Bilirubin is independently associated with oxidized LDL levels in young obese patients

Research

Henrique Nascimento, Ana Inês Alves, Susana Coimbra, Cristina Catarino, Diana Gomes, Elsa Bronze-da-Rocha, Elísio Costa, Petronila Rocha-Pereira, Luísa Aires, Jorge Mota, Helena Ferreira Mansilha, Carla Rêgo, Alice Santos-Silva and Luís Belo

Diabetology Metabolic Syndrome 2015, 7:4 
doi:10.1186/1758-5996-7-4

Published: 23 January 2015

Abstract (provisional)

Background

Bilirubin can prevent lipid oxidation in vitro, but the association in vivo with oxidized
low-density lipoprotein (Ox-LDL) levels has been poorly explored. Our aim is to the
association of Ox-LDL with total bilirubin (TB) levels and with variables related
with metabolic syndrome and inflammation, in young obese individuals.

Findings: 125 obese patients (13.4 years; 53.6% females) were studied. TB, lipid profile
including Ox-LDL, markers of glucose metabolism, and levels of C-reactive protein
(CRP) and adiponectin were determined. Anthropometric data was also collected.

In all patients, Ox-LDL correlated positively with BMI, total cholesterol, LDLc, triglycerides
(TG), CRP, glucose, insulin and HOMAIR; while inversely with TB and HDLc/Total cholesterol
ratio (P 0.05 for all). In multiple linear regression analysis, LDLc, TG, HDLc and
TB levels were significantly associated with Ox-LDL (standardized Beta: 0.656, 0.293,
-0.283, -0.164, respectively; P 0.01 for all). After removing TG and HDLc from the
analysis, HOMAIR was included in the regression model. In this new model, LDLc remained
the best predictor of Ox-LDL levels (beta = 0.665, P 0.001), followed by TB (beta
= -0.202, P = 0.002) and HOMAIR (beta = 0.163, P = 0.010).

Conclusions

Lower bilirubin levels may contribute to increased LDL oxidation in obese children
and adolescents, predisposing to increased cardiovascular risk.