Alkaline Phosphatase and Outcomes in Patients With Preserved Renal Function

Prediction of atrial fibrillation and stroke using machine learning models in UK Biobank

Objective

Atrial fibrillation (AF) is the most common cardiac arrythmia, and it is associated with increased risk for ischemic stroke, which is underestimated, as AF can be asymptomatic. The aim of this study was to develop optimal ML models for prediction of AF in the population, and secondly for ischemic stroke in AF patients.

Methods

To develop ML models for prediction of 1) AF in the general population and 2) ischemic stroke in patients with AF we constructed XGBoost, LightGBM, Random Forest, Deep Neural Network, Support Vector Machine and Lasso penalised logistic regression models using UK-Biobank's extensive real-world clinical data, questionnaires, as well as biochemical and genetic data, and their predictive performances were compared. Ranking and contribution of the different features was assessed by SHapley Additive exPlanations (SHAP) analysis. The clinical tool CHA2DS2-VASc for prediction of ischemic stroke among AF patients, was used for comparison to the best performing ML model.

Findings

The best performing model for AF prediction was LightGBM, with an area-under-the-roc-curve (AUROC) of 0.729 (95% confidence intervals (CI): 0.719, 0.738). The best performing model for ischemic stroke prediction in AF patients was XGBoost with AUROC of 0.631 (95% CI: 0.604, 0.657). The improved AUROC in the XGBoost model compared to CHA2DS2-VASc was statistically significant based on DeLong's test (p-value = 2.20E-06). In addition, the SHAP analysis showed that several peripheral blood biomarkers (e.g. creatinine, glycated haemoglobin, monocytes) were associated with ischemic stroke, which are not considered by CHA2DS2-VASc.

Implications

The best performing ML models presented have the potential for clinical use, but further validation in independent studies is required. Our results endorse the incorporation of some routinely measured blood biomarkers for ischemic stroke prediction in AF patients.

Impact of alkaline phosphatase on clinical outcomes in patients with ischemic stroke: a nationwide registry analysis

Background

Data on the association between serum alkaline phosphatase (ALP) levels and clinical outcomes in patients with ischemic stroke (IS) are inconsistent and limited. Therefore, this study aimed to investigate the correlation between ALP and prognosis in patients with IS.

Methods

Patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) from the Third China National Stroke Registry were divided into four groups according to the quartiles of serum ALP levels on admission. Cox proportional hazards and logistic regression models were used to evaluate the correlation between ALP and the risk of all-cause mortality, disability (modified Rankin Scale (mRS) score 3-5), and poor functional outcomes (mRS score 3-6).

Results

A total of 11,405 patients were included in the study. Higher levels of ALP were associated with all-cause mortality at 3 months (adjusted hazard ratio [HR] per standard deviation [SD]: 1.16; 95% confidence interval (CI): 1.07-1.27; p = 0.001) and 1 year (adjusted HR: 1.11; 95% CI: 1.03-1.20; p = 0.010). At the 3-month follow-up, each SD increase of ALP was associated with a 12 and 14% higher risk of disability (adjusted odds ratio (OR): 1.12; 95% CI: 1.06-1.18; p < 0.001) and poor functional outcomes (adjusted OR: 1.14; 95% CI: 1.08-1.20; p < 0.001). Similar results were observed at the 1-year follow-up. Higher ALP levels were associated with an increased risk of all-cause mortality, disability, and poor functional outcomes in patients with "others" subtypes (including other determined etiology and undetermined etiology) (p < 0.05).

Conclusion

Elevated ALP levels were associated with an increased risk of all-cause mortality, disability, and poor function outcomes in patients with IS. Heterogeneity was observed among the subtypes of different etiologies.

Role of serum alkaline phosphatase as a potential biomarker of severity and prognosis in intracerebral hemorrhage

OBJECTIVES

Alkaline phosphatase (ALP) catalyzes the hydrolysis of pyrophosphate and facilitates vascular calcification. We aimed at investigating serum ALP levels in intracerebral hemorrhage (ICH) patients and ascertaining its relationship to severity and prognosis.

METHODS

Serum ALP levels from 148 patients and 148 healthy controls were detected. Glasgow coma scale (GCS) score and hematoma volume at admission were recorded to evaluate hemorrhagic severity. Modified Rankin Scale (mRS) score > 2 at 90 days after onset was judged as a poor prognosis.

RESULTS

Serum ALP levels in patients with ICH were substantially elevated compared with healthy controls, and were significantly related to hematoma volume and GCS score. Serum ALP levels significantly distinguished ICH patients at risk for unfavorable prognosis. Serum ALP levels > 78.5 U/L in ICH patients may indicated a unfavorable prognosis with 69.1 % sensitivity and 83.6 % specificity, and served as an independent predictor for unfavorable prognosis.

CONLUSIONS

Elevated serum ALP levels were intimately connected with increased severity and 90-day unfavorable prognosis in patients with ICH. Serum ALP could be a potential biomarker for severity and prognosis of ICH.

Associations of serum alkaline phosphatase level with all-cause and cardiovascular mortality in the general population

Background and aims

There are few population studies on the associations of serum alkaline phosphatase (AlkP) with all-cause and cardiovascular mortality. We aimed to investigate the relevancy of serum AlkP with all-cause and cardiovascular mortality in the general population.

Methods and results

Our research included 34,147 adults in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014. Cox proportional hazards regression models were used to assess the associations of serum AlkP with all-cause and cardiovascular mortality. Mediation analysis was used to analyze mechanisms that might link serum AlkP to all-cause and cardiovascular mortality. After 139.7 ± 57.8 months of follow-up, 5413 participants experienced all-cause death and 1820 participants experienced cardiovascular death. Mortality rates per 1000 person-years from various diseases increased with increasing serum concentrations of AlkP, especially all-cause death, cerebrovascular disease and cardiovascular death. High serum AlkP level significantly increased all-cause and cardiovascular mortality. After multivariate adjustment, the highest AlkP group had the highest risk to experience all-cause (hazard ratio [HR] = 1.30, P < 0.001) and cardiovascular mortality (HR = 1.39, P < 0.001) than the lowest AlkP group. γ-glutamyl transpeptidase (GGT) (13.33% and 15.79%), followed by Vitamin D (8.33% and 7.14%) and C-reactive protein (CRP) (7.69% and 10.35%) were identified as possible major mediators.

Conclusion

Higher AlkP concentrations were associated with higher all-cause and cardiovascular mortality, largely related to mediated factors such as GGT, Vitamin D, and CRP. These findings suggest that lower serum AlkP level may reduce all-cause and cardiovascular mortality in general population.

Association between alkaline phosphatase/albumin ratio and the prognosis in patients with chronic kidney disease stages 1-4: results from a C-STRIDE prospective cohort study

Background

The alkaline phosphatase-to-albumin ratio (APAR) has been demonstrated to be a promising non-invasive biomarker for predicting prognosis in certain diseases. However, the relationship between APAR and prognosis in non-dialysis chronic kidney disease (CKD) patients remains unclear. This study aims to identify the association between APAR and prognosis among CKD stages 1-4 in China.

Methods

Patients with CKD stages 1-4 were consecutively recruited from 39 clinical centers in China from 2011 to 2016. New occurrences of end-stage kidney disease (ESKD), major adverse cardiovascular and cerebrovascular events, and all-cause deaths were the outcome events of this study. Subdistribution hazard competing risk and Cox proportional hazards regression models were adopted.

Results

A total of 2,180 participants with baseline APAR values were included in the analysis. In the primary adjusted analyses, higher APAR level [per 1-standard deviation (SD) increase in natural logarithm transformed (ln-transformed) APAR] was associated with 33.5% higher risk for all-cause deaths [adjusted hazard ratio (HR) 1.335, 95% confidence interval (CI) 1.068-1.670]. In addition, there was evidence for effect modification of the association between APAR and ESKD by baseline estimated glomerular filtration rate (eGFR) (P interaction < 0.001). A higher APAR level (per 1-SD increase in ln-transformed APAR) was associated with a greater risk of ESKD among participants with eGFR ≥ 60 ml/min/1.73 m2 (adjusted SHR 1.880, 95% CI 1.260-2.810) but not in eGFR < 60 ml/min/1.73 m2.

Conclusion

Higher APAR levels in patients with CKD stages 1-4 seemed to be associated with an increased risk of all-cause death. Thus, APAR appears to be used in risk assessment for all-cause death among patients with CKD stages 1-4.

Serum alkaline phosphatase was independently associated with depression in patients with cerebrovascular disease

Background and purpose

Blood markers have important value in the diagnosis of depressive disorders. Serum alkaline phosphatase (ALP) not only predicts stroke recurrence and poor functional prognosis in cerebrovascular disease (CVD) patients but also increases significantly in middle-aged women with depression. Thus, it has not been reported whether serum ALP is associated with the development of depression and/or vascular depression (VDe) in CVD patients.

Methods

This was a cross-sectional study of 353 CVD patients (stroke patients, n = 291; cerebral small vessel disease (CSVD) patients, n = 62). Baseline demographic information, fasting blood markers (such as blood counts, liver function, kidney function and lipids), and brain CT/MRI scans were collected. CVD patients were divided into non-depression, suspected vascular depression (SVD), and positive vascular depression (PVD) groups according to their Hamilton Rating Scale for Depression (HAMD) scores. Univariate analysis of baseline data, blood markers, and the prevalence of lesions (> 1.5 cm) was performed. Subsequently, the diagnostic performance of the univariate and combined variables for SVD and PVD was analyzed using binary logistic regression. The diagnostic value of the multivariate model for VDe was analyzed by ordinal logistic regression.

Results

(1) Serum ALP (p = 0.003) and hypersensitive C-reactive protein (hs-CRP, p = 0.001) concentrations increased as HAMD scores increased, and the prevalence of brain atrophy (p = 0.016) and lesions in the basal ganglia (p = 0.001) and parietal (p = 0.001), temporal (p = 0.002), and frontal lobes (p = 0.003) also increased, whereas the concentrations of hemoglobin (Hb, p = 0.003), cholinesterase (ChE, p = 0.001), and high-density lipoprotein cholesterol (HDL-C, p = 0.005) declined. Among these variables, hs-CRP (r = 0.218, p < 0.001) had a weak positively association with HAMD scores, and ChE (r = -0.226, p < 0.001) had a weak negative association. (2) The combination of Hb, hs-CRP, ChE, ALP, and HDL-C improved diagnostic performance for VDe [AUC = 0.775, 95% CI (0.706, 0.844), p < 0.001]. (3) Hb (OR = 0.986, p = 0.049), ChE (OR = 0.999, p = 0.020), ALP (OR = 1.017, p = 0.003), and basal ganglia lesions (OR = 2.197, p < 0.001) were important factors impacting VDe development. After adjusting for Hb, hs-CRP, ChE, HDL-C, lesions in the above mentioned four locations, sex, age and the prevalence of CSVD and brain atrophy, ALP [OR = 1.016, 95% CI (1.005, 1.027), p = 0.004] was independently associated with VDe.

Conclusion

Hb, hs-CRP, ChE, ALP, and HDL-C concentrations are potential blood markers of depression in CVD patients and, when combined, may improve diagnostic performance for VDe. Serum ALP was independently associated with VDe in patients with CVD.

Non-Linear Association Between Serum Alkaline Phosphatase and 3-Month Outcomes in Patients With Acute Stroke: Results From the Xi'an Stroke Registry Study of China

Background

Alkaline phosphatase (ALP) is associated with an increased risk of cardiovascular events and is closely related to adverse outcomes after stroke. However, the regional investigation into the associations of ALP with acute stroke (AS) outcomes is limited. This study aimed to identify the association between serum ALP levels and clinical outcomes 3 months after AS in the Xi'an district of China.

Methods

We enrolled all patients with AS from 4 hospitals in the Xi'an district from January to December 2015. ALP levels and related patient information were collected at admission, and the events of stroke outcomes were followed up 1 and 3 months after diagnosis. ALP levels were analyzed as continuous variables and quartiles (Q1–Q4). The outcomes included all-cause mortality, recurrent stroke, and poor functional outcomes (modified Rankin Scale score of 3–6) within 3 months. A multivariate logistic regression and interaction analyses were performed to evaluate the independent association between serum ALP level and 3-month stroke outcomes.

Results

Overall, 2,799 patients with AS were enrolled in this study. The mean age was 63.9 ± 12.5 years. In the Q4 (≥93.0 U/L) group, the incidences of all-cause mortality, recurrent stroke, and poor functional outcomes were 7.8, 2.7, and 24.9%, respectively. After being adjusted for confounding variables, patients in Q4 (≥93.0 U/L) were related to an increased risk of all-cause mortality [odds ratio (OR) = 2.17, 95% CI: 1.19–3.96; P = 0.011] and patients in Q3 (76.8–92.9 U/L) were related to a lower risk of recurrent stroke (OR = 0.37, 95% CI: 0.14–0.97; P = 0.043) at the 3-month time point, compared to those in Q2 (63.0–76.7 U/L). The optimal range of ALP for all-cause mortality was seen in Q2, with a nadir level of 70 U/L. However, differences were statistically insignificant between ALP levels and poor functional outcomes (P > 0.05). Moreover, there was no significant interaction between ALP levels and age, gender, drinking status, smoking status, or pneumonia (P > 0.05) for all outcomes.

Conclusion

Non-linear associations were observed between serum ALP levels and 3-month outcomes in patients with AS. It might be beneficial to reduce the risk of all-cause mortality and recurrent stroke by maintaining ALP at optimal ranges.

Prognostic values of serum alkaline phosphatase and globulin levels in patients undergoing intravenous thrombolysis

Background

In previous studies, alkaline phosphatase (ALP) level was a prognostic factor for patients with ischemic stroke, and globulin level was associated with hemorrhagic transformation (HT) after intravenous thrombolysis (IVT). However, the association between these serum biomarkers and prognosis in patients with acute ischemic stroke (AIS) who undergo IVT remains unclear. This study aimed to investigate the characteristics of serum ALP and globulin levels after IVT and to assess the relationship between these serum biomarkers and prognosis.

Materials and methods

This retrospective study used a prospectively collected database. We included patients with AIS who received recombinant tissue plasminogen activator (rt-PA) IVT. Demographic information, vascular risk factors, laboratory test results, and other stroke-related data were collected for analysis. Clinical outcomes included HT and 3-month poor outcome (modified Rankin Scale scores ≥ 2) after IVT. The association of ALP and globulin levels with HT and poor outcome was investigated using multivariate logistic regression analysis. An individualized prediction model based on ALP and globulin levels for functional outcomes was established.

Results

We enrolled 750 patients in this study; 452 patients (60.3%) had poor outcome, and 117 patients (15.6%) had HT after IVT. After adjusting for all confounders, serum globulin level [OR = 1.055; 95% confidence intervals (CI): 1.006–1.107; P = 0.028] was independently associated with HT in patients with IVT. Serum ALP (OR = 1.009; 95% CI: 1.002–1.016; P = 0.010) and globulin levels (OR = 1.062; 95% CI: 1.020–1.107; P = 0.004) were associated with 3-month poor outcome in these patients. The constructed individualized prediction model for the 3-month poor outcome comprised the National Institutes of Health Stroke Scale (NIHSS) score, Trial of Org 10172 in Acute Stroke Treatment (TOAST), history of antihypertensive therapy, ALP and globulin levels. The area under the curve of the training and validation sets were 0.726 and 0.706, respectively, revealing that the model had good discriminating power. The P-values for the Hosmer-Lemeshow test in the training and validation sets were 0.978 and 0.148, respectively, indicating the model had good calibration.

Conclusion

This study found that higher serum globulin levels were independently associated with HT. Additionally, higher serum ALP and globulin levels were independently associated with a poor outcome in patients after IVT.

Relationship between serum alkaline phosphatase and poor 3-month prognosis in acute ischemic stroke patients with preserved renal function: results from Xi'an Stroke Registry Study of China

Background

In recent years, alkaline phosphatase (ALP) has been considered as one of the independent risk factors of acute ischemic stroke (AIS) and leads to worse clinical outcomes in patients with renal failure. In this study, we aim to investigate whether serum ALP level is associated with poor early-term prognosis in relationship of AIS patients with preserved renal function.

Methods

A prospectively collected database of AIS patients hospitalized in the Xi’an district of China from January to December, 2015 was analyzed. The demographics, serum ALP levels and stroke outcomes of all patients at 3 months were reviewed. Patients were routinely followed-up for 3 months. Serum ALP level was analyzed as a continuous variable and quintiles (Q1-Q5). Multivariate logistic regression model and a two-piecewise linear regression model were used to investigate the relationship and to determine the threshold effect regarding serum ALP levels and poor 3-month prognosis of AIS patients with preserved renal function.

Results

Overall, 1922 AIS patients were enrolled with 62.3% of them being men. The risk of having a poor 3-month prognosis was significantly increased in Q1, Q2, Q3 and Q5, when compared to that in Q4 being as the reference. The highest risk was noted in Q5 (odds ratio 2.21, 95% confidence interval: 1.32–3.73, P = 0.003) after being adjusted for confounders. Further analysis revealed a J-shaped curvilinear relationship between ALP levels and a poor 3-month prognosis of strokes (optimal threshold ALP level = 90 U/L). The relationship between both parameters was not significantly affected by age, sex, drinking, hypertension and leukocyte count (stratified by 10 × 10⁹/L) (P for interaction > 0.05).

Conclusions

Serum ALP was noted as an independent risk factor for a poor 3-month prognosis of AIS patients with preserved renal function. ALP levels higher than 90 U/L could cause an increased risk of a poor 3-month prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02779-y.

TNAP as a therapeutic target for cardiovascular calcification: a discussion of its pleiotropic functions in the body

Cardiovascular calcification (CVC) is associated with increased morbidity and mortality. It develops in several diseases and locations, such as in the tunica intima in atherosclerosis plaques, in the tunica media in type 2 diabetes and chronic kidney disease, and in aortic valves. In spite of the wide occurrence of CVC and its detrimental effects on cardiovascular diseases (CVD), no treatment is yet available. Most of CVC involve mechanisms similar to those occurring during endochondral and/or intramembranous ossification. Logically, since tissue-nonspecific alkaline phosphatase (TNAP) is the key-enzyme responsible for skeletal/dental mineralization, it is a promising target to limit CVC. Tools have recently been developed to inhibit its activity and preclinical studies conducted in animal models of vascular calcification already provided promising results. Nevertheless, as its name indicates, TNAP is ubiquitous and recent data indicate that it dephosphorylates different substrates in vivo to participate in other important physiological functions besides mineralization. For instance, TNAP is involved in the metabolism of pyridoxal phosphate and the production of neurotransmitters. TNAP has also been described as an anti-inflammatory enzyme able to dephosphorylate adenosine nucleotides and lipopolysaccharide. A better understanding of the full spectrum of TNAP's functions is needed to better characterize the effects of TNAP inhibition in diseases associated with CVC. In this review, after a brief description of the different types of CVC, we describe the newly uncovered additional functions of TNAP and discuss the expected consequences of its systemic inhibition in vivo.

Association Between Alkaline Phosphatase and Clinical Outcomes in Patients With Spontaneous Intracerebral Hemorrhage

Background: Spontaneous intracerebral hemorrhage (ICH) is associated with high rates of mortality and morbidity. Alkaline phosphatase (ALP) is related to increased risk of cardiovascular events and is also closely associated with adverse outcomes after ischemic or hemorrhagic stroke. However, there are limited data about the effect of ALP on clinical outcomes after ICH. Therefore, we aimed to investigate the relationship between serum ALP level and prognosis in ICH patients. Methods: From January 2014 to September 2016, 939 patients with spontaneous ICH were enrolled in our study from 13 hospitals in Beijing. Patients were categorized into four groups based on the ALP quartiles (Q1, Q2, Q3, Q4). The main outcomes were 30-day, 90-day, and 1-year poor functional outcomes (modified Rankin Scale score of 3-6). Multivariable logistic regression and interaction analyses were performed to evaluate the relationships between ALP and clinical outcomes after ICH. Results: In the logistic regression analysis, compared with the third quartile of ALP, the adjusted odds ratios of the Q1, Q2, and Q4 for 30-day poor functional outcome were 1.31 (0.80-2.15), 1.16 (0.71-1.89), and 2.16 (1.32-3.55). In terms of 90-day and 1-year poor functional outcomes, the risks were significantly higher in the highest quartile of ALP compared with the third quartile after adjusting the confounding factors [90-day: highest quartile OR = 1.86 (1.12-3.10); 1-year: highest quartile OR = 2.26 (1.34-3.80)]. Moreover, there was no significant interaction between ALP and variables like age or sex. Conclusions: High ALP level (>94.8 U/L) was independently associated with 30-day, 90-day, and 1-year poor functional outcomes in ICH patients. Serum ALP might serve as a predictor for poor functional outcomes after ICH onset.

Serum Alkaline Phosphatase Levels and Increased Risk of Brain Hemorrhage in Hemodialysis Patients: The Q-Cohort Study

Aim: Elevated serum alkaline phosphatase (ALP) levels have been associated with increased risks of all-cause and cardiovascular mortality in patients receiving hemodialysis. However, little is known about the impact of serum ALP levels on the development of stroke, such as brain hemorrhage and infarction.

Methods: A total of 3,497 patients receiving maintenance hemodialysis registered in the multicenter observational Q-Cohort Study were analyzed. The primary outcomes were the incidences of brain hemorrhage and infarction. The covariate of interest was serum ALP levels. Patients were divided into tertiles based on their serum ALP levels (U/L) at baseline (T1, ＜69.3; T2, 69.3–98.4; T3, ＞98.4). The risks of brain hemorrhage, brain infarction, and composite stroke were estimated using Cox proportional hazards models and competing risk models with all-cause death as a competing risk.

Results: A total of 89 patients developed brain hemorrhage and 195 patients developed brain infarction during the 4-year follow-up period. The risk of brain hemorrhage in the highest tertile (T3) was significantly higher than that in the lowest tertile (T1) (multivariable-adjusted hazard ratio [95% confidence interval], 1.93 [1.12–3.35], subdistribution hazard ratio, 1.91 [1.10–3.30]). However, there was no significant association between serum ALP levels and the risk of brain infarction or composite stroke.

Conclusions: Higher serum ALP levels are associated with an increased risk of brain hemorrhage, but not brain infarction, in patients receiving maintenance hemodialysis. High serum ALP level is thus an important risk factor for brain hemorrhage in hemodialysis patients.

Increased Serum Alkaline Phosphatase and Functional Outcome in Patients with Acute Ischemic Stroke Presenting a Low Ankle-Brachial Index

Aims: Elevated serum alkaline phosphatase (ALP) levels are associated with an increased risk of cerebrocardiovascular diseases. However, the associations of ALP with peripheral arterial disease (PAD) and outcomes in patients with acute ischemic stroke (AIS) are not well-known.

Methods: We examined the association between ALP levels and the ankle–brachial index (ABI) in 2111 consecutive patients with AIS. A poor functional outcome was defined as a modified Rankin Scale (mRS) score of 3–6 at 3 months after stroke. A low ABI was defined as a value of ≤ 0.9.

Results: Of the total cohort, 482 patients (22.8%) had a low ABI. ALP levels were higher in patients with a low ABI than in those without (p＜0.001). The multivariable logistic analysis revealed that quartiles of ALP levels were significantly associated with a low ABI (odds ratio [OR]: 1.20, 95% confidence interval [CI]: 1.08–1.33). Of the 1322 patients with a premorbid mRS score of 0–2, 434 patients (32.8%) had a poor outcome. The multivariable analysis revealed that elevated serum ALP levels and a low ABI were independently associated with poor stroke outcomes after adjustment for baseline characteristics (OR: 1.21, 95% CI: 1.07–1.38, and OR: 2.00, 95% CI: 1.40–2.84, respectively).

Conclusions: Increased serum ALP levels are significantly associated with a low ABI. These indicators are independent prognostic factors for poor stroke outcomes at 3 months.

Predictors of Stroke Outcome Extracted from Multivariate Linear Discriminant Analysis or Neural Network Analysis

Aim: The prediction of functional outcome is essential in the management of acute ischemic stroke patients. We aimed to explore the various prognostic factors with multivariate linear discriminant analysis or neural network analysis and evaluate the associations between candidate factors, baseline characteristics, and outcome.

Methods: Acute ischemic stroke patients ( n =1,916) with premorbid modified Rankin Scale (mRS) scores of 0–2 were analyzed. The prediction models with multivariate linear discriminant analysis (quantification theory type II) and neural network analysis (log-linearized Gaussian mixture network) were used to predict poor functional outcome (mRS 3–6 at 3 months) with various prognostic factors added to age, sex, and initial neurological severity at admission.

Results: Both models revealed that several nutritional statuses and serum alkaline phosphatase (ALP) levels at admission improved the predictive ability. Of the 1,484 patients without missing data, 560 patients (37.7%) had poor outcomes. The patients with poor outcomes had higher ALP levels than those without (294.3±259.5 vs. 246.3±92.5 U/l, P ＜0.001). Multivariable logistic analyses revealed that higher ALP levels (1-SD increase) were independently associated with poor stroke outcomes after adjusting for several confounding factors, including the neurological severity, malnutrition status, and inflammation (odds ratio 1.21, 95% confidence interval 1.02–1.49). Several nutritional indicators extracted from prediction models were also associated with poor outcome.

Conclusion: Both the multivariate linear discriminant and neural network analyses identified the same indicators, such as nutritional status and serum ALP levels. These indicators were independently associated with functional stroke outcome.

Risk factors affecting the 1-year outcomes of minor ischemic stroke: results from Xi'an stroke registry study of China

BACKGROUND

The prevalence of stroke recurrence, disability, and all-cause mortality of patients with minor ischemic stroke (MIS) remains problematic. The aim of the present study was to identify risk factors associated with adverse outcomes at 1 year after MIS in the Xi'an region of China.

METHODS

This prospective cohort study included MIS patients above 18 years old with National Institutes of Health Stroke Scale (NIHSS) score ≤ 3 who were treated in any of four hospitals in Xi'an region of China between January and December 2015. The 1-year prevalence of stroke recurrence, disability, and all-cause mortality were evaluated, respectively. Multivariate logistic regression analysis was performed to assess the association between the identified risk factors and clinical outcomes.

RESULTS

In this study, 131(10.5%, 131/1252) patients were lost to follow-up at 1 year. A total of 1121 patients were included for analysis, the prevalence of stroke recurrence, disability, and all-cause mortality at 1 year after MIS were 3.4% (38/1121), 9.3% (104/1121), and 3.3% (37/1121), respectively. Multivariate logistic regression analysis identified age, current smoking, and pneumonia as independent risk factors for stroke recurrence. Age, pneumonia, and alkaline phosphatase were independent risk factors for all-cause mortality. Independent risk factors for disability were age, pneumonia, NIHSS score on admission, and leukocyte count.

CONCLUSIONS

The 1-year outcomes of MIS in Xi'an region of China were not optimistic, especially with a high prevalence of disability. The present study indicated that age and pneumonia were the common independent risk factors affecting the 1-year outcomes of MIS in Xi'an region of China.

Alkaline Phosphatase Activity Is a Key Determinant of Vascular Responsiveness to Norepinephrine

Here, we tested the hypothesis that TNAP (tissue nonspecific alkaline phosphatase) modulates vascular responsiveness to norepinephrine. In the isolated, Tyrode's-perfused rat mesentery, 50 µmol/L of L-p-bromotetramisole (L-p-BT; selective TNAP inhibitor, Ki=56 µmol/L) significantly reduced TNAP activity and caused a significant 9.0-fold rightward-shift in the norepinephrine concentration versus vasoconstriction relationship. At 100 µmol/L, L-p-BT further reduced mesenteric TNAP activity and caused an additional significant right-shift of the norepinephrine concentration versus vasoconstriction relationship. A higher concentration (200 µmol/L) of L-p-BT had no further effect on either mesenteric TNAP activity or norepinephrine-induced vasoconstriction. L-p-BT did not alter vascular responses to vasopressin, thus ruling-out nonspecific suppression of vascular reactivity. Since in the rat mesenteric vasculature α1-adrenoceptors mediate norepinephrine-induced vasoconstriction, these finding indicate that TNAP inhibition selectively interferes with α1-adrenoceptor signaling. Additional experiments showed that the effects of TNAP inhibition on norepinephrine-induced vasoconstriction were not mediated by accumulation of pyrophosphate or ATP (TNAP substrates) nor by reduced adenosine levels (TNAP product). TNAP inhibition significantly reduced the Hillslope of the norepinephrine concentration versus vasoconstriction relationship from 1.8±0.2 (consistent with positive cooperativity of α1-adrenoceptor signaling) to 1.0±0.1 (no cooperativity). Selective activation of A1-adenosine receptors, which are known to participate in coincident signaling with α1-adrenoceptors, reversed the suppressive effects of L-p-BT on norepinephrine-induced vasoconstriction. In vivo, L-p-BT administration achieved plasma levels of ≈60 µmol/L and inhibited mesenteric vascular responses to exogenous norepinephrine and sympathetic nerve stimulation. TNAP modulates vascular responses to norepinephrine likely by affecting positive cooperativity of α1-adrenoceptor signaling via a mechanism involving A1 receptor signaling.

Increased serum alkaline phosphatase and early neurological deterioration in patients with atherothrombotic brain infarction attributable to intracranial atherosclerosis

Objective

The purpose of this study was to determine whether increased alkaline phosphatase (ALP) was associated with early neurological deterioration (END) in patients with atherothrombotic brain infarction (ATBI) attributable to intracranial atherosclerosis (ICAS) or not.

Methods

We analyzed data derived from 70 patients (47 men; mean age, 72.4 ± 12.8 years) with symptomatic ICAS who were admitted within 3 days of ATBI onset between April 2013 and December 2018. We defined END as an increase of ≥2 in the National Institutes of Health Stroke Scale scores during the first 72 h of hospitalization.

Results

Eleven (15.7%) patients had END. Serum ALP levels on admission were significantly higher among patients with, than without END (median [interquartile range], 296 [233-338] vs. 216 [187-262] U/L, p = .0081).

Conclusion

Increased serum ALP levels on admission may be able to predict developing END in patients with symptomatic ICAS.

Serum Alkaline Phosphatase Level is Associated with Angiographic Vasospasm, Delayed Cerebral Ischemia-Caused Clinical Deterioration, and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Alkaline phosphatase (ALP) has been implicated to be associated with poor outcome in ischemic stroke patients, yet its role in aneurysmal subarachnoid hemorrhage (aSAH) patients is unknown. The current study aimed to investigate the on-admission and short-term variation trend of ALP levels in aSAH patients as well as its associations with vasospasm, delayed cerebral ischemia (DCI), and outcome after aSAH.

METHODS

Between January 2014 and May 2018, all consecutive aSAH patients were prospectively enrolled. Blood samples from patients and 78 healthy individuals were obtained. Baseline information, clinical data, and radiologic data were collected, and serum ALP levels during hospitalization were measured. Patients were followed up for 6 months.

RESULTS

One hundred and ninety-six aSAH patients were included. The serum ALP levels in aSAH patients were significantly higher compared to controls (71 vs. 61 U/L, p = 0.0002), yet did not differ significantly between patients with severe (WFNS 4-5) and mild clinical condition (72 vs. 63 U/L, p = 0.3362). However, ALP was significantly higher in patients with severe radiologic status (modified Fisher 3-4) compared to those with mild radiologic status (77 vs. 61.5 U/L, p = 0.0005). A significant correlation emerged between modified Fisher score and ALP level (r = 0.246, p = 0.001). Multivariable analysis found that higher ALP level was associated with angiographic vasospasm (OR 1.019, 95% CI 1.002-1.036, p = 0.026) and DCI-caused clinical deterioration (OR 1.019, 95% CI 1.001-1.037, p = 0.037), while higher WFNS score, modified Fisher score, and ALP level were independently associated with unfavorable outcome (serum ALP level, OR 1.083, 95% CI 1.041-1.127, p < 0.001). Trend analysis of ALP level based on 103 patients' data revealed a significant decrease in ALP level on post-admission day 7-9 (median; on-admission day vs. post-admission day 7-9, 72 vs. 60 U/L, p = 0.0012; post-admission day 3-5 vs. day 7-9, 70 vs. 60 U/L, p = 0.0052) and subsequent increase in ALP level on post-admission day 12-14 (median, 84 U/L, p < 0.0001). Higher ALP levels were observed in patients with unfavorable outcome on on-admission day, post-admission day 3-5, and 12-14 (median; unfavorable vs. favorable; on-admission day, 86 vs. 67 U/L, p = 0.0122; post-admission day 3-5, 80 vs. 64 U/L, p = 0.0044; post-admission day 7-9, 75 vs. 53.5 U/L, p < 0.0001) but not on post-admission day 12-14.

CONCLUSIONS

Elevated serum ALP level is associated with vasospasm, DCI-caused clinical deterioration, and functional outcome after aSAH. Further studies are required to examine the potential role of serum ALP as an outcome predictor for aSAH patients.

Nutritional Status and Mortality Predictability for Time-Varying Serum Alkaline Phosphatase in Hemodialysis Patients: A Longitudinal Study

OBJECTIVE

Higher serum alkaline phosphatase (sALP) levels associate with a poor prognosis in maintenance hemodialysis patients. However, little is known about the meaning of lower sALP in this population. We hypothesized that lower sALP concentrations may express nutritional status and survival accordingly.

METHODS

A retrospective, longitudinal cohort study of a clinical database containing the medical records of 554 patients (367 men and 187 women, mean age 67.6 ± 14.2 years) receiving maintenance hemodialysis from November 2007 to July 2018 in a single center was conducted. sALP, nutritional, bone turnover, and inflammatory marker levels were recorded at 0, 6, 12, 18, 24, 30,and 36 months followed by 58 additional months of clinical observations.

RESULTS

The median sALP level was 90.0 (71.0-125.8) U/L. In a linear mixed effects model adjusted for baseline demographics and clinical parameters, each 1.0 U/L increase above the mean sALP at baseline was associated with 0.7% slower rate of decline in geriatric nutritional risk index per 3 years (P = .02 for sALP × time interaction). sALP remained associated with the rate of change in geriatric nutritional risk index, even after controlling for C-reactive protein and intact parathyroid hormone levels. For each 1.0 U/L increase in sALP over time, the fully adjusted all-cause mortality hazard ratio using Cox models with the time-varying risk effect was 0.996 (95% confidence interval 0.993-1.000, P = .04).

CONCLUSIONS

Increasing longitudinal levels of sALP associate with improved nutritional status and lower mortality rates. sALP can be used as an integrated marker, combining the properties of the nutritional marker, the marker of mineral-bone disease and inflammation, according to its levels.

Extreme Gradient Boosting Model Has a Better Performance in Predicting the Risk of 90-Day Readmissions in Patients with Ischaemic Stroke

OBJECT

Ischemic stroke readmission within 90 days of hospital discharge is an important quality of care metric. The readmission rates of ischemic stroke patients are usually higher than those of patients with other chronic diseases. Our aim was to identify the ischemic stroke readmission risk factors and establish a 90-day readmission prediction model for first-time ischemic stroke patients.

METHODS

The readmission prediction model was developed using the extreme gradient boosting (XGboost) model, which can generate an ensemble of classification trees and assign a predictive risk score to each feature. The patient data were split into a training set (5159) and a validation set (911). The prediction results were evaluated with the receiver operating characteristic (ROC) curve and time-dependent ROC curve, which were compared with the outputs from the logistic regression (LR) model.

RESULTS

A total of 6070 adult patients (39.6% female, median age 67 years) without any ischemic attack (IS) history were included, and 520 (8.6%) were readmitted within 90 days. The XGboost-based prediction model achieved a standard area under the curve (AUC) value of .782 (.729-.834), and the best time-dependent AUC value was .808 in 54 days for the validation set. In contrast, the LR model yielded a standard AUC value of .771 (.714-.828) and best time-dependent AUC value of .797.

CONCLUSIONS

The XGboost model obtained a better risk prediction for 90-day readmission for first-time ischemic stroke patients than the LR model. This model can also reveal the high risk factors for stroke readmission in first-time ischemic stroke patients.

Platelet Count Predicts Adverse Clinical Outcomes After Ischemic Stroke or TIA: Subgroup Analysis of CNSR II

Background: The clinical significance of platelet count (PC) for ischemic cerebrovascular disease is not well-established and further risk stratification according to baseline PC within normal range has not been reported before. We aim to evaluate the prognostic effect of baseline circulating PC within normal range on the risk of long-term recurrent stroke, mortality and functional outcomes after ischemic stroke or TIA.

Methods: We derived data from eligible patients with ischemic stroke or TIA from the China National Stroke Registry (CNSR) II. Participants were divided into quintiles according to baseline PC within normal range (100–450 × 10⁹/L). Multivariable cox regression and logistic regression were adopted to explore the correlation of baseline PC with recurrent stroke, mortality and poor functional outcomes (modified Rankin Scale 3~6) within 1-year follow-up.

Results: Among the16842 eligible participants, the average age was 64.7 ± 11.9, 1,241 (7.4%) had recurrent stroke, 1,377 (8.2%) died, and 3,557 (21.1%) ended up with poor functional outcomes after 1-year follow-up. Compared with the third PC quintile (186–212 × 10⁹/L), patients in the top quintile (249–450 × 10⁹/L) presented with increased risk of recurrent stroke (adjusted hazard ratio 1.21, [1.02–1.45]), all-cause mortality (adjusted hazard ratio 1.43, [1.19–1.73]), and poor functional outcome (adjusted odds ratio 1.49, [1.28–1.74]), while patients in the lowest PC quintile(100–155 × 10⁹/L) had higher risk of poor functional outcome (adjusted odds ratio 1.19, [1.02–1.38]).

Conclusion: In ischemic stroke or TIA patients with platelet count within normal range, platelet count may be a qualified predictor for long-term recurrent stroke, mortality, and poor functional outcome.

Alkaline phosphatase: a potential biomarker for stroke and implications for treatment

Stroke is the fifth leading cause of death in the U.S., with more than 100,000 deaths annually. There are a multitude of risks associated with stroke, including aging, cardiovascular disease, hypertension, Alzheimer's disease (AD), and immune suppression. One of the many challenges, which has so far proven to be unsuccessful, is the identification of a cost-effective diagnostic or prognostic biomarker for stroke. Alkaline phosphatase (AP), an enzyme first discovered in the 1920s, has been evaluated as a potential biomarker in many disorders, including many of the co-morbidities associated with stroke. This review will examine the basic biology of AP, and its most common isoenzyme, tissue nonspecific alkaline phosphatase (TNAP), with a specific focus on the central nervous system. It examines the preclinical and clinical evidence which supports a potential role for AP in stroke and suggests potential mechanism(s) of action for AP isoenzymes in stroke. Lastly, the review speculates on the clinical utility of AP isoenzymes as potential blood biomarkers for stroke or as AP-targeted treatments for stroke patients.