Association of Serum Bilirubin Level with Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study of 1672 Obese Children

Cristina Bellarosa,Claudio Tiribelli,Alessandro Sartorio,Annalisa Bianco,Diana Caroli,Sabrina Cicolini,Giorgio Bedogni

doi:10.3390/jcm10132812

Abstract

As in adults, obesity also plays a central role in the development of metabolic syndrome (MS) in children. Non-alcoholic fatty liver disease (NAFLD) is considered a manifestation of MS. Not only MS but also NAFLD seem to be inversely associated with serum bilirubin concentrations, an important endogenous tissue protector when only mild elevated. The aim of the study was to evaluate the association between serum bilirubin levels and the prevalence of MS and NAFLD in Italian obese children and adolescents. A retrospective cross-sectional study was performed in 1672 patients aged from 5 to 18 years. Clinical and laboratory parameters were assessed. NAFLD was measured by liver ultrasonography. The study was approved by the Ethical Committee of the Istituto Auxologico Italiano (research project code 1C021_2020, acronym BILOB). MS was present in 24% and fatty liver (FL) in 38% of this population. Bilirubin was not associated with FL and MS as a whole, but it was inversely associated only with selected components of MS, i.e., large WC, high blood pressure and high triglycerides. Our data suggest that bilirubin is not protective against MS and NAFLD in the presence of severe obesity.

Highlights

The prevalence of overweight and obesity in children and adolescents has substantially increased in recent years [1]
Pooling data from studies performed mainly in tertiary care centers, the mean prevalence of Non-alcoholic fatty liver disease (NAFLD) in children from general population studies was between 7.6% and 34.2% in studies based on child obesity clinics [18]
As the gender disparity in serum bilirubin does not manifest before 10 years of age [36], it has been postulated that hormonal changes at puberty might change bilirubin metabolism [55]

Summary

Introduction

The prevalence of overweight and obesity in children and adolescents has substantially increased in recent years [1]. Obesity plays a central role in the development of metabolic syndrome (MS) [2,3] in children and adolescents. Metabolic syndrome is an important clustering of metabolic abnormalities and anthropometric characteristics entailing an increased risk for mortality from cardiovascular and all causes in adults [4,5,6], as well as an increase in type-2 diabetes and early cardiovascular disease in adolescence [7]. There is increasing evidence that obesity, hyperglycemia and insulin resistance are risk factors for NAFLD in children [15,16,17]. Pooling data from studies performed mainly in tertiary care centers, the mean prevalence of NAFLD in children from general population studies was between 7.6% and 34.2% in studies based on child obesity clinics [18]

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Discussion

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