Oxidative Stress and Related Biomarkers in Gilbert’s Syndrome: A Secondary Analysis of Two Case-Control Studies

Abstract

Bilirubin is an important antioxidant and a modulator of biological functions. However, most of the protection against oxidative stress was shown in vitro or ex vivo. The aim of this case-control study was to investigate whether subjects with Gilbert’s syndrome (GS) experience different levels of lipid and protein oxidation (as well as differences in oxidative stress related markers) compared to healthy controls. GS subjects (n = 119) demonstrated higher serum levels of unconjugated bilirubin (p p p p p p p p n = 119). Furthermore, the resting heart rate was significantly lower in the GS group (p n = 104, average age 50 years) compared to those of the younger group (n = 134, average age 27 years). Although not all markers related to oxidative stress were different between the groups (e.g., malondialdehyde, homocysteine, oxLDL, and myeloperoxidase; p > 0.05), the observed differences contribute to the explanation of why GS serves as an important protector in the pathogenesis of metabolic, oxidative stress related diseases.

Keywords

• bilirubin
• unconjugated bilirubin
• oxidative stress
• inflammation
• antioxidants
• FRAP