Abstract

Introduction: Bilirubin is the end product of heme catabolism. At physiological levels, bilirubin is a potent antioxidant and anti-inflammatory molecule. Oxidative stress and inflammation are major events linked to cardiovascular disease (CVD) and metabolic syndrome (MS), in which CVD is considered as one of the leading cause of death. A Mildly increased circulating total serum bilirubin level (TSB) seems to be a promising target for decreasing the prevalence of CVD and MS. The aim of this study is to evaluate the association of TSB with CVD and MS among Palestinian-population. Methods: A retrospective study was conducted in 2021 for 1446 participants and the medical records were collected from AL-Ahli hospital- Palestine. The examined samples were divided into four quartiles based on TSB (Q1= 0.1-0.4mg/dl, Q2 = 0.5-0.8mg/dl, Q3 = 0.9- 1.2mg/dl, Q4 = >1.2 mg/dl). The prevalence of CVD, MS and the correspondence laboratory parameters (e.g. bilirubin, lipid profile, and HbA1c) were analyzed in relation to TSB. Results: Total serum bilirubin and HDL were significantly lower in CVD patients compared to non-CVD persons. TSB, direct bilirubin and HDL were significantly higher in persons without MS compared to patients with MS. The prevalence of CVD in bilirubin level quartiles from 1-4 (95%CI in parentheses) was 33.7% (95%CI 28.5-42.1), 36% (95%CI 32.3-40.3), 7.7% (95% 3.4-11.8), 4.7% (95%CI 0.8-8.4) respectively (p-value <0.001). The prevalence of MS in bilirubin level quartiles from 1-4 (95%CI in parentheses) was 7.1% (95% 4.5-8.9), 5.7% (95%CI 3.2-7.1), 1.4% (95%CI 1.1-1.6), 0.8% (95%CI 0.6-1) respectively (p-value <0.05). Conclusions: In Palestinian adults, TSB is inversely related to the prevalence of CVD and MS. We suggest that TSB should be routinely tested in patients with risk of CVD and MS.