.2 (5%) IU/L of ALT and AST respectively, which is fairly small compared with the large effect of PNPLA3- rs738409-G allele that is associated with a –28% increase in serum ALT.

Addressing Childhood Obesity: Opportunities for Prevention

The overweight and obesity epidemic among children and adolescents in the United States continues to worsen, with notable racial, ethnic, and socioeconomic disparities. Risk factors for pediatric obesity include genetics; environmental and neighborhood factors; increased intake of sugar-sweetened beverages (SSBs), fast-food, and processed snacks; decreased physical activity; shorter sleep duration; and increased personal, prenatal, or family stress. Pediatricians can help prevent obesity by measuring body mass index at least yearly and providing age- and development-appropriate anticipatory guidance to families. Public policies and environmental interventions aim to make it easier for children to make healthy nutrition and physical activity choices. Interventions focused on family habits and parenting strategies have also been successful at preventing or treating childhood obesity.

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

Objective:

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

Methods:

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

Result:

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

Conclusion:

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

1H-MRS Measured Ectopic Fat in Liver and Muscle in Danish Lean and Obese Children and Adolescents

Objectives

This cross sectional study aims to investigate the associations between ectopic lipid accumulation in liver and skeletal muscle and biochemical measures, estimates of insulin resistance, anthropometry, and blood pressure in lean and overweight/obese children.

Methods

Fasting plasma glucose, serum lipids, serum insulin, and expressions of insulin resistance, anthropometry, blood pressure, and magnetic resonance spectroscopy of liver and muscle fat were obtained in 327 Danish children and adolescents aged 8–18 years.

Results

In 287 overweight/obese children, the prevalences of hepatic and muscular steatosis were 31% and 68%, respectively, whereas the prevalences in 40 lean children were 3% and 10%, respectively. A multiple regression analysis adjusted for age, sex, body mass index z-score (BMI SDS), and pubertal development showed that the OR of exhibiting dyslipidemia was 4.2 (95%CI: [1.8; 10.2], p = 0.0009) when hepatic steatosis was present. Comparing the simultaneous presence of hepatic and muscular steatosis with no presence of steatosis, the OR of exhibiting dyslipidemia was 5.8 (95%CI: [2.0; 18.6], p = 0.002). No significant associations between muscle fat and dyslipidemia, impaired fasting glucose, or blood pressure were observed.

Liver and muscle fat, adjusted for age, sex, BMI SDS, and pubertal development, associated to BMI SDS and glycosylated hemoglobin, while only liver fat associated to visceral and subcutaneous adipose tissue and intramyocellular lipid associated inversely to high density lipoprotein cholesterol.

Conclusion

Hepatic steatosis is associated with dyslipidemia and liver and muscle fat depositions are linked to obesity-related metabolic dysfunctions, especially glycosylated hemoglobin, in children and adolescents, which suggest an increased cardiovascular disease risk.

A double-blind, placebo-controlled randomized trial to evaluate the efficacy of docosahexaenoic acid supplementation on hepatic fat and associated cardiovascular risk factors in overweight children with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Very little information is available on whether docosahexaenoic acid (DHA) supplementation has a beneficial effect on liver fat and cardiovascular disease (CVD) risk factors in children with nonalcoholic fatty liver disease (NAFLD). In a double-blind, placebo-controlled randomized trial we investigated whether 6-month treatment with DHA improves hepatic fat and other fat depots, and their associated CVD risk factors in children with biopsy-proven NAFLD.

METHODS AND RESULTS

Of 58 randomized children, 51 (25 DHA, 26 placebo) completed the study. The main outcome was the change in hepatic fat fraction as estimated by magnetic resonance imaging. Secondary outcomes were changes in visceral adipose tissue (VAT), epicardial adipose tissue (EAT), and left ventricular (LV) function, as well as alanine aminotransferase (ALT), triglycerides, body mass index-standard deviation score (BMI-SDS), and insulin sensitivity. At 6 months, the liver fat was reduced by 53.4% (95% CI, 33.4-73.4) in the DHA group, as compared with 22.6% (6.2-39.0) in the placebo group (P = 0.040 for the comparison between the two groups). Likewise, in the DHA group VAT and EAT were reduced by 7.8% (0-18.3) and 14.2% (0-28.2%), as compared with 2.2% (0-8.1) and 1.7% (0-6.8%) in the placebo group, respectively (P = 0.01 for both comparisons). There were no significant between-group changes for LV function as well as BMI-SDS and ALT, while fasting insulin and triglycerides significantly decreased in the DHA-treated children (P = 0.028 and P = 0.041, respectively).

CONCLUSIONS

DHA supplementation decreases liver and visceral fat, and ameliorates metabolic abnormalities in children with NAFLD.

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

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

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

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

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

Children's Hospital Association consensus statements for comorbidities of childhood obesity

BACKGROUND

Childhood obesity and overweight affect approximately 30% of US children. Many of these children have obesity-related comorbidities, such as hypertension, dyslipidemia, fatty liver disease, diabetes, polycystic ovary syndrome (PCOS), sleep apnea, psychosocial problems, and others. These children need routine screening and, in many cases, treatment for these conditions. However, because primary care pediatric providers (PCPs) often are underequipped to deal with these comorbidities, they frequently refer these patients to subspecialists. However, as a result of the US pediatric subspecialist shortage and considering that 12.5 million children are obese, access to care by subspecialists is limited. The aim of this article is to provide accessible, user-friendly clinical consensus statements to facilitate the screening, interpretation of results, and early treatment for some of the most common childhood obesity comorbidities.

METHODS

Members of the Children's Hospital Association (formerly NACHRI) FOCUS on a Fitter Future II (FFFII), a collaboration of 25 US pediatric obesity centers, used a combination of the best available evidence and collective clinical experience to develop consensus statements for pediatric obesity-related comorbidities. FFFII also surveyed the participating pediatric obesity centers regarding their current practices.

RESULTS

The work group developed consensus statements for use in the evaluation and treatment of lipids, liver enzymes, and blood pressure abnormalities and PCOS in the child with overweight and obesity. The results of the FFFII survey illustrated the variability in the approach for initial evaluation and treatment as well as pattern of referrals to subspecialists among programs.

CONCLUSIONS

The consensus statements presented in this article can be a useful tool for PCPs in the management and overall care of children with overweight and obesity.

Increased susceptibility to methotrexate-induced toxicity in nonalcoholic steatohepatitis

Hepatic drug metabolizing enzymes and transporters play a crucial role in determining the fate of drugs, and alterations in liver function can place individuals at greater risk for adverse drug reactions (ADRs). We have shown that nonalcoholic steatohepatitis (NASH) leads to changes in the expression and localization of enzymes and transporters responsible for the disposition of numerous drugs. The purpose of this study was to determine the effect of NASH on methotrexate (MTX) disposition and the resulting toxicity profile. Sprague Dawley rats were fed either a control or methionine-choline-deficient diet for 8 weeks to induce NASH, then administered a single ip vehicle, 10, 40, or 100 mg/kg MTX injection followed by blood, urine, and feces collection over 96 h with terminal tissue collection. At the onset of dosing, Abcc1-4, Abcb1, and Abcg2 were elevated in NASH livers, whereas Abcc2 and Abcb1 were not properly localized to the membrane, similar to that previously observed in human NASH. NASH rodents receiving 40-100 mg/kg MTX exhibited hepatocellular damage followed by initiation of repair, whereas damage was absent in controls. NASH rodents receiving 100 mg/kg MTX exhibited slightly greater renal toxicity, indicating multiple organ toxicity, despite the majority of the dose being excreted by 6 h. Intestinal toxicity in NASH however, was strikingly less severe than controls, and coincided with reduced fecal MTX excretion. Because MTX-induced gastrointestinal toxicity limits the dose escalation necessary for cancer remission, these data suggest a greater risk for life-threatening MTX-induced hepatic and renal toxicity in NASH in the absence of overt gastrointestinal toxicity.

Antioxidant supplements reduced oxidative stress and stabilized liver function tests but did not reduce inflammation in a randomized controlled trial in obese children and adolescents

Oxidative stress and low-grade systemic inflammation may contribute to the pathogenesis of obesity-induced comorbidities, including nonalcoholic fatty liver disease. Increasing intake of dietary antioxidants might be beneficial, but there are few data in obese children. To examine the effect of antioxidant supplementation on biomarkers of oxidative stress, inflammation, and liver function, we randomly assigned overweight or obese children and adolescents (n = 44; mean ± SD age: 12.7 ± 1.5 y) participating in a lifestyle modification program to a 4-mo intervention with daily antioxidants (vitamin E, 400 IU; vitamin C, 500 mg; selenium, 50 μg) or placebo. We measured anthropometrics, antioxidant status, oxidative stress (F(2)-isoprostanes, F(2)-isoprostane metabolites), inflammation, liver enzymes, fasting insulin and glucose, and lipid profile at baseline and endpoint. There was a significant treatment effect of antioxidant supplementation on antioxidant status [α-tocopherol, β = 23.2 (95% CI: 18.0, 28.4); ascorbic acid, β = 70.6 (95% CI: 51.7, 89.4); selenium, β = 0.07 (95% CI: 0.01, 0.12)] and oxidative stress [8-iso-prostaglandin F2α, β = -0.11 (95% CI: -0.19, -0.02)] but not on any of the inflammatory markers measured. There was a significant treatment effect on alanine aminotransferase [β = -0.13 (95% CI: -0.23, -0.03)], a trend toward a significant effect on aspartate aminotransferase [β = -0.04 (95% CI: -0.09, 0.01)], and no significant effect on γ-glutamyltransferase [β = -0.03 (95% CI: -0.11, 0.06)]. In summary, antioxidant supplementation for 4 mo improved antioxidant-oxidant balance and modestly improved liver function tests; however, it did not reduce markers of systemic inflammation despite significant baseline correlations between oxidative stress and inflammation. The study was registered at clinicaltrials.gov as NCT01316081.

Nonalcoholic fatty liver disease and type 2 diabetes in obese children

Nonalcoholic fatty liver disease (NAFLD) is commonly found in adults and adolescents with type 2 diabetes (T2DM). The cause-effect relations of these 2 conditions are complex and it is difficult to decipher whether one drives the other or vice versa. Genetic predispositions, along with obesity, are probably shared culprits of both. NAFLD may precede the diagnosis of diabetes and play a critical role of driving its development by way of increasing hepatic and whole body insulin resistance. On the other hand, T2DM is associated with hyperinsulinemia, a resistance to some of the effects of gut derived peptides and increased systemic free fatty acids, that can all promote hepatic lipid deposition. Thus, each condition may promote the development of the other and their mutual presence creates a vicious cycle. Upon studying this complex interplay from another angle, reduction of liver fat significantly improves glucose metabolism in patients with T2DM highlighting the tight pathophysiological link between them.

Type 2 diabetes mellitus in pediatrics: a new challenge

BACKGROUND

The increased prevalence of childhood obesity in the last few years has been accompanied by the increase in prevalence of type 2 diabetes in pediatrics. In this paper, we will review the risk factors and the pathogenic determinants leading to type 2 diabetes in youth.

DATA SOURCES

We searched on PubMed with the key words: obesity, type 2 diabetes, children, adolescents, youth, non-alcoholic fatty liver disease, genes and selected those publications written in English that we judged to be relevant to the topic of the review.

RESULTS

Based on the data present in the literature, we reviewed the following three topics: 1) the role of ectopic fat deposition, in particular of fatty liver, in the pathogenesis of pediatric type 2 diabetes; 2) the progression to type 2 diabetes in pediatrics and how it differs from adults, and 3) current theraputic options.

CONCLUSION

Type 2 diabetes in youth is a complex disease, creating new challenges in treatment and prevention.

Oxidized metabolites of linoleic acid as biomarkers of liver injury in nonalcoholic steatohepatitis

The rising prevalence of obesity in the last few decades has been accompanied by an increase in nonalcoholic fatty liver disease (NAFLD). NAFLD encompasses a spectrum of liver pathology from isolated hepatic steatosis to steatohepatitis and advanced fibrosis. Dietary habits characterized by consumption of high-caloric, lipid-rich diets play a major role in the development of NAFLD. Recent studies have uncovered the importance of certain components of the diet. In this review, we will focus on the growing evidence for a central role of n-6 polyunsaturated fatty acids. We will discuss novel findings linking oxidative stress and increased production of reactive oxygen species in the liver to oxidation of n-6 polyunsaturated fatty acids and production of specific lipid oxidation metabolites. In particular, we will highlight the potential role of these metabolites as noninvasive markers to diagnose and monitor the extent of liver damage in patients with NAFLD.

A 360-degree overview of paediatric NAFLD: recent insights

Non-alcoholic fatty liver disease (NAFLD) is a multi-faceted disorder, which ranges from simple steatosis to non-alcoholic steatohepatitis (NASH) with/without fibrosis. The effects of specific risk factors, such as obesity and sedentary lifestyle, on predisposing genetic settings eventually lead to the development of NAFLD in children. The complex interplay between genes and environment in NAFLD pathogenesis is sustained by multiple mechanisms that involve liver crosstalk with other organs and tissues, especially gut and adipose tissue. Unfortunately, natural history of paediatric NAFLD is lacking, and the etiopathogenesis is still in the process of being defined. Potential early predictors and suitable non-invasive diagnostic tools can be discovered based on the pathogenetic mechanisms and histological patterns. This will also help design novel treatments and a comprehensive and successful management strategy for patients. In this review, we discuss the recent advances made in genetics, etiopathogenesis, diagnosis, and therapeutic management of NAFLD, focusing especially on the obesity-related steatotic liver condition.

The association between hepatic fat content and liver injury in obese children and adolescents: effects of ethnicity, insulin resistance, and common gene variants

OBJECTIVE

Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) are highly prevalent in obese youth. Herein, we aimed to study the association between hepatic fat accumulation as assessed by magnetic resonance imaging and circulating levels of cytokeratin-18 (CK-18) fragments, a robust NASH biomarker, and to explore the impact on this association of ethnicity, insulin resistance, and single nucleotide polymorphisms (SNPs) associated with steatosis (rs738409 in the PNPLA3, rs1260326 in the GCKR) or NASH severity (rs2645424 in the FDFT1).

RESEARCH DESIGN AND METHODS

Two-hundred twenty-nine obese youths (87 Caucasians, 61 African Americans, and 81 Hispanics; mean age, 12.8 ± 2.9 years; mean BMI, 31.4 ± 7.4) underwent magnetic resonance imaging, oral glucose tolerance test, and CK-18 levels measurement; 12 subjects underwent liver biopsy.

RESULTS

African Americans showed lower CK-18 levels than Hispanics (P < 0.001) and Caucasians (P = 0.004). Hepatic fat content (HFF%) and whole body insulin sensitivity index (WBISI) modulated CK-18 levels in Caucasians and Hispanics (P = 0.02 and P = 0.011), but not in African Americans; in fact, CK-18 was associated with HFF% and WBISI in Caucasians (P = 0.0018 and P < 0.0001) and Hispanics (P < 0.0001 and P = 0.02), but not in African Americans (both P = 0.5). The PNPLA3 SNP showed association in Caucasians (P = 0.02) and Hispanics (P = 0.05), and FDFT1 SNP showed an association in Caucasians (P = 0.05) and Hispanics (P = 0.02), with the same trend in African Americans (P = 0.07).

CONCLUSIONS

African Americans have lower levels of CK-18 than Caucasians and Hispanics irrespective of HFF% and insulin resistance. Moreover, SNPs in the PNPLA3 and FDFT1 may drive the individual predisposition to development of hepatic injury.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the Western world. It is closely associated with metabolic syndrome. The alarming epidemics of diabetes and obesity have fueled an increasing prevalence of NAFLD, particularly among these high-risk groups. Histologically, NAFLD encompasses a disease spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), which is characterized by hepatocyte injury, inflammation, and variable degrees of fibrosis on liver biopsy. Non-alcoholic steatohepatitis can progress to cirrhosis in a fraction of patients. There is currently little understanding of risk factors for disease progression and the disease pathogenesis has not been fully defined. Liver biopsy remains the gold standard for diagnosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. There are no well-established pharmacological agents for treatment of NASH, although this is a subject of ongoing research.

Overview of paediatric obesity for the paediatric mental health provider

Childhood obesity represents a significant challenge for paediatric healthcare delivery. As obesity rates increase, obese children and adolescents are at significant risk for the development of a myriad of medical and surgical problems as well as mental health problems. Moreover, children with mental health problems are increasingly presenting to their psychiatrists with obesity. Treatment of paediatric obesity requires a multidisciplinary approach with incorporation of the family into the treatment plan although still typically only offering suboptimal results. Paediatric providers from all disciplines should focus efforts primarily on obesity prevention and encouragement of healthy lifestyles, while incorporating treatment for obesity when such efforts fail. The goals of this article are to provide an overview of the epidemiology, pathophysiology, genetics, clinical features and treatment strategies for paediatric obesity.