Gilbert’s syndrome as a protection against the development of other diseases

Abstract

Introduction and purpose Gilbert's syndrome is a condition caused by a mutation in the gene responsible for the enzyme UDP-glucuronosyltransferase 1A1, which conjugates bilirubin in hepatocytes. Its less efficient functioning results in disorder of bilirubin metabolism which leads to increased level of this compound. It has been observed that there is interesting correlation between elevated levels of bilirubin and the risk of developing certain diseases in patients with this condition. The aim of this review is to understand the correlation between elevated bilirubin levels and the risk of developing selected diseases in individuals with Gilbert's syndrome and how to use this knowledge in innovative therapeutic options. 
 State of knowledge Bilirubin was considered a non-functional waste product of heme breakdown, used to be seen as a concerning indicator of liver disease or even a potentially harmful substance for the nervous system. However, lately it turns out that bilirubin has strong antioxidant properties, which help to scavenge free radicals and inhibit lipid oxidation. Recent studies have shown that even slightly elevated levels of bilirubin in the blood, such as those commonly found in individuals with Gilbert's syndrome may protect these patients against diseases associated with increased oxidative stress, an overactive immune response and metabolic dysfunction. 
 Conclusions As a result, individuals with Gilbert's syndrome are observed to have a lower risk of developing diseases related to oxidative stress, such as cardiovascular diseases and cancer. In these patients mortality rate compared to the population with normobilirubinemia is decreased. Based on available studies, it has also been concluded that inducing mild hyperbilirubinemia - iatrogenic Gilbert's syndrome - using appropriate substances may have health benefits.