Emergence of blood urea nitrogen as a biomarker of neurohormonal activation in heart failure

The blood urea nitrogen-to-creatinine ratio is associated with acute kidney injury among COVID-19 patients

INTRODUCTION

To explore the associations between the blood urea nitrogen-to-creatinine ratio (BCR), acute kidney injury (AKI), and in-hospital mortality in coronavirus disease 2019 (COVID-19) patients.

METHODS

COVID-19 patients from Ruijin Hospital LuWan Branch, Shanghai Jiao Tong University School of Medicine were enrolled in this study. Clinical data and laboratory parameters were collected. AKI was defined using two serum creatinine tests according to KDIGO guidelines. Cox regression and receiver operating characteristic (ROC) curve analyses were performed.

RESULTS

Five hundred and sixty-seven COVID-19 patients were enrolled, 44.1% of whom were male. The mean age was 75 years. Among all patients, 17 patients developed AKI, and 30 patients died during hospitalization. Compared to non-AKI patients, the BCR in AKI patients was significantly greater. BCR was significantly associated with AKI (unadjusted HR 1.04, 95% CI: 1.02-1.05, p < 0.001; adjusted HR 1.06, 95% CI 1.02-1.10, p = 0.001). BCR was also a risk factor of in-hospital mortality (unadjusted HR 1.03, 95% CI: 1.02-1.05, p < 0.001; adjusted HR 1.04, 95% CI: 1.01-1.08, p = 0.019). The BCR threshold was 38.9, with 70.6% sensitivity and 87.1% specificity for predicting AKI, while a threshold of 33.0 predicted mortality. Subgroup analysis revealed that BCR could predict AKI and mortality in different subgroups according to sex, age, diabetes mellitus, and estimated glomerular filtration rate.

CONCLUSIONS

The BCR, a simple index, is associated with AKI onset and mortality in COVID-19 patients. The BCR possesses certain specificity for AKI screening, which indicates an effective clinical indicator for screening patients at high risk of AKI.

Genetic insights into blood urea nitrogen as a risk factor for coronary artery disease: a Mendelian randomization study in East Asians

BACKGROUND

Previous studies have reported the association between blood urea nitrogen (BUN) and cardiovascular diseases (CVDs) but the causality has not yet been proved. Our study aimed to assess the causal effect of BUN levels on several CVDs using the two-sample Mendelian randomization (MR) method. This is the first MR study examining causal relationships between BUN and multiple cardiovascular diseases.

METHODS

Using data from genome-wide association studies (GWAS) of East Asians, we identified single nucleotide polymorphisms (SNPs) associated with BUN levels as instrumental variables. Specifically, SNPs reaching genome-wide significance (p < 5 × 10-8) were selected from a large-scale BUN dataset comprising (n = 148,767). To ensure robustness, multiple MR methods, including MR-Egger, weighted median, inverse variance weighting (IVW), simple mode, and weighted mode, were employed to evaluate the causal relationship between BUN levels and CVDs. Sensitivity analyses were conducted to assess the reliability and stability of the results.

RESULT

The IVW approach showed that a higher level of BUN was associated with an increased risk of coronary artery disease (CAD) (OR = 1.42, 95% CI = 1.226 - 1.644, p = 2.89 × 10-6). For atrial fibrillation (OR = 0.868, 95% CI = 0.678 - 1.110, p = 0.258), arrhythmia (OR = 0.907, 95% CI = 0.777 - 1.059, p = 0.216), and congestive heart failure (OR = 0.924, 95% CI = 0.781 - 1.092, p = 0.353), no significant associations were found. Sensitivity analyses indicated the results were robust.

CONCLUSION

This MR work shows that elevated BUN levels are a potential biomarker for CAD risk but lack causal associations with other CVDs. These findings suggest avenues for risk stratification and CAD prevention strategies, emphasizing the clinical utility of BUN monitoring in at-risk populations.

Predictive value of blood urea nitrogen to creatinine ratio and estimated plasma volume status in heart failure

BACKGROUND

The blood urea nitrogen to creatinine ratio (BCR) and estimated plasma volume status (ePVS) may be prognostic markers in heart failure (HF), but their combined efficacy is unclear. This research aims to determine the prognostic utility of BCR and ePVS in critically ill HF patients in the intensive care unit.

METHODS

Data from the MIMIC-IV database were analyzed. ePVS was calculated using hemoglobin and hematocrit levels with Strauss-derived Duarte method. The primary outcome was 1-year all-cause mortality (ACM). Receiver operating characteristic (ROC) curves identified cutoff values for BCR and ePVS. To assess the connection between BCR, ePVS, and 1-year ACM, the Kaplan-Meier (KM) method, Cox proportional hazards models, subgroup analysis, and limited cubic spline were employed. Harrell's C statistic evaluated predictive power.

RESULTS

Among 11,066 participants, optimal thresholds for mortality were BCR > 22.81 and ePVS > 7.16 ml/g. BCR demonstrated a non-linear J-shaped correlation with ACM, while ePVS displayed a linear relationship. Multivariate Cox analysis indicated higher level of BCR was linked to higher 1-year ACM (HR = 1.39, 95% CI: 1.30-1.49, P < 0.001), as was increased level of ePVS (HR = 1.09, 95% CI: 1.02-1.16, P = 0.012). Notably, HF patients with both high BCR and ePVS faced a significantly greater mortality risk than those with lower levels of both markers (HR = 1.54, 95% CI: 1.40-1.69, P < 0.001). Combining BCR and ePVS improved prognostic accuracy.

CONCLUSIONS

BCR and ePVS independently predict 1-year ACM in HF patients, with their combined use offering improved prognostic accuracy.

Fucoidan Alleviates Porcine Epidemic Diarrhea Virus-Induced Intestinal Damage in Piglets by Enhancing Antioxidant Capacity and Modulating Arginine Metabolism

Porcine epidemic diarrhea virus (PEDV) causes severe intestinal damage, posing significant threats to the swine industry. Fucoidan (FUC), a biologically active compound, exhibits antiviral activity against multiple viruses. This study aimed to investigate the protective effects of FUC on PEDV-induced intestinal injury in piglets and explore its underlying mechanisms. A total of 28 healthy crossbred piglets were randomly allocated into four experimental groups using a 2 × 2 factorial design: (1) a control group, (2) an FUC group, (3) a PEDV group, and (4) an FUC+PEDV group. From day 4 to day 10, the piglets in the FUC and FUC+PEDV groups were orally administered fucoidan at a dosage of 20 mg/kg body weight (BW) each day. On day 8, the piglets in the PEDV and FUC+PEDV groups were orally administered PEDV at a dose of 3 × 105.5 TCID50. The results show that FUC supplementation significantly decreased plasma DAO activity (p < 0.05) and increased the villus height, villus area, as well as the villus height/crypt depth (p < 0.05) in the intestine when compared to the PEDV-infected piglets. This indicates that FUC could alleviate the disruption of intestinal morphology and function caused by PEDV infection. FUC enhanced the antioxidant capacity of the piglets by increasing SOD and GSH-Px activity. Transcriptional profiling combined with quantitative analysis revealed that FUC regulates immune responses, substance transport, and arginine metabolism. Notably, FUC downregulated arginase 1 expression, which may redirect arginine toward nitric oxide synthesis, thereby establishing an antiviral state in the host. These findings highlight the potential application of FUC as a natural agent for mitigating PEDV-induced intestinal damage and improving gut health. Additionally, monitoring the health status of piglets is necessary when FUC is applied in practical applications.

Cadmium disrupted homeostasis of proximal renal tubular cells via targeting ATF4-CHOP complex into the nucleus

Cadmium, a ubiquitous toxic metal and environmental pollutant, is associated with several renal metabolic disorders and disrupts the homeostasis of kidneys in humans and animals. However, the precise molecular mechanism remains poorly elucidated. The present study investigated the role of the ATF4-CHOP nuclear transcriptional axis and its interactions with cellular pathways in cadmium-induced nephrotoxicity. We acquired 120 one-day-old chickens, randomly divided them into four groups (Con, Cd35, Cd70, Cd140), and were treated with graded cadmium doses for 90 days. The kidney tissues were collected for comprehensive histopathological, biochemical, and molecular analyses using western blotting, qRT-PCR, immunofluorescence, and tunel assay. Subsequently, we revealed that cadmium exposure induced ER stress, significantly upregulated CHOP expression, and activated pro-apoptotic ATF4-CHOP axis. Our findings revealed a complex interplay, where ER stress activated inflammation. Concurrently, mitochondrial disruption elevated ROS production and oxidative stress, which impaired renal homeostasis. Moreover, inhibition of autophagy and mitophagy led to the accumulation of damaged cell organelles, further exacerbating apoptotic signaling. Our results elucidate that an integrated network of cellular stress pathways mediates cadmium-induced renal toxicity, with the ATF4-CHOP axis acting as a crucial pro-apoptotic pathway. This study provides critical insights into the mechanisms of cadmium-induced nephrotoxicity and potential therapeutic interventions to mitigate heavy metal-induced renal homeostasis disruption and renal damage.

Establishment and validation of a nomogram for predicting esophagogastric variceal bleeding in patients with liver cirrhosis

BACKGROUND

Patients with decompensated liver cirrhosis suffering from esophagogastric variceal bleeding (EGVB) face high mortality.

AIM

To investigate the risk factors for EGVB in patients with liver cirrhosis and establish a diagnostic nomogram.

METHODS

Patients with liver cirrhosis who met the inclusion criteria were randomly divided into training and validation cohorts in a 6:4 ratio in this retrospective research. Univariate analysis, least absolute shrinkage and selection operator regression, and multivariate analysis were employed to establish the nomogram model. Calibration curve, the area under the receiver operating characteristic curve (AUC), and decision curve analysis (DCA) were applied to assess the discrimination, accuracy, and clinical practicability of the nomogram, respectively.

RESULTS

A total of 1115 patients were enrolled in this study. The nomogram was established based on white blood cells (P < 0.001), hemoglobin (P < 0.001), fibrinogen (P < 0.001), total bilirubin (P = 0.007), activated partial thromboplastin time (P = 0.002), total bile acid (P = 0.012), and ascites (P = 0.006). The calibration curve indicated that the actual observation results were in good agreement with the prediction results of the model. The AUC values of the diagnostic model were 0.861 and 0.859 in the training and validation cohorts, respectively, which were higher than that of the aspartate aminotransferase-to-platelet ratio index, fibrosis index based on 4 factors, and aspartate aminotransferase-to-alanine aminotransferase ratio. Additionally, DCA indicated that the net benefit value of the model was higher than that of the other models.

CONCLUSION

This research constructed and validated a nomogram with perfect performance for predicting EGVB events in patients with liver cirrhosis, which could help clinicians with timely diagnosis, individualized treatment, and follow-up.

Moderating Role of Anemia on the Association between Blood Urea Nitrogen and Atherosclerotic Cardiovascular Disease in Hypertension

Background

Anemia or blood urea nitrogen (BUN) are both associated with atherosclerotic cardiovascular disease (ASCVD) in hypertension (HTN). However, the relationship between anemia, BUN, and ASCVD remains unclear in HTN. This study aimed to investigate the relationship between BUN, anemia, and ASCVD in HTN patients, and further investigated the moderating effect of anemia on the relationship between BUN and ASCVD.

Methods

In total, 15,109 HTN patients were included based on the National Health and Nutritional Examination Survey (NHANES) from 1999 to 2018. The weighted univariate logistic regression model was utilized to select potential covariates. The relationship between BUN, anemia, and ASCVD was investigated using weighted univariate and multivariate logistic regression models. All results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs).

Results

A total of 15,109 HTN patients were included for final analysis. BUN level ≥4.69 mmol/L was related to higher odds of ASCVD in HTN patients (OR = 1.68, 95% CI: 1.51-1.88). Similarly, anemia was also associated with increased odds of ASCVD in HTN patients (OR = 1.45, 95% CI: 1.22-1.73). In patients with anemia, a BUN level ≥4.69 mmol/L was associated with increased odds of ASCVD when compared to patients who had a BUN level <4.69 mmol/L (OR = 2.95, 95% CI: 2.05-4.25). Anemia affected the association between BUN and ASCVD in HTN patients.

Conclusions

Anemia moderates the association between BUN and ASCVD in HTN patients, amplifying the adverse effects. The findings show the importance of comprehensive management strategies that included renal function monitoring and anemia treatment in HTN patients.

Association of blood urea nitrogen to glucose ratio with 365-day mortality in critically ill patients with chronic kidney disease: a retrospective study

Low blood glucose levels and high urea nitrogen levels affect patient prognosis, but few studies have investigated whether the blood urea nitrogen to glucose (BGR) ratio predicts the risk of death.This retrospective research examined the connection between the BGR and 365-day mortality in patients with chronic kidney disease (CKD) stages 1-4 admitted to an intensive care unit (ICU). The study utilized data from 6,380 patients in the Medical Information Mart for Intensive Care IV version 2.2 (MIMIC-IV v2.2), taking into account confounding factors such as demographics, vital signs, laboratory indicators, and comorbidities. The study employed both univariate and multivariate Cox regression analyses stratified by BGR quartiles. Additionally, restricted cubic spline regression and inflection point analysis were used to explore the linear relationship between BGR and 365-day mortality, while Kaplan-Meier curve analysis was used to observe mortality changes under different BGR stratifications. Subgroup and mediating effect analyses were performed to evaluate the robustness of BGR's effect on 365-day mortality. The study found a cumulative 365-day mortality rate of 34.2% among CKD stages 1-4 patients, with a 2.43-fold increase in the risk of death associated with BGR and at least a 44% increase in the risk of death for each unit increase in BGR (P = 0.022). A significant nonlinear relationship was identified, showing a stepwise change in the risk of death with a marked increase in the slope of the curve for BGR values below 0.52 and above 0.9 (P < 0.001). Subgroup analyses indicated interactions between BGR and factors such as age, sepsis, first-day antibiotic use, and cerebrovascular disease (P < 0.05). In conclusion, this study confirms that BGR is a significant and stable predictor of 1-year mortality risk in patients with CKD stages 1-4. Interventions aimed at timely adjustment, correction of metabolic imbalances, reduction of inflammation, and management of BGR levels are beneficial for reducing mortality in this patient population.

Association Between Blood Urea Nitrogen to Serum Albumin Ratio and Mortality in Critically Ill Patients With Chronic Obstructive Pulmonary Disease: A Retrospective Study

Background

Epidemiological studies suggest that elevated blood urea nitrogen (BUN) and reduced serum albumin could independently predict adverse clinical outcomes in patients with chronic obstructive pulmonary disease (COPD). However, the predictive performance of BUN-albumin ratio (BAR) in critically ill patients with COPD remains to be confirmed. This study aimed to investigate the association between BAR and all-cause mortality in intensive care unit (ICU) patients with COPD.

Methods

This was a retrospective study that included COPD patients with BUN and serum albumin value on the first day of each ICU admission and data were obtained from the eICU Collaborative Research Database. The included COPD patients were divided into three groups stratified by BAR tertiles (T1-T3). Multivariate logistic regression and Cox proportional hazards models were used to examine the association between BAR and all-cause in-hospital and ICU mortality, respectively. Kaplan-Meier curves were plotted to evaluate survival differences among three groups and discrepancies were compared with the log-rank test.

Results

A total of 4037 patients were included in the final analysis and the in-hospital and ICU mortality rates were 11.79% and 6.51%, respectively. The multivariate logistic regression analyses showed that continuous BAR was a significant risk predictor of in-hospital mortality (OR: 1.039, 95% CI: 1.026-1.052, P < 0.001) and ICU mortality (OR: 1.030, 95% CI: 1.015-1.045, P < 0.001) in fully adjusted model. The Cox proportional hazards models revealed that patients in the highest BAR tertile (T3) were significantly associated with higher risk of in-hospital mortality (HR: 1.983, 95% CI: 1.419-2.772, P < 0.001) and ICU mortality (HR: 2.166, 95% CI: 1.373-3.418, P < 0.001). The Kaplan-Meier curves showed that the survival differences of all-cause mortality were statistically significant in three tertile groups (log-rank P < 0.0001). Correlated subgroup analyses indicated that this positive association might vary in certain population settings.

Conclusion

High level of BAR is associated with the increasing all-cause mortality in critically ill patients with COPD. As an innovative and promising biomarker, BAR might be useful in predicting high risk of death in patients with COPD.

Association of blood urea nitrogen with 28-day mortality in critically ill patients: A multi-center retrospective study based on the eICU collaborative research database

OBJECTIVE

Blood urea nitrogen (BUN) is a commonly used biomarker for assessing kidney function and neuroendocrine activity. Previous studies have indicated that elevated BUN levels are associated with increased mortality in various critically ill patient populations. The focus of this study was to investigate the relationship between BUN and 28-day mortality in intensive care patients.

METHODS

This was a multi-centre retrospective cohort study that made use of data from the eICU Collaborative Research Database. The primary exposure variable was BUN, and the outcome was 28-day mortality. The following variables were included as covariates: age, gender, BMI, white blood cell count, creatinine, GCS score, APACHE IV score, and diabetes. The statistical analyses included univariate and multivariate logistic regression, as well as generalized additive modelling, which was employed to assess the non-linear relationship between BUN and mortality.

RESULTS

A total of 63,757 elderly patients were included in the study, with a 28-day mortality of 6.5%. The univariate analysis indicated that elevated BUN quartiles were associated with an increased risk of mortality. The results of the multivariate analysis further confirmed the non-linear relationship between BUN and mortality. When BUN was less than 32 mg/dL, there was a significant positive association, with an adjusted odds ratio of 1.230 (95% CI: 1.154-1.311, p<0.0001) for every 10 mg/dL increase in BUN. However, when BUN was greater than or equal to 32 mg/dL, BUN level had no significant effect on mortality.

CONCLUSION

BUN showed a nonlinear, threshold correlation with 28-day mortality in critically ill patients. The higher the BUN, the greater the risk of death if the BUN is below the threshold.

Blood Urea Nitrogen to Left Ventricular Ejection Ratio as a Predictor of Short-Term Outcome in Acute Myocardial Infarction Complicated by Cardiogenic Shock

INTRODUCTION

Cardiogenic shock (CS) is the most critical complication after acute myocardial infarction (AMI) with mortality above 50%. Both blood urea nitrogen and left ventricular ejection fraction were important prognostic indicators. We aimed to evaluate the prognostic value of admission blood urea nitrogen to left ventricular ejection fraction ratio (BUNLVEFr) in patients with AMI complicated by CS (AMI-CS).

METHODS

268 consecutive patients with AMI-CS were divided into two groups according to the admission BUNLVEFr cut-off value determined by Youden index. The primary endpoint was 30-day all-cause mortality and the secondary endpoint was the composite events of major adverse cardiovascular events (MACEs). Cox proportional hazard models were performed to analyze the association of BUNLVEFr with the outcome.

RESULTS

The optimal cut-off value of BUNLVEFr is 16.63. The 30-day all-cause mortality and MACEs in patients with BUNLVEFr≥16.63 was significantly higher than in patients with BUNLVEFr<16.63 (30-day all-cause mortality: 66.2% vs. 17.1%, p < 0.001; 30-day MACEs: 80.0% vs. 48.0%, p < 0.001). After multivariable adjustment, BUNLVEFr≥16.63 remained an independent predictor for higher risk of 30-day all-cause mortality (HR = 3.553, 95% CI: 2.125-5.941, p < 0.001) and MACEs (HR = 2.026, 95% CI: 1.456-2.820, p < 0.001). Subgroup analyses found that the effect of BUNLVEFr was consistent in different subgroups (all p-interaction>0.05).

CONCLUSION

The admission BUNLVEFr provided important prognostic information for AMI-CS patients.

The association of blood urea nitrogen-to-creatinine ratio and in-hospital mortality in acute ischemic stroke patients with atrial fibrillation: data from the MIMIC-IV database

Objective

This research aimed to investigate the association between the blood urea nitrogen-to-creatinine (BUN/Cr) ratio and the rate of in-hospital mortality in patients with acute ischemic stroke (AIS) and atrial fibrillation (AF), who are also receiving care in intensive care unit (ICU).

Methods

A retrospective study was conducted using the MIMIC-IV database. We collected data on BUN/Cr levels at admission for patients with AIS and concurrent AF. To assess the association between BUN/Cr and in-hospital mortality rate, statistical analysis was conducted employing multivariable logistic regression models and restricted cubic spline models. These models were utilized to investigate the potential relationship and provide insights into the impact of BUN/Cr on the likelihood of in-hospital mortality. Interaction and subgroup analyses were performed to evaluate the consistency of the correlation.

Results

There were a total of 856 patients (age ≥ 18 years) with a median age of 78.0 years, of which 466 (54.4%) were female. Out of 856 patients, 182 (21.26%) died in the hospital. Upon controlling for confounding factors, the multivariable logistic regression analysis elucidated that patients falling within the third trisection (Q3 > 22.41 mg/dL) exhibited a noticeably increased susceptibility to in-hospital mortality when contrasted with their counterparts positioned in the second trisection (Q2: 17.2-22.41 mg/dL) (OR = 2.02, 95% CI: 1.26-3.26, p = 0.004). A non-linear J-shaped relationship was observed between BUN/Cr at ICU admission and in-hospital mortality rate (p = 0.027), with a turning point at 19.63 mg/dL. In the threshold analysis, there was a 4% rise in in-hospital mortality for each 1 mg/dL increase in BUN/Cr (OR: 1.04, 95% CI: 1.01-1.06, p = 0.012).

Conclusion

In patients with AIS complicated by AF, BUN/Cr at admission shows a J-shaped correlation with in-hospital mortality rate. When BUN/Cr exceeds 19.63 mg/dL, the in-hospital mortality rate increases.

Serum urea increase during hospital stay is associated with worse outcomes after in-hospital cardiac arrest

BACKGROUND

Evaluate the association between serum urea at admission and during hospital stay with return of spontaneous circulation (ROSC) and in-hospital mortality in patients with in-hospital cardiac arrest (IHCA).

METHODS

This retrospective study included patients over 18 years with IHCA attended from May 2018 to December 2022. The exclusion criteria were the absence of exams to calculate delta urea and the express order of "do-not-resuscitate". Data were collected from the electronic medical records. Serum admission urea and urea 24 hours before IHCA were also collected and used to calculate delta urea.

RESULTS

A total of 504 patients were evaluated; 125 patients were excluded due to the absence of variables to calculate delta urea and 5 due to "do-not-resuscitate" order. Thus, we included 374 patients in the analysis. The mean age was 65.0 ± 14.5 years, 48.9% were male, 45.5% had ROSC, and in-hospital mortality was 91.7%. In logistic regression models, ROSC was associated with lower urea levels 24 hours before IHCA (OR: 0.996; CI95%: 0.992-1.000; p: 0.032). In addition, increased levels of urea 24 hours before IHCA (OR: 1.020; CI95%: 1.008-1.033; p: 0.002) and of delta urea (OR: 1.001; CI95%: 1.001-1.019; p: 0.023) were associated with in-hospital mortality. ROC curve analysis showed that the area under the ROC curve for mortality prediction was higher for urea 24 hours before IHCA (Cutoff > 120.1 mg/dL) than for delta urea (Cutoff > 34.83 mg/dL).

CONCLUSIONS

In conclusion, increased serum urea levels during hospital stay were associated with worse prognosis in IHCA.

Blood urea nitrogen to creatinine ratio is associated with in-hospital mortality in critically ill patients with venous thromboembolism: a retrospective cohort study

Background

The relationship between the blood urea nitrogen to creatinine ratio (BCR) and the risk of in-hospital mortality among intensive care unit (ICU) patients diagnosed with venous thromboembolism (VTE) remains unclear. This study aimed to assess the relationship between BCR upon admission to the ICU and in-hospital mortality in critically ill patients with VTE.

Methods

This retrospective cohort study included patients diagnosed with VTE from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary endpoint was in-hospital mortality. Univariate and multivariate logistic regression analyses were conducted to evaluate the prognostic significance of the BCR. Receiver operating characteristic (ROC) curve analysis was utilized to determine the optimal cut-off value of BCR. Additionally, survival analysis using a Kaplan-Meier curve was performed.

Results

A total of 2,560 patients were included, with a median age of 64.5 years, and 55.5% were male. Overall, the in-hospital mortality rate was 14.6%. The optimal cut-off value of the BCR for predicting in-hospital mortality in critically ill VTE patients was 26.84. The rate of in-hospital mortality among patients categorized in the high BCR group was significantly higher compared to those in the low BCR group (22.6% vs. 12.2%, P < 0.001). The multivariable logistic regression analysis results indicated that, even after accounting for potential confounding factors, patients with elevated BCR demonstrated a notably increased in-hospital mortality rate compared to those with lower BCR levels (all P < 0.05), regardless of the model used. Patients in the high BCR group exhibited a 77.77% higher risk of in-hospital mortality than those in the low BCR group [hazard ratio (HR): 1.7777; 95% CI: 1.4016-2.2547].

Conclusion

An elevated BCR level was independently linked with an increased risk of in-hospital mortality among critically ill patients diagnosed with VTE. Given its widespread availability and ease of measurement, BCR could be a valuable tool for risk stratification and prognostic prediction in VTE patients.

Blood urea nitrogen to serum albumin ratio as a new prognostic indicator in type 2 diabetes mellitus patients with chronic kidney disease

Chronic kidney disease (CKD) is often a common comorbidity in critically ill patients with type 2 diabetes mellitus (T2DM). This study explored the relationship between blood urea nitrogen to serum albumin ratio (BAR) and mortality in T2DM patients with CKD in intensive care unit (ICU). Patients were recruited from the Medical Information Mart database, retrospectively. The primary and secondary outcomes were 90-day mortality, the length of ICU stay, hospital mortality and 30-day mortality, respectively. Cox regression model and Kaplan-Meier survival curve were performed to explore the association between BAR and 90-day mortality. Subgroup analyses were performed to determine the consistency of this association. A total of 1920 patients were enrolled and divided into the three groups (BAR < 9.2, 9.2 ≤ BAR ≤ 21.3 and BAR > 21.3). The length of ICU stay, 30-day mortality, and 90-day mortality in the BAR > 21.3 group were significantly higher than other groups. In Cox regression analysis showed that high BAR level was significantly associated with increased greater risk of 90-day mortality. The adjusted HR (95%CIs) for the model 1, model 2, and model 3 were 1.768 (1.409-2.218), 1.934, (1.489-2.511), and 1.864, (1.399-2.487), respectively. Subgroup analysis also showed the consistency of results. The Kaplan-Meier survival curve analysis revealed similar results as well that BAR > 21.3 had lower 90-day survival rate. High BAR was significantly associated with increased risk of 90-day mortality. BAR could be a simple and useful prognostic tool in T2DM patients with CKD in ICU.

Blood urea nitrogen to serum albumin ratio: a novel mortality indicator in intensive care unit patients with coronary heart disease

The blood urea nitrogen to albumin ratio (BAR) has been demonstrated as a prognostic factor in sepsis and respiratory diseases, yet its role in severe coronary heart disease (CHD) remains unexplored. This retrospective study, utilizing data from the Medical Information Mart for Intensive Care-IV database, included 4254 CHD patients, predominantly male (63.54%), with a median age of 74 years (IQR 64-83). Primary outcomes included in-hospital, 28-day and 1-year all-cause mortality after ICU admission. The Kaplan-Meier curves, Cox regression analysis, multivariable restricted cubic spline regression were employed to assess association between BAR index and mortality. In-hospital, within 28-day and 1-year mortality rates were 16.93%, 20.76% and 38.11%, respectively. Multivariable Cox proportional hazards analysis revealed associations between the increased BAR index and higher in-hospital mortality (HR 1.11, 95% CI 1.02-1.21), 28-day mortality (HR 1.17, 95% CI 1.08-1.27) and 1-year mortality (HR 1.23, 95% CI 1.16-1.31). Non-linear relationships were observed for 28-day and 1-year mortality with increasing BAR index (both P for non-linearity < 0.05). Elevated BAR index was a predictor for mortality in ICU patients with CHD, offering potential value for early high-risk patient identification and proactive management by clinicians.

Blood urea nitrogen to albumin ratio is associated with cerebral small vessel diseases

Blood urea nitrogen (BUN) to albumin ratio (BAR) is a comprehensive parameter that reflects renal, inflammatory, nutritional, and endothelial functions. BAR has been shown to be associated with various cancers, pneumonia, sepsis, and pulmonary and cardiovascular diseases; however, few studies have been conducted on its association with cerebrovascular diseases. In this study, we evaluated the association between BAR and cerebral small vessel disease (cSVD) in health check-up participants. We assessed consecutive health check-up participants between January 2006 and December 2013. For the cSVD subtype, we quantitatively measured the volume of white matter hyperintensity (WMH) and qualitatively measured the presence of lacune and cerebral microbleeds (CMBs). The BAR was calculated by dividing BUN by albumin as follows: BAR = BUN (mg/dl)/albumin (g/dl). A total of 3012 participants were evaluated. In multivariable linear regression analysis, BAR showed a statistically significant association with WMH volume after adjusting for confounders [β = 0.076, 95% confidence interval (CI): 0.027-0.125]. In multivariable logistic regression analyses, BAR was significantly associated with lacunes [adjusted odds ratio (aOR) = 1.20, 95% CI: 1.00-1.44] and CMBs (aOR = 1.28, 95% CI: 1.06-1.55). BAR was associated with all types of cSVD in the health check-up participants.

Blood urea nitrogen and clinical prognosis in patients with COVID-19: A retrospective study

The aim of this study was to estimate the association between blood urea nitrogen (BUN) and clinical prognosis in patients with COVID-19. A multicenter, retrospective study was conducted in adult patients with COVID-19 in 3 hospitals in Zhenjiang from January 2023 to May 2023. Patients were divided into survival and death group based on whether they survived at day 28. The demographic, comorbidities, and laboratory data were independently collected and analyzed, as well as clinical outcomes. Total 141 patients were enrolled and 23 (16.3%) died within 28 days. Patients who died within 28 days had a higher level of BUN compared with survivors. Bivariate logistic regression analysis showed that BUN was a risk factor for 28-day mortality in patients with COVID-19. ROC curve showed that BUN could predict 28-day mortality of COVID-19 patients (AUC = 0.796, 95%CI: 0.654-0.938, P < .001). When the cutoff value of BUN was 7.37 mmol/L, the sensitivity and specificity were 84.62% and 70.31%. Subgroup analysis demonstrated that hyper-BUN (≥7.37 mmol/L) was associated with increased 28-day mortality among COVID-19 patients. Patients with COVID-19 who died within 28 days had a higher level of BUN, and hyper-BUN (≥7.37 mmol/L) was associated with increased 28-day mortality.

Blood urea nitrogen to serum albumin ratio is associated with all-cause mortality in patients with AKI: a cohort study

Background

This study aims to investigate the relationship between blood urea nitrogen to serum albumin ratio (BAR) and all-cause mortality in patients with acute kidney injury (AKI) and evaluate the effect of BAR on the prognosis of AKI.

Methods

Adult patients with AKI admitted to the ICU in the Medical Information Mart for Intensive Care IV (MIMIC-IV) were selected in a retrospective cohort study. BAR (mg/g) was calculated using initial blood urea nitrogen (mg/dl)/serum albumin (g/dl). According to the BAR, these patients were divided into quartiles (Q1-Q4). Kaplan-Meier analysis was used to compare the mortality of the above four groups. Multivariate Cox regression analysis was used to evaluate the association between BAR and 28-day mortality and 365-day mortality. The receiver operating characteristic (ROC) curve was plotted and the area under the curve (AUC) was calculated, and the subgroup analysis was finally stratified by relevant covariates.

Results

A total of 12,125 patients with AKI were included in this study. The 28-day and 365-day mortality rates were 23.89 and 39.07%, respectively. Kaplan-Meier analysis showed a significant increase in all-cause mortality in patients with high BAR (Log-rank p < 0.001). Multivariate Cox regression analysis showed that BAR was an independent risk factor for 28-day mortality (4.32 < BAR≤7.14: HR 1.12, 95% CI 0.97-1.30, p = 0.114; 7.14 < BAR≤13.03: HR 1.51, 95% CI 1.31-1.75, p < 0.001; BAR>13.03: HR 2.07, 95% CI 1.74-2.47, p < 0.001; Reference BAR≤4.32) and 365-day mortality (4.32 < BAR≤7.14: HR 1.22, 95% CI 1.09-1.36, p < 0.001; 7.14 < BAR≤13.03: HR 1.63, 95% CI 1.46-1.82, p < 0.001; BAR>13.03: HR 2.22, 95% CI 1.93-2.54, p < 0.001; Reference BAR ≤ 4.32) in patients with AKI. The AUC of BAR for predicting 28-day mortality and 365-day mortality was 0.649 and 0.662, respectively, which is better than that of blood urea nitrogen and sequential organ failure assessment. In addition, subgroup analysis showed a stable relationship between BAR and adverse outcomes in patients with AKI.

Conclusion

BAR is significantly associated with increased all-cause mortality in patients with AKI. This finding suggests that BAR may help identify people with AKI at high risk of mortality.

Risk assessment for mortality in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: A retrospective cohort study

Background and Aims

Primary percutaneous coronary intervention (PCI) is the treatment of choice in ST-elevation myocardial infarction (STEMI) patients. This study aims to evaluate predictors of in-hospital and long-term mortality among patients with STEMI undergoing primary PCI.

Methods

In this registry-based study, we retrospectively analyzed patients with STEMI undergoing primary PCI enrolled in the primary angioplasty registry of Sina Hospital. Independent predictors of in-hospital and long-term mortality were determined using multivariate logistic regression and Cox regression analyses, respectively.

Results

A total of 1123 consecutive patients with STEMI were entered into the study. The mean age was 59.37 ± 12.15 years old, and women constituted 17.1% of the study population. The in-hospital mortality rate was 5.0%. Multivariate analyses revealed that older age (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.02-1.10), lower ejection fraction (OR: 0.97, 95% CI: 0.92-0.99), lower mean arterial pressure (OR: 0.95, 95% CI: 0.93-0.98), and higher white blood cells (OR: 1.17, 95% CI: 1.06-1.29) as independent risk predictors for in-hospital mortality. Also, 875 patients were followed for a median time of 21.8 months. Multivariate Cox regression demonstrated older age (hazard ratio [HR] = 1.04, 95% CI: 1.02-1.06), lower mean arterial pressure (HR = 0.98, 95% CI: 0.97-1.00), and higher blood urea (HR = 1.01, 95% CI: 1.00-1.02) as independent predictors of long-term mortality.

Conclusion

We found that older age and lower mean arterial pressure were significantly associated with the increased risk of in-hospital and long-term mortality in STEMI patients undergoing primary PCI. Our results indicate a necessity for more precise care and monitoring during hospitalization for such high-risk patients.

Carbon nanomaterials for sweat-based sensors: a review

Sweat is easily accessible from the human skin's surface. It is secreted by the eccrine glands and contains a wealth of physiological information, including metabolites and electrolytes like glucose and Na ions. Sweat is a particularly useful biofluid because of its easy and non-invasive access, unlike other biofluids, like blood. On the other hand, nanomaterials have started to show promise operation as a competitive substitute for biosensors and molecular sensors throughout the last 10 years. Among the most synthetic nanomaterials that are studied, applied, and discussed, carbon nanomaterials are special. They are desirable candidates for sensor applications because of their many intrinsic electrical, magnetic, and optical characteristics; their chemical diversity and simplicity of manipulation; their biocompatibility; and their effectiveness as a chemically resistant platform. Carbon nanofibers (CNFs), carbon dots (CDs), carbon nanotubes (CNTs), and graphene have been intensively investigated as molecular sensors or as components that can be integrated into devices. In this review, we summarize recent advances in the use of carbon nanomaterials as sweat sensors and consider how they can be utilized to detect a diverse range of analytes in sweat, such as glucose, ions, lactate, cortisol, uric acid, and pH.

Prognostic Value of Blood Urea Nitrogen for Short-Term Mortality in Patients with Infective Endocarditis

INTRODUCTION

Blood urea nitrogen (BUN) is a metabolic product validated to be an independent risk factor in the prognosis of several diseases. However, the prognostic value of BUN in patients with infective endocarditis (IE) remains unevaluated.

METHODS

A total of 1371 patients with a diagnosis of IE were included and divided into four groups according to BUN (mmol/L) at admission: < 3.5 (n = 343), 3.5-4.8 (n = 343), 4.8-6.8 (n = 341), and ≥ 6.8 (n = 344). Restricted cubic spline was used to assess the association of BUN with in-hospital mortality. Multivariate analysis was performed to identify the independent risk factors for adverse outcomes.

RESULTS

The in-hospital mortality reached 7.4%, while the 6-month mortality was 9.8%. The restricted cubic spline plot exhibited an approximately linear relationship between BUN and in-hospital mortality. Receiver operating characteristics curve analysis showed that the optimal cut-off of BUN for predicting in-hospital death was 6.8 mmol/L. Kaplan-Meier analysis showed that patients with BUN > 6.8 mmol/L had a higher 6-month mortality than other groups (log rank = 97.9, P < 0.001). Multivariate analysis indicated that BUN > 6.8 mmol/L was an independent predictor indicator for both in-hospital [adjusted odds ratio (aOR) = 2.365, 95% confidence interval (CI) 1.292-4.328, P = 0.005] and 6-month mortality [adjusted hazard ratio (aHR) = 2.171, 95% CI 1.355-3.479, P = 0.001].

CONCLUSIONS

BUN is suitable for independently predicting short-term mortality in patients with IE.

Investigation of red blood cell and platelet indices in adult dogs suffered from myxomatous mitral valve disease with and without pulmonary hypertension

Background

Pulmonary hypertension (PH) is a common complication of cardiopulmonary disease. In dogs, PH commonly occurs secondary to myxomatous mitral valve disease (MMVD). Red blood cell and platelet indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), mean platelet volume (MPV) and platelet distribution width (PDW), have previously been found to be indicators for predicting and prognosing PH in humans. Therefore, this study aimed to investigate whether these indices are associated with MMVD and/or PH in dogs.

Methods

Two hundred and forty-six dogs were retrospectively recruited for the study and classified into 4 groups: normal (n = 49), MMVD (n =102), PH (n =17), MMVD+PH (n =78). A sub-analysis was performed in dogs with MMVD without evidence of PH according to stage B1 (n =20), stage B2 (n =15), stage C (n =67). The data are expressed as median (interquartile range).

Results and discussion

No significant differences (p < 0.05) were found in MCV, RDW and MPV among all groups (normal, MMVD, PH and MMVD+PH). However, decreases in MCH and MCHC were found in MMVD [22.40 (20.90-23.50) pg and 35.25 (33.08-36.90) g/dL], MMVD+PH [22.25 (20.85-23.98) pg and 35.65 (33.30-37.33) g/dL] and PH groups [21.20 (20.60-22.20) pg and 33.80 (32.75-35.70) g/dL] compared to the normal dogs [24.29 (23.55-24.90) pg and 38.20 (37.50-39.05) g/dL] (p < 0.001). Decreases in PDW were found in dogs in the MMVD+PH [15.10 (14.98-15.30) %] groups compared to dogs in the normal group [15.30 (15.10-15.50) %] (p = 0.004). Sub-analysis of MMVD dogs without PH showed a decrease in MCH in dogs with stage B2 MMVD [21.00 (20.50-22.90) pg] and stage C MMVD [22.40 (20.90-23.20) pg] compared to normal dogs [24.29 (23.55-24.90) pg] (p < 0.001). MCHC of dogs with stage B1 [36.55 (33.53-37.78) g/dL] (p = 0.004), B2 [32.90 (32.00-35.00) g/dL] (p < 0.001) and C MMVD [35.30 (33.30-36.80) g/dL] (p < 0.001) were lower than those of normal dogs [38.20 (37.50-39.05) g/dL]. PDW in the stage C MMVD group [15.10 (15.00-15.30) %] was reduced compared to the normal group [15.30 (15.10-15.50) %] (p  = 0.042) and the stage B1 MMVD group [15.35 (15.23-15.68) %] (p = 0.002). MCH, MCHC and PDW were negatively correlated with the left atrial and left ventricular size.

Conclusion

Decreases in MCH and MCHC are related to MMVD, precapillary PH and postcapillary PH while PDW are associated with MMVD severity but not with the presence of PH.

The Worsening Renal Perfusion Index Predicts the Prognoses of Heart Failure Patients Treated with Sacubitril/Valsartan

INTRODUCTION

Sacubitril/valsartan (S/V) reduces all-cause mortality in patients with heart failure with reduced ejection fraction (HFrEF), but it may decline their estimated glomerular filtration rates (eGFR). In addition to eGFR, this clinical study aimed to develop a blood urea nitrogen (BUN)-based index to evaluate the status of renal perfusion and then identify predictors of all-cause death or heart transplant in patients with HFrEF receiving S/V.

METHODS

From the recruited 291 patients with HFrEF who were prescribed S/V from March 2017 to March 2019, we collected demographic, drug history, laboratory, echocardiographic, and clinical data from 1 year before S/V initiation until December 2020. Regression analysis was conducted by fitting Cox's models with time-dependent covariates for the survival time and applying the modern stepwise variable selection procedure. The smoothing spline method was used to detect nonlinearity in effect and yield optimal cut-off values for continuous covariates.

RESULTS

In the Cox's model, decreased hemoglobin level, decreased mean left ventricular ejection fraction, declined daily dose of S/V, decreased eGFR within 3 months, and increased BUN levels within 1 month and 9 months over time were significantly associated with an increased risk of all-cause death or heart transplant in patients with HFrEF.

CONCLUSIONS

Adequate maintenance of renal perfusion is crucial for the continuous use of S/V and to avoid worsening renal function in patients with HFrEF. We defined the maximum increase in BUN levels within a specified period as the Worsening Renal Perfusion Index (WRPSV Index) to capture the prognostic effect of renal hypoperfusion in patients with HFrEF.

Development and comparison of machine learning-based models for predicting heart failure after acute myocardial infarction

AIMS

Heart failure (HF) is one of the common adverse cardiovascular events after acute myocardial infarction (AMI), but the predictive efficacy of numerous machine learning (ML) built models is unclear. This study aimed to build an optimal model to predict the occurrence of HF in AMI patients by comparing seven ML algorithms.

METHODS

Cohort 1 included AMI patients from 2018 to 2019 divided into HF and control groups. All first routine test data of the study subjects were collected as the features to be selected for the model, and seven ML algorithms with screenable features were evaluated. Cohort 2 contains AMI patients from 2020 to 2021 to establish an early warning model with external validation. ROC curve and DCA curve to analyze the diagnostic efficacy and clinical benefit of the model respectively.

RESULTS

The best performer among the seven ML algorithms was XgBoost, and the features of XgBoost algorithm for troponin I, triglycerides, urine red blood cell count, γ-glutamyl transpeptidase, glucose, urine specific gravity, prothrombin time, prealbumin, and urea were ranked high in importance. The AUC of the HF-Lab9 prediction model built by the XgBoost algorithm was 0.966 and had good clinical benefits.

CONCLUSIONS

This study screened the optimal ML algorithm as XgBoost and developed the model HF-Lab9 will improve the accuracy of clinicians in assessing the occurrence of HF after AMI and provide a reference for the selection of subsequent model-building algorithms.

Association between blood urea nitrogen to creatinine ratio and neurologically favourable outcomes in out-of-hospital cardiac arrest in adults: A multicentre cohort study

BACKGROUND

We aimed to investigate the association between blood urea nitrogen to creatinine ratio (BCR) and survival with favourable neurological outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This prospective, multicentre, observational study conducted in Osaka, Japan enrolled consecutive OHCA patients transported to 16 participating institutions from 2012 through 2019. We included adult patients with non-traumatic OHCA who achieved a return of spontaneous circulation and whose blood urea nitrogen and creatinine levels on hospital arrival were available. Based on BCR values, they were divided into: 'low BCR' (BCR <10), 'normal BCR' (10 ≤ BCR < 20), 'high BCR' (20 ≤ BCR < 30), and 'very high BCR' (BCR ≥ 30). We evaluated the association between BCR values and neurologically favourable outcomes, defined as cerebral performance category score of 1 or 2 at one month after OHCA.

RESULTS

Among 4415 eligible patients, the 'normal BCR' group had the highest favourable neurological outcome [19.4 % (461/2372)], followed by 'high BCR' [12.5 % (141/1127)], 'low BCR' [11.2 % (50/445)], and 'very high BCR' groups [6.6 % (31/471)]. In the multivariable analysis, adjusted odds ratios for 'low BCR', 'high BCR', and 'very high BCR' compared with 'normal BCR' for favourable neurological outcomes were 0.58 [95 % confidence interval (CI 0.37-0.91)], 0.70 (95 % CI 0.49-0.99), and 0.40 (95 % CI 0.21-0.76), respectively. Cubic spline analysis indicated that the association between BCR and favourable neurological outcomes was non-linear (p for non-linearity = 0.003). In subgroup analysis, there was an interaction between the aetiology of arrest and BCR in neurological outcome (p for interaction <0.001); favourable neurological outcome of cardiogenic OHCA patients was lower when the BCR was higher or lower, but not in non-cardiogenic OHCA patients.

CONCLUSIONS

Both higher and lower BCR were associated with poor neurological outcomes compared to normal BCR, especially in cardiogenic OHCA patients.

Prevalence & Factors Associated With Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention at a Tertiary Healthcare Facility in Tanzania

BACKGROUND

Coronary artery disease (CAD) is the leading cause of mortality and morbidity globally. Percutaneous coronary intervention (PCI) is a minimally-invasive lifesaving intervention for these patients; however, acute kidney injury (AKI) is a serious complication of the procedure commonly occurring due to radiocontrast-induced nephropathy.

METHODS

A retrospective cross-sectional analytical study was carried out at the Aga Khan Hospital, Dar es Salaam (AKH,D), Tanzania. A total of 227 adults who underwent a percutaneous coronary intervention from August 2014 to December 2020 were enrolled. The AKI was defined based on an increase in absolute and rise in percentage creatinine using the Acute Kidney Injury Network (AKIN), and contrast-induced acute kidney injury (CI-AKI) by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Bivariable and multivariable logistic regression was utilized to analyze factors associated with AKI and the outcomes of these patients.

RESULTS

Twenty-two of the 227 (9.7%) participants sustained AKI. The majority of the study population was male and of Asian ethnicity. No statistically significant factors were associated with AKI. The in-hospital mortality rate was 9% for the AKI versus 2% for non-AKI groups. The AKI group had a longer hospital stay and required ICU care and organ support including hemodialysis.

CONCLUSIONS

Nearly 1-in-10 patients undergoing PCI are likely to develop AKI. The in-hospital mortality rate is x4.5 times higher for patients with AKI post-PCI compared to those without AKI. Further larger studies are recommended to determine factors associated with AKI in this population.

Blood urea nitrogen - independent marker of mortality in sepsis

BACKGROUND

This retrospective study examines the relationship between admission Blood Urea Nitrogen (BUN) levels and clinical outcomes in patients with sepsis from two separate cohorts in the Czech Republic and the United States.

METHODS

The study included 9126 patients with sepsis between January 2014 and December 2018. Kaplan-Meier survival curves and Cox regression were used to analyse the data. An optimal cut-off was calculated by means of the Youden-Index.

RESULTS

BUN at ICU admission was categorized as 10-20, 20-40 and >40 mg/dL. Comparing the group with the highest BUN levels to the one with lowest levels, we found HR for 28 days mortality 2.764 (CI 95% 2.37-3.20; P<0.001). We derived an optimal cut-off for prediction of 28 days mortality of 23 mg/dL. The association between BUN and 28 days mortality remained significant after adjusting for potential confounders - for APACHE IV (HR 1.374; 95%CI 1.20-1.58; P<0.001), SAPS2 (HR 1.545; 95%CI 1.35-1.77; P<0.001), eGFR (HR 1.851; 95%CI 1.59-2.16; P<0.001) and several other variables in an integrative model.

CONCLUSIONS

Our findings support the BUN level as an independent and easily available predictor of 28 days mortality in septic critically ill patients admitted to an ICU.

Association of Blood Urea Nitrogen with Cardiovascular Diseases and All-Cause Mortality in USA Adults: Results from NHANES 1999-2006

In the general population, there is little evidence of a link between blood urea nitrogen (BUN) and long-term mortality. The goal of this study was to explore whether higher BUN concentration is a predictor of cardiovascular disease (CVD) and all-cause mortality. From 1999 to 2006, the National Health and Nutrition Examination Survey (NHANES) included 17,719 adult individuals. Death outcomes were ascertained by linkage to the database records through 31 December 2015. The Cox proportional hazard regression model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD and all-cause mortality in individuals. We also performed stratified analyses based on age, gender, drinking, smoking, history of hypertension and diabetes. During a mean follow-up 11.65 years, a total of 3628 deaths were documented, of which 859 were due to CVD. Participants with higher BUN had a higher risk of CVD and all-cause death compared to those with lower BUN. After multifactor adjustment for demographics, major lifestyle factors, and hypertension and diabetes history, higher BUN levels compared with lower levels were significantly associated with higher risk of CVD (HR: 1.48 [1.08, 2.02], P-trend < 0.001) and all-cause mortality (HR: 1.48 [1.28, 1.72], P-trend < 0.001). In subgroup analyses, we found that the trend in the association of BUN with the risk of death remained strong in female subjects. Greater BUN levels were linked to higher CVD and all-cause mortality in the NHANES of American adults. The importance of BUN in predicting death is supported by our research.

Blood Urea Nitrogen Is Associated with In-Hospital Mortality in Critically Ill Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Propensity Score Matching Analysis

Background: Elevated blood urea nitrogen (BUN) level is associated with a higher risk of mortality in various diseases; however, the association between BUN level and in-hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) admitted to the intensive care unit (ICU) is not known. This study aimed to investigate the relationship between BUN level and in-hospital mortality in patients with AECOPD admitted to the ICU. Methods: In this retrospective cohort study, AECOPD patients were identified from the Medical Information Mart for Intensive Care (MIMIC-IV) database. Multivariate regression was used to elucidate the relationship between BUN level and in-hospital mortality, and propensity score matching (PSM) was used to adjust confounders. Receiver operating characteristics and Kaplan−Meier curves were used to evaluate the relationship between BUN level and in-hospital mortality. Results: Data from 1201 patients were analyzed. The all-cause in-hospital mortality was 13.7%. BUN levels were significantly higher in non-survivors compared to the survival group before (p < 0.001) and after (p = 0.005) PSM. Multivariate analysis indicated that elevated BUN levels were independently associated with increased risk of in-hospital mortality both before (p = 0.002) and after (p = 0.015) PSM. The optimal BUN cut-off value for in-hospital mortality in critical patients with AECOPD before (>23 mg/dL) and after (>22 mg/dL) PSM was comparable. Compared with the low BUN group, the hazard ratio (HR) of the high BUN group was 1.8987 (before PSM) and 1.7358 (after PSM). Conclusions: Higher BUN levels were significantly associated with an increased risk of in-hospital mortality in critically ill patients with AECOPD. As a widely available and rapidly measured biomarker, BUN may be useful in the risk stratification of critically ill AECOPD patients. The results need to be verified in prospective studies.

Clinical impact of blood urea nitrogen, regardless of renal function, in heart failure with preserved ejection fraction

BACKGROUND

Blood urea nitrogen (BUN) reflects decreased glomerular filtration rate (GFR). The effect of BUN on clinical outcomes, excluding the impact of GFR, in heart failure with preserved ejection fraction (HFpEF) patients remains unknown.

METHODS

We enrolled HFpEF (left ventricular ejection fraction ≥50%) patients hospitalized due to acute decompensated heart failure (HF) from PURSUIT-HFpEF registry which was prospective, multicenter and observational study. For excluding the effect of renal function on BUN value, propensity score-matching was performed using the variables which were associated with GFR. The incidence of composite of all-cause death and HF readmission among the patients stratified by BUN and the association between BUN and echocardiographic parameters in HFpEF patients were evaluated.

RESULTS

We finally analyzed 1029 patients. In the present study, BUN cut-off value was defined as 24.4 mg/dL, which was the median value in overall population. The high and low BUN groups consisted of 193 patients after 1:1 propensity score-matching, respectively. The median follow-up duration was 401 days and the composite endpoint occurred in 129 patients (33.4%). Kaplan-Meier analysis showed the high BUN group had a significantly greater risk of the composite endpoint than the low group in the propensity score-matched pairs (p = 0.032). BUN value significantly correlated with left atrial volume index by multiple regression analysis using echocardiographic parameters (standardized beta-coefficient = 0.139, p = 0.043).

CONCLUSION

BUN was a useful marker for the composite of all-cause death and HF readmission, regardless of the baseline renal function and correlated with left atrial function in HFpEF patients.

CLINICAL TRIAL REGISTRATION

UMIN000021831 <https://uplaod.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000024414>; PURSUIT-HFpEF.

Diagnostic Values of Blood Urea Nitrogen (BUN), Creatinine (Cr), and the Ratio of BUN to Cr for Distinguishing Heart Failure from Asthma and Chronic Obstructive Pulmonary Disease

Background

In clinical practise, it can be challenging to tell the difference between asthma and chronic obstructive pulmonary disease (COPD) and heart failure (HF), which share comparable dyspnea symptoms. We aimed to examine whether renal function indexes blood urea nitrogen (BUN), creatinine (Cr), and the ratio of BUN to Cr (BUN/Cr) can be used to distinguish HF from asthma and COPD.

Methods

A total of 170 patients were admitted for dyspnea symptoms in this retrospective study. There are 69 patients with HF (HF group), 50 patients with asthma (asthma group), and 51 patients diagnosed with COPD (COPD group). The levels of BUN, Cr, and the ratio of BUN/Cr in the three groups were compared. Student's t-test or the one-way analysis of variance (ANOVA) test was used to compare means. Using the area under the receiver operating characteristic curve, model differentiation was evaluated (AUC). Z-test comparisons of AUC were carried out.

Results

Compared with the asthma/COPD group (asthma group + COPD group) or the COPD group, the levels of BUN and Cr were raised in the HF group, while there was no significant difference of the BUN/Cr ratio. Compared with those in the asthma group, the levels of BUN, Cr, and BUN/Cr ratio were significantly increased in the HF group (all p < 0.05), whereas no significant differences of BUN, Cr, and BUN/Cr ratio were found between asthma and COPD. The AUC in distinguishing HF from asthma/COPD were 0.736 and 0.751 for BUN and Cr, respectively, and no significant difference was observed between BUN and Cr. The cutoff values (specificity, sensitivity, and Youden index) in distinguishing between HF and asthma/COPD were 20.45 mg/dL (79.21%, 56.52%, and 0.357) for BUN and 0.782 mg/dL (72.28%, 68.12%, and 0.404) for Cr, respectively.

Conclusions

BUN and Cr showed accurate and reliable diagnostic values which could be potential biomarkers for differentiating HF from asthma and/or COPD.

Prognostic significance of blood urea nitrogen/creatinine ratio in chronic HFpEF

BACKGROUND

The prognostic significance of blood urea nitrogen (BUN)/creatinine ratio specifically in chronic heart failure with preserved ejection fraction (HFpEF) patients remained unclear. We aimed to evaluate the association of BUN/creatinine ratio (baseline level and visit-to-visit variation) with the risk of adverse clinical outcomes among patients with chronic HFpEF.

METHODS AND RESULTS

This is a secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. Of the enrolled 3445 participants in the TOPCAT trial, associations between BUN/creatinine and clinical outcomes were examined in a subset of 1521 (baseline measurements level) and 1453 (visit-to-visit variation) participants. A multivariable Cox proportional hazard model was used to assess the prognostic significance of BUN/creatinine ratio and BUN/creatinine ratio variation for the prespecified clinical outcomes. A higher BUN/creatinine ratio was associated with a higher risk of all-cause mortality (hazard ratio [HR] = 1.52, 95%CI, 1.21-1.91; p < .001) as well as cardiovascular disease mortality (HR = 1.83, 95%CI, 1.35-2.49; p < .001) in the fully adjusted model. Greater visit-to-visit variability in BUN/creatinine ratio tended to be independently associated with a higher risk of heart failure hospitalization and primary endpoint (p < .001 for both outcomes). Furthermore, those findings were consistent across participants stratified by the presence of chronic kidney disease at baseline.

CONCLUSIONS

Higher BUN/creatinine ratio and greater BUN/creatinine ratio variability are independently associated with adverse outcomes in HFpEF participants in the TOPCAT trial.

Coexisting Morbidity Burden in Hospitalized Elderly Patients with New-Onset Heart Failure vs Acutely Decompensated Chronic Heart Failure

Coexisting morbidities (CM) are common in patients with heart failure (HF). This study evaluated the CM burden and its clinical significance in elderly hospitalized patients with new-onset (De-novo) HF (n = 84) and acutely decompensated chronic HF (ADCHF) (n = 122). All had HF symptoms associated with: (a) LVEF <50%, or, (b) left ventricular ejection fraction (LVEF) ≥50% and NT-proBNP ≥300 pg/mL. The primary endpoint was the composite of all-cause death/HF rehospitalization at 6 months. Age was similar between patients with new-onset HF and ADCHF [82 (12.5) vs 80 (11) years, respectively; P = .549]. The CM burden was high in both groups. However, the number of CM [3 (2) vs 4 (1.75)] and the prevalence of multimorbidity [CM ≥2; 65 (77.4%) vs 108 (88.5%)] were lower in new-onset HF ( P = .016 and P = .035, respectively). The survival probability without the primary endpoint was higher in new-onset HF than in ADCHF ( P = .001) driven by less rehospitalizations ( P = .001). In the total study population significant primary endpoint predictors were red blood cell distribution width (RDW), urea, and coronary artery disease (CAD) prevalence (AUC of the model =.7685), whereas significant death predictors were RDW, urea, and the number of CM (AUC = .7859), all higher in ADCHF. Thus, the higher CM burden in ADCHF than in new-onset HF most likely contributed to the worse outcome.

Blood urea nitrogen to creatinine ratio is associated with in-hospital mortality among critically ill patients with cardiogenic shock

Backgrounds

Although Blood urea nitrogen (BUN) and serum creatinine concentration (Cr) has been widely measured in daily clinical practice, BUN-to-Cr ratio (BCR) for prognosis among patients admitted with cardiogenic shock (CS) remains unknown. The present study was conducted to assess the prognostic effectiveness of BCR on CS.

Methods and results

Records of data for patients with CS were extracted from public database of the Medical Information Mart for Intensive Care-III (MIMIC-III). The primarily endpoint was in-hospital mortality. We incorporated multivariate Cox regression model and Kaplan–Meier curve to evaluate the relationship between BCR and in-hospital mortality, adjusting for potential confounders. Data of 1137 patients with CS were employed for the final cohort, with 556 in the low BCR (< 20) and 581 in the high BCR (≥ 20) group. In the multivariate Cox model and Kaplan–Meier curve, compared to low BCR, we found high BCR was independently associated with significantly improved in-hospital survival for CS (HR 0.66, 95% CI 0.51–0.84; P < 0.01). The benefit of high BCR on in-hospital survival for CS was remaining among subgroups of acute kidney injury (AKI) and non-AKI.

Conclusions

Our analysis indicated that high BCR, as compared to low BCR, was correlated with improved in-hospital survival for participants with CS, with or without AKI. The results need to be proved in large prospective studies.

Elevated Blood Urea Nitrogen to Serum Albumin Ratio Is an Adverse Prognostic Predictor for Patients Undergoing Cardiac Surgery

Background

Elevated blood urea nitrogen (BUN) and reduced albumin have been prominently correlated with unfavorable outcomes in patients with cardiovascular diseases. However, whether combination BUN and albumin levels could predict the adverse outcomes of cardiac surgery patients remains to be confirmed. Here, we investigated the prognostic effect of the preoperative BUN to serum albumin ratio (BAR) in cardiac surgery patients.

Methods

Data were obtained from the Medical Information Mart for Intensive Care (MIMIC) III and eICU databases and classified into a training cohort and validation cohort. The BAR (mg/g) was calculated by initial BUN (mg/dl)/serum albumin (g/dl). The primary outcome was in-hospital mortality. Secondary outcomes were 1-year mortality, prolonged length at intensive care unit, and duration of hospital stay. The associations of BAR with outcomes were explored by multivariate regression analysis and subgroup analyses. Then, C statistics were performed to assess the added prognostic impact of BAR beyond a baseline risk model.

Results

Patients with in-hospital death had significantly higher levels of BAR. Multivariate regression analysis identified BAR, as a categorical or continuous variable, as an independent factor for adverse outcomes of cardiac surgery (all p < 0.05). Subgroup analyses demonstrated a significant relationship between elevated BAR and in-hospital mortality in different subclasses. The addition of BAR to a baseline model provided additional prognostic information benefits for assessing primary outcome. Results were concordant in the external validation cohort.

Conclusions

Increased preoperative BAR is a potent predictor of unfavorable outcomes in patients undergoing cardiac surgery.

Blood Urea Nitrogen/Albumin Ratio and Mortality Risk in Patients with COVID-19

Introduction

We researched blood urea nitrogen (BUN), albumin and their ratio (BAR), and compared them with C-reactive protein (CRP), D-dimer, and computed tomography severity scores (CT-SS), to predict in-hospital mortality.

Methods

One-hundred and thirty-one coronavirus disease-2019 (COVID-19) confirmed patients brought to the emergency department (ED) were dispensed to the survivor or non-survivor group, in light of in-hospital mortality. Information on age, gender, complaints, comorbidities, laboratory parameters, and outcome were gathered from the patient's record files.

Results

The median BUN, mean total protein, mean albumin, median BAR, median creatinine, median CRP, and median D-dimer were recorded. CT-SS were utilized in categorizing the patient as mild, moderate, and severe. In-hospital mortality occurred in 42 (32.06%) patients (non-survivor group) and did not occur in 89 (67.94%) patients (survivor group). The median BUN (mg/dL) and BAR (mg/gm) values were significantly raised in the non-survivor group than in the survivor group [BUN: 23.48 (7.51–62.75) and 20.66 (4.07–74.67), respectively (p = 0.009); BAR: 8.33 mg/g (2.07–21.86) and 6.11 mg/g (1.26–23.33); (p = 0.0003)]. The mean albumin levels (gm/dL) in the non-survivor group were significantly lower than in the survivor group [2.96 ± 0.35 and 3.27 ± 0.35, respectively (p <0.0001)]. Albumin with an odd's ratio of 6.14 performed the best in predicting in-hospital mortality, followed by D-dimer (4.98). BAR and CRP had similar outcome of 3.75; BUN showed an OR of 3.13 at the selected cutoff value.

Conclusion

The BUN, albumin, and BAR were found to be dependable predictors of in-hospital mortality in COVID-19 patients, with albumin (hypoalbuminemia) performing even better.

How to cite this article

Singh S, Singh K. Blood Urea Nitrogen/Albumin Ratio and Mortality Risk in Patients with COVID-19. Indian J Crit Care Med 2022;26(5):626–631.

Blood urea nitrogen to serum albumin ratio as a new prognostic indicator in critical patients with chronic heart failure

Aims

Chronic heart failure (CHF) is often a common comorbidity in critically ill patients admitted to the intensive care unit (ICU) and carries an extremely poor prognosis. The study aimed to investigate the relationship between the blood urea nitrogen to serum albumin ratio (BAR) and the prognosis of patients with CHF admitted to the ICU.

Methods and results

This retrospective cohort study included 1545 critically ill patients with CHF as a diagnosed comorbidity admitted to the ICU deposited in the MIMIC‐III database, of whom 90 day all‐cause mortality was 27.6% (n = 427) and in‐hospital mortality was 17.3% (n = 267). The results of multiple logistic regression analysis indicated that BAR is an independent risk factor for in‐hospital mortality in critically ill patients with CHF [compared with BAR ≤ 0.83; 0.83 < BAR ≤ 1.24: odds ratio (OR) 2.647, 95% confidence interval (CI) 1.797–3.900, P < 0.001; BAR ≥ 1.24: OR 3.628, 95% CI 2.604–5.057, P < 0.001]. Multiple COX regression analysis found a relationship between BAR and all‐cause mortality at 90 day follow‐up (0.83 < BAR ≤ 1.24: OR 1.948, 95% CI 1.259–3.014, P < 0.003; BAR ≥ 1.24: OR 1.807, 95% CI 1.154–2.830, P < 0.01; BAR ≤ 0.83 as a reference). Kaplan–Meier curves also showed similar results as well (P < 0.001). The areas under the receiver operating characteristic curves for predicting in‐hospital mortality and 90 day all‐cause mortality were 0.622 and 0.647, respectively.

Conclusions

BAR is an independent risk factor for in‐hospital mortality and 90 day mortality in critically ill patients with CHF admitted to the ICU.

Development and validation of a nomogram to predict the risk of peripheral artery disease in patients with type 2 diabetes mellitus

OBJECTIVE

To develop and validate a nomogram for predicting the risk of peripheral artery disease (PAD) in patients with type 2 diabetes mellitus (T2DM) and assess its clinical application value.

METHODS

Clinical data were retrospectively collected from 474 patients with T2DM at the Air Force Medical Center between January 2019 and April 2022. The patients were divided into training and validation sets using the random number table method in a ratio of 7:3. Multivariate logistic regression analysis was performed to identify the independent risk factors for PAD in patients with T2DM. A nomogram prediction model was developed based on the independent risk factors. The predictive efficacy of the prediction model was evaluated using the consistency index (C-index), area under the curve (AUC), receiver operating characteristic (ROC) curve, Hosmer-Lemeshow (HL) test, and calibration curve analysis. Additionally, decision curve analysis (DCA) was performed to evaluate the prediction model's performance during clinical application.

RESULTS

Age, disease duration, blood urea nitrogen (BUN), and hemoglobin (P<0.05) were observed as independent risk factors for PAD in patients with T2DM. The C-index and the AUC were 0.765 (95% CI: 0.711-0.819) and 0.716 (95% CI: 0.619-0.813) for the training and validation sets, respectively, indicating that the model had good discriminatory power. The calibration curves showed good agreement between the predicted and actual probabilities for both the training and validation sets. In addition, the P-values of the HL test for the training and validation sets were 0.205 and 0.414, respectively, indicating that the model was well-calibrated. Finally, the DCA curve indicated that the model had good clinical utility.

CONCLUSION

A simple nomogram based on three independent factors-duration of diabetes, BUN, and hemoglobin levels-may help clinicians predict the risk of developing PAD in patients with T2DM.

Blood Urea Nitrogen for Short-Term Prognosis in Patients with Cardiogenic Shock Complicating Acute Myocardial Infarction

PURPOSE

Cardiogenic shock (CS) is the leading cause of death in patients with acute myocardial infarction (AMI). Our study aimed to evaluate the short-term prognostic value of admission blood urea nitrogen (BUN) in patients with CS complicating AMI.

MATERIALS AND METHODS

218 consecutive patients with CS after AMI were enrolled. The primary endpoint was 30-day mortality. The association of admission BUN and 30-day mortality and major adverse cardiovascular event (MACE) was investigated by Cox regression. The integrated discrimination improvement (IDI) and net reclassification improvement (NRI) further examined the predictive value of BUN.

RESULTS

During a period of 30-day follow-up, 105 deaths occurred. Compared to survivors, nonsurvivors had significantly higher admission BUN (p < 0.001), creatinine (p < 0.001), BUN/creatinine (p = 0.03), and a lower glomerular filtration rate (p < 0.001). The area under the curve (AUC) of the 4 indices for predicting 30-day mortality was 0.781, 0.734, 0.588, and 0.773, respectively. When compared to traditional markers associated with CS, the AUC for predicting 30-day mortality of BUN, lactate, and left ventricular ejection fraction were 0.781, 0.776, and 0.701, respectively. The optimal cut-off value of BUN for predicting 30-day mortality was 8.95 mmol/L with Youden-Index analysis. Multivariate Cox analysis indicated BUN >8.95 mmol/L was an important independent predictor for 30-day mortality (HR 2.08, 95%CI 1.28-3.36, p = 0.003) and 30-day MACE (HR 1.85, 95%CI 1.29-2.66, p = 0.001). IDI (0.053, p = 0.005) and NRI (0.135, p = 0.010) showed an improvement in the accuracy for mortality prediction of the new model when BUN was included compared with the standard model of predictors in previous scores.

CONCLUSION

An admission BUN >8.95 mmol/L was robustly associated with increased short-term mortality and MACE in patients with CS after AMI. The prognostic value of BUN was superior to other renal markers and comparable to traditional markers. This easily accessible index might be promising for early risk stratification in CS patients following AMI.

The association of blood urea nitrogen levels upon emergency admission with mortality in acute exacerbation of chronic obstructive pulmonary disease

Background and purpose

High blood urea nitrogen (BUN) is associated with an elevated risk of mortality in various diseases, such as heart failure and pneumonia. Heart failure and pneumonia are common comorbidities of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, data on the relationship of BUN levels with mortality in patients with AECOPD are sparse. The purpose of this study was to evaluate the correlation between BUN level and in-hospital mortality in a cohort of patients with AECOPD who presented at the emergency department (ED).

Methods

A total of 842 patients with AECOPD were enrolled in the retrospective observational study from January 2018 to September 2020. The outcome was all-cause in-hospital mortality. Receiver operating characteristic (ROC) curve analysis and logistic regression models were performed to evaluate the association of BUN levels with in-hospital mortality in patients with AECOPD. Propensity score matching was used to assemble a cohort of patients with similar baseline characteristics, and logistic regression models were also performed in the propensity score matching cohort.

Results

During hospitalization, 26 patients (3.09%) died from all causes, 142 patients (16.86%) needed invasive ventilation, and 190 patients (22.57%) were admitted to the ICU. The mean level of blood urea nitrogen was 7.5 ± 4.5 mmol/L. Patients in the hospital non-survivor group had higher BUN levels (13.48 ± 9.62 mmol/L vs. 7.35 ± 4.14 mmol/L, p < 0.001) than those in the survivor group. The area under the curve (AUC) was 0.76 (95% CI 0.73–0.79, p < 0.001), and the optimal BUN level cutoff was 7.63 mmol/L for hospital mortality. As a continuous variable, BUN level was associated with hospital mortality after adjusting respiratory rate, level of consciousness, pH, PCO_2, lactic acid, albumin, glucose, CRP, hemoglobin, platelet distribution width, D-dimer, and pro-B-type natriuretic peptide (OR 1.10, 95% CI 1.03–1.17, p=0.005). The OR of hospital mortality was significantly higher in the BUN level ≥7.63 mmol/L group than in the BUN level <7.63 mmol/L group in adjusted model (OR 3.29, 95% CI 1.05–10.29, p=0.041). Similar results were found after multiple imputation and in the propensity score matching cohort.

Conclusions

Increased BUN level at ED admission is associated with hospital mortality in patients with AECOPD who present at the ED. The level of 7.63 mmol/L can be used as a cutoff value for critical stratification.

Algorithm for predicting cardiovascular events in low/moderate risk patients using traditional and new factors: data from 10-year follow-up study

Aim. To create an advanced algorithm for predicting cardiovascular events (CVE) in low/moderate risk patients using a complex of traditional and new factors.

Material and methods. The study included 700 patients with Systematic Coronary Risk Evaluation (SCORE) <5%, examined in 20092010. In addition to standard investigations, blood biochemistry tests, including high-sensitivity C-reactive protein (hsCRP), and sphygmography were carried. In 2019, a follow-up phone call was made to participants to identify recent CVEs: cardiovascular death, myocardial infarction, unstable angina, stroke, revascularization. The response rate was 79,6% (n=557; men, 100; women, 457).

Results. CVEs were observed in 48 (8,6%) patients. The risk of CVEs increases systolic blood pressure (SBP) >130 mmHg (odds ratio (OR), 1,9 (95% confidence interval (CI), 1,0-3,6)), hsCRP >2,3 mg/L (OR, cardio-ankle vascular index (CAVI) >8,05 (OR, 1,25 (95% CI, 1,0-1,6)). In patients with a combination of ≥2 lipid profile abnormalities, SBP >130 mm Hg, hsCRP >2,3 mg/L and pulse wave velocity >13 m/s, the probability of developing CVEs (including cardiovascular death) increases 3,55 times (95% CI, 1,32-7,67).

Conclusion. Levels of pulse wave velocity, CAVI, urea and hsCRP should be considered as additional risk factors for CVE in patients with low/moderate risk, estimated using standard scales. Combinations of traditional and new risk factors demonstrate a cumulative effect.

The Value of Blood Urea Nitrogen in the Prediction of Risks of Cardiovascular Disease in an Older Population

Background: High blood urea nitrogen (BUN) is associated with adverse outcomes in patients with cardiac disease risks. However, no study has explored whether BUN can predict the risk of cardiovascular disease (CVD) in the healthy older population. This study aims to explore the incidence and risk factors of CVD among a healthy older population community in China. Design and Methods: This study was designed as a cohort study with a 4-year follow-up. We recruited 5,000 older people among 137,625 residents of the Gaohang community. In the baseline, subjects were asked to participate in medical screening and biological tests, and answered survey questions. During the follow-up period (2014-2017), the researchers regularly tested the subjects' indicators and assessment scales. We monitored the occurrence of CVD and explored the relationship between BUN and CVD via a Cox regression analysis. Results: During the follow-up, subjects were newly diagnosed with CVD including heart failure (HF), heart disease events, atrial fibrillation, diabetes, hypertension, metabolic syndrome, and kidney disease. The Cox regression analysis found an association between baseline BUN and incident CVD in female subjects, with higher BUN associated with increased risk of AF in females and kidney disease in both male and females. No association was found between BUN and CVD in male subjects. Conclusions: Current results indicate that BUN is a valuable predictive biomarker of CVD. A higher BUN level (>13.51 mg/dL) is associated with an increased occurrence of HF but a decreased occurrence of diabetes and metabolic symptoms in normal older females.

Liver proteome alterations in psychologically distressed rats and a nootropic drug

BACKGROUND

Chronic psychological distress is considered today a pandemic due to the modern lifestyle and has been associated with various neurodegenerative, autoimmune, or systemic inflammation-related diseases. Stress is closely related to liver disease exacerbation through the high activity of the endocrine and autonomic nervous systems, and the connection between the development of these pathologies and the physiological effects induced by oxidative stress is not yet completely understood. The use of nootropics, as the cognitive enhancer and antioxidant piracetam, is attractive to repair the oxidative damage. A proteomic approach provides the possibility to obtain an in-depth comprehension of the affected cellular processes and the possible consequences for the body. Therefore, we considered to describe the effect of distress and piracetam on the liver proteome.

METHODS

We used a murine model of psychological stress by predatory odor as a distress paradigm. Female Sprague-Dawley rats were distributed into four experimental groups (n = 6 - 7/group) and were exposed or not to the stressor for five days and treated or not with piracetam (600 mg/kg) for six days. We evaluated the liver proteome by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1D-SDS-PAGE) followed by liquid chromatography-tandem mass spectrometry (GeLC-MS/MS). Besides, we analyzed the activity of liver antioxidant enzymes, the biochemical parameters in plasma and rat behavior.

RESULTS

Our results showed that distress altered a wide range of proteins involved in amino acids metabolism, glucose, and fatty acid mobilization and degradation on the way to produce energy, protein folding, trafficking and degradation, redox metabolism, and its implications in the development of the non-alcoholic fatty liver disease (NAFLD). Piracetam reverted the changes in metabolism caused by distress exposure, and, under physiological conditions, it increased catabolism rate directed towards energy production. These results confirm the possible relationship between chronic psychological stress and the progression of NAFLD, as well as we newly evidenced the controversial beneficial effects of piracetam. Finally, we propose new distress biomarkers in the liver as the protein DJ-1 (PARK7), glutathione peroxidase 1 (GPX), peroxiredoxin-5 (PRDX5), glutaredoxin 5 (GLRX5), and thioredoxin reductase 1 (TXNDR1), and in plasma as biochemical parameters related to kidney function such as urea and blood urea nitrogen (BUN) levels.

Age- and sex-specific reference intervals for blood urea nitrogen in Chinese general population

Blood urea nitrogen (BUN) is a nitrogenous end product of protein metabolism. This study aims to explore the age- and sex-specific distribution of BUN among healthy Chinese adults. A total of 24,006 BUN values from healthy adults (14,148 males and 9858 females) were included in the cross-sectional study. Males had a higher median BUN value compared to females (4.6 mmol/L vs. 4.1 mmol/L). BUN values showed a positive correlation with body mass index (BMI), cholesterol, and blood sugar (P < 0.0001). However, eGFR showed a negative correlation with the BUN reference value (P < 0.0001) in both sexes. Multiple linear regression analysis confirmed that the positive associations of BUN levels and age were statistically significant after adjusting confounding factors (P < 0.001). Thus, the serum BUN values increased by 0.21 mmol/L for males and 0.282 mmol/L for females per 10 years. The BUN values corresponding to the 1st, 2.5th, 50th, 97.5th, and 99th percentiles for any specific age in both sex were also calculated. These results indicate that the serum BUN reference value is significantly affected by age and gender, and thus, its interpretation is age- and sex-dependent.