Bilirubin in metabolic syndrome and associated inflammatory diseases: New perspectives

Association of Pretreatment Serum Indirect Bilirubin Levels With Prognostic and Therapeutic Value in Patients With Newly Diagnosed Acute Myeloid Leukemia

BACKGROUND

Bilirubin has anti-inflammatory, antioxidant, and anti-cancer properties, with an inverse relationship between its levels and cancer risk and prognosis. However, the prognostic value of serum bilirubin in acute myeloid leukemia (AML) remains uncertain.

METHODS

This retrospective study analyzed pretreatment serum total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL) in 284 AML patients and 316 healthy controls. The prognostic significance of serum bilirubin levels was determined using the Kaplan-Meier method and Cox proportional hazards model.

RESULTS

Pretreatment TBIL and IBIL levels were significantly lower in AML patients compared to controls. TBIL and IBIL levels were significantly higher in the CR/CRh/CRi group than in the non-CR/CRh/CRi group and increased significantly after chemotherapy. Elevated pretreatment TBIL and IBIL were associated with longer overall survival (OS) (p < 0.05) and progression-free survival (PFS) (p < 0.05). Pretreatment IBIL was an independent prognostic factor for OS (hazard ratio [HR], 0.47; 95% confidence interval [CI] 0.28-0.79; p < 0.05) and PFS (HR, 0.53; 95% CI 0.33-0.85; p < 0.05).

CONCLUSION

Elevated pretreatment IBIL levels are correlated with improved OS and PFS, acting as an independent favorable prognostic indicator for AML.

Association of breast milk microbiota and metabolites with neonatal jaundice

Background

Breast milk is the primary source of nutrition during early life, and existing research indicates that the development of jaundice in breastfed newborns may be linked to specific nutrients or bioactive substances present in breast milk. However, the association between the microbiota and small-molecule metabolites in breast milk and the development of neonatal jaundice remains unproven. This study aimed to investigate the development of jaundice in breastfed neonates in relation to breast milk microbiota and metabolites.

Methods

Based on the conditions of exclusive breastfeeding, we selected healthy newborns without significant jaundice and their mothers on day 4 (96-120 h after birth) as the healthy control group, and jaundiced newborns and their mothers as the jaundice group. Breast milk samples were collected from mothers in both groups on postnatal day 4 and analyzed for microbiota and small-molecule metabolites using 16S rRNA gene sequencing and an liquid chromatography-tandem mass spectrometry techniques.

Results

A total of 104 mother-child pairs were included in the study, of which 51 pairs were in the healthy control group and the other 53 pairs were in the jaundice group. Our results demonstrated that there was no significant difference between the species composition and diversity of the breast milk flora in the healthy control and jaundice groups. At the genus level, the abundance of Lactobacillus, Ackermannia, and Bifidobacterium was significantly higher in the breast milk of the healthy control group than in the jaundice group. Metabolomics analysis revealed a total of 27 significantly different metabolites between the two groups. Notably, breast milk from the healthy control group had elevated levels of 24 metabolites, predominantly lipids family, including sphingolipids, phospholipids, and fatty acid derivatives.

Conclusion

This study suggests that there is a link between the development of neonatal jaundice and breast milk microbiota and metabolites. Breast milk from mothers of healthy newborns contains higher levels of beneficial bacteria and lipid family compared to mothers of newborns with jaundice. This study offers new insights into the relationship between breastfeeding and neonatal jaundice.

The Correlation Between Plasma Bilirubin Concentrations and Glomerular Filtration Rate and Creatinine in Type 2 Diabetes with Renal Damage

Background

Diabetic nephropathy is one of the causes of chronic kidney disease with a very complex mechanism, in which oxidative stress plays an important role and bilirubin acts as an effective antioxidant, protecting cells from damage caused by oxidative stress.

Objective

The aim of the study was to investigate the relationship between plasma bilirubin concentration with glomerular filtration rate and creatinine in patients with type 2 diabetes with renal damage.

Methods

Total amount of 60 patients with type 2 diabetes with renal damage. Study design was descriptive.

Results

Mean age 64.1±4.76. The rate of decreased glomerular filtration rate was 86.7% and increased albuminuria accounted for 96.7%. The concentration of total bilirubin in plasma decreased correspondingly to the decrease in glomerular filtration rate. The concentration of total, free and conjugated bilirubin was negatively correlated with creatinine concentration (r=-0.48), (r=-0.37), (r=-0.34) and positively correlated with glomerular filtration rate (r=0.54), (r=0.45), (r=0.41) with p<0.05). The area under the curve (AUC) of total bilirubin concentration was 0.7, lower than the area under the curve (AUC) of creatinine concentration 0.8, uric acid 0.74.

Conclusion

Plasma bilirubin concentration is inversely correlated with creatinine concentration and positively correlated with glomerular filtration rate.

Proteomics Profiling of Bilirubin Nanoparticle Treatment against Myocardial Ischemia-Reperfusion Injury

In myocardial infarction, ischemia-reperfusion injury (IRI) poses a significant challenge due to a lack of effective treatments. Bilirubin, a natural compound known for its anti-inflammatory and antioxidant properties, has been identified as a potential therapeutic agent for IRI. Currently, there are no reports about proteomic studies related to IRI and bilirubin treatment. In this study, we explored the effects of bilirubin nanoparticles in a rat model of myocardial IRI. A total of 3616 protein groups comprising 76,681 distinct peptides were identified using LC-MS/MS, where we distinguished two kinds of protein groups: those showing increased expression in IRI and decreased expression in IRI with bilirubin treatment, and vice versa, accounting for 202 and 35 proteins, respectively. Our proteomic analysis identified significant upregulation in the Wnt and insulin signaling pathways and increased Golgi markers, indicating their role in mediating bilirubin nanoparticle's protective effects. This research contributes to the proteomic understanding of myocardial IRI and suggests bilirubin nanoparticles as a promising strategy for cardiac protection, warranting further investigation in human models.

Association of total bilirubin and prognosis in disorders of consciousness

Accurate prediction of the recovery of Disorders of Consciousness (DoC) is of paramount significance for clinicians and families. Serum total bilirubin (TBIL) formed by activation of heme oxygenase 2, is associated with incidence and prognosis of cardiovascular and cerebrovascular diseases. However, studies that based TBIL and DoC are limited. The study attempted to examine the association between serum TBIL levels and prognosis in patients with DoC. One hundred and sixty-eight patients with DoC in the Second hospital of Shandong University from June 2021 to June 2023 were recruited. The clinical characteristics and venous blood samples were collected within 24 h after admission. The diagnosis of DoC was determined by two skilled investigators employing various behavioral evaluations along the coma recovery scale-revised (CRS-R) and the investigators conducted follow-up assessments of diagnosis at 1, 3, and 6 months after admission. For statistical analysis, we categorized patients with an improvement in clinical diagnosis from study entry as having a "good outcome". In total, 139 individuals enrolled in the study. The median TBIL level was 8.2 μmol/L. Good recovery of DoC at 1, 3, and 6 months occurred in 25 (18.0%), 41 (29.5%), and 56 (40.3%) patients, respectively. After full adjustment, a significant association was found between TBIL levels and the prognosis of DoC at 1, 3, and 6 months. When TBIL levels were analyzed as categorical variables, an increasing trend in the tertiles of TBIL levels demonstrated a significant positive association with the recovery of DoC at 1, 3, and 6 months. Stratified analysis revealed that the association between serum TBIL levels and the recovery of DoC remained consistent across different sub-populations. A high serum TBIL level is associated with an improved likelihood of recovery of DoC. Additional research is required to elucidate the underlying pathophysiological causal association between TBIL levels and DoC.

High-normal serum bilirubin is a useful indicator to assess the risk of diabetic retinopathy in type 2 diabetes: A real-world study

BACKGROUND

To investigate the association of serum bilirubin within normal range, especially unconjugated bilirubin (UCB), with diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this cross-sectional, real-world study, 7617 T2DM patients were stratified into quartiles based on serum UCB levels. DR was determined by digital fundus photography and further classified into non-proliferative diabetic retinopathy (NPDR) and PDR. The associations of serum bilirubin levels and UCB quartiles with DR were investigated by logistic regression analysis.

RESULTS

After controlling for age, sex, and diabetes duration, the DR prevalence was significantly decreased across the serum UCB quartiles (40.4 %, 33.4 %, 29.7 %, 26.6 % for each quartile, respectively, p < 0.001 for trend). The subjects with DR had lower serum total bilirubin (TB) and UCB, rather than conjugated bilirubin (CB), compared with those without DR (p = 0.003 for TB, p < 0.001 for UCB, and p = 0.528 for CB, respectively), while all three types of serum bilirubin in the subjects with PDR were obviously lower than those with NPDR (p = 0.006 for TB, and p < 0.001 for UCB and CB, respectively). After adjustment for confounding factors, logistic regression demonstrated negative associations of serum TB and UCB levels, rather than CB, with the presence of DR (OR: 0.844, 95%CI: 0.774-0.920, p < 0.001 for TB; OR: 0.828, 95%CI: 0.763-0.899, p < 0.001 for UCB; and OR: 0.984, 95%CI: 0.900-1.074, p = 0.713 for CB, respectively). Additionally, a fully-adjusted analysis revealed a negative correlation between UCB quartiles and DR (p < 0.001).

CONCLUSION

High-normal serum TB and UCB were closely associated with the decreased odds of DR, while all types of serum bilirubin were negatively correlated with the severity of DR in T2DM patients. Serum bilirubin may be used as a potential indicator to assess the risk and severity of DR in T2DM.

Bilirubin, once a toxin but now an antioxidant alleviating non-alcoholic fatty liver disease in an autophagy-dependent manner in high-fat diet-induced rats: a molecular and histopathological analysis

Background and purpose

As an endogenous antioxidant, bilirubin has surprisingly been inversely correlated with the risk of non-alcoholic fatty liver disease (NAFLD). Thereupon, the current evaluation was designed to assess the positive effects of bilirubin on the autophagy flux, as well as the other pathogenic processes and parameters involved in the expansion of NAFLD.

Experimental approach

Thirty adult male rats weighing 150-200 g with free access to sucrose solution (18%) were randomly subdivided into 5 groups (n = 6). Subsequently, the animals were euthanized, and their blood specimens and liver tissue samples were collected to measure serum biochemical indices, liver histopathological changes, intrahepatic triglycerides content, and tissue stereological alterations. Furthermore, the expression levels of autophagy-related genes (Atgs) were measured to assess the state of the autophagy flux.

Findings/Results

Fasting blood glucose, body weight, as well as liver weight, liver-specific enzyme activity, and serum lipid profile indices markedly decreased in rats that underwent a six-week bilirubin treatment compared to the control group. In addition, histopathological studies showed that hepatic steatosis, fibrosis, inflammation, and necrosis significantly decreased in the groups that received bilirubin compared to the control animals. Bilirubin also caused significant alterations in the expression levels of the Atgs, as well as the Beclin- 1 protein.

Conclusion and implication

Bilirubin may have potential ameliorative effects on NAFLD-associated liver damage. Moreover, the beneficial effects of bilirubin on intrahepatic lipid accumulation and steatosis were comparable with the group that did not ever receive bilirubin.

Clinical implications of persistent joint pain after gout flare

OBJECTIVES

A subset of gout patients developed persistent joint pain after flares. Analysis of this clinical phenomenon may shed further light on the factors related to worsening gout and even provide clues to its pathogenesis.

METHODS

We analyzed the clinical, laboratory, and ultrasound data of gout patients to explore the associations of these data with persistent joint pain after gout flares.

RESULTS

A total of 1029 gout patients were included: 182 (17.7%) patients with persistent joint pain and 847 (82.3%) patients with nonpersistent joint pain. Patients with persistent joint pain had more total involved joints, more gout flares in the past year, and more joints with simultaneous gout flares (P<0.01). Among the ultrasound-detected lesions, patients with persistent joint pain had a higher incidence of tophus (36.4% vs. 21.1%) and bone erosion (18.6% vs. 8.6%) (P<0.05). Higher UA and lower TBil were found in patients with persistent joint pain (P<0.001). Hypertension (54.9% vs. 38.7%) and metabolic syndrome (58.8% vs. 46.4%) were both more frequent in patients with persistent joint pain (P<0.05). TBil was negatively correlated with the incidence of persistent joint pain (P<0.001, r=-0.190), UA values (P<0.001, r=-0.125), and metabolic syndrome scores (P<0.001, r=-0.192). A correlation curve was fitted using LOESS (locally weighted region).

CONCLUSION

Persistent joint pain after gout flares is a marker of increased disease burden in gout. The significance of the level of total bilirubin for the exacerbation of gout deserves further study.

Activation of Nrf2/HO-1 signaling pathway exacerbates cholestatic liver injury

Nuclear factor erythroid 2-related factor-2 (Nrf2) antioxidant signaling is involved in liver protection, but this generalization overlooks conflicting studies indicating that Nrf2 effects are not necessarily hepatoprotective. The role of Nrf2/heme oxygenase-1 (HO-1) in cholestatic liver injury (CLI) remains poorly defined. Here, we report that Nrf2/HO-1 activation exacerbates liver injury rather than exerting a protective effect in CLI. Inhibiting HO-1 or ameliorating bilirubin transport alleviates liver injury in CLI models. Nrf2 knockout confers hepatoprotection in CLI mice, whereas in non-CLI mice, Nrf2 knockout aggravates liver damage. In the CLI setting, oxidative stress activates Nrf2/HO-1, leads to bilirubin accumulation, and impairs mitochondrial function. High levels of bilirubin reciprocally upregulate the activation of Nrf2 and HO-1, while antioxidant and mitochondrial-targeted SOD2 overexpression attenuate bilirubin toxicity. The expression of Nrf2 and HO-1 is elevated in serum of patients with CLI. These results reveal an unrecognized function of Nrf2 signaling in exacerbating liver injury in cholestatic disease.

COVID-19 and β-thalassemia: in lieu of evidence and vague nexus

Coronavirus disease 19 (COVID-19) is an infectious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2) causing acute systemic disorders and multi-organ damage. β-thalassemia (β-T) is an autosomal recessive disorder leading to the development of anemia. β-T may lead to complications such as immunological disorders, iron overload, oxidative stress, and endocrinopathy. β-T and associated complications may increase the risk of SARS-CoV-2, as inflammatory disturbances and oxidative stress disorders are linked with COVID-19. Therefore, the objective of the present review was to elucidate the potential link between β-T and COVID-19 regarding the underlying comorbidities. The present review showed that most of the β-T patients with COVID-19 revealed mild to moderate clinical features, and β-T may not be linked with Covid-19 severity. Though patients with transfusion-dependent β-T (TDT) develop less COVID-19 severity compared to non-transfusion-depend β-T(NTDT), preclinical and clinical studies are recommended in this regard.

Association between serum total bilirubin and diabetic kidney disease in US diabetic patients

Background

Bilirubin has been widely reported to be a protective factor against diabetic kidney disease (DKD) in Asian populations. However, few large-sample analyses have been conducted in American populations. This study aimed to investigate the association between serum total bilirubin (STB) level and DKD in a US diabetic cohort.

Methods

This cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Univariate and multivariate logistic regression analyses were performed to assess the association between STB level and DKD. Three models were conducted to control the potential confounding factors. Subgroup analysis was carried out for further validation.

Results

Among the 5,355 participants, the median age [interquartile range (IQR)] was 62 [52-71] years; 2,836 (52.96%) were male, and 1,576 (29.43%) were diagnosed with DKD. In the entire cohort, no significant association between STB level and DKD was observed in any logistic regression models (p > 0.05). Subgroup analysis revealed that, in U.S. diabetic males, STB levels > 11.98 µmol/L were associated with a nearly 30% lower risk of DKD than STB levels ≤ 8.55 µmol/L. Additionally, a moderate STB level (8.56-11.98 μmol/L) was found associated with a nearly 25% lower risk of DKD in U.S. diabetic patients over 65 years old.

Conclusion

The association of STB level with DKD may depict differences across diverse populations, among which the impact of race, sex, and age requires thorough consideration and relevant inferences should be interpreted cautiously.

Total bilirubin and bilirubin-to-triglycerides ratio predict changes in glycated hemoglobin in healthy children

Objective

Bilirubin and triglycerides can regulate insulin secretion and glucose uptake. The aim of our study is to analyze associations between total bilirubin (TB) and the bilirubin-to-triglycerides ratio (BTR) with metabolic markers in healthy prepubertal children.

Methods

Subjects were 246 healthy children (mean age 8), of whom 142 (58%) were reevaluated 4 years later (mean age 12). The subjects were stratified according to age into three groups (<7.8 years; 7.8-9.6 years; and >9.6 years; n=82 each) at baseline and into two groups (<12.9 years and ≥12.9 years; n=71 each) at follow-up. Anthropometrics and laboratory parameters [TB and its fractions (direct and indirect bilirubin), triglycerides, HDL-cholesterol, glucose, insulin, HOMA-IR, HOMA-B and glycated hemoglobin (HbA1c)] were assessed at both baseline and follow-up.

Results

TB and BTR showed independent and negative association with baseline and follow-up HbA1c. These associations were stronger for BTR and in the highest age group. No independent associations were observed with HOMA-IR or HOMA-B.

Conclusion

TB and BTR are independently associated with HbA1c and predict its changes over time in healthy children. Our results indicate that TB and BTR may be useful parameters in studies of glucose tolerance in healthy children.

Transitioning from having no metabolic abnormality nor obesity to metabolic impairment in a cohort of apparently healthy adults

INTRODUCTION

The global prevalence of metabolic syndrome and its association with increased morbidity and mortality has been rigorously studied. However, the true prevalence of "metabolic health", i.e. individuals without any metabolic abnormalities is not clear. Here, we sought to determine the prevalence of "metabolically healthy" individuals and characterize the "transition phase" from metabolic health to development of dysfunction over a follow-up period of 5 years.

METHODS

We included 20,507 individuals from the Tel Aviv Sourasky Medical Center Inflammation Survey (TAMCIS) which comprises apparently healthy individuals attending their annual health survey. A second follow-up visit was documented after 4.8 (± 0.6) years. We defined a group of metabolically healthy participants without metabolic abnormalities nor obesity and compared their characteristics and change in biomarkers over time to participants who developed metabolic impairment on their follow-up visit. The intersections of all metabolic syndrome components and elevated high sensitivity C-reactive protein (hs-CRP) were also analyzed.

RESULTS

A quarter of the cohort (5379 individuals, (26.2%) did not fulfill any metabolic syndrome criteria during their baseline visit. A total of 985 individuals (12.7% of returning participants) developed metabolic criteria over time with hypertension being the most prevalent component to develop among these participants. Individuals that became metabolically impaired over time demonstrated increased overlap between metabolic syndrome criteria and elevated hs-CRP levels. The group that became metabolically impaired over time also presented higher delta values of WBC, RBC, liver biomarkers, and uric acid compared with participants who were consistently metabolically impaired. LDL-C (low-density lipoprotein cholesterol) delta levels were similar.

CONCLUSIONS

Roughly one-quarter of apparently healthy adults are defined as "metabolically healthy" according to current definitions. The transition from health to metabolic dysfunction is accompanied with active inflammation and several non-metabolic syndrome biomarkers. Aggressive screening for these biomarkers, blood pressure and hs-CRP might help identify apparently healthy individuals at increased risk of developing metabolic syndrome over time.

Association between total bilirubin and gender-specific incidence of fundus arteriosclerosis in a Chinese population: a retrospective cohort study

To investigate the gender-specific relationship between total bilirubin (TBIL) and fundus arteriosclerosis in the general population, and to explore whether there is a dose-response relationship between them. In a retrospective cohort study, 27,477 participants were enrolled from 2006 to 2019. The TBIL was divided into four groups according to the quartile. The Cox proportional hazards model was used to estimate the HRs with 95% CIs of different TBIL level and fundus arteriosclerosis in men and women. The dose-response relationship between TBIL and fundus arteriosclerosis was estimated using restricted cubic splines method. In males, after adjusting for potential confounders, the Q2 to Q4 level of TBIL were significantly associated with the risk of fundus arteriosclerosis. The HRs with 95% CIs were 1.217 (1.095-1.354), 1.255 (1.128-1.396) and 1.396 (1.254-1.555), respectively. For females, TBIL level was not associated with the incidence of fundus arteriosclerosis. In addition, a linear relationship between TBIL and fundus arteriosclerosis in both genders (P < 0.0001 and P = 0.0047, respectively). In conclusion, the incidence of fundus arteriosclerosis is positively correlated with serum TBIL level in males, but not in females. In addition, there was a linear dose-response relationship between TBIL and incidence of fundus arteriosclerosis.

Toward nanotechnology-enabled application of bilirubin in the treatment and diagnosis of various civilization diseases

Bilirubin, an open chain tetrapyrrole, has powerful antioxidant, anti-inflammatory, immuno-suppressive, metabolic-modulating and anti-proliferative activities. Bilirubin is a natural molecule that is produced and metabolized within the human body, making it highly biocompatible and well suited for clinical use. However, the use of bilirubin has been hampered by its poor water solubility and instability. With advanced construction strategies, bilirubin-derived nanoparticles (BRNPs) have not only overcome the disadvantages of bilirubin but also enhanced its therapeutic effects by targeting damaged tissues, passing through physiological barriers, and ensuring controlled sustained release. We review the mechanisms underlying the biological activities of bilirubin, BRNP preparation strategies and BRNP applications in various disease models. Based on their superior performance, BRNPs require further exploration of their efficacy, biodistribution and long-term biosafety in nonhuman primate models that recapitulate human disease to promote their clinical translation.

Ameliorative effects of bilirubin on cell culture model of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is defined as the most prevalent hepatic disorder that affects a significant population worldwide. There are several genes/proteins, involving in the modulation of NAFLD pathogenesis; sirtuin1 (SIRT1), TP53-inducible regulator gene (TIGAR), and autophagy-related gene 5 (Atg5) are considered a chief group of these modulators that principally act by regulating the hepatic lipid metabolism, as well as preventing the lipid accumulation. Surprisingly, bilirubin, especially in its unconjugated form, might be able to alleviate NAFLD progression by decreasing lipid accumulation and regulating the expression levels of the above-stated genes.

METHODS AND RESULTS

Herein, the interactions between bilirubin and the corresponding genes' products were first analyzed by docking assessments. Afterwards, HepG2 cells were cultured under the optimum conditions, and then were incubated with high concentrations of glucose to induce NAFLD. After treating normal and fatty liver cells with particular bilirubin concentrations for 24- and 48-hour periods, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay, colorimetric method, and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) were employed to assess cell viability status, intracellular triglycerides content, and mRNA expression levels of the genes, respectively. Intracellular lipid accumulation of HepG2 cells was significantly decreased after treating with bilirubin. Bilirubin also increased SIRT1 and Atg5 gene expression levels in fatty liver cells. TIGAR gene expression levels were variable upon the conditions and the cell type, suggesting a dual role for TIGAR during the NAFLD pathogenesis.

CONCLUSION

Our findings indicate the potential of bilirubin in the prevention from or amelioration of NAFLD through influencing SIRT1-related deacetylation and the process of lipophagy, as well as decreasing the intrahepatic lipid content. In vitro model of NAFLD was treated with unconjugated bilirubin under the optimal conditions.Desirably, bilirubin moderated the accumulation of triglycerides within the cells possibly through modulation of the expression of SIRT1, Atg5, and TIGAR genes. In the context, bilirubin was shown to increase the expression levels of SIRT1 and Atg5, while the expression of TIGAR was demonstrated to be either increased or decreased, depending on the treatment conditions. Created with BioRender.com.

Prognostic value of liver damage assessed through direct bilirubin levels and skeletal muscle weakness in patients with heart failure

BACKGROUND

Patients with heart failure (HF) often exhibit signs of liver dysfunction such as high bilirubin concentrations, leading to physical dysfunction and poor prognosis. Nevertheless, the relationship between direct bilirubin (DB), a fractionated form of total bilirubin, and dynapenia remains unclear, as does their effect on prognosis.

OBJECTIVES

This study investigated the association between DB concentrations and dynapenia in patients with HF.

METHODS

This retrospective study included patients with HF who underwent assessments for DB concentration, and handgrip and leg strengths to evaluate dynapenia and muscle weakness, respectively. Multiple logistic regression analyses examined the associations of DB with muscle strength and dynapenia. Additionally, we examined the prognostic value of comorbid high DB concentrations (≥0.5 mg/dL) and dynapenia. The endpoint was all-cause mortality.

RESULTS

Of 853 inpatients, high DB was identified in 147 and dynapenia in 377 (44.2%). Multiple regression analysis revealed that high DB was independently associated with decreased muscle strength (handgrip strength, P = 0.027; leg strength, P = 0.002). After adjusting for covariates, the high DB group (odds ratio: 1.800, 95% confidence interval [CI]: 1.203-2.695, P = 0.004) had a significantly higher risk of dynapenia than the low DB group. During the follow-up period, 189 patients died (median, 1.77 years; interquartile range, 0.64-3.81 years). The risk of death was significantly higher in the high DB and dynapenia group, even after adjusting for HF severity (hazard ratio: 2.610, 95% CI: 1.680-4.051, P<0.001).

CONCLUSIONS

High DB is associated with muscle weakness, and when combined with dynapenia, DB predicts a poorer prognosis in patients with HF.

Breast milk jaundice affects breastfeeding: From the perspective of intestinal flora and SCFAs-GPR41/43

Breast milk jaundice (BMJ) is one of the main factors leading to interruption or early termination of breastfeeding. Interrupting breastfeeding to treat BMJ may increase the adverse consequences for infant growth and disease prevention. The Intestinal flora and metabolites are increasingly recognized as a potential therapeutic target in BMJ. First, dysbacteriosis can lead to a decrease in the metabolite short-chain fatty acids. At the same time, SCFA can act on specific G protein-coupled receptors 41 and 43 (GPR41/43), and a decrease in SCFA downregulates the GPR41/43 pathway, leading to a diminished inhibition of intestinal inflammation. In addition, intestinal inflammation leads to a decrease in intestinal motility and a large amount of bilirubin enters the enterohepatic circulation. Ultimately, these changes will result in the development of BMJ. In this review, we will describe the underlying pathogenetic mechanism of the intestinal flora effects on BMJ.

Serum Bilirubin Levels and Disease Severity in Patients with Pneumoconiosis

Aim

To investigate the association between serum bilirubin and disease severity in patients with pneumoconiosis.

Methods

The study comprised 45 patients with pneumoconiosis retrospectively; all pneumoconiosis patients were classified into I, II, and III stage according to the radiological severity.

Results

Serum direct bilirubin levels were significantly lower in III stage pneumoconiosis patients than those in I/II stage (p = 0.012) but not serum indirect bilirubin. Serum direct bilirubin was negatively correlated with radiological severity in patients with pneumoconiosis (r = -0.320; p = 0.032); by multiple linear-regression analysis, we observed that serum direct bilirubin levels had independent association with radiological severity in patients with pneumoconiosis (beta = -0.459; p = 0.005).

Conclusions

Serum direct bilirubin levels are negatively associated with disease severity in patients with pneumoconiosis.

Serum total bilirubin and new-onset hypertension in perimenopausal women: a cross-sectional study

OBJECTIVE

Previous studies have shown negative associations between total bilirubin (TBIL) and hypertension. However, the association of TBIL with new-onset hypertension in perimenopausal women is unknown.

METHODS

A total of 196 perimenopausal women were included in this cross-sectional study of which 85 had new-onset hypertension. All participants underwent 24-hour ambulatory blood pressure monitoring and a clinical assessment including anthropometrics. Sociodemographic, lifestyle, and menopausal symptoms (modified Kupperman Index [mKI]) were measured by questionnaire. A fasting blood sample was taken to measure a wide range of biomarkers and hormone levels. Restricted cubic spline regression was used to investigate potential nonlinearity. Multivariable logistic and robust linear regression analyses adjusting for minimal sufficient adjustment sets based on directed acyclic graphs were performed to test the association of TBIL with hypertension/blood pressure. We examined mKI-stratified analyses and a TBIL-mKI interaction term to explore potential effect modification by number of menopausal symptoms.

RESULTS

Hypertensive women had significantly lower TBIL levels than did normotensive women (11.15 vs 12.55 μmol/L, P = 0.046). Univariate restricted cubic spline regression showed nonsignificant nonlinearity ( P value for nonlinearity, 0.339). Multivariable regression analyses adjusted for minimal sufficient adjustment sets revealed that higher TBIL level was associated with lower odds of hypertension (odds ratio, 0.91 per μmol/L TBIL; 95% confidence interval [CI], 0.84-0.98; P = 0.019). Total bilirubin showed a significant inverse association with average 24-hour diastolic blood pressure ( β = -0.36 mm Hg per μmol/L TBIL; 95% CI, -0.62 to -0.10; P = 0.008) but not with 24-hour systolic blood pressure ( β = -0.37 mm Hg per μmol/L TBIL; 95% CI, -0.79 to 0.06; P = 0.090). Stratified analyses suggested stronger inverse associations of TBIL with hypertension and 24-hour blood pressure in women with fewer menopausal symptoms (mKI ≤10), although the TBIL-mKI interaction was not significant.

CONCLUSIONS

In perimenopause, TBIL was inversely associated with diastolic blood pressure and new-onset hypertension, diagnosed using 24-hour ambulatory blood pressure monitoring.

Machine-learning based prediction and analysis of prognostic risk factors in patients with candidemia and bacteraemia: a 5-year analysis

Bacteraemia has attracted great attention owing to its serious outcomes, including deterioration of the primary disease, infection, severe sepsis, overwhelming septic shock or even death. Candidemia, secondary to bacteraemia, is frequently seen in hospitalised patients, especially in those with weak immune systems, and may lead to lethal outcomes and a poor prognosis. Moreover, higher morbidity and mortality associated with candidemia. Owing to the complexity of patient conditions, the occurrence of candidemia is increasing. Candidemia-related studies are relatively challenging. Because candidemia is associated with increasing mortality related to invasive infection of organs, its pathogenesis warrants further investigation. We collected the relevant clinical data of 367 patients with concomitant candidemia and bacteraemia in the first hospital of China Medical University from January 2013 to January 2018. We analysed the available information and attempted to obtain the undisclosed information. Subsequently, we used machine learning to screen for regulators such as prognostic factors related to death. Of the 367 patients, 231 (62.9%) were men, and the median age of all patients was 61 years old (range, 52-71 years), with 133 (36.2%) patients aged >65 years. In addition, 249 patients had hypoproteinaemia, and 169 patients were admitted to the intensive care unit (ICU) during hospitalisation. The most common fungi and bacteria associated with tumour development and Candida infection were Candida parapsilosis and Acinetobacter baumannii, respectively. We used machine learning to screen for death-related prognostic factors in patients with candidemia and bacteraemia mainly based on integrated information. The results showed that serum creatinine level, endotoxic shock, length of stay in ICU, age, leukocyte count, total parenteral nutrition, total bilirubin level, length of stay in the hospital, PCT level and lymphocyte count were identified as the main prognostic factors. These findings will greatly help clinicians treat patients with candidemia and bacteraemia.

New strategy for clinical etiologic diagnosis of acute ischemic stroke and blood biomarker discovery based on machine learning

Acute ischemic stroke (AIS) is a syndrome characterized by high morbidity, prevalence, mortality, recurrence and disability. The longer the delay before proper treatment of a stroke, the greater the likelihood of brain damage and disability. Computed tomography and nuclear magnetic resonance are the primary choices for fast diagnosis of AIS in the early stage, which can provide certain information about infarction location and degree, and even the vascular distribution of lesions responsible for strokes. However, this is quite difficult to achieve in small clinics or at-home diagnoses. Hematology tests could quickly obtain a large number of pathology-related indicators, and offer an effective method for rapid AIS diagnosis when combined with the machine learning technique. To explore a reliable, predictable method for early clinical etiologic diagnosis of AIS, a retrospective study was deployed on 456 AIS patients at the early stage and 28 reference subjects without the symptoms of AIS, by means of the selected significant traits amongst 64 clinical and blood traits in conjunction with powerful machine learning strategies. Five representative biomarkers were closely related to cardioembolic (CE), 22 to large artery atherosclerosis (LAA), and 15 to small vessel occlusion (SVO) strokes, respectively. With these biomarkers, different etiologic subtypes of stroke patients were determined with high accuracy of >0.73, sensitivity of >0.73, and specificity of >0.70, which was comparable to the accuracy obtained in the emergency department by clinical diagnosis. The proposed method may offer an alternative strategy for the etiologic diagnosis of AIS at the early stage when integrating significant blood traits into machine learning.

A rapid and safe strategy was proposed for clinical etiologic diagnosis of acute ischemic stroke at the early stage using clinical hematology traits and machine learning. Blood biomarkers were effectively identified.

Genetic polymorphism of ADAM17 and decreased bilirubin levels are associated with allergic march in the Korean population

Background

The “allergic march” refers to changes in the frequency and intensity of allergic diseases with age. Classically, the allergic march begins with atopic dermatitis in infancy and leads to asthma and rhinitis as it continues. There are many factors that induce the allergic march; however, TNF-α may play an important role in inducing inflammation. Therefore, the therapeutic potential of TNF alpha-targeting agents is being considered for allergic march treatment.

Methods

We performed a correlation study to determine whether genetic polymorphisms of ADAM17 and clinical serum values between allergic and normal groups affect disease development by using the cohort data of the Korean genome epidemiologic research project. Gene association study was performed using PLINK version 1.07 (http://pngu.mgh.harvard.edu/–purcell/plink) and other statistical analysis was performed using PASW Statistics (version 18.0, SPSS Inc. Chicago, IL, USA).

Results

ADAM17 (also called TNF-α converting enzyme or TACE) showed a statistically significant association with the allergic march. The 13 and 8 SNPs in ADAM17 were significantly associated with asthma and allergies, respectively. Among them, on average, SNP of rs6432011 showed the greatest statistical correlation with asthma (P = 0.00041, OR = 1.95, 95% CI 1.35–2.82) and allergies (P = 0.02918, OR = 1.35, 95% CI 1.03–1.78). The effect of SNPs in ADAM17 on transcription factor binding was confirmed using RegulomeDB. The six SNPs are located in the genomic expression quantitative trait loci (eQTL) region and can affect transcription factor binding and gene expression. In clinical serum analysis, bilirubin levels were significantly decreased in the allergic group. The multivariate logistic regression analysis revealed that the low-bilirubin groups indicated a 3.22-fold increase in the prevalence of asthma compared with the high-bilirubin group.

Conclusions

The ADAM17 gene and low bilirubin levels are associated with the allergic march in the Korean population, which can provide new guidelines for managing this disease progression phenomena.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01170-7.

Associations between serum total bilirubin, obesity and type 2 diabetes

BACKGROUND

This study aims to examine the cross-sectional association between serum total bilirubin (STB) and type 2 diabetes (T2D) risk in the general population, and whether obesity could moderate this association.

METHODS

We used data from the 1999-2018 National Health and Nutrition Examination Surveys (NHANES), including a total of 38,641 US adult participants who were 18 years or older. The STB was classified as the low, moderate, and high groups according to tertiles.

RESULTS

We found that participants with lower STB had a significantly higher risk of T2D than those with moderate (OR = 0.81; 95% CI 0.74, 0.89; P < 0.001) and high (OR = 0.65; 95% CI 0.59, 0.73; P < 0.001) STB. Also, a significant interaction between body mass index (BMI) and STB on T2D was observed (P < 0.001). Stratified analysis showed that low STB was associated with a 20% and 27% decrease of T2D risk for moderate and high STB groups in obese patients, however, these effect estimates were smaller in the population with lower BMI (< 30 kg/m²). Similar associations of STB with glycohemoglobin and insulin resistance were observed.

CONCLUSION

This study suggests that STB is associated with an elevated risk of T2D. More importantly, we reported for the first time that BMI may moderate the association between bilirubin and T2D.

The Protective Role of the Heme Catabolic Pathway in Hepatic Disorders

Significance: As the central metabolic organ, the liver is exposed to a variety of potentially cytotoxic, proinflammatory, profibrotic, and carcinogenic stimuli. To protect the organism from these deleterious effects, the liver has evolved a number of defense systems, which include antioxidant substrates and enzymes, anti-inflammatory tools, enzymatic biotransformation systems, and metabolic pathways. Recent Advances: One of the pivotal systems that evolved during phylogenesis was the heme catabolic pathway. Comprising the important enzymes heme oxygenase and biliverdin reductase, this complex pathway has a number of key functions including enzymatic activities, but also cell signaling, and DNA transcription. It further generates two important bile pigments, biliverdin and bilirubin, as well as the gaseous molecule carbon monoxide. These heme degradation products have potent antioxidant, immunosuppressive, and cytoprotective effects. Recent data suggest that the pathway participates in the regulation of metabolic and hormonal processes implicated in the pathogenesis of hepatic and other diseases. Critical Issues: This review discusses the impact of the heme catabolic pathway on major liver diseases, with particular focus on the involvement of cellular targeting and signaling in the pathogenesis of these conditions. Future Directions: To utilize the biological consequences of the heme catabolic pathway, several unique therapeutic strategies have been developed. Research indicates that pharmaceutical, nutraceutical, and lifestyle modifications positively affect the pathway, delivering potentially long-term clinical benefits. However, further well-designed studies are needed to confirm the clinical benefits of these approaches. Antioxid. Redox Signal. 35, 734-752.

Association of Total Bilirubin With All-Cause and Cardiovascular Mortality in the General Population

Objective: The study aims to investigate the association of total bilirubin with all-cause and cause-specific mortality in the general population.

Methods: A total of 37,234 adults from the United States National Health and Nutrition Examination Survey 1999–2014 were enrolled. Baseline levels of total bilirubin associated with risk of mortality were evaluated on a continuous scale (restricted cubic splines) and by quartile categories with Cox regression models.

Results: Higher levels of total bilirubin was positively associated with an increased risk of all-cause mortality [hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.46–1.72; p < 0.001]. Compared with individuals with the lowest quartile of bilirubin, the multivariable adjusted hazard ratio for all-cause mortality was 1.25 (1.14–1.37) for individuals in the highest quartile. Restricted cubic splines indicated that the association was non-linear in cardiovascular mortality and cancer mortality while linear in all-cause mortality.

Conclusions: Total bilirubin was associated with all-cause and cause-specific mortality in the general population.

Case Report: Hyperbilirubinemia in Gilbert Syndrome Attenuates Covid-19-Induced Metabolic Disturbances

Gilbert syndrome (GS) is a liver disorder characterized by non-hemolytic unconjugated hyperbilirubinemia. On the other hand, Coronavirus disease 2019 (Covid-19) is a recent viral infectious disease presented as clusters of pneumonia, triggered by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Little is known on the association between SARS-CoV-2 and GS, despite different studies have recently stated a link between hyperbilirubinemia and SARS-CoV-2 severity. In this case-report study we described a 47-year-old man, a known case of GS since the age of 4, presented to the emergency department with fever (39.8°C), dry cough, dyspnea, headache, myalgia, sweating and jaundice diagnosed with Covid-19-induced pneumonia. Interestingly, GS patient exhibited a rapid clinical recovery and short hospital stay compared to other SARS-CoV-2 positive patient, seeming that hyperbilirubinemia may exert a protective effect of against Covid-19 induced-cardiometabolic disturbances. Data obtained here underlines that the higher resistance against Covid-19 evidenced by the GS patient seems to be due to the antioxidant, anti-inflammatory, and antiviral effects of unconjugated bilirubin.

Non-targeted metabolomics of quinoa seed filling period based on liquid chromatography-mass spectrometry

Quinoa (Chenopodium quinoa Willd.), an herb belonging to the amaranth family, is rich in minerals, amino acids, vitamins, proteins, and flavonoids. Its grain, compared with other major grains, has unique nutritional value with tremendous applications. This study used four independently bred high-generation lines (seed colors) of quinoa as materials to further understand the metabolic differences in the filling periods of quinoa varieties. Additionally, the non-targeted metabolome of quinoa seeds 35 and 42 days after flowering, respectively, were studied via liquid chromatography-mass spectrometry. The two filling periods of yellow, white, black, and red quinoa grains resulted in significant differences in the metabolites, particularly in L-methionine, S-adenosyl-L-homocysteine, S-adenosyl-L-methionine, pyruvate, fumarate, and oxaloacetate. Soluble sugar, amino acid, and fatty acid contents in quinoa increased after 42 days of flowering. There were metabolic differences between the sugar phosphates (L-fucose, D-mannose-6-phosphate, xylulose-5-phosphate, sedoheptulose-7-phosphate), amino acid (alanine), and organic compounds (kynurenate, tryptamine, serotonin, bilirubin) among the four quinoa varieties. The relative difference in the metabolites was largest when the yellow quinoa grain was compared with the other quinoa varieties and smallest when the red and black varieties were compare. The results of this study provide a basis for the reproduction and identification of new quinoa varieties, as well as for screening potential quality control target genes by combining genomics and transcriptomics.