Low serum total bilirubin concentration in patients with type 1 diabetes mellitus complicated by retinopathy and nephropathy

Serum bilirubin as a biomarker of oxidative stress in children with type 1 diabetes mellitus: An observational study

This study aims to explore whether bilirubin can act as a biomarker of oxidative stress in type 1 diabetes mellitus (T1DM) by analyzing the serum bilirubin levels and possible influencing factors in different disease states and durations in children with T1DM. This is a retrospective study. The medical records of 1652 inpatients with T1DM and 101 healthy children in Shanxi Provincial Children's Hospital from 2014 to 2023 were collected and divided into different subgroups. The relevant indices in different disease states and durations in the T1DM group were statistically analyzed, particularly the serum bilirubin levels and possible influencing factors. Compared to children without diabetic ketoacidosis (DKA)/diabetic ketosis (DK), children with DKA/DK exhibited higher random blood glucose (RBG), HbA1C, total bilirubin (TBil), and indirect bilirubin (IBil) (P < .05). Compared to the control group, the levels of TBil and IBil in the newly-diagnosed and established T1DM children were statistically significantly higher (P < .05). Compared to newly-diagnosed T1DM children, serum TBil and IBil levels were statistically significantly lower in the established T1DM group and subgroups with different disease durations (P < .05). TBil and IBil were correlated with the status of blood glucose control and can be reflected by RBG, HbA1C, and DKA/DK (P < .05), but had no correlation was observed with disease duration (P > .05). Serum bilirubin possesses the potential to be a biomarker of oxidative stress in T1DM children.

Evaluation of some oxidative markers in diabetes and diabetic retinopathy

Aims

Diabetes mellitus and diabetic retinopathy (DR) are major public health concerns globally. Oxidative stress plays a central role in the pathogenesis of diabetes and DR. The aim of this study was to investigate the association of malondialdehyde, uric acid and bilirubin with diabetes and diabetic retinopathy development.

Methods

This study was conducted on 110 diabetics (with and without retinopathy). Beside 40 healthy individuals as a control group. The level of three markers (malondialdehyde, uric acid and bilirubin) was estimated in the studied groups. Receiver operating characteristic analysis and a logistic regression model was performed.

Results

The present study revealed significantly higher uric acid and malondialdehyde levels, while bilirubin showed significantly lower levels in diabetics compared to control and similarly in diabetic retinopathy compared to those without DR. Furthermore, combination of the three markers increased the accuracy and effect size for differentiation between diabetes with and without DR. In addition, higher levels of uric acid and malondialdehyde were associated with risk of diabetes and DR development.

Conclusion

This study concluded that higher levels of uric acid and malondialdehyde were associated with increase in the risk of diabetes and DR development, while bilirubin wasn't associated with decreasing the risk of diabetes or DR. However, the combination of malondialdehyde, uric acid and bilirubin may be a valuable addition to the current options for the prognosis of DR. In addition, malondialdehyde may be independent predictor of diabetes and DR as well as uric acid may be used as independent biomarker to predict the risk of DR.

Lower serum total bilirubin concentration is associated with higher prevalence of gestational diabetes mellitus in Japanese pregnant women

We aimed to clarify the pathophysiological significance of total bilirubin (TB) in gestational diabetes mellitus (GDM). This was a cross-sectional study that included 616 pregnant Japanese women (368 normal glucose tolerance [NGT] and 248 GDM). Serum TB concentration, homeostasis model assessment of insulin resistance (HOMA-IR), and other clinical parameters were compared in NGT and GDM women. TB concentration was also compared according to the number of abnormal OGTT values. Logistic regression analysis was used to evaluate the association between TB and GDM prevalence. A multiple linear regression model was used to evaluate the association between TB and HOMA-IR. TB concentrations were significantly lower in GDM women than in NGT women. This result did not change after adjustments for TB sampling timing were made. Out of 248 GDM women, the prevalences of 1- and 2/3- abnormal OGTT values (1- and 2/3-AV) GDM were 72.2% (n = 179) and 27.8% (n = 69), respectively. In the multiple comparisons, TB concentrations were significantly lower in women with 2/3-AV GDM than in women with NGT and 1-AV GDM. Multiple logistic regression analysis showed that TB was a significantly associated factor for 2/3-AV, but not for total GDM. HOMA-IR was significantly higher in GDM women than in NGT women. The univariate, but not multivariate, analysis showed that TB was a significantly associated factor for HOMA-IR. Our findings suggest that hypobilirubinemia may be involved in the pathogenesis of GDM.

Serum bilirubin levels are negatively associated with diabetic retinopathy in patients with type 1 diabetes and normal renal function

INTRODUCTION

Previous studies suggested that total serum bilirubin levels are negatively associated with diabetic retinopathy (DR) and nephropathy in patients with diabetes mellitus. The objective of this study was to explore the relationship between serum total bilirubin levels and prevalence of DR in patients with type 1 diabetes (T1DM) and normal renal function.

METHODS

Study included 163 T1DM with normal renal function (urinary albumin excretion rate <30 mg/24 h, estimated glomerular filtration rate (eGFR) >60 ml min^-11.73 m^-2). Photo-documented retinopathy status was made according to the EURODIAB protocol.

RESULTS

Patients with DR were older (49 vs 42 years, p = 0.001), had higher systolic blood pressure (130 vs 120 mmHg, p = 0.001), triglycerides (0.89 vs 0.77 mmol/L, p = 0.01), and lower serum total bilirubin (12 vs 15 U/L, p = 0.02) and eGFR (100 vs 106 ml min^-11.73 m^-2, p = 0.03). In multivariate logistic regression analysis, only total serum bilirubin was significantly associated with risk of DR in our subjects (OR 0.88, CI 0.81-0.96, p = 0.006).

CONCLUSION

These data suggest that serum total bilirubin levels are independently negatively associated with DR in T1DM with normal renal function. Prospective studies are needed to confirm whether lower serum total bilirubin has predictive value for the development of DR in T1DM with normal renal function.

Serum bilirubin concentration is associated with eGFR and urinary albumin excretion in patients with type 1 diabetes mellitus

AIMS

Although relationships of serum bilirubin concentration with estimated glomerular filtration rate (eGFR) and urinary albumin excretion (UAE) in patients with type 2 diabetes have been reported, whether such relationships exist in patients with type 1 diabetes is unknown.

METHODS

A total of 123 patients with type 1 diabetes were investigated in this cross-sectional study. The relationship between bilirubin (total and indirect) concentrations and log(UAE) as well as eGFR was examined by Pearson's correlation analyses. Multivariate regression analyses were used to assess the association of bilirubin (total and indirect) with eGFR as well as log(UAE).

RESULTS

A positive correlation was found between serum bilirubin concentration and eGFR; total bilirubin (r=0.223, p=0.013), indirect bilirubin (r=0.244, p=0.007). A negative correlation was found between serum bilirubin concentration and log(UAE); total bilirubin (r=-0.258, p=0.005), indirect bilirubin (r=-0.271, p=0.003). Multivariate regression analyses showed that indirect bilirubin concentration was an independent determinant of eGFR and log(UAE).

CONCLUSIONS

Bilirubin concentration is associated with both eGFR and log(UAE) in patients with type 1 diabetes. Bilirubin might have a protective role in the progression of type 1 diabetic nephropathy.