Association of bilirubin and malondialdehyde levels with retinopathy in type 2 diabetes mellitus

Abstract

Introduction:Bilirubin as an antioxidant and malondialdehyde (MDA) as an oxidant have been shown to be associated with various complications of type 2 diabetes mellitus (DM).Aims and Objectives:The aim was to measure the levels of serum bilirubin and MDA in type 2 DM patients with and without diabetic retinopathy (DR) and to correlate them with severity of DR.Materials and Methods:A total number of 120 subjects out of which 40 were controls without type 2 DM and the rest 80 were type 2 DM patients were included in the study. Of those 80 diabetics, 44 patients did not have DR and 36 patients had DR.Results:The total bilirubin, direct bilirubin, indirect bilirubin were higher in controls as compared to cases (P = 0.017, 0.033, 0.024). Serum MDA levels were found to be higher in diabetics as compared to controls (P = 0.00). The values of all the three parameters, that is, total bilirubin, direct bilirubin and indirect bilirubin were lower in patients with retinopathy as compared to those without retinopathic changes (P = 0.00, 0.020, and 0.007). Subjects were assigned to quartiles based on serum total bilirubin concentration. The prevalence of DR was significantly lower among persons with the highest bilirubin quartile compared to those with the lowest quartile. The severity of DR was inversely proportional to the total bilirubin levels (P = 0.001). The multiple logistic regression analysis showed total bilirubin to be associated with prevalence of DR (P = 0.035).Conclusions:The levels of total bilirubin were significantly lower in patients with DR and also in the late stages of retinopathy as compared to those without retinopathy and in controls but MDA levels did not show any association with DR.

Proliferative Diabetic Retinopathy: An Overview of Vitreous Immune and Biomarkers

“…MDA exerts its oxidative stress effect inside [25]. On the other hand, several studies found an increase in MDA serum of diabetic patients compared to control patients, but there was no significant difference in MDA serum level between non-proliferative DR and proliferative DR patients [24,27]. Our study found a mean activity level of MDA in the vitreous of patients with PDR at 1.661 ± 1.21 nmol/mL [26].…”

Effect of bilirubin concentration on the risk of diabetic complications: A meta-analysis of epidemiologic studies

“…Four hundred and ninety-eight studies were read in full, and 471 studies were excluded for various reasons. In total, 27 studies 7 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 satisfied the inclusion criteria for our meta-analysis. A flow chart of the screening process is shown in Fig.…”

“…The 27 studies were from five countries (one study was carried out in Australia 7 , thirteen in China 18 19 24 26 27 29 30 33 34 35 40 43 , one in India 28 , six in Japan 20 23 25 31 36 42 and six in Korea 21 22 37 38 39 41 ) and included five cohort studies 7 19 23 31 36 , sixteen cross-sectional studies 20 21 22 25 30 32 33 34 35 37 38 39 40 41 42 43 and six case-control studies 18 24 26 27 28 29 . Eleven studies assessed DN 19 22 23 24 25 29 31 32 33 40 43 , twelve assessed DR 18 19 25 26 27 28 30 34 35 36 40 , two assessed diabetic peripheral neuropathy (DPN) 39 40 ...…”

Elevated Serum Total Bilirubin Concentrations Are Negatively Associated with Diabetic Retinopathy among the Chinese Northeastern Population

“…The Heinz Nixdorf Recall study found that bilirubin showed a potential protective role in the atherosclerosis process [ 16 ]. Several studies have found that STBC was negatively associated with diabetic microvascular and macrovascular complications [ 17 – 19 ], and in 2017, a meta-analysis found that there was a negative association between STBC and diabetic complications [ 20 ]. A total of 674 patients with type 2 diabetes in Japan revealed that STBC was significantly lower in patients with retinopathy than in those without [ 10 ].…”