Serum Albumin and Post-Stroke Outcomes: Analysis of UK Regional Registry Data, Systematic Review, and Meta-Analysis

Hypoalbuminemia associates with poor acute ischemic stroke (AIS) outcomes. We hypothesised a non-linear relationship and aimed to systematically assess this association using prospective stroke data from the Norfolk and Norwich Stroke and TIA Register. Consecutive AIS patients aged ≥40 years admitted December 2003-December 2016 were included. Outcomes: In-hospital mortality, poor discharge, functional outcome (modified Rankin score 3-6), prolonged length of stay (PLoS) > 4 days, and long-term mortality. Restricted cubic spline regressions investigated the albumin-outcome relationship. We updated a systematic review (PubMed, Scopus, and Embase databases, January 2020-June 2023) and undertook a meta-analysis. A total of 9979 patients were included; mean age (standard deviation) = 78.3 (11.2) years; mean serum albumin 36.69 g/L (5.38). Compared to the cohort median, albumin < 37 g/L associated with up to two-fold higher long-term mortality (HRmax; 95% CI = 2.01; 1.61-2.49) and in-hospital mortality (RRmax; 95% CI = 1.48; 1.21-1.80). Albumin > 44 g/L associated with up to 12% higher long-term mortality (HRmax1.12; 1.06-1.19). Nine studies met our inclusion criteria totalling 23,597 patients. Low albumin associated with increased risk of long-term mortality (two studies; relative risk 1.57 (95% CI 1.11-2.22; I2 = 81.28)), as did low-normal albumin (RR 1.10 (95% CI 1.01-1.20; I2 = 0.00)). Strong evidence indicates increased long-term mortality in AIS patients with low or low-normal albumin on admission.

NIR-I emissive cyanine derived molecular probe for selective monitoring of hepatic albumin levels during hyperglycemia

In this study, we report a small molecule optical marker BI-CyG derived from the structural engineering of a cyanine scaffold. The developed probe offers suitable advantages over existing cyanine-based albumin specific probes in terms of its excitation and emission wavelengths, which are 760 and 830-832 nm, respectively. Structural tuning of the cyanine architecture leading to extended π-conjugation and resulting in a suitable bathochromic shift in the emission wavelength of the probe is represented in this study. The probe besides emitting in the NIR region, also possesses the desirable characteristics of being a potential target selective optical marker, as established from various biophysical studies. Molecular modelling and simulation studies provided critical insights into the binding of the probe in the protein microenvironment, which was further supported by experimental studies. The probe displayed intracellular albumin selectivity and was utilized for demonstrating alteration in albumin levels in pathological states such as hyperglycemia in hepatic cells. The present study also sheds some light on using BI-CyG as an imaging probe and on the role of metformin as a suitable drug for balancing hyperglycemia-induced reduced intra-hepatic albumin levels. The study, thus, attempts to highlight the structural derivatization of cyanine to afford a potential probe for serum albumin and its deployment to image altering albumin levels in an induced pathological condition, hyperglycemia.

The systemic inflammation score is a prognostic factor for patients with ischemic stroke who have not undergone intravenous thrombolysis or endovascular thrombectomy therapy

BACKGROUND

The systemic inflammation score (SIS) has been utilised as a representative biomarker for evaluating nutritional and inflammation status. However, the predictive value of SIS has not been reported in patients with acute ischemic stroke (AIS). We aimed to evaluate whether SIS is associated with prognosis in stroke.

METHODS

A total of 4801 patients with AIS were included in the study. The primary outcome was a modified Rankin Scale score>2 at the 3-month follow-up. A total of 4801 patients were randomly allocated into training (n=3361) and validation cohorts (n=1440) at a ratio of 7:3. Model performance was validated using the receiver operating characteristic (ROC) curve and calibration curve. Additionally, a comparison was made between the nomogram and the THRIVE score in regards to their respective predictive capabilities.

RESULTS

Overall, 1091(32.5%) patients in the training cohort and 446 (31.0%) patients in the validation cohort experienced an unfavorable outcome. The multivariate logistic regression analysis revealed that a high SIS, age, NIHSS, diabetes and prior stroke were associated with unfavorable outcome. Our nomogram was developed based on the variables mentioned above. The area under the curve (AUC) of the training set and the validation set are 0.702 and 0.708, respectively, indicating that the model has modest agreement and discrimination. The results of AUC, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) showed that nomogram had significantly higher predictive value than THRIVE scores (all P<0.001). However, unlike the THRIVE publication, all patients who had undergone intravenous thrombolysis or endovascular thrombectomy therapy were excluded in our study. In consequence, our derived THRIVE scores cannot be compared to those in the original THRIVE study.

CONCLUSION

The SIS exhibits potential as a simple prognostic biomarker, and the nomogram, which utilizes the SIS, may serve as a valuable tool for clinicians in the early identification of patients at heightened risk for unfavorable outcomes.

Association of serum albumin to globulin ratio with outcomes in acute ischemic stroke

BACKGROUND

Serum albumin to globulin ratio (A/G) has been widely used as a representative biomarker for assessing inflammation and nutrition status. However, in patients with acute ischemic stroke (AIS), the predictive value of serum A/G has rarely been reported. We aimed to evaluate whether serum A/G is associated with prognosis in stroke.

METHODS

We analyzed data from the Third China National Stroke Registry. The patients were categorized into quartile groups according to the serum A/G at admission. Clinical outcomes included poor functional outcomes (modified Rankin Scale [mRS] score of 3-6 or 2-6) and all-cause mortality at 3 months and1 year. Multivariable logistic regressions and Cox proportional hazards regressions were used to evaluate the association of serum A/G with the risk of poor functional outcomes and all-cause mortality.

RESULTS

A total of 11, 298 patients were included in this study. After adjustment for confounding factors, patients in the highest serum A/G quartile had a lower proportion of mRS score 2-6 (odds ratio [OR], 0.87; 95% confidence interval [CI], 0.76-1.00) and mRS score 3-6 (OR, 0.87; 95% CI, 0.73-1.03) at 3 months follow-up. At 1 year follow-up, there was a significant association between higher serum A/G and mRS score 3-6 (OR, 0.68; 95% CI, 0.57-0.81). We also found that the highest serum A/G was related to decreased risk of all-cause mortality (hazard ratio [HR], 0.58; 95% CI, 0.36-0.94) at 3 months follow-up. Similar results were found at 1-year follow-up.

CONCLUSIONS

Lower serum A/G levels were associated with poor functional outcomes and all-cause mortality at 3 months and 1-year follow-up in patients with acute ischemic stroke.

Near-infrared emissive cyanine probes for selective visualization of the physiological and pathophysiological modulation of albumin levels

With the promising advantages of the near-infrared region (NIR) emissive markers for serum albumin becoming very prominent recently, we devised CyG-NHS as the cyanine derived longest NIR-I emissive optical marker possessing albumin selective recognition ability in diverse biological milieu. Multiscale modeling involving molecular docking, molecular dynamics, and implicit solvent binding free energy calculations have been employed to gain insights into the unique binding ability of the developed probe at domain-I of albumin, in contrast to the good number of domain IIA or IIIA binding probes available in the literature reports. The binding free energy was found to be -31.8 kcal mol^-1 majorly predominated by hydrophobic interactions. Besides, the conformational dynamics of CyG-NHS in an aqueous medium and the albumin microenvironment have been comprehensively studied and discussed. The potentiality of this optical platform to monitor the intracellular albumin levels in human hepatoma (HepG2) cells in different pathophysiological states has been demonstrated here. Also, the competency of the phenformin drug in restoring the albumin levels in chronic hyperinsulinemic and hypercholesterolemic in vitro models has been established through the visualization approach. Altogether, the findings of this study throw light on the significance of the development of a suitable optical marker for the visualization of critical bioevents related to albumin.

Elevated Albumin to Globulin Ratio on Day 7 is Associated with Improved Function Outcomes in Acute Ischemic Stroke Patients with Intravenous Thrombolysis

Background and Purpose

Albumin to globulin ratio (A/G) has been established as a representative biomarker for assessing inflammation and nutritional status. However, the prognostic value of A/G has rarely been reported in acute ischemic stroke (AIS) patients with intravenous thrombolysis (IVT).

Methods

A total of 311 AIS patients who had undergone IVT and completed 3-month follow-up were retrospectively recruited in this study. Albumin (Alb), globulin (Glb) and A/G on admission, within 24 hours after IVT and on day 7 were recorded. Poor outcome was defined as death or major disability (modified Rankin Scale, 3–6) at 3 months.

Results

Among the 311 cases, 260 patients had admission blood samples, 296 cases had blood samples within 24 hours after IVT and 126 cases had blood samples on day 7. The patients with and without available blood samples were well-balanced. During the first 24 h, we observed A/G to increase significantly compared with baseline whereas at day 7 it was almost back to baseline in patients with a poor outcome. Receiver operating characteristic (ROC) curves analysis showed that A/G had a better performance in discriminating patients at high risk and low risk of a poor outcome than either Alb or Glb alone and carried the highest predictive ability on day 7 (AUC = 0.807). Lower 7-day A/G was independently associated with a poor outcome (per-SD increase, OR = 0.182, 95% CI: 0.074–0.446).

Conclusion

A/G is an important prognostic indicator for AIS outcomes and merits dynamic monitoring.

Albumin Level at Admission to the Intensive Care Unit Is Associated With Prognosis in Cardiac Arrest Patients

Aim Cardiac arrest is a global health concern with consistently high mortality. It is also a common condition seen in the intensive care unit (ICU). We aimed to investigate the importance of albumin level on admission, which is a widely available and simple test, to predict in-hospital mortality in cardiac arrest patients. Methods The retrospective study collected data from the eICU Collaborative Research Database. It contains data from 171 hospitals, 276 ICU wards, and 4,529 patients who were treated for cardiac arrest from 2014 to 2015. We analyzed the patients' laboratory results and vital signs during the first 24 hours after admission to the ICU. The primary outcome was in-hospital mortality, and the secondary outcome was the length of ICU stay among survivors. Results In total, 2,414 patients were eligible. After adjusting for severity scores, including the Acute Physiology and Chronic Health Evaluation (APACHE) IV and Sequential Organ Failure Assessment (SOFA) scores, serum albumin was found to be a protective factor for survival (odds ratio of mortality: 0635, 95% confidence interval: 0.458-0.734, P<0.001). Among patients who survived until discharge, those with hypoalbuminemia had a long duration of stay in the ICU (P=0.005). Conclusion The higher albumin level at admission to the ICU was associated with lower mortality in patients with cardiac arrest.

Low serum albumin levels predict poor outcome in patients with acute ischaemic stroke or transient ischaemic attack

BACKGROUND

To examine the relationship of serum albumin with poor functional outcome and mortality in patients with acute ischaemic stroke (AIS) or transient ischaemic attack (TIA), and perform a meta-analysis to summarise the association.

METHODS

We analysed data from the Third China National Stroke Registry (CNSR-Ⅲ). Patients were divided into four groups based on serum albumin levels at admission. The outcomes included poor functional outcome (modified Rankin Scale (mRS) score of 3 to 6) and mortality at 3 months and 1 year. Multiple logistic regression models and Cox regression models were used to evaluate the association, respectively. We used a fixed-effect model to calculate the risk ratio for poor functional outcome and a random-effect model for mortality in the meta-analysis.

RESULTS

A total of 13 618 patients were enrolled. During the 3-month follow-up period, compared with 40 to 44.9 g/L group, patients in <35 g/L group had an increased risk of poor functional outcome and mortality (adjusted OR 1.37 (95% CI 1.12 to 1.67); adjusted HR 2.13 (95% CI 1.41 to 3.23)). The relationship in per 10 g/L decreased serum albumin with prognosis was consistently inversed (adjusted OR 1.17 (95% CI 1.01 to 1.35); adjusted HR 1.86 (95% CI 1.30 to 2.64)). Also, low serum albumin levels were independently correlated with clinical outcomes at 1 year. In the meta-analysis, the OR for poor functional outcome pooled 3 studies per 1 g/L decrease was 1.03 (95% CI 1.02 to 1.05), and the HR for mortality pooled 5 studies was 1.07 (95% CI 1.03 to 1.11).

CONCLUSIONS

Low serum albumin levels predict poor functional outcome and mortality in patients with AIS or TIA.

Serum Level of Transferrin Unique Peptide Is Decreased in Patients With Acute Ischemic Stroke

Objectives: Free irons are transported into brain tissues by transferrin and play an important role in neuronal/glial cell damage. Lower serum levels of transferrin have been found in patients with ischemic stroke, compared with healthy subjects. In present study, we investigated whether transferrin unique peptide (TF-UP) could be employed as a serum biomarker for brain tissue damage in acute ischemic stroke. Methods: The venous blood samples of 94 ischemic stroke patients and 35 brain tumor-stroke mimics (BT-SM) patients were collected within the first 72 h (Median time 23.25, Interquartile range 60.75) of acute onset in the emergency room. Total TF-UP and total albumin unique peptide (Alb-UP) were identified with liquid chromatography/mass spectrometry (LC-MS/MS) and quantified by multiple reaction monitoring (MRM) method using labeled reference peptide (LRP) for further analysis. Results: Median ratio of total TF-UP/LRP was 0.85 (Interquartile range, 0.21) in the brain tumor-stroke mimics (BT-SM) group, and 0.45 (0.14) in the ischemic stroke group; median Alb-UP/LRP ratio was 0.66 (0.16) in the BT-SM group, and 0.55 (0.20) in the ischemic stroke group. The overall trend from low to high levels was statistically significant for TF-UP/LRP (P < 0.0001), but not for Alb-UP/LRP (P = 0.1667). According to the receiver operating characteristic (ROC) curve, the area under the curve (AUC) was 0.9565 and the optimal cutoff value of serum TF-UP was 0.6317, which yielded a sensitivity of 91.49% and a specificity of 88.57%. The odds ratio (95% confidence intervals) of serum TF-UP/LRP was 83.31 (23.43, 296.22, P < 0.0001). Conclusions: Serum TF-UP/LRP level is decreased in patients with acute ischemic stroke in comparison with brain tumor, and it may serve as a serum biomarker for the neuronal/glial cell damage in cerebral infarction.

Plasma Glial Fibrillary Acidic Protein in the Differential Diagnosis of Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Plasma GFAP (glial fibrillary acidic protein) has recently emerged as a potential biomarker for the differentiation of acute intracerebral hemorrhage (ICH) from acute ischemic stroke (AIS). We prospectively assessed the diagnostic accuracy of GFAP in the differential diagnosis of ICH.

METHODS

Consecutive patients presenting to the emergency department within 6 hours from symptom onset were evaluated. All patients underwent extensive diagnostic work-up and were classified according to discharge diagnosis in AIS, ICH, subarachnoid hemorrhage, and stroke mimics. GFAP was also measured in healthy volunteers (controls). Baseline stroke severity was evaluated using National Institutes of Health Stroke Scale. Receiver operating characteristic curve analysis was used to identify the optimal cutoff point for the differentiation between subgroups. Correlation analyses of GFAP plasma concentrations with baseline National Institutes of Health Stroke Scale and onset to sampling time were performed with the nonparametric Spearman rank test and fractional polynomial regression, respectively.

RESULTS

Our study population consisted of 270 individuals (AIS: 121, ICH: 34, stroke mimics: 31, subarachnoid hemorrhage: 5, controls: 79). No differences on baseline stroke severity and onset to sampling time were detected between AIS and ICH. Higher median plasma GFAP values were documented in ICH compared with AIS, stroke mimics, and controls (P<0.001). Receiver operating characteristic analysis highlighted a cutoff value of 0.43 ng/mL as the optimal threshold for the differentiation between ICH and AIS (sensitivity: 91%, specificity: 97%). No association was detected between plasma GFAP concentrations and baseline stroke severity for both AIS (P=0.515) and ICH (P=0.387). In the fractional polynomial analysis, the association between GFAP concentration and onset to sampling time was best described by a J-shaped curve for AIS and an inverted U-shaped curve for ICH, with a peak at 2 hours.

CONCLUSIONS

Plasma GFAP seems to be a sensitive and specific biomarker for the differentiation of ICH from both AIS and other acute neurological disorders, with the optimal diagnostic yield being present in the second hour from symptom onset.

Methods of albumin estimation in clinical biochemistry: Past, present, and future

Estimation of serum and urinary albumin is routinely performed in clinical biochemistry laboratories. In the past, precipitation-based methods were popular for estimation of human serum albumin (HSA). Currently, dye-binding or immunochemical methods are widely practiced. Each of these methods has its limitations. Research endeavors to overcome such limitations are on-going. The current trends in methodological aspects of albumin estimation guiding the field have not been reviewed. Therefore, it is the need of the hour to review several aspects of albumin estimation. The present review focuses on the modern trends of research from a conceptual point of view and gives an overview of recent developments to offer the readers a comprehensive understanding of the subject.