Circulating Adipsin as a Biomarker of Liver Fat Content in Prepubertal Children Born Small-for-Gestational-Age

Adipsin is a serine protease secreted mainly by adipocytes with a key role in the regulation of lipid metabolism and energy homeostasis. Individuals born small-for-gestational-age (SGA) with excessive postnatal catch-up in weight are at risk of developing central (hepato-visceral) fat deposition and features of metabolic dysfunction-associated steatotic liver disease (MASLD). We assessed cross-sectionally the serum concentrations of adipsin in seventy-five prepubertal children, aged ~7.8 yr, born appropriate-for-gestational-age (AGA, N = 40) or SGA (with spontaneous catch-up, N = 35) and their association with markers of abdominal adiposity and metabolic health. Assessments included anthropometry, serum adipsin, glucose, insulin, high-molecular-weight adiponectin (HMW-adip), lipids, and abdominal fat partitioning by magnetic resonance imaging (MRI). SGA children had higher serum adipsin levels [1.9 mg/L ± 0.4 vs. 1.4 mg/L ± 0.1 (mean ± SEM); p < 0.001], a less favorable endocrine–metabolic profile, and more hepato-visceral fat. Adipsin concentrations correlated inversely with birth weight and HMW-adip concentrations and positively with markers of insulin resistance, abdominal adiposity, and with the percentage of liver fat. Circulating adipsin concentrations are increased in prepubertal catch-up SGA children and are associated with features of MASLD. Circulating adipsin may become a novel biomarker of ectopic fat accumulation, linking early growth patterns to markers of metabolic risk.