Direct, indirect and total bilirubin and risk of incident coronary heart disease in the Dongfeng-Tongji cohort

Correlation between bone mineral density and type 2 diabetes mellitus in elderly men and postmenopausal women

The relationship between bone mineral density and type 2 diabetes is still controversial. The aim of this study is to investigate the relationship between type 2 diabetes mellitus (T2DM) and bone mineral density (BMD) in elderly men and postmenopausal women. The participants in this study included 692 postmenopausal women and older men aged ≥ 50 years, who were divided into the T2DM group and non-T2DM control group according to whether or not they had T2DM. The data of participants in the two groups were collected from the inpatient medical record system and physical examination center systems, respectively, of the Tertiary Class A Hospital. All data analysis is performed in SPSS Software. Compared with all T2DM group, the BMD and T scores of lumbar spines 1-4 (L1-L4), left femoral neck (LFN) and all left hip joints (LHJ) in the non-T2DM group were significantly lower than those in the T2DM group (P < 0.05), and the probability of major osteoporotic fracture in the next 10 years (PMOF) was significantly higher than that in T2DM group (P < 0.001). However, with the prolongation of the course of T2DM, the BMD significantly decreased, while fracture risk and the prevalence of osteoporosis significantly increased (P < 0.05). We also found that the BMD of L1-4, LFN and LHJ were negatively correlated with homeostatic model assessment-insulin resistance (HOMA-IR) (P = 0.028, P = 0.01 and P = 0.047, respectively). The results also showed that the BMD of LHJ was positively correlated with indirect bilirubin (IBIL) (P = 0.018). Although the BMD was lower in the non-T2DM group than in the T2DM group, the prolongation of the course of T2DM associated with the lower BMD. And the higher prevalence of osteoporosis and fracture risk significantly associated with the prolongation of the course of T2DM. In addition, BMD was significantly associated with insulin resistance (IR) and bilirubin levels in T2DM patients.Registration number: China Clinical Trials Registry: MR-51-23-051741; https://www.medicalresearch.org.cn/search/research/researchView?id=c0e5f868-eca9-4c68-af58-d73460c34028 .

Non-linear associations of circulating total bilirubin concentration with the risk of nonalcoholic fatty liver disease and all-cause mortality

INTRODUCTION AND OBJECTIVES

Accumulating evidence has supported that mild elevated total bilirubin exerts antioxidant and anti-inflammatory properties in multiple metabolic diseases. We aimed to explore the association of circulating total bilirubin concentration with non-alcoholic fatty liver disease (NAFLD) risk and all-cause mortality and examine the potential nonlinear relationships between them.

MATERIAL AND METHODS

We used nationally representative data from the National Health and Nutrition Examination Survey (NHANES). NAFLD was assessed using the fatty liver index (FLI) and United States fatty liver index (USFLI), respectively.

RESULTS

A total of 35 912 and 17 329 participants were included in FLI-NAFLD (case with NAFLD was diagnosed by FLI) and USFLI-NAFLD (case with NAFLD was diagnosed by USFLI) groups, respectively. The mean age of total population was 46.25 years, and 48.51% were male. Compared to participants with lowest quintile of total bilirubin concentration, those with highest quintile had lower risk of NAFLD in both FLI-NAFLD (OR: 0.48, 95% CI: 0.40, 0.59) and USFLI-NAFLD (OR: 0.55, 95% CI: 0.43, 0.70) groups. Compared to participants with lowest quintile of total bilirubin concentration, the association between total bilirubin concentration and all-cause mortality was not significant among those with highest quintile of total bilirubin concentration (HR: 0.89, 95% CI: 0.66, 1.20). The restricted spline curves showed the nonlinear U-shaped association of total bilirubin concentration with NAFLD risk and all-cause mortality. The segmented linear regression analysis showed negative associations between total bilirubin concentration and risk of NAFLD in both FLI-NAFLD (OR: 0.94, 95% CI: 0.93, 0.95) and USFLI-NAFLD (OR: 0.95, 95% CI: 0.93, 0.96) groups when total bilirubin concentration was below the turning point (FLI-NAFLD: 18.81 μmol/L; USFLI-NAFLD: 15.39 μmol/L) and these associations were not significant when total bilirubin concentration was higher than the turning point. Furthermore, all-cause mortality decreased (OR: 0.97, 95%CI: 0.95, 1.00) with increased total bilirubin concentration up to the turning point (11.97 μmol/L), and then all-cause mortality increased with increasing total bilirubin concentration (OR: 1.03, 95%CI: 1.02, 1.04).

CONCLUSIONS

We found that higher circulating total bilirubin concentration within the physiological range was associated with decreased risk of NAFLD and all-cause mortality among NAFLD patients.

Supra-Blan2 t score as a multisystem-based risk score to predict poor 3-month outcome in acute ischemic stroke patients with intravenous thrombolysis

AIM

To develop and validate a novel weighted score integrating multisystem laboratory and clinical variables to predict poor 3-month outcome (mRS score of 3-6) in acute ischemic stroke (AIS) patients with intravenous thrombolysis (IVT) therapy.

METHODS

We retrospectively analyzed data from Trial of Revascularization Treatment for Acute Ischemic Stroke study. The Supra-Blan2 t score was derived using the data on age, the National Institutes of Health Stroke Scale score, history of atrial fibrillation, blood sugar level, neutrophil count, direct bilirubin level, platelet-lymphocyte ratio, and TnI level in the derivation cohort of 433 patients, and validated in a cohort of 525 patients. Furthermore, we compared the performance of the Supra-Blan2 t score with DRAGON, TURN, and SPAN-100 scores.

RESULTS

The discrimination capacity in the derivation and validation cohorts was good for poor 3-month outcome (the area under the curve was 0.821 and 0.843, respectively). The cumulative incidence of poor 3-month outcome significantly increased across risk categories in the derivation (low-risk, 9.2%; medium-risk, 17.4%; and high-risk, 58.8%) and validation cohorts (12.7%, 36.5%, and 73.6%, respectively). The performance of the Supra-Blan2 t score was similar to or superior to DRAGON, TURN, and SPAN-100 scores.

CONCLUSION

The Supra-Blan2 t score, based on easily available multisystem laboratory and clinical variables, reliably predicted poor 3-month functional outcome in AIS patients treated with IVT therapy featuring good calibration and discrimination.

High indirect bilirubin levels as an independent predictor of postoperative myasthenic crisis: a single-center, retrospective study

Background

Thymectomy is an efficient and standard treatment strategy for patients with myasthenia gravis (MG), postoperative myasthenic crisis (POMC) is the major complication related to thymectomy and has a strongly life-threatening effect. As a biomarker, whether the bilirubin level is a risk factor for MG progression remains unclear. This study aimed to investigate the association between the preoperative bilirubin level and postoperative myasthenic crisis (POMC).

Methods

We analyzed 375 patients with MG who underwent thymectomy at Tangdu Hospital between January 2012 and September 2021. The primary outcome measurement was POMC. The association between POMC and bilirubin level was analyzed by restricted cubic spline (RCS). Indirect bilirubin (IBIL) was divided into two subgroups based on the normal upper limit of IBIL, 14 μmol/L.

Results

Compared with non-POMC group, IBIL levels were significantly higher in patients with POMC. Elevated IBIL levels were closely associated with an increased risk of POMC (p for trend = 0.002). There was a dose-response curve relationship between IBIL levels and POMC incidence (p for non-linearity = 0.93). However, DBIL levels showed a U-shaped association with POMC incidence. High IBIL level (≥14 μmol/L) was an independent predictive factor for POMC [odds ratio = 3.47, 95% confidence interval (CI): 1.56-7.8, p = 0.002]. The addition of high IBIL levels improved the prediction model performance (net reclassification index = 0.186, 95% CI: 0.039-0.334; integrated discrimination improvement = 0.0345, 95% CI: 0.005-0.065).

Conclusion

High preoperative IBIL levels, especially those exceeding the normal upper limit, could independently predict the incidence of POMC.

Predictive value of serum creatinine and total bilirubin for long-term death in patients with ischemic heart disease: A cohort study

BACKGROUND

Ischemic heart disease (IHD) has a high mortality in the population. Although serum creatinine (Cr) and serum total bilirubin (TBil) are rapid and readily available biomarkers in routine blood tests, there is a lack of literature on the prognostic value of combined Cr and TBil tests for IHD. This study aimed to evaluate a combined equation based on Cr and TBil to predict the long-term risk of death in IHD and to find indicators sensitive to the prognosis of IHD patients.

METHOD

In this study, 2625 patients with IHD were included, and the combined value and combined equations of Cr and TBil were obtained by logistic regression analysis based on Cr and TBil collected at the time of admission. Patients were divided into four groups according to the quartiles of the combined value. COX proportional hazard regression model was used to analyze the risk factors for long-term death in IHD patients. Receiver operating characteristic (ROC) curves were used to evaluate the prognostic effect of Cr, TBil and combined value on long-term death events.

RESULTS

Logistic regression analysis was performed for long-term death events with Cr and TBil as independent variables, and the logit regression model was Logit(P) = 0.0129×TBil+0.007×Cr-0.417. Multifactorial Cox regression analysis showed that high values of the equation were independent risk factors for long-term death events (all-cause death: HR 1.457, 95% CI 1.256-1.689, P<0.001; cardiovascular death: HR 1.452, 95% CI 1.244-1.695, P<0.001). Combined Cr and TBil value are more valuable in predicting long-term death (AUC: 0.609, 95% CI 0.587-0.630, P<0.001).

CONCLUSION

Combined Cr and TBil assay is superior to single biomarkers for predicting long-term death in patients with IHD. High values of the equation are independent predictors of long-term death and can be used to identify patients at high risk for IHD.

Predictive values of bilirubin for in-hospital adverse events in patients with ST-segment elevation myocardial infarction after primary percutaneous coronary intervention

PURPOSE

To investigate the association between serum bilirubin levels and in-hospital Major Adverse Cardiac Events (MACE) in patients with ST-segment Elevation Myocardial Infarction (STEMI) undergoing primary Percutaneous Coronary Intervention (PCI).

METHODS

A total of 418 patients with STEMI who underwent primary PCI were enrolled from October 1st, 2021 to October 31st 2022. The average age of enrolled participants was 59.23 years, and 328 patients (78.50%) were male patients. Patients were divided into MACE (patients with angina pectoris after infarction, recurrent myocardial infarction, acute heart failure, cardiogenic shock, malignant arrhythmias, or death after primary PCI) (n = 98) and non-MACE (n = 320) groups. Univariate and multivariate logistic regression analyses were performed to estimate the association between different bilirubin levels including Total Bilirubin (TB), Direct Bilirubin (DB), Indirect Bilirubin (IDB), and risk of in-hospital MACE. The area under the Receiver Operating Characteristic (ROC) curve was used to determine the accuracy of bilirubin levels in predicting in-hospital MACE.

RESULTS

The incidence of MACE in STEMI patients increased from the lowest to the highest bilirubin tertiles. Multivariate logistic regression analysis showed that increased total bilirubin level was an independent predictor of in-hospital MACE in patients with STEMI (p for trend = 0.02). Compared to the first TB group, the ORs for risk of MACE were 1.58 (95% CI 0.77‒3.26) and 2.28 (95% CI 1.13‒4.59) in the second and third TB groups, respectively. The ROC curve analysis showed that the areas under the curve for TB, DB and IDB in predicting in-hospital MACE were 0.642 (95% CI 0.578‒0.705, p < 0.001), 0.676 (95% CI 0.614‒0.738, p < 0.001), and 0.619 (95% CI 0.554‒0.683, p < 0.001), respectively.

CONCLUSIONS

The current study showed that elevated TB, DB, and IDB levels are independent predictors of in-hospital MACE in patients with STEMI after primary PCI, and that DB has a better predictive value than TB and IDB.

Targeting endothelial vascular cell adhesion molecule-1 in atherosclerosis: drug discovery and development of vascular cell adhesion molecule-1-directed novel therapeutics

Vascular cell adhesion molecule-1 (VCAM-1) has been well established as a critical contributor to atherosclerosis and consequently as an attractive therapeutic target for anti-atherosclerotic drug candidates. Many publications have demonstrated that disrupting the VCAM-1 function blocks monocyte infiltration into the sub-endothelial space, which effectively prevents macrophage maturation and foam cell transformation necessary for atherosclerotic lesion formation. Currently, most VCAM-1-inhibiting drug candidates in pre-clinical and clinical testing do not directly target VCAM-1 itself but rather down-regulate its expression by inhibiting upstream cytokines and transcriptional regulators. However, the pleiotropic nature of these regulators within innate immunity means that optimizing dosage to a level that suppresses pathological activity while preserving normal physiological function is extremely challenging and oftentimes infeasible. In recent years, highly specific pharmacological strategies that selectively inhibit VCAM-1 function have emerged, particularly peptide- and antibody-based novel therapeutics. Studies in such VCAM-1-directed therapies so far remain scarce and are limited by the constraints of current experimental atherosclerosis models in accurately representing the complex pathophysiology of the disease. This has prompted the need for a comprehensive review that recounts the evolution of VCAM-1-directed pharmaceuticals and addresses the current challenges in novel anti-atherosclerotic drug development.

Circulating Total Bilirubin and Long-Term Prognosis in Patients With Previous Myocardial Infarction

Background

Although experimental studies have demonstrated the protective role of total bilirubin (TBil) in cardiovascular diseases, several previous clinical observations are controversial. More importantly, no data are currently available regarding the relation of TBil to major adverse cardiovascular events (MACE) in patients with previous myocardial infarction (MI).

Objectives

This study sought to explore the association between TBil and long-term clinical outcomes in patients with previous MI.

Methods

A total of 3,809 patients who are post-MI were consecutively enrolled in this prospective study. Cox regression models using HRs and CIs were applied to investigate associations between the TBil concentration category (group 1: bottom to median tertiles within the reference range; group 2: top tertile; group 3: above reference range) and main outcome (recurrent MACE) as well as secondary outcomes (hard endpoints and all-cause mortality).

Results

During the 4-year follow-up period, 440 patients (11.6%) suffered from recurrent MACE. Kaplan-Meier survival analysis showed the lowest MACE incidence in group 2 (P < 0.001). When compared with the reference group (group 1) in multivariable analysis, a J-shaped association was apparent for MACE, with decreased risk in group 2 (HR: 0.76; 95% CI: 0.59-0.96) and elevated risk in group 3 (HR: 1.29; 95% CI: 1.03-1.61). Similar associations were identified regarding hard endpoints and all-cause mortality. Moreover, TBil demonstrated incremental discriminatory strength when added to the predictive model.

Conclusions

In this prospective cohort study with long-term follow-up, higher TBil levels within the physiological range reduced the incidence of long-term cardiovascular events in patients who are post-MI.

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.

Association Between Serum Bilirubin, Lipid Levels, and Prevalence of Femoral and Carotid Atherosclerosis: A Population-Based Cross-Sectional Study

BACKGROUND

Bilirubin may prevent lipid peroxidation and have important antiatherosclerotic effects. We determined associations of serum bilirubin and lipid with peripheral atherosclerosis.

METHODS

We included 4290 participants (35% men; median age, 60 years) from the southeast China who underwent B-mode ultrasound examination. Increased intima-media thickness or a focal structure encroaching into the arterial lumen by at least 0.5 mm or >50% of the surrounding intima-media thickness value was regarded as having atherosclerosis. Fasting serum bilirubin and lipid levels were measured. Cholesterol/(HDL [high-density lipoprotein] cholesterol+bilirubin), and LDL (low-density lipoprotein cholesterol)/(HDL+bilirubin) ratios were calculated. Unconditional and multinomial logistic regression models were used to examine associations of bilirubin or lipid with prevalence of peripheral atherosclerosis. Mediation analyses were performed to assess the effect of bilirubin on atherosclerosis risk mediated via lipid.

RESULTS

Compared with participants with the lowest levels of bilirubin, those with the highest tertile were less likely to have carotid or femoral atherosclerosis (odds ratios were 0.55-0.74). The highest levels of bilirubin significantly reduced the odds of concurrent carotid and femoral atherosclerosis by 35% to 45%. Participants with the highest levels of cholesterol, LDL, cholesterol/(HDL+bilirubin), and LDL/(HDL+bilirubin) ratios had 2.8- to 3.7-fold increased odds of concurrent carotid and femoral atherosclerosis. LDL accounted for 25.65% of the total bilirubin-atherosclerosis association. LDL and cholesterol mediated the associations between direct bilirubin and atherosclerosis (proportion: 20.40%, 9.67%, respectively).

CONCLUSIONS

Increased serum bilirubin levels are inversely associated with the prevalence of carotid or femoral atherosclerosis. LDL and cholesterol may mediate these associations.

Development and validation of a nomogram to predict mortality risk in patients with ischemic heart disease

Background

Ischemic Heart Disease (IHD) is the leading cause of death from cardiovascular disease. Currently, most studies have focused on factors influencing IDH or mortality risk, while few predictive models have been used for mortality risk in IHD patients. In this study, we constructed an effective nomogram prediction model to predict the risk of death in IHD patients by machine learning.

Methods

We conducted a retrospective study of 1,663 patients with IHD. The data were divided into training and validation sets in a 3:1 ratio. The least absolute shrinkage and selection operator (LASSO) regression method was used to screen the variables to test the accuracy of the risk prediction model. Data from the training and validation sets were used to calculate receiver operating characteristic (ROC) curves, C-index, calibration plots, and dynamic component analysis (DCA), respectively.

Results

Using LASSO regression, we selected six representative features, age, uric acid, serum total bilirubin, albumin, alkaline phosphatase, and left ventricular ejection fraction, from 31 variables to predict the risk of death at 1, 3, and 5 years in patients with IHD, and constructed the nomogram model. In the reliability of the validated model, the C-index at 1, 3, and 5 years was 0.705 (0.658-0.751), 0.705 (0.671-0.739), and 0.694 (0.656-0.733) for the training set, respectively; the C-index at 1, 3, and 5 years based on the validation set was 0.720 (0.654-0.786), 0.708 (0.650-0.765), and 0.683 (0.613-0.754), respectively. Both the calibration plot and the DCA curve are well-behaved.

Conclusion

Age, uric acid, total serum bilirubin, serum albumin, alkaline phosphatase, and left ventricular ejection fraction were significantly associated with the risk of death in patients with IHD. We constructed a simple nomogram model to predict the risk of death at 1, 3, and 5 years for patients with IHD. Clinicians can use this simple model to assess the prognosis of patients at the time of admission to make better clinical decisions in tertiary prevention of the disease.

Role of bilirubin in the prognosis of coronary artery disease and its relationship with cardiovascular risk factors: a meta-analysis

Background

Bilirubin is a heme catabolism product with antioxidant, anti-inflammatory, and anti-apoptotic properties and is implicated in the prognosis of several diseases. This study evaluates the prognostic role of bilirubin in coronary artery disease (CAD) patients.

Methods

After identifying studies from the literature, meta-analyses were performed to achieve a) overall estimates of serum total bilirubin levels in patients with myocardial infarction (MI), non-MI CAD and healthy individuals; b) odds ratios (OR) of adverse outcomes between higher and lower total bilirubin levels; c) standardized mean difference (SMD) in total bilirubin levels in patients with high vs low CAD severity; and d) correlation between disease severity and total bilirubin. Metaregression analyses were performed to examine the relationship between cardiovascular risk factors and increasing quantiles of total bilirubin levels.

Results

Forty-three studies were identified. Pooled serum total bilirubin levels were 0.72 mg/dl [95% confidence interval (CI): 0.60, 0.83] in MI patients; 0.65 mg/dl [95% CI: 0.60, 0.69] in non-MI CAD patients; and 0.66 mg/dl [95% CI: 0.56, 0.75] in healthy individuals. Higher total bilirubin levels were associated with greater odds of adverse outcomes in MI patients (OR: 1.08 [95% CI: 0.99, 1.18]) but lower odds in non-MI CAD patients (OR: 0.80 [95%CI: 0.73, 0.88]). Compared to non-severe cases, total bilirubin levels were higher in patients with severe MI (SMD 0.96 [95% CI: − 0.10, 2.01]; p = 0.074) but were lower in severe non-MI CAD patients (SMD − 0.30 [95%CI: − 0.56, − 0.03]; p = 0.02). Total bilirubin levels correlated positively with MI severity (r = 0.41 [95% CI: 0.24, 0.59]; p < 0.01) but correlated negatively with non-MI CAD severity (r =  − 0.17 [95% CI: − 0.48, 0.14]; p = 0.28). Female sex was inversely associated with increasing quantiles of bilirubin (meta-regression coefficient: − 8.164 [− 14.531, − 1.769]; p = 0.016) in MI patients.

Conclusion

Prognostic role of bilirubin for CAD appears complicated, as different odds are observed for MI and non-MI CAD patients which weakens the case of causal involvement of bilirubin in CAD etiology or prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02899-w.

Association between total bilirubin and bone mineral density level in adolescents

Background

Increasing bone mass accumulation in adolescence and obtaining greater peak bone mass is one of the effective methods to prevent osteoporosis in the future. We aimed to examine the association between total bilirubin and bone mineral density (BMD) level in adolescents.

Methods

We used the data from 2005–2010 and 2013–2014 cycles of National Health and Nutrition Examination Survey (NHANES). The BMD levels in the region of lumbar spine and femoral regions, including total femur, femoral neck, trochanter, and intertrochanter were measured. Univariable and multivariable linear regression model were used to assess the relationship between total bilirubin concentration and BMD.

Results

A total of 3741 participants aged 12–19 years were ultimately included in the study. There were 1997 (53.38%) males and 1744 (46.62%) females. Univariate analysis results showed that age, sex, race, education, income, body mass index, dietary calcium intake, and diabetes were correlated with BMD levels. Compared with the lowest quartile of total bilirubin concentration, the highest quartile of total bilirubin concentration was positively associated with BMD levels in the regions of total femur (β = 0.036, 95% CI = 0.021 to 0.050, P < 0.001), femur neck (β = 0.030, 95% CI = 0.016 to 0.044, P < 0.001), trochanter (β = 0.033, 95% CI = 0.019 to 0.046, P < 0.001), intertrochanter (β = 0.040, 95% CI = 0.023 to 0.056, P < 0.001), and lumbar spine (β = 0.032, 95% CI = 0.018 to 0.045, P < 0.001). We also observe the same trend in sensitivity analysis (P for trend < 0.001).

Conclusion

Our study demonstrated that total bilirubin concentration was positively associated with BMD levels in adolescents in United States. Total bilirubin concentration might be a protective marker against bone loss in adolescents.

Longitudinal Associations Between Serum Bilirubin Level and Carotid Atherosclerosis Plaque in a Health Screening Population

This study aimed to determine the relationship between bilirubin levels and carotid atherosclerosis (CAS) in the health screening population. After propensity score matching, this retrospective cohort study included 4360 subjects who underwent health examinations regularly in Hebei General Hospital between January 2010 and December 2019 and had no carotid plaque at baseline. After an average follow-up of 26.76 months, the main endpoint Cox regression analysis of carotid plaques was performed. After adjusting the confounding factors, Cox regression analysis showed that when serum total bilirubin (TBIL) and unconjugated bilirubin (UCB) increased by 1 standard deviation (SD), the risk of carotid plaque decreased by 7.30% (95% confidence interval (CI): 2.80-11.60%) and 15.70% (95% CI: 11.40-19.80%), respectively. When conjugated bilirubin (CB) increased by 1 SD, the risk of carotid plaques increased by 24.3% (95% CI: 19.7-29.0%). TBIL and UCB levels were negatively associated with CAS, and CB levels were positively associated with CAS.

Elevated serum bilirubin may significantly reduce coronary heart disease risk in females: A prospective cohort study

BACKGROUND AND AIMS

There is still inconsistent evidence over the protective effect of total bilirubin on the development of coronary heart disease (CHD). Therefore, we aimed to investigate the association between bilirubin in population subtypes and the risks of CHD between different gender and menstruation subgroups.

METHODS AND RESULTS

In this prospective cohort study, 29,750 participants free of CHD with an average age of 47 ± 14 years were recruited at baseline; of these, 720 CHD first-attack cases were collected after 7-years of follow up. The covariate-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) of CHD with 95% confidence intervals (CIs). The serum bilirubin concentration was quarterly stratified based on the distribution of healthy population without CHD onset. The HRs of incident CHD decreased with elevated bilirubin in females (ρ trend<0.05), but not males. In postmenopausal females, compared with the lowest quartile of total bilirubin, the adjusted HRs for the third and fourth quartiles were 0.64 (95% CI: 0.45, 0.93) and 0.59 (95% CI: 0.42, 0.86), the adjusted HRs in the third and fourth quartiles of direct bilirubin were 0.56 (0.39, 0.82) and 0.56 (0.38, 0.81), and for indirect bilirubin, corresponding HR in the highest quartile was 0.56 (0.38, 0.83).

CONCLUSION

Elevated serum bilirubin was inversely associated with adjusted HRs of CHD in females, especially postmenopausal females. The relationship between elevated direct bilirubin and reduced HRs of CHD may be closer than indirect bilirubin in postmenopausal females.

The Nonlinear Relationship Between Total Bilirubin and Coronary Heart Disease: A Dose-Response Meta-Analysis

Background: Evidence suggests that the total bilirubin has a protective effect on coronary heart disease (CHD), but the dose-response relationship remains controversial, and there is no meta-analysis to assess the relationship.

Methods: As of October 1, 2021, relevant literature was selected from four databases (PubMed, Web of Science, Cochrane Library, and Embase) by using a retrieval strategy. The dose-response curve between the total bilirubin and CHD was fitted by a restricted cubic spline. Stata 12.0 was used for statistical analysis.

Results: A total of 170,209 (6,342 cases) participants from 7 prospective studies were analyzed in our meta-analysis. We calculated the pooled relative risks (RRs) and 95% CIs for the association between serum bilirubin level and risk of CHD using random-effects models. Compared with the first quantile, the bilirubin level in the third quantile had a protective effect on the risk of CHD (RR, 0.90; 95% CI, 0.82–0.99). The restricted cubic spline functions depicted a U-type curve relationship between bilirubin (3.42–49 μmol/L) and CHD (P_linear < 0.001). When the bilirubin level was in the range of 3.42–13μmol/L, the protective effect of bilirubin on CHD was enhanced with increasing bilirubin levels. When the bilirubin level exceeded 13μmol/L, the protective effect of bilirubin weakened, and a dangerous effect gradually appeared with further increases in bilirubin levels.

Conclusions: Compared with a low bilirubin level, a high bilirubin level has a protective effect on the risk of CHD, and there was a U-shaped dose-response relationship between them.

Dose-Response Association Between Bilirubin and Cardiovascular Disease: A Systematic Review and Meta-analysis

The association between bilirubin (BIL) and cardiovascular disease (CVD) remains controversial. We performed a meta-analysis of prospective studies to evaluate this association in the general population. We searched PubMed, EMBASE, Web of Science, Cochrane, and Scopus databases through to September 2021. The Newcastle-Ottawa Quality Assessment Scale was used to assess study quality. The pooled effect estimate was calculated by the fixed-effect model or random-effect model. We included 12 prospective studies (368 567 participants). The pooled risk ratio of CVD for the lowest vs highest groups of BIL levels was .75 (95% CI: .58-.97) with high heterogeneity (I² = 87.5%, P < .001). Similar associations were observed for coronary heart disease and stroke. We further performed a "dose-response" meta-analysis, and a significant U-shaped relationship between circulating (most values were serum bilirubin, but a few were plasma bilirubin) BIL and CVD (P < .01) was observed. The lowest risk of CVD events was observed in participants with a BIL of 17-20 µmol/L in serum and/or plasma. In conclusion, there was a U-shaped dose-response relationship between BIL and CVD, especially for men. Further studies are needed to confirm our findings and identify the mechanisms involved as well as any prognostic or therapeutic potential.

Low-normal serum unconjugated bilirubin levels are associated with late but not early carotid atherosclerotic lesions in T2DM subjects

AIMS

We aimed to examine the association of serum unconjugated bilirubin (UCB) within normal limits with carotid atherosclerosis in Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional, real-world study was performed in 8,006 hospitalized T2DM patients including 4,153 men and 3,853 women with normal UCB. The subjects were stratified into quintiles based on serum UCB levels (<6.2, 6.2-7.9, 8.0-8.9, 9.0-10.9, and >10.9 μmol/l, respectively). Carotid atherosclerotic lesions detected by ultrasonography, including carotid intima-media thickness (CIMT), carotid plaque, and stenosis, were compared among the five groups. The associations of serum UCB levels and quintiles with carotid atherosclerotic lesions were also determined by multiple logistic regression.

RESULTS

The prevalence of carotid plaque (55.3%, 49.5%, 47.4%, 43.8%, and 37.5%, respectively; p < 0.001 for trend) and stenosis (15.2%, 12.2%, 9.1%, 7.7%, and 5.4%, respectively; p < 0.001 for trend) was progressively lower across the UCB quintiles even after adjusting for age, sex, and duration of diabetes. Results of a fully adjusted multiple logistic regression analysis revealed that serum UCB levels and quintiles were significantly associated with carotid plaque and stenosis. Compared with the subjects in the lowest UCB quintile, the risk of carotid plaque decreased by 25.5%, 28.7%, 33.5%, and 42.8%, and that of carotid stenosis by 24.6%, 37.4%, 44.9%, and 47.3%, respectively, in those from the second to highest UCB quintiles. High serum UCB within the normal range was a protective factor against carotid plaque [odds ratio (OR) 0.810, 95% confidence interval (CI) 0.747-0.878; p < 0.001] and stenosis [OR 0.722, 95% CI 0.647-0.805; p < 0.001]. However, no significant association was observed between serum UCB and CIMT in T2DM patients. Furthermore, C-reactive protein (CRP) levels were significantly higher in the subjects with carotid atherosclerosis than in those without carotid atherosclerosis and clearly decreased across the UCB quintiles.

CONCLUSIONS

Serum UCB within normal limits is inversely associated with late carotid atherosclerotic lesions including carotid plaque and stenosis but not CIMT, an early carotid atherosclerotic lesion in T2DM patients. High-normal UCB may be protective against carotid atherosclerosis by its anti-inflammation effect, which was indicated by significantly decreased CRP levels from the lowest to highest UCB quintiles.

Predictive value of different bilirubin subtypes for clinical outcomes in patients with acute ischemic stroke receiving thrombolysis therapy

Aims

To explore the association of total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL) levels with, as well as the incremental predictive value of different bilirubin subtypes for, poor outcomes in acute ischemic stroke patients after thrombolysis.

Methods

We analyzed 588 individuals out of 718 AIS participants, and all patients were followed up at 3 months after thrombolysis. The primary outcome was 3‐month death and major disability (modified Rankin Scale (mRS) score of 3–6). The secondary outcomes were 3‐month mortality (mRS score of 6), moderate‐severe cerebral edema, and symptomatic intracranial hemorrhage (sICH), respectively.

Results

Elevated DBIL pre‐thrombolysis was associated with an increased risk of primary outcome (OR 3.228; 95% CI 1.595–6.535; p for trend = 0.014) after fully adjustment. Elevated TBIL pre‐thrombolysis showed the similar results (OR 2.185; 95% CI 1.111–4.298; p for trend = 0.047), while IBIL pre‐thrombolysis was not significantly associated with primary outcome (OR 1.895; 95% CI 0.974–3.687; p for trend = 0.090). Multivariable‐adjusted spline regression model showed a positive linear dose‐response relationship between DBIL pre‐thrombolysis and risk of primary outcome (p for linearity = 0.004). Adding DBIL pre‐thrombolysis into conventional model had greater incremental predictive value for primary outcome, with net reclassification improvement (NRI) 95% CI = 0.275 (0.084–0.466) and integrated discrimination improvement (IDI) 95% CI = 0.011 (0.001–0.024). Increased DBIL post‐thrombolysis had an association with primary outcome (OR 2.416; 95%CI 1.184–4.930; p for trend = 0.039), and it also elevated the incremental predictive value for primary outcome, with NRI (95% CI) = 0.259 (0.066–0.453) and IDI (95% CI) = 0.025 (0.008–0.043).

Conclusion

Increased DBIL pre‐thrombolysis had a stronger association with, as well as greater incremental predictive value for, poor outcomes than TBIL and IBIL did in AIS patients after thrombolysis, which should be understood in the context of retrospective design. The effect of DBIL on targeted populations should be investigated in further researches.

Factor Analysis of Metabolic Syndrome and Its Relationship with the Risk of Cardiovascular Disease in Ethnic Populations in Rural Xinjiang, China

Background

This cohort study created a risk equation of CVD for the Uyghur and Kazakh ethnic groups with metabolic syndrome (MetS) in Xinjiang and its associated factors, evaluated the model’s feasibility, and provided theoretical support for the prevention and early diagnosis of CVD.

Methods

A total of 5655 participants from Xinyuan and Jiashi counties in Xinjiang from 2010 to 2012 were selected, including 3770 and 1885 training and validation samples, respectively. A factor analysis was performed on 975 patients with MetS in the training sample, whereas potential factors related to CVD were extracted from 21 MetS biomarkers. Cox regression was used to create and verify a CVD-risk prediction model based on training samples. The receiver operating characteristic curve was drawn to evaluate the model’s prediction efficiency.

Results

The cumulative incidence of CVD was 9.20% (training sample, 9.12%; validation sample, 9.36%). Nine potential factors were extracted from the training sample population with MetS to predict the CVD risk: lipid (hazard ratio [HR], 1.205), obesity (HR, 1.047), liver function (HR, 1.042), myocardial enzyme (HR, 1.008), protein (HR, 1.024), blood pressure (HR, 1.027), liver enzyme (HR, 1.012), renal metabolic (HR, 1.015), and blood glucose (HR, 1.010). The area under the curve of the training and validation samples was 0.841 (95% confidence interval [CI], 0.821–0.861) and 0.889 (95% CI, 0.870–0.909), respectively.

Conclusion

The CVD prediction model created with nine potential factors in patients with MetS in Kazakh and Uyghur has a good predictive power.

Mucosal-Associated Invariant T Cell Dysregulation Correlates With Conjugated Bilirubin Level in Chronic HBV Infection

BACKGROUND AND AIMS

Mucosal-associated invariant T (MAIT) cells are nonconventional T cells restricted to major histocompatibility complex class I-related protein 1 (MR1). They are highly abundant in human liver and activated by T-cell receptor (TCR)-dependent and TCR-independent mechanisms to exhibit rapid, innate-like effector responses. However, the roles of MAIT cells in chronic HBV infection are still open for study. This study aims to test their antiviral potential and investigate their dynamic changes and regulating factors during chronic HBV infection.

APPROACH AND RESULTS

Blood samples from 257 chronic HBV-infected patients were enrolled, and nontumor liver specimens were collected from 58 HBV-infected HCC patients. Combining cell-culture experiments and human data, we showed that MAIT cells had strong cytotoxicity against HBV-transfected hepatocytes in an MR1-dependent way. However, circulating and hepatic MAIT cells in HBV-infected patients decreased significantly compared to controls. Correlation analysis suggested that MAIT cell frequency was associated with disease progression and inversely correlated with serum-conjugated bilirubin level. In particular, conjugated bilirubin not only directly promoted MAIT cell activation and apoptosis, but also impaired TCR-induced proliferation and expansion of MAIT cells, which could be partially rescued by IL-2 in the absence of conjugated bilirubin. Despite that MAIT cells from patients with high conjugated bilirubin levels showed decreased cytokine-producing capacity, the increased TCR-dependent antiviral cytokine production suggested MAIT cells as an important guardian of chronic HBV with high conjugated bilirubin.

CONCLUSIONS

We reveal the MR1-dependent, anti-HBV potential of MAIT cells and identify conjugated bilirubin as a major factor dysregulating its frequency and function in chronic HBV-infected patients, suggesting a therapeutic target for MAIT-cell-based immunity against chronic HBV infection.

Lower Serum Indirect Bilirubin Levels are Inversely Related to Carotid Intima-Media Thickness Progression

BACKGROUND

Bilirubin has been recognized as a potential endogenous inhibitor of atherosclerosis, being inversely associated with carotid intima-media thickness (CIMT). However, little information is available concerning the correlation between serum indirect bilirubin (IBIL), especially long-term IBIL level, and early atherosclerosis progression. This study was designed to evaluate the relationship between serum IBIL level and CIMT progression.

METHODS

A total of 2205 participants were enrolled in this Asymptomatic Polyvascular Abnormalities Community study (APAC study). CIMT was measured at baseline and 2-year follow-up. The participants were divided into four groups based on their serum IBIL levels at baseline. Both baseline and average serum IBIL values during the 2-year follow up were used in the analysis. Multivariable logistic regression and linear regression were used to assess the associations between serum IBIL and CIMT progression.

RESULTS

The results showed that 51.93% (1145/2205) of participants were diagnosed with CIMT progression during the 2-year follow-up. Baseline serum IBIL level was significantly associated with the incidence of CIMT progression after adjusting for other potential confounding factors. Compared with the first quartile, adjusted odds ratios (OR) of the second, third, and fourth quartiles of IBIL were 0.70 [95% confidence interval (CI), 0.55-0.90], 0.68 (95% CI, 0.52-0.87), and 0.63 (95% CI, 0.49-0.82) (P = 0.0006), respectively. Serum IBIL level during the follow-up was also associated with CIMT progression in the univariate analysis (P = 0.0022), although no longer significant after adjusting for potential confounders in the multiple linear regression.

CONCLUSION

The study demonstrated the inverse relationship between serum IBIL and CIMT progression. Lower serum IBIL level is an independent predictor of subclinical atherosclerosis.

Relation of Direct, Indirect, and Total bilirubin to Adverse Long-term Outcomes Among Patients With Acute Coronary Syndrome

Bilirubin is known as an antioxidant. However, there have been controversies over whether bilirubin is protective against cardiovascular disease or not. In addition, no study has examined the association between subtypes of total bilirubin (direct bilirubin [DB] and indirect bilirubin [IDB]) and long-term outcomes of acute coronary syndrome (ACS) patients. We included 533 consecutive patients with ACS. All the patients were followed up for the composite end point of cardiac death, revascularization, and acute heart failure. At a median follow-up of 2.4 years, Kaplan-Meier curve demonstrated that higher serum DB levels were significantly associated with major adverse cardiac events (MACE) (p <0.05). However, total bilirubin (TB) and IDB were not associated with MACE by Kaplan-Meier analysis. Cox analysis showed that high TB and DB were associated with increased risk of MACE in ACS even after adjustment of cardiovascular risk factors. The receiver operating characteristic curve illustrated that DB had a predictive value of MACE in ACS. In conclusion, we firstly reported that high TB and DB but not IDB were associated with increased risk of MACE in Chinese ACS, and the prognostic value of DB was superior to that of TB or IDB.

Genome-Wide Association Study (GWAS) on Bilirubin Concentrations in Subjects with Metabolic Syndrome: Sex-Specific GWAS Analysis and Gene-Diet Interactions in a Mediterranean Population

Although, for decades, increased serum bilirubin concentrations were considered a threatening sign of underlying liver disease and had been associated with neonatal jaundice, data from recent years show that bilirubin is a powerful antioxidant and suggest that slightly increased serum bilirubin concentrations are protective against oxidative stress-related diseases, such as cardiovascular diseases. Therefore, a better understanding of the gene-diet interactions in determining serum bilirubin concentrations is needed. None of the previous genome-wide association studies (GWAS) on bilirubin concentrations has been stratified by sex. Therefore, considering the increasing interest in incorporating the gender perspective into nutritional genomics, our main aim was to carry out a GWAS on total serum bilirubin concentrations in a Mediterranean population with metabolic syndrome, stratified by sex. Our secondary aim was to explore, as a pilot study, the presence of gene-diet interactions at the GWAS level. We included 430 participants (188 men and 242 women, aged 55–75 years, and with metabolic syndrome) in the PREDIMED Plus-Valencia study. Global and sex-specific GWAS were undertaken to analyze associations and gene-diet interaction on total serum bilirubin. Adherence (low and high) to the Mediterranean diet (MedDiet) was analyzed as the dietary modulator. In the GWAS, we detected more than 55 SNPs associated with serum bilirubin at p < 5 × 10⁻⁸ (GWAS level). The top-ranked were four SNPs (rs4148325 (p = 9.25 × 10⁻²⁴), rs4148324 (p = 9.48 × 10⁻²⁴), rs6742078 (p = 1.29 × 10⁻²³), rs887829 (p = 1.39 × 10⁻²³), and the rs4148324 (p = 9.48 × 10⁻²⁴)) in the UGT1A1 (UDP glucuronosyltransferase family 1 member A1) gene, which replicated previous findings revealing the UGT1A1 as the major locus. In the sex-specific GWAS, the top-ranked SNPs at the GWAS level were similar in men and women (the lead SNP was the rs4148324-UGT1A1 in both men (p = 4.77 × 10⁻¹¹) and women (p = 2.15 × 10⁻¹⁴), which shows homogeneous genetic results for the major locus. There was more sex-specific heterogeneity for other minor genes associated at the suggestive level of GWAS significance (p < 1 × 10⁻⁵). We did not detect any gene-MedDiet interaction at p < 1 × 10⁻⁵ for the major genetic locus, but we detected some gene-MedDiet interactions with other genes at p < 1 × 10⁻⁵, and even at the GWAS level for the IL17B gene (p = 3.14 × 10⁻⁸). These interaction results, however, should be interpreted with caution due to our small sample size. In conclusion, our study provides new data, with a gender perspective, on genes associated with total serum bilirubin concentrations in men and women, and suggests possible additional modulations by adherence to MedDiet.

Serum bilirubin is negatively associated with white blood cell count

OBJECTIVE

Bilirubin is considered an important antioxidant, anti-inflammatory factor and immunomodulator. The current investigation aimed to explore the association between bilirubin and white blood cell (WBC) count in a large Chinese cohort.

METHODS

A total of 61091 participants (29259 males, 31832 females) were recruited from a Chinese tertiary hospital. Data were sorted by sex, and the association between bilirubin and WBC count was analyzed after dividing bilirubin levels into quartiles.

RESULTS

Most parameters (including age, body mass index, systolic blood pressure, diastolic blood pressure, alanine aminotransferase, total bilirubin, blood urea nitrogen, creatinine, uric acid, triglycerides and WBC count) were significantly higher in men than in women. Bilirubin displayed significant negative relationships with most other measured variables. Linear logistic regression analysis further indicated their negative relationships. Females showed a significantly higher frequency of leucopenia than males. Significant associations of leucopenia with high bilirubin quartiles were shown in binary logistic regression models for both sexes, with a much closer association in men than in women. For instance, for men with bilirubin levels in quartile 4, the adjusted likelihood of leucopenia was 1.600-times higher than that of men with values in quartile 1. For women with bilirubin levels in quartile 4, the adjusted likelihood of leucopenia was 1.135-times higher than that of women with values in quartile 1.

CONCLUSION

Bilirubin is negatively related to WBC count. Significant associations exist between leucopenia and high bilirubin quartiles, and these associations are more obvious in men than in women.

The U-Shaped Association between Bilirubin and Diabetic Retinopathy Risk: A Five-Year Cohort Based on 5323 Male Diabetic Patients

AIMS

This study aimed at assessing the impact of baseline bilirubin (TBiL) on the incidence of diabetic retinopathy (DR) based on a five-year cohort study which consisted of 5323 Chinese male diabetic patients.

METHODS

A cohort study based on 5323 male diabetic patients was conducted in Beijing, from 2009 to 2013. Both baseline TBiL and follow-up changes were measured. Cox proportional risk model was used to calculate the hazard ratio (HR) of TBiL for DR risk.

RESULTS

During the follow-up period, there were 269 new DR cases. The incidence of five-year follow-up was 5.1% (95% CI: 4.5%~5.6%). The TBiL level of those who had diabetic retinopathy was lower than that of those without (12.51+ 1.20 mol/L and 13.11+ 1.32 μmol/L, P = 0.033). And more interestingly, along with the quintiles of baseline TBiL, there showed a U-shaped curve with DR incidence. And the RRs were 0.928 (95% CI: 0.646-1.331), 0.544 (95% CI: 0.365-0.811), 0.913 (95% CI: 0.629-1.324), and 1.035 (95% CI: 0.725-1.479) for the second, third, fourth, and fifth quintiles of baseline TBiL levels, respectively, compared with the first quintile. For follow-up TBiL changes, after being adjusted for related covariables and baseline TBiL levels (as continuous variable) in the model, the RRs for DR were 1.411 (95% CI: 1.081-1.842) for those who had decreased TBiL level and 0.858 (95% CI: 0.770-0.947) for those who had increased TBiL level during follow-up. And this association was more prominent among those with lower baseline TBiL level.

CONCLUSIONS

Serum TBiL had a U-shaped relationship with DR incidence, which was independent of control status of diabetes and other related covariates.