Relationship of elevated bilirubin level with subclinical atherosclerosis and oxidative stress in Gilbert syndrome

This study aims to determine oxidant status and left ventricular mass index (LVMI) and their relationship with mild hyperbilirubinemia in patients with Gilbert syndrome (GS).

A total of 84 patients, including 41 (48.8%) patients with GS and 43 (51.2%) patients without GS, were included in the study. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were studied for oxidant status.

TAS was found to be higher in the GS patients compared to the non-GS patients (1.7±0.1 vs. 1.5±0.2; p=0.002); there was no significant difference between the groups in terms of mean TOS and mean OSI (p>0.05). No significant difference was observed between the GS and non-GS patients in terms of mean left ventricular volume and mean LVMI (p>0.05). However, subgroup analysis based on sex showed that GS patients had lower LVMI for both sexes. In GS patients, TAS level had a positive correlation with albumin (r=0.319; p=0.042), triglyceride (r=0.392; p=0.011), total bilirubin (r=0.420; p=0.006), direct bilirubin (r=0.361; p=0.020), and indirect bilirubin (r=0.338; p=0.0311) levels; no correlation was revealed between TAS level and other laboratory findings (p>0.05). The regression model showed that risk factors of direct bilirubin (?±SE=0.13±0.03; p<0.001), uric acid (?±SE=0.04±0.01; p=0.001), and albumin (?±SE=0.17±0.04; p<0.001) were independent predictors of TAS level.

This study revealed a relationship between mild hyperbilirubinemia and antioxidant balance in GS. Although statistical significance was not reached, LVMI was found to be lower in the GS group compared to the non-GS group for both sexes.