ASSOCIATION BETWEEN SERUM BILIRUBIN LEVELS AND CORONARY ARTERY DISEASE: A CASE-CONTROL STUDY

Abstract

Background: Bilirubin is a strong antioxidant under physiological conditions and suppresses the oxidation of lipids and low density lipoproteins and prevents free radical injury. Lesser serum bilirubin levels are associated with Protein Kinase C activation, inflammation, and oxidative stress, which are known mediators of endothelial and microvascular dysfunction. Aim: to assess the association between serum bilirubin levels and coronary artery disease in comparison with controls without coronary artery disease. Material and methods: A case-control study was conducted in the Department of Medicine, Nalanda Medical College and Hospital Patna, Bihar, India from Jan 2019 to Jan 2020. Total of 160 subjects were included in the study with 80 cases and 80 controls. General and systemic examination was conducted on all study subjects including laboratory investigations like complete blood count, renal function test, lipid profile, viral markers such as HBsAG, HCVIgM and liver function test which includes total bilirubin, direct and indirect, liver enzymes, albumin and globulin levels. Results: The mean age among the cases male and female respectively was 62.76±8.2 and 63.85±8.3 and controls group were 61.85±8.4 and 62.38±8.5 years male and female respectively. 60% were male and 40% female in case group and 63.75% patients were male and 36.25% patients were female in control. The most common risk factors for CVD like diabetes, hypertension, smoking, obesity and family history of CVD was found to be slightly higher among the cases than the control groups but it was not found to be statistically significant and it proves that the controls were matched for almost all the risk factors for CVD except for dyslipidemia which was found to be significantly higher among the CVD patients than the controls. The mean duration of CVD was 4.4±2.8 years. The various liver function test parameters were compared between the cases and controls it was found that the serum bilirubin levels which includes total bilirubin, direct bilirubin and indirect bilirubin was found to be lower among the case group compared to the control group and this difference was found to be statistically significant, whereas the other parameters like SGOT, SGPT and GGT levels did not show much difference between the case and control groups and the difference in values were not statistically significant .we found a perfect linear correlation between the ejection fraction and serum bilirubin levels, as the ejection fraction decreases the serum bilirubin levels was also decreasing and all the serum bilirubin parameters were found to be very low in patients with ejection fraction 60% and this association was found to be statistically significant (p <0.05). Conclusion: relationship between the decreased serum bilirubin levels and the event of CAD; in this manner, bilirubin level can fill in as a prognostic factor, together with other significant factors for recognizing an individual who is in the peril of coronary artery disease.