The association of ultra-processed food intake with adolescent metabolic dysfunction-associated steatotic liver disease in the NHANES.

INTRODUCTION: Metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major public health concern. A thorough analysis of the link between ultra-processed food (UPF) intake and MASLD in the adolescent population is lacking. METHODS: Adolescent participants of the National Health and Nutrition Examination Survey (NHANES) pre-pandemic cohort were included. Different controlled attenuation parameter (CAP) cut-offs were used to assess MASLD. The percentage energy intake of UPF, categorized according to the NOVA classification, to total energy intake was taken as the main outcome marker. Structural equation modelling (SEM) was used to better quantify the causal connection between UPF and liver steatosis. RESULTS: UPF consumption constituted a median 75% (62-86) of total energy intake. There was no significant correlation between UPF intake and CAP (ρ = 0.061, p = 0.091). The median proportion UPF intake was not associated with steatosis severity. SEM similarly yielded a weak and non-significant correlation of 0.078. In participants with MASLD, total energy intake was significantly higher (p < 0.001) and sugar-containing beverage (SCB) consumption showed a non-significant trend towards higher consumption. CONCLUSIONS: No clinically relevant association between UPF intake and MASLD in adolescents could be demonstrated. Our results nonetheless suggest that total energy intake and consumption of SCBs are important contributors to paediatric obesity and MASLD.

Adipose Tissue Insulin Resistance Correlates with Disease Severity in Pediatric Metabolic Dysfunction-Associated Steatotic Liver Disease: A Prospective Cohort Study.

OBJECTIVES: To assess the role of adipose tissue insulin resistance (Adipo-IR) in the pathogenesis of pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) and to determine Adipo-IR evolution during a lifestyle intervention program. STUDY DESIGN: In this prospective cohort study, children and adolescents with severe obesity were recruited between July 2020 and December 2022 at an inpatient pediatric rehabilitation center. Treatment consisted of dietary intervention and physical activity. Liver steatosis and fibrosis were evaluated using ultrasound examination and transient elastography with controlled attenuation parameter and liver stiffness measurement. Every 4-6 months, anthropometric measurements, serum biochemical analysis, ultrasound examination, and elastography were repeated. Adipo-IR was estimated by the product of the fasting serum insulin times the fasting free fatty acid concentration, and hepatic IR by the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), respectively. RESULTS: Of 200 patients with obesity, 56% had evidence of steatosis on ultrasound examination and 26% were diagnosed with fibrosis (≥F2). Adipo-IR increased progressively from lean controls to patients with obesity to patients with MASLD and MASLD with fibrosis. Adipo-IR was already increased in patients with only mild steatosis (P = .0403). Patients with more insulin-sensitive adipose tissue exhibited a lower liver fat content (P < .05) and serum alanine transaminase levels (P = .001). Adipo-IR correlated positively with visceral adipose tissue weight, waist circumference, and the visceral adipose tissue/gynoid adipose tissue ratio (P < .001), but not with total body fat percentage (P = .263). After 4-6 months of lifestyle management, both MASLD and Adipo-IR improved. CONCLUSIONS: Our data suggest that Adipo-IR is associated with the presence of pediatric MASLD, particularly steatosis.

Age-Dependent Signature of Serum Inflammatory Cytokines in Healthy Children and Young Adults.

The study of sensitive and specific biomarkers, such as blood inflammatory cytokines, could provide an answer to the challenges faced in the differential diagnosis of patients with systemic inflammation. Limited data exist on the impact of age on serum levels of inflammatory cytokines. We collected serum samples of 42 healthy children and young adults (1 month to 21 years). Serum levels of interleukin 1 receptor antagonist (IL-1Ra), IL-1ß, IL-6, IL-18, tumor necrosis factor-alpha (TNF-α), CXCL9, and CXCL10 were measured. Data were analyzed for three different age groups (<6, 6-17, and 18-21 years). IL-18, TNF-α, and CXCL9 values varied significantly according to age group. Median values of IL-18 and TNF-α decline with age, whereas CXCL9 and CXCL10 are lowest at 6-17 years. IL-1Ra is stable among age groups. In the majority of cases, IL-1ß and IL-6 are not measurable above the lower limit of quantification. A scoping literature review revealed highly variable data on IL-1Ra, IL-18, TNF-α, and CXCL10. For CXCL9, pediatric reference data are scarce. In conclusion, we report an age-dependent signature of multiple inflammatory cytokines measured in the serum of healthy children and young adults, suggesting the need to use age-specific reference values in future pediatric studies.