AUTHOR=Brandt Stephanie , von Schnurbein Julia , Denzer Christian , Kratzer Wolfgang , Wabitsch Martin 

TITLE=Lower Circulating Leptin Levels Are Related to Non-Alcoholic Fatty Liver Disease in Children With Obesity

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.881982

DOI=10.3389/fendo.2022.881982

ISSN=1664-2392

ABSTRACT=Background: While for individuals with obesity an association between hyperleptinemia and an increased risk of non-alcoholic fatty liver disease (NAFLD) is assumed, a leptin deficiency is also related to the development of NAFLD early in life in ob/ob mice, in patients with leptin deficiency due to biallelic likely pathogenic variants in the leptin gene, and in patients with lipodystrophy. 
Objectives: To investigate the association of circulating leptin levels in pre-pubertal children with obesity and steatosis hepatis.
Methods: The cross-sectional study consisted data of n=97 (n male=76) pre-pubertal children (11.8±1.5 years) with obesity (BMIz: 2.4±0.4). Fasting concentrations of cardiometabolic parameters were measured: insulin, c-peptide, glucose, triglyceride, cholesterol, HDL, LDL, AST, ALT, GGT, leptin. Steatosis hepatis was diagnosed by an ultrasound examination (mild, moderate or severe). Patients were categorized into two groups: low z-score of circulating leptin levels (≤25th percentile) vs. normal z-score of circulating leptin levels.
Results: One-third of the children with obesity were diagnosed with steatosis hepatis (I°: 63.6%, II°/III°: 36.4%). Children with steatosis hepatis had significantly lower z-scores of circulating leptin levels compared to children with an unremarkable liver ultrasonography (-2.1±0.8 vs. -0.7±0.6). Z-scores of circulating leptin levels correlate negatively with degree of steatosis hepatis. Children with low z-scores of circulating leptin levels had significantly higher triglyceride, fasting insulin and c-peptide levels compared to children with normal z-scores of circulating leptin levels. 
Conclusion: Prepubertal children with NAFLD and obesity and partial leptin deficiency might be defined as a clinical subgroup.