Risk and protective factors of non-alcoholic fatty liver disease in paediatric obesity: A nationwide nested case-control study

Steatotic Liver Disease in Pediatric Obesity and Increased Risk for Youth-Onset Type 2 Diabetes

OBJECTIVE

To assess 1) the association between metabolic dysfunction-associated steatotic liver disease (MASLD) in pediatric obesity and youth-onset type 2 diabetes, 2) the joint effect of MASLD and intermediate hyperglycemia on type 2 diabetes risk, and 3) the effect of obesity treatment on type 2 diabetes risk.

RESEARCH DESIGN AND METHODS

A cohort study using the Swedish Childhood Obesity Treatment Register (Barnobesitas Registret i Sverige [BORIS]) (1999-2020) linked with national registers was conducted. We included 10,346 children with overweight or obesity and 59,336 matched control individuals. MASLD was defined by transaminases and diagnosis code, separately. Type 2 diabetes was ascertained from national registers.

RESULTS

In the obesity cohort, median age at type 2 diabetes diagnosis was 16.9 (quartile 1 [Q1], quartile 3 [Q3]: 14.7, 21.4) years, median follow-up was 8.1 (Q1, Q3: 5.1, 11.7) years. Cumulative incidence of type 2 diabetes at age 30 was 22.7% (obesity and MASLD), 9.9% (obesity alone), and 0.7% (control individuals). MASLD was associated with risk for type 2 diabetes (hazard ratio [HR] 2.71 [95% CI 2.14-3.43]), independently of age, sex, degree of obesity, intermediate hyperglycemia, and parental type 2 diabetes. Joint effect of MASLD and intermediate hyperglycemia increased type 2 diabetes risk (HR 9.04 [6.38-12.79]). Optimal response in obesity treatment reduced the risk (HR 0.23 [0.09-0.57]).

CONCLUSIONS

MASLD, defined by transaminases or diagnosis code, in pediatric obesity is associated with increased risk for youth-onset type 2 diabetes. MASLD interacts synergistically with intermediate hyperglycemia to dramatically increase the risk. Optimal response in obesity treatment reduces type 2 diabetes risk, despite MASLD.

Is Helicobacter pylori infection a risk factor for non-alcoholic fatty liver disease in children?

Helicobacter pylori infection has been investigated as a potential risk factor for non-alcoholic fatty liver disease (NAFLD). Some studies suggest a possible link between the two conditions. The purpose of this study is to study the relationship between H. pylori infection and NAFLD in pediatrics and its relation to NAFLD grades. A case-control study to identify predictors of NAFLD and a comparative cross-sectional approach to determine factors affecting NAFLD grades were adopted. One hundred NAFLD children (ultrasound-based) and a control group of 100 non-NAFLD children were recruited. Both groups were evaluated by detecting H. pylori stool antigen. Immunoglobulin G antibodies to Cag A (cytotoxin-associated gene A), Vac A (vacuolating cytotoxin A), Gro EL (chaperonin Gro EL), HCPC (Helicobacter cysteine-rich protein C), and Ure A (Urease subunit A) were assessed in the serum of those with positive stool antigen. H. pylori infection was significantly higher in NAFLD children compared to the control group (64% versus 25%, p-value < .001). (NAFLD children showed higher Cag A and Vac A positivity (34, 10%) versus (2%, 0%) in the control group, respectively, p-value < .001). The regression model showed that H. pylori positivity (OR (odds ratio) = 5.021, 95% CI (confidence interval): 1.105-22.815), homeostatic model assessment of insulin resistance (Homa IR) (OR = 18.840, 95% CI: 3.998-88.789), waist percentile (OR = 1.184, 95% CI: 1.044-1.344), and triglycerides (OR = 1.029, 95% CI: 1.012-1.047) were predictors for NAFLD. Cag A positivity (OR = 2.740, 95% CI: 1.013-7.411) was associated with higher NAFLD grade (grade 2 fatty liver).

CONCLUSIONS

H. pylori infection could increase the risk of NAFLD in children. Triglycerides, waist circumference, and Homa IR are significant independent predictors of NAFLD.

WHAT IS KNOWN

• NAFLD has become one of the most common liver diseases among children because of the increased prevalence of pediatric obesity. • Dyslipidemia and insulin resistance play a central role in NAFLD pathogenesis. • NAFLD could be explained by the multiple-hit hypothesis. The gut microbiota is an important factor in this hypothesis (gut liver axis).

WHAT IS NEW

• Helicobacter pylori infection could increase the risk of NAFLD in children. • H. pylori Cytotoxin-associated gene A (Cag A) positivity is associated with higher NAFLD grade.

Prediction of insulin resistance and elevated liver transaminases using serum uric acid and derived markers in children and adolescents

OBJECTIVE

To investigate the relationship of serum uric acid (Uacid) and derived parameters as predictors of insulin resistance (IR) and elevated liver transaminases in children and adolescents METHODS: Data of 1648 participants aged 10-18 years was analyzed using nationwide survey. Logistic regression analysis was performed with IR and elevated liver transaminases as dependent variables, and odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles 2 and 3 of each parameter in comparison to tertile 1, which served as the reference. Receiver operating characteristic (ROC) curves were generated to assess predictability of the parameters for IR and elevated liver transaminases.

RESULTS

Hyperuricemia, IR, and elevated liver transaminases were significantly associated with each other. All Uacid and derived markers showed continuous increase in ORs and 95% CIs for IR and elevated liver transaminases across the tertiles of several biochemical and metabolic variables of interest (all p < 0.001), and were also significantly predictive in ROC curve. Overall, Uacid combined with obesity indices showed higher ORs and area under the curve (AUC) compared to Uacid alone. Uacid-body mass index (BMI) standard deviation score presented the largest AUC for IR. For elevated liver transaminases, Uacid-BMI and Uacid-waist-to-height ratio showed the largest AUC.

CONCLUSIONS

Uacid combined with obesity indices are robust markers for prediction of IR and elevated liver transaminases in children and adolescents. Uacid and derived markers have potential as simple markers which do not require fasting for screening of IR and elevated liver transaminases in children and adolescents.

Gestational and Developmental Contributors of Pediatric MASLD

Pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) is common and can be seen as early as in utero. A growing body of literature suggests that gestational and early life exposures modify the risk of MASLD development in children. These include maternal risk factors, such as poor cardiometabolic health (e.g., obesity, gestational diabetes, rapid weight gain during pregnancy, and MASLD), as well as periconceptional dietary exposures, degree of physical activity, intestinal microbiome, and smoking. Paternal factors, such as diet and obesity, also appear to play a role. Beyond gestation, early life dietary exposures, as well as the rate of infant weight gain, may further modify the risk of future MASLD development. The mechanisms linking parental health and environmental exposures to pediatric MASLD are complex and not entirely understood. In conclusion, investigating gestational and developmental contributors to MASLD is critical and may identify future interventional targets for disease prevention.

Height and Growth Velocity in Children and Adolescents Undergoing Obesity Treatment: A Prospective Cohort Study

CONTEXT

Pediatric obesity affects endocrine conditions, which may alter growth.

OBJECTIVE

This work aimed to investigate the effect of obesity severity and obesity treatment outcome on growth.

METHODS

This prospective cohort study included children (aged 3-18 years) enrolled in the Swedish Childhood Obesity Treatment Register (BORIS) (1998-2020). Obesity was categorized as class I and class II obesity. Obesity treatment outcome was measured as body mass index (BMI) z score changes and categorized into good (BMI z score reduction of ≥0.25), intermediate, and poor (increasing BMI z score). Height for age z score, final height, and growth velocity were compared between class I and class II obesity. Further, the effect of obesity treatment outcome on growth velocity during 2-year follow-up was assessed.

RESULTS

A total of 27 997 individuals (mean age 10.2 ± 3.6 years) were included. Individuals with class II obesity were on average taller than those with class I obesity during childhood. Among males, reduced growth spurt was observed in class I obesity, and even absent in class II obesity. Females exhibited a similar but less pronounced pattern. Good obesity treatment outcome yielded lower growth velocity at ages 3 to 9 years but higher growth velocity at ages 10 to 13 years compared to poor treatment outcome.

CONCLUSION

Obesity severity is positively associated with height and growth velocity in childhood. A hampered growth spurt during puberty should be anticipated, particularly in adolescents with severe obesity. Therefore no difference in final height between class I and class II obesity is expected. Successful obesity treatment does not harm, but rather normalizes, the growth velocity pattern.

Analysis of risk factors for non-alcoholic fatty liver disease in hospitalized children with obesity before the late puberty stage

Objective

This study aimed to determine the clinical characteristics of obese pediatric non-alcoholic fatty liver disease (NAFLD) in central China and verify the applicability of some known risk factors for pediatric NAFLD before late puberty.

Methods

This was a retrospective case-control study. A total of 1,029 inpatients at Wuhan Children's Hospital before the late puberty stage were enrolled in the study, including 815 children with obesity (non-NAFLD group) and 214 children with obesity and NAFLD (NAFLD group) diagnosed by liver ultrasound. Subgroup analyses were performed according to sex and puberty. The anthropometric indices and laboratory test data of these 1,029 children were sorted. After intergroup comparison, a logistic regression model was used to determine the risk factors for pediatric NAFLD. Significant risk factors for NAFLD were further tested using receiver operating characteristic (ROC) curves to evaluate their ability to predict an early diagnosis of NAFLD.

Results

The NAFLD group had a mean age of 11.03 ± 1.66, with 11.18 ± 1.66 and 10.27 ± 1.45 years for male and female children, respectively (p < 0.05 and p < 0.01, respectively). Even subdivided by both sex and puberty, raised body mass index (BMI), homeostatic model-insulin resistance, triglycerides, alanine transaminase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (γ-GT) were still found in the non-NAFLD and NAFLD groups (p < 0.05 and p < 0.01, respectively). The results of logistic regression analysis showed that BMI (odds ratio [OR], 1.468;95% confidence interval [CI], 1.356-1.590; p<0.001) and ALT (OR, 1.073;95%CI, 1.060-1.087; P<0.001) were two most independent risk factors for NAFLD. The maximal OR for BMI was 1.721 (95% CI, 1.336-2.217). In the female group, the maximal OR of ALT was found to be 1.104 (95% CI, 1.061-1.148). Age and thyroid-stimulating hormone (TSH) and γ-GT levels were also risk factors, but they appeared only in some groups. The results of the ROC analysis showed that ALT was a better predictor of pediatric NAFLD than BMI. The maximum area under the ROC curve in six of the nine groups belongs to ALT.

Conclusions

BMI, ALT, and age are risk factors for NAFLD in children with obesity before late puberty. BMI had the greatest exposure risk for NAFLD, and ALT had the highest predictive value for the diagnosis of NAFLD. At the stratified level, for exposure risk, age was specific to the male sex, TSH was specific to the early puberty stage, and γ-GT was specific to the female sex plus the prepuberty stage. On a stratified level, for the female sex, even with age stratification, BMI rather than ALT has a better ability for the diagnosis of NAFLD.

Prevalence and associated factors of metabolic-associated fatty liver disease in overweight Finnish children and adolescents

Introduction

Data on the prevalence of pediatric fatty liver disease remain limited, partly due to challenges in diagnosis. A novel concept of metabolic-associated fatty liver disease (MAFLD) makes it possible to establish the diagnosis in overweight children with sufficiently elevated alanine aminotransferase (ALT). We investigated the prevalence, risk factors, and metabolic co-morbidities of MAFLD in a large group of overweight children.

Methods

Data on 703 patients aged 2-16 years examined due to overweight in different levels of healthcare in 2002-2020 were collected retrospectively from patient records. MAFLD was here defined as ALT >2x reference (>44 U/l in girls and >50 U/l in boys) in overweight children according to recently updated definition. Patients with MAFLD and without it were compared, and subgroup analyses were conducted among boys and girls.

Results

Median age was 11.5 years, and 43% were girls. Altogether 11% were overweight, 42% obese and 47% severely obese. Abnormal glucose metabolism was present in 44%, dyslipidemia in 51%, hypertension in 48% and type 2 diabetes (T2D) in 2%. MAFLD prevalence varied between 14-20% in examined years without significant change (p=0.878). The pooled prevalence over the years was 15% (boys 18%, girls 11%; p=0.018), peaking in girls at early puberty and increasing in boys with age and puberty. Associated factors in boys were T2D (OR 7.55, 95% CI 1.23-46.2), postpubertal stage (5.39, 2.26-12.8), increased fasting insulin (3.20, 1.44-7.10), hypertriglyceridemia (2.97, 1.67-5.30), hyperglycemia (2.88, 1.64-5.07), decreased high-density lipoprotein (HDL) cholesterol (2.16, 1.18-3.99), older age (1.28, 1.15-1.42) and higher body-mass-index (1.01, 1.05-1.15), and in girls T2D (18.1, 3.16-103), hypertriglyceridemia (4.28, 1.99-9.21), and decreased HDL (4.06, 1.87-8.79).

Conclusion

Prevalence of MAFLD was 15%, with no statistically significant increase in the 2000s. The condition was associated in general with male gender, puberty stage and disturbances in glucose and lipid metabolism, and higher age and BMI in boys.

The association between perinatal factors and cardiometabolic risk factors in children and adolescents with overweight or obesity: A retrospective two-cohort study

BACKGROUND

Children with obesity have an increased risk of cardiometabolic risk factors, but not all children carry a similar risk. Perinatal factors, i.e., gestational age (GA) and birth weight for GA, may affect the risk for metabolic complications. However, there are conflicting data whether the association between birth size and cardiometabolic risk factors is independent among children with obesity. Moreover, differential effects of GA and birth weight for GA on cardiometabolic risk factors in pediatric obesity are still unexplored. We aimed to investigate the association between birth weight for GA and cardiometabolic risk factors in children and adolescents with overweight or obesity and to assess whether the association is modified by prematurity.

METHODS AND FINDINGS

We conducted a retrospective study of 2 cohorts, using data from the world's 2 largest registers of pediatric obesity treatment-The Swedish childhood obesity treatment register (BORIS) and The Adiposity Patients Registry (APV) (1991 to 2020). Included were individuals with overweight or obesity between 2 to 18 years of age who had data of birth characteristics and cardiometabolic parameters. Birth data was collected as exposure variable and the first reported cardiometabolic parameters during pediatric obesity treatment as the main outcome. The median (Q1, Q3) age at the outcome measurement was 11.8 (9.4, 14.0) years. The main outcomes were hypertensive blood pressure (BP), impaired fasting glucose, elevated glycated hemoglobin (HbA1c), elevated total cholesterol, elevated low-density lipoprotein (LDL) cholesterol, elevated triglycerides, decreased high-density lipoprotein (HDL) cholesterol, and elevated transaminases. With logistic regression, we calculated the odds ratio (OR) and its 95% confidence interval (CI) for each cardiometabolic parameter. All the analyses were adjusted for sex, age, degree of obesity, migratory background, and register source. In total, 42,760 (51.9% females) individuals were included. Small for GA (SGA) was prevalent in 10.4%, appropriate for GA (AGA) in 72.4%, and large for GA (LGA) in 17.2%. Most individuals (92.5%) were born full-term, 7.5% were born preterm. Median (Q1, Q3) body mass index standard deviation score at follow-up was 2.74 (2.40, 3.11) units. Compared with AGA, children born SGA were more likely to have hypertensive BP (OR = 1.20 [95% CI 1.12 to 1.29], p < 0.001), elevated HbA1c (1.33 [1.06 to 1.66], p = 0.03), and elevated transaminases (1.21 [1.10 to 1.33], p < 0.001) as well as low HDL (1.19 [1.09 to 1.31], p < 0.001). On the contrary, individuals born LGA had lower odds for hypertensive BP (0.88 [0.83 to 0.94], p < 0.001), elevated HbA1c (0.81 [0.67 to 0.97], p < 0.001), and elevated transaminases (0.88 [0.81 to 0.94], p < 0.001). Preterm birth altered some of the associations between SGA and outcomes, e.g., by increasing the odds for hypertensive BP and by diminishing the odds for elevated transaminases. Potential selection bias due to occasionally missing data could not be excluded.

CONCLUSIONS

Among children and adolescents with overweight/obesity, individuals born SGA are more likely to possess cardiometabolic risk factors compared to their counterparts born AGA. Targeted screening and treatment of obesity-related comorbidities should therefore be considered in this high-risk group of individuals.

Pediatric obesity-Long-term consequences and effect of weight loss

Childhood obesity is, according to the WHO, one of the most serious challenges of the 21st century. More than 100 million children have obesity today. Already during childhood, almost all organs are at risk of being affected by obesity. In this review, we present the current knowledge about diseases associated with childhood obesity and how they are affected by weight loss. One major causative factor is obesity-induced low-grade chronic inflammation, which can be observed already in preschool children. This inflammation-together with endocrine, paracrine, and metabolic effects of obesity-increases the long-term risk for several severe diseases. Type 2 diabetes is increasingly prevalent in adolescents and young adults who have had obesity during childhood. When it is diagnosed in young individuals, the morbidity and mortality rate is higher than when it occurs later in life, and more dangerous than type 1 diabetes. Childhood obesity also increases the risk for several autoimmune diseases such as multiple sclerosis, Crohn's disease, arthritis, and type 1 diabetes and it is well established that childhood obesity also increases the risk for cardiovascular disease. Consequently, childhood obesity increases the risk for premature mortality, and the mortality rate is three times higher already before 30 years of age compared with the normal population. The risks associated with childhood obesity are modified by weight loss. However, the risk reduction is affected by the age at which weight loss occurs. In general, early weight loss-that is, before puberty-is more beneficial, but there are marked disease-specific differences.