PEDIATRIC VISCERAL ADIPOSITY INDEX ADAPTATION CORRELATES WITH HOMA-IR, MATSUDA, AND TRANSAMINASES

Pro- and anti-inflammatory cytokines are the game-changers in childhood obesity-associated metabolic disorders (diabetes and non-alcoholic fatty liver diseases)

Childhood obesity is a chronic inflammatory epidemic that affects children worldwide. Obesity affects approximately 1 in 5 children worldwide. Obesity in children can worsen weight gain and raise the risk of obesity-related comorbidities like diabetes and non-alcoholic fatty liver disease (NAFLD). It can also negatively impact the quality of life for these children. Obesity disrupts immune system function, influencing cytokine (interleukins) balance and expression levels, adipokines, and innate and adaptive immune cells. The altered expression of immune system mediators, including interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-17 (IL-17), interleukin-18 (IL-18), transforming growth factor (TGF), tumor necrosis factor (TNF), and others, caused inflammation, progression, and the development of pediatric obesity and linked illnesses such as diabetes and NAFLD. Furthermore, anti-inflammatory cytokines, including interleukin-2 (IL-2), have been shown to have anti-diabetes and IL-1 receptor antagonist (IL-1Ra) anti-diabetic and pro-NAFLFD properties, and interleukin-10 (IL-10) has been shown to have a dual role in managing diabetes and anti-NAFLD. In light of the substantial increase in childhood obesity-associated disorders such as diabetes and NAFLD and the absence of an effective pharmaceutical intervention to inhibit immune modulation factors, it is critical to consider the alteration of immune system components as a preventive and therapeutic approach. Thus, the current review focuses on the most recent information regarding the influence of pro- and anti-inflammatory cytokines (interleukins) and their molecular mechanisms on pediatric obesity-associated disorders (diabetes and NAFLD). Furthermore, we discussed the current therapeutic clinical trials in childhood obesity-associated diseases, diabetes, and NAFLD.

Correlation of the Pediatric Metabolic Index with NAFLD or MAFLD diagnosis, and serum adipokine levels in children

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is characterized by ectopic fat deposition in the liver. However, a recent classification of this condition, which also integrates the presence of coexisting metabolic disorders, termed Metabolic dysfunction Associated Fatty Liver Disease (MAFLD), has been proposed. NAFLD is increasingly common in early childhood, partly due to the increase in metabolic disease in this age. Thus, studying hepatic steatosis in the metabolic context has become important in this population as well. However, NAFLD, and thus MAFLD, diagnosis in children is challenging by the lack of non-invasive diagnostic tools comparable to the gold standard of hepatic biopsy. Recent studies have reported that the Pediatric Metabolic Index (PMI) could be a marker of insulin resistance and abnormal liver enzymes, but its association with NAFLD, MAFLD, or altered adipokines in these conditions has not been reported. The aim of this study is to evaluate the correlation between PMI with the diagnosis of NAFLD or MAFLD, together with serum levels of leptin and adiponectin, in school-age children.

METHODS

A cross sectional study was carried out in two hundred and twenty-three children without medical history of hypothyroidism, genetic, or chronic diseases. Anthropometry, liver ultrasound, and serum levels of lipids, leptin, and adiponectin were evaluated. The children were classified as having NAFLD or non-NAFLD, and a subgroup of MAFLD in the NAFLD group was analyzed. The PMI was calculated by the established formulas for age and gender.

RESULTS

PMI correlated positively with the presence and severity of NAFLD (r=0.62, p<0.001 and r= 0.79, p<0.001 respectively) and with the presence of MAFLD (r=0.62; p<0.001). Also, this index correlated positively with serum leptin levels (r=0.66; p<0.001) and negatively with serum adiponectin levels (r= -0.65; p<0.001). PMI showed to be a good predictor for diagnosing NAFLD in school-age children when performing a ROC curve analysis (AUROC=0.986, p< 0.0001).

CONCLUSION

PMI could be a useful tool for the early diagnosis of NAFLD or MAFLD in children. However, future studies are necessary to establish validated cut-off points for each population.

Predictors of non-alcoholic fatty liver disease in children

OBJECTIVE

Abdominal obesity is strongly associated with the development of non-alcoholic fatty liver disease (NAFLD). Early identification and intervention may reduce the risk. We aim to improve pediatric NAFLD screening by comparing discriminative performance of six abdominal obesity indicators.

METHODS

We measured anthropometric indicators (waist circumference [WC], waist-to-hip ratio [WHR], waist-to-height ratio [WHtR]), body composition indicators (trunk fat index [TFI], visceral fat area [VFA]), and endocrine indicator (visceral adiposity index [VAI]) among 1350 Chinese children aged 6-8 years. Using Spearman correlation, receiver operating characteristic (ROC) curves, and Logistic regression, we validated their ability to predict NAFLD.

RESULTS

All six indicators can predict NAFLD robustly, with area under the curve (AUC) values ranged from 0.69 to 0.96. TFI, WC, and VFA rank in the top three for the discriminative performance. TFI was the best predictor with AUC values of 0.94 (0.92-0.97) and 0.96 (0.92-0.99), corresponding to cut-off values of 1.83 and 2.31 kg/m² for boys and girls, respectively. Boys with higher TFI (aOR = 13.8), VFA (aOR = 11.1), WHtR (aOR = 3.1), or VAI (aOR = 2.8), and girls with higher TFI (aOR = 21.0) or VFA (aOR = 17.5), were more likely to have NAFLD.

CONCLUSION

User-friendly body composition indicators like TFI can identify NAFLD and help prevent the progress of liver disease.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) ( www.chictr.org.cn/enIndex.aspx , No. ChiCTR2100044027); retrospectively registered on 6 March 2021.

IMPACT

Abdominal obesity increases the risk of pediatric non-alcoholic fatty liver disease (NAFLD). This study compared the discriminative performance of multiple abdominal obesity indicators measured by different methods in terms of accuracy and fastidious cut-off values through a population-based child cohort. Our results provided solid evidence of abdominal obesity indicators as an optimal screening tool for pediatric NAFLD, with area under the curve (AUC) values ranged from 0.69 to 0.96. User-friendly body composition indicators like TFI show a greater application potential in helping physicians perform easy, reliable, and interpretable weight management to prevent the progress of liver damage.

The Visceral Adiposity Index in Non-Alcoholic Fatty Liver Disease and Liver Fibrosis-Systematic Review and Meta-Analysis

(1) Background: In order to avoid a liver biopsy in non-alcoholic fatty liver disease (NAFLD), several noninvasive biomarkers have been studied lately. Therefore, we aimed to evaluate the visceral adiposity index (VAI) in NAFLD and liver fibrosis, in addition to its accuracy in predicting NAFLD and NASH. (2) Methods: We searched PubMed, Embase, Scopus, and Cochrane Library, identifying observational studies assessing the VAI in NAFLD and liver fibrosis. QUADAS-2 was used to evaluate the quality of included studies. The principal summary outcomes were mean difference (MD) and area under the curve (AUC). (3) Results: A total of 24 studies were included in our review. VAI levels were significantly increased in NAFLD (biopsy-proven and ultrasound-diagnosed), simple steatosis vs. controls, and severe steatosis vs. simple steatosis. However, no significant MD was found according to sex, liver fibrosis severity, simple vs. moderate and moderate vs. severe steatosis, pediatric NAFLD, and NASH patients. The VAI predicted NAFLD (AUC 0.767) and NASH (AUC 0.732). (4) Conclusions: The VAI has a predictive value in diagnosing NAFLD and NASH, with significantly increased values in adult NAFLD patients, simple steatosis compared to controls, and severe steatosis compared to simple steatosis.

Adiponectin is Inversely Associated with Insulin Resistance in Adolescents with Nonalcoholic Fatty Liver Disease

BACKGROUND

Insulin resistance(IR) is confirmed as a key feature of nonalcoholic fatty liver disease (NAFLD) in children and adolescents. Numerous studies report that adiponectin (APN) levels are inversely associated with the status of IR in adults with NAFLD. This study aimed to investigate the relationship between serum total APNand homeostasis model assessment insulin resistance(HOMA-IR) in adolescents with NAFLD.

METHODS

382 newly-diagnosed NAFLD adolescents, aged 9-16 years old, were enrolled and divided into 3 subgroups according to the APNtertile. Simple and multiple linear regression analyses were performed to assess the correlation between HOMA-IR and APN in boys and girls, respectively.

RESULTS

The HOMA-IR values tended to decrease in boys according to APN tertiles: 5.6(4.4-7.3) vs. 5.2(4.6-6.9) vs. 4.9(4.1-5.8) (P<0.01), and there was a significant difference in the HOMA-IR values among three APN tertile subgroups in girls(P<0.01).Univariate analysis showed thatbody mass index, waist circumference, weight-to-height ratio, fasting blood glucose, insulin, triglyceride, and APN were significantly associated with HOMA-IR in boys (P<0.05). In girls, body mass index, fasting blood glucose, insulin, total cholesterol, triglyceride, and APN were significantly associated with HOMA-IR (P<0.05).APN was found to be a significant determinant for HOMA-IR only in boys (β=-0.147, P<0.01).

CONCLUSION

Our findings showed that APN was an independent and significant determinant for increased HOMA-IR in boys with NAFLD. Further studies are needed to explore the underlying mechanisms.

Angiopoietin-like 8 (ANGPTL8) as a potential predictor of NAFLD in paediatric patients with Prader-Willi Syndrome

PURPOSE

Angiopoietin-like 8 (ANGPTL8) is a liver- and adipose tissue-produced protein that predicts non-alcoholic fatty liver disease (NAFLD) and altered metabolic homeostasis in the general population as well as in persons with common and genetic obesity, including the Prader-Willi syndrome (PWS). However, its metabolic correlate in paediatric patients with respect to PWS is unknown.

METHODS

This cross-sectional study investigated circulating ANGPTL8 and adipocytokines levels in 28 PWS and 28 age-, sex- and BMI-matched children and adolescents (age, 7.0-17.8y) in relation to NAFLD and metabolic homeostasis assessed by OGTT, paediatric metabolic index (PMI) and fatty liver index (FLI), liver ultrasonography (US), as well as dual-energy X-ray absorptiometry (DEXA) for analysis of fat (FM) and fat-free mass (FFM).

RESULTS

At the set level of significance, PWS children showed lower values of FFM (p < 0.01) but healthier insulin profiles (p < 0.01) and PMI values (p < 0.05) than matched controls. By US, the prevalence of NAFLD was similar between groups but less severe in PWS than controls. Analysis of ANGPTL8 levels showed no difference between groups, yet only in PWS ANGPTL8 levels were associated with ALT levels, FLI values and NAFLD. In stepwise multivariable regression analysis on merged data, ANGPTL8 levels were independently predicted by BMI SDS, leptin levels and NAFLD.

CONCLUSION

ANGPTL8 levels are similar in PWS and controls and, overall, they are directly associated with the presence and severity of NAFLD in patients with PWS.

Normalization of γ-glutamyl transferase levels is associated with better metabolic control in individuals with nonalcoholic fatty liver disease

BACKGROUND

The normalization of liver biochemical parameters usually reflects the histological response to treatment for nonalcoholic fatty liver disease (NAFLD). Researchers have not clearly determined whether different liver enzymes exhibit various metabolic changes during the follow-up period in patients with NAFLD.

METHODS

We performed a retrospective analysis of patients with NAFLD who were receiving therapy from January 2011 to December 2019. Metabolism indexes, including glucose levels, lipid profiles, uric acid levels and liver biochemical parameters, were measured. Magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) and liver ultrasound were used to evaluate steatosis. All patients received recommendations for lifestyle modifications and guideline-recommended pharmacological treatments with indications for drug therapy for metabolic abnormalities.

RESULTS

Overall, 1048 patients with NAFLD were included and received lifestyle modification recommendations and pharmaceutical interventions, including 637 (60.7%) patients with abnormal GGT levels and 767 (73.2%) patients with abnormal ALT levels. Patients with concurrent ALT and GGT abnormalities presented higher levels of metabolism indexes and higher liver fat content than those in patients with single or no abnormalities. After 12 months of follow-up, the cumulative normalization rate of GGT was considerably lower than that of ALT (38% vs. 62%, P < 0.001). Greater weight loss resulted in higher cumulative normalization rates of GGT and ALT. Weight loss (OR = 1.21, 95% CI 1.11-1.32, P < 0.001), ALT normalization (OR = 2.75, 95% CI 1.41-5.36, P = 0.01) and lower TG and HOMA-IR values (OR = 2.03, 95% CI 1.11-3.71, P = 0.02; OR = 2.04, 95% CI 1.07-3.89, P = 0.03) were independent protective factors for GGT normalization. Elevated baseline GGT (OR = 0.99, 95% CI 0.98-0.99, P = 0.01) was a risk factor.

CONCLUSIONS

For NAFLD patients with concurrently increased ALT and GGT levels, a lower normalization rate of GGT was observed, rather than ALT. Good control of weight and insulin resistance was a reliable predictor of GGT normalization.

Serum carotenoids and Pediatric Metabolic Index predict insulin sensitivity in Mexican American children

High concentrations of carotenoids are protective against cardiometabolic risk traits (CMTs) in adults and children. We recently showed in non-diabetic Mexican American (MA) children that serum α-carotene and β-carotene are inversely correlated with obesity measures and triglycerides and positively with HDL cholesterol and that they were under strong genetic influences. Additionally, we previously described a Pediatric Metabolic Index (PMI) that helps in the identification of children who are at risk for cardiometabolic diseases. Here, we quantified serum lycopene and β-cryptoxanthin concentrations in approximately 580 children from MA families using an ultraperformance liquid chromatography-photodiode array and determined their heritabilities and correlations with CMTs. Using response surface methodology (RSM), we determined two-way interactions of carotenoids and PMI on Matsuda insulin sensitivity index (ISI). The concentrations of lycopene and β-cryptoxanthin were highly heritable [h2 = 0.98, P = 7 × 10-18 and h2 = 0.58, P = 1 × 10-7]. We found significant (P ≤ 0.05) negative phenotypic correlations between β-cryptoxanthin and five CMTs: body mass index (- 0.22), waist circumference (- 0.25), triglycerides (- 0.18), fat mass (- 0.23), fasting glucose (- 0.09), and positive correlations with HDL cholesterol (0.29). In contrast, lycopene only showed a significant negative correlation with fasting glucose (- 0.08) and a positive correlation with HDL cholesterol (0.18). Importantly, we found that common genetic influences significantly contributed to the observed phenotypic correlations. RSM showed that increased serum concentrations of α- and β-carotenoids rather than that of β-cryptoxanthin or lycopene had maximal effects on ISI. In summary, our findings suggest that the serum carotenoids are under strong additive genetic influences and may have differential effects on susceptibility to CMTs in children.