Carbohydrates and diet patterns in nonalcoholic fatty liver disease in children and adolescents

Exposure to volatile organic compounds and polycyclic aromatic hydrocarbons is associated with the risk of non-alcoholic fatty liver disease in Korean adolescents: Korea National Environmental Health Survey (KoNEHS) 2015-2017

Non-alcoholic fatty liver disease (NAFLD) is one of the most frequent liver diseases among adolescents. Several animal studies have suggested that volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) increase NAFLD risk. However, few epidemiological studies have confirmed the association between VOCs, PAHs and NAFLD in the general adolescent population. Therefore, we analyzed 798 adolescents from the Korean National Environmental Health Survey (KoNEHS), 2015-2017, to examine the associations of urinary metabolites of VOCs and PAHs with serum alanine aminotransferase (ALT) activity and NAFLD prevalence. We performed linear regression, logistic regression, and Bayesian kernel machine regression (BKMR) to evaluate the association of urinary VOCs and PAHs metabolites with ALT levels and NAFLD prevalence. After adjusting for all covariates, urinary benzylmercapturic acid and 2-hydroxyfluorene levels were found to increase ALT activity and NAFLD prevalence. Additionally, the BKMR analyses showed a significantly positive overall effect on ALT activity and NAFLD prevalence with urinary concentrations of VOCs and PAHs metabolites, with 2-hydroxyfluorene as the biggest contributor. Our study suggests that exposure to low-level VOCs and PAHs may have a detrimental effect on NAFLD risk in adolescents. Given the increasing prevalence of NAFLD in adolescents, future cohort studies are confirmed to comprehend the effect of these chemicals on NAFLD risk.

The association between urinary polycyclic aromatic hydrocarbon metabolites and liver function among US population: a cross-sectional study

Most studies have focused on the pulmonary toxicity of inhaled PAHs to date; therefore, their hepatotoxic consequences are yet unknown. The main aim of this study is to examine the association between urinary polycyclic aromatic hydrocarbons (PAHs) and liver function parameters among the US population. The data included in this study were from the National Health and Nutritional Examination Survey (NHANES) 2003-2016. Finally, we included 2515 participants from seven cycles of the NHANES. Logistic regression was performed to calculate the association between each PAH and liver function parameters (elevated vs. normal) with odds ratio (OR) and 95% confidence intervals (CIs), along with adjustment for confounding variables. P < 0.05 was considered to indicate a statistically significant difference. All analyses were performed using R software 4.0.1. In the present study, all 2515 individuals were aged ≥ 18 years, 1211 males, and 1304 females. The average age normal was 45.56 ± 20.20, and the elevated was 46.04 ± 19.73 years, respectively. The results of logistic regression indicated that increased 9-hydroxyfluorene (OR  = 2.11, 95% CI = [1.52, 2.95], P < 0.001), 2-hydroxyfluorene (OR  = 1.61, 95% CI = [1.23, 2.11], P < 0.001), and 3-hydroxyfluorene (OR  = 1.54, 95% CI = [1.21, 1.95], P < 0.001) were associated with elevated GGT. In conclusion, 9-hydroxyfluorene is associated with elevated GGT level, and the effect of 9-hydroxyfluorene on GGT is modified by other PAHs, which means that 9-hydroxyfluorene has a greater influence on GGT when other PAHs are increased.

Metabolic dysfunction-associated fatty liver disease in obese youth with insulin resistance and type 2 diabetes

PURPOSE OF REVIEW

The aim of this review is to present the new definition of the disease, defining the epidemiology, risk factors with a particular attention to the role of insulin resistance (IR) and to define the main treatments explored.

RECENT FINDINGS

Nonalcoholic fatty liver disease (NAFLD) was previously considered a primary liver disease, but it would be more correct to consider it a component of the metabolic syndrome (MetS) in which IR might play a key role. Based on these findings, it has been recently proposed to modify the classic term of NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD) that better reflects the pathophysiology of this complex disease.

SUMMARY

Currently, no treatments approved in childhood are available, thus the only recommended approach is the prevention and correction of the known risk factors, and particularly of IR. However, further studies are needed to better clarify the pathogenetic mechanisms of NAFLD in order to establish more tailored therapies.

Non-alcoholic fatty liver disease in obese children and adolescents: a role for nutrition?

Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in children, paralleling the increasing prevalence of obesity worldwide. The pathogenesis of paediatric NAFLD is not fully understood, but it is known that obesity, nutrition, lifestyle variables, genetic and epigenetic factors may be causally involved in the development of this common metabolic liver disease. In particular, obesity and nutrition are among the strongest risk factors for paediatric NAFLD, which may exert their adverse hepatic effects already before birth. Excess energy intake induces hypertrophy and hyperplasia of adipose tissue with subsequent development of systemic insulin resistance, which is another important risk factor for NAFLD. Diet composition and in particular simple carbohydrate intake (especially high fructose intake) may promote the development of NAFLD, whereas non-digestible carbohydrates (dietary fiber), by affecting gut microbiota, may favour the integrity of gut wall and reduce inflammation, opposing this process. Saturated fat intake may also promote NAFLD development, whereas unsaturated fat intake has some beneficial effects. Protein intake does not seem to affect the development of NAFLD, but further investigation is needed. In conclusion, lifestyle modifications to induce weight loss, through diet and physical activity, remain the mainstay of treatment for paediatric NAFLD. The use of dietary supplements, such as omega-3 fatty acids and probiotics, needs further study before recommendation.

Urinary biomarkers of polycyclic aromatic hydrocarbons and their associations with liver function in adolescents

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Fructose, Omega 3 Fatty Acids, and Vitamin E: Involvement in Pediatric Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is currently the most common form of liver disease in both adults and children, becoming the leading cause for liver transplant in many countries. Its prevalence has increased considerably in recent years, mainly due to the explosive increase in pediatric obesity rates. NAFLD is strongly associated with central obesity, diabetes, dyslipidemia and insulin resistance, and it has been considered as the hepatic manifestation of the metabolic syndrome. Its complex pathophysiology involves a series of metabolic, inflammatory and oxidative stress processes, among others. Given the sharp increase in the prevalence of NAFLD and the lack of an appropriate pharmacological approach, it is crucial to consider the prevention/management of the disease based on lifestyle modifications such as the adoption of a healthy nutrition pattern. Herein, we review the literature and discuss the role of three key nutrients involved in pediatric NAFLD: fructose and its participation in metabolism, Omega-3 fatty acids and its anti-inflammatory effects and vitamin E and its action on oxidative stress.

Perspectives on youth-onset nonalcoholic fatty liver disease

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nonalcoholic Fatty Liver Disease in Children: Unique Considerations and Challenges

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence in concert with the global epidemic of obesity and is being diagnosed at increasingly younger ages. The unique histologic features and early presentation of disease in pediatrics suggest that children and adults may differ with regard to etiopathogenesis, with children displaying a greater vulnerability to genetic and environmental factors. Of significant relevance to pediatrics, in utero and perinatal stressors may alter the lifelong health trajectory of a child, increasing the risk of NAFLD and other cardiometabolic diseases. The development and progression of disease in childhood is likely to carry increased risk of long-term morbidity. Novel biomarkers and therapeutic agents are needed to avoid the otherwise inevitable health and societal consequences of this rapidly expanding pediatric population.

IMPACT OF CURRENT DIET AT THE RISK OF NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD)

The nonalcoholic fatty liver disease (NAFLD) affects approximately 20%-30% of general population and is even more prevalent among obese individuals. The risk factors mainly associated with NAFLD are diseases related to the metabolic syndrome, genetics and environment. In this review, we provide a literature compilation evaluating the evidence behind dietary components, including calories intake, fat, protein, fibers and carbohydrate, especially fructose which could be a trigger to development and progression of the NAFLD. In fact, it has been demonstrated that diet is an important factor for the development of NAFLD and its association is complex and extends beyond total energy intake.

Complementary foods in baby food pouches: position statement from the Nutrition Commission of the German Society for Pediatrics and Adolescent Medicine (DGKJ, e.V.)

Pureed complementary feeding products packed in squeezable plastic pouches, usually with a spout and a screw cap, have been increasingly marketed. The Committee on Nutrition recommends that infants and young children should not suck pureed or liquid complementary foods from baby food pouches. Complementary foods should be offered with a spoon or should be fed as finger foods. Infants and young children should be given the opportunity to get to know a variety of foods and food textures including pieces of foods, supported by responsive feeding between the child and their parents or caregivers. Complementary foods marketed in baby food pouches often have a high energy density and are predominantly extremely high in sugar content, with up to almost 90% of the total energy content. Regular consumption bears the risks of imbalanced nutrient provision and increased risks for dental caries and overweight. Complementary foods for infants and young children should have a balanced composition following the recommendations of the German Society of Pediatrics and Adolescent Medicine (DGKJ) and should contain only limited amounts of sugar. We discourage the feeding of pureed complementary foods from baby food pouches.

What Do We Know about Diet and Markers of Cardiovascular Health in Children: A Review

Chronic diseases such as cancer, diabetes, and cardiovascular diseases (CVD) are the main health concerns in the 21st century, with CVD as the number one cause of mortality worldwide. Although CVD hard endpoints such as stroke or heart attack do not usually occur in children, evidence shows that the manifestation of CVD risk factors begins in childhood, preceding clinical complications of CVD in adulthood. Dietary intake is a modifiable risk factor that has been shown to make a substantial contribution to the risk of CVD in adulthood. However, less is known about the association between dietary intake and markers of cardiovascular health in children. This review summarises the current evidence on the relationship between dietary intake and markers of cardiovascular health including traditional CVD risk factors, physical fitness, and indices of arterial stiffness and wave reflection in children. Original research published in English, between January 2008 and December 2018 fulfilling the objective of this review were screened and included. Findings show that adaptation of a healthy lifestyle early in life can be beneficial for reducing the risk of CVD later in life. Furthermore, keeping arterial stiffness low from a young age could be a potential CVD prevention strategy. However, limited studies are available on diet-arterial stiffness relationship in children, and future research is required to better understand this association to aid the development and implementation of evidence-based strategies for preventing CVD-related complications later in life.

Childhood Fructoholism and Fructoholic Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is an emerging entity, becoming the most prevalent pediatric chronic liver disease. Its broad spectrum of histological findings, comorbidities, and complications, including cirrhosis and liver failure, can occur in childhood, emphasizing the severity of pediatric NAFLD. Current lifestyle and diet modifications have been linked to the increasing prevalence of NAFLD, including the rise of fructose consumption, a monosaccharide present in foods that contain added sugar, such as sugar‐sweetened beverages. Excessive fructose consumption is believed to cause addiction like alcohol and other drugs. As such, the new term “fructoholism” refers to the consumption of a substance (fructose) that can cause psychological and physical damage and become a major public health concern, highlighting the seriousness of the excessive consumption of fructose in the pediatric age. Hepatic fructose metabolization leads to hepatic steatosis and progression to fibrosis through mechanisms comparable to alcoholic liver disease, hence the term “fructoholic liver disease.” Conclusion: The importance of implementing reliable global strategies, such as education campaigns to promote healthy diet, increasing taxes on foods that contain added sugars, subsidies to promote accessibility to fruit and vegetables, and strict food industry regulation to reduce sugar intake in children and adolescents, cannot be overemphasized.