Sex Differences in Body Composition and MASLD in Children With Overweight and Obesity

Aim: To explore the relationships between body composition, indices of hepatic fibrosis, and sonographic evidence of hepatic steatosis in children with overweight and obesity. Methods: One hundred and seventy individuals (age 12.7 ± 3.4 years, 38.2% boys) with overweight/obesity (BMI z-score 2.02 ± 0.54) underwent bioelectrical impedance analysis (fat percentage, truncal-to-total fat ratio, muscle-to-fat ratio [MFR]). Hepatic assessments included ultrasonography to detect liver steatosis, alanine transaminase (ALT), aspartate aminotransferase (AST)/ALT ratio, and nonalcoholic fatty liver disease fibrosis score (NFS). A forward logistic regression model, adjusting for sex, age, and socio-economic position, was conducted. Results: The odds for sonographic hepatic steatosis increased by 3.8-fold for each SD decrease in MFR z-score (OR = 0.263, 95% CI [0.067–1.031], p = 0.05). The strongest correlation among boys was between MFR z-score and AST/ALT ratio (r = 0.530, p < 0.001), whereas the strongest correlation among girls was between fat percentage and NFS (r = 0.503, p < 0.001). Individuals with sonographic hepatic steatosis had higher fat mass (p = 0.003), lower MFR z-score (p = 0.020), greater insulin resistance (p = 0.018), and atherogenic dyslipidemic index (p = 0.037) compared to those without. Conclusions: We identified sex differences in the association between body composition and hepatic fibrosis indices. The relationship between adverse body composition and increased odds of hepatic steatosis underscores the importance of its assessment within this at-risk population.