Association of serum bilirubin levels and glycemic measurements in Type 2 diabetic patients

Abstract

Introduction: Bilirubin, a waste product of the heme catabolic pathway, has proven to be a natural antioxidant associated with a lower prevalence of oxidative stress-mediated diseases. This study evaluates the association of serum bilirubin levels with Glycated Hemoglobin (HbA1c), Fasting Blood Sugar (FBS) and Post Prandial Blood Sugar (PPBS) in diabetic patients. Methods: A retrospective analytical study was conducted at the Department of Haematology of the Sri Jayewardenepura General Hospital. Data was obtained through a laboratory information system of randomly selected 201 adult patients diagnosed with T2DM and grouped as poorly and well controlled using HbA1c values over and below 7%, respectively. Normal ranges for serum bilirubin, FBS, and PPBS were (0.3-1.2) mg/dL, (75-110) mg/dL and (80-140) mg/dL, respectively. Data were analyzed using (SPSS) version 20, descriptive statistical methods, Pearson’s Correlation test and independent sample t-test. P<0.05 was considered significant. Results: A negative correlation between total bilirubin and HbA1c (r = -0.234, p=0.001) was observed. There was no statistically significant correlation between total bilirubin level and FBS (p=0.131), PPBS (p=0.408), and age (p=0147). However, the mean values of total bilirubin (p=0.001), FBS (p<0.001) and PPBS (p<0.001) were significant between diabetes well controlled and poorly controlled groups. A statistically positive correlation was observed between HbA1c and FBS (p<0.001) and PPBS (p<0.001), but not with age (p=0.887). Conclusion: There was a significant relationship between total bilirubin with FBS, and PPBS in both groups. A significant negative correlation was found between total bilirubin and HbA1c, suggesting a potential protective or modulatory role of bilirubin in glycemic control. No significant correlation was observed between total bilirubin levels and FBS, PPBS, or age in the total population.
Keywords: T2DM, HbA1c, bilirubin, FBS, PPBS