Relationship and Cigarette Smoking to Serum Bilirubin, Basra, Iraq

Background: One modifiable risk factor for cardiovascular disease is cigarette smoking. Smokers have lower levels of bilirubin, a powerful antioxidant. This study evaluates the association between bilirubin subtypes and cigarette smoking in healthy men. The study aimed to estimate the levels of total serum bilirubin (TSB), direct bilirubin (DBILI), indirect bilirubin (IDBILI), as well as AST, ALT, and ALP, to determine the relationship and the changes that occur in smokers compared with non-smokers. Method: A total of 80 male participants (50 smokers and 30 non-smokers) were included. Total serum bilirubin (TSB), direct bilirubin (DBILI), indirect bilirubin (IBILI), aspartate aminotransferase (AST/GOT), alkaline phosphatase (ALP), and alanine aminotransferase (ALT/GPT) were all tested. Results: The results showed that smokers had significantly higher levels of direct bilirubin (DBILI) and significantly lower levels of indirect bilirubin (IBILI) and ALT compared to non-smokers. No significant differences were found for TSB, AST, ALP, or age between the two groups. Correlation analysis revealed that age was positively associated with TSB, IBILI, AST, and ALP in non-smokers, but these relationships were absent in smokers. Conclusion: The findings suggest that cigarette smoking alters bilirubin metabolism and liver enzyme activity, potentially through mechanisms involving oxidative stress and hepatocellular damage. Monitoring these biomarkers could be useful for assessing early hepatic impact in smokers. The study emphasizes the need for preventive health interventions and further research on the hepatic effects of smoking.