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Serum levels of alkaline phosphatase (ALP) and phosphate are primarily used as markers of liver disease or bone

disease in clinical practice. Recent epidemiological studies have demonstrated that elevated ALP or phosphate levels are associated with the presence of atherosclerosis in coronary and peripheral arteries, increased cardiovascular events, and mortality.1–5 ALP and phosphate are also considered to be sur-rogate markers of systemic inflammation, malnutrition, and metabolic syndrome, which may lead to worse clinical out-comes in patients with stroke.1,3 Therefore, we investigated whether ALP/phosphate is associated with cerebral athero-sclerosis and long-term functional outcomes in patients with acute cerebral infarction.

MethodsThis was a hospital-based, retrospective observational study. Candidates were patients admitted with a first-ever acute cere-bral infarction. Patient inclusion and exclusion criteria are shown in Figure I in the online-only Data Supplement. Serum ALP and phosphate levels were measured at admission using peripheral ve-nous blood with a Hitachi 7600-210 automatic analyzer (HITACHI, Tokyo, Japan). We collected data, including baseline characteristics, National Institutes of Health Stroke Scale score at admission, risk factors, and laboratory findings.

Cerebral atherosclerosis was defined as occlusion or significant stenosis (≥50%) of cerebral artery on the basis of digital subtraction angiography, magnetic resonance angiography, or computed tomo-graphic angiography. The presence of cerebral atherosclerosis was assessed in intracranial cerebral arteries (anterior cerebral, middle cerebral, posterior cerebral, basilar, intracranial internal carotid, and intracranial vertebral arteries) and extracranial cerebral arter-ies (extracranial internal carotid and extracranial vertebral arteries). Then, patients were subdivided into 4 groups according to the loca-tion of cerebral atherosclerosis (no atherosclerosis, only intracranial, only extracranial, and both intracranial and extracranial atheroscle-rosis). We also collected data for the presence of coronary artery disease and peripheral artery disease. We defined a poor functional outcome as a modified Rankin Scale score of >2 at 3 months af-ter stroke onset. Definition of risk factors, collected data, and sta-tistical methods is shown in the Methods in the online-only Data Supplement. The Institutional Review Board of Severance Hospital, Yonsei University Health System, approved this study and waived the need for informed consent because of the retrospective and ob-servational nature of the study.

ResultsOf the 1043 patients, 62.51% were men, and their mean age was 65.82±12.79 years. Mean values were 62.45±19.61 U/L for ALP and 1.07±0.21 mmol/L for phosphate. Clinical char-acteristics and their associations with ALP/phosphate are

Background and Purpose—Higher serum alkaline phosphatase (ALP) and phosphate levels are associated with atherosclerotic disease and an increased risk of cardiovascular events. However, the association of ALP/phosphate with cerebral atherosclerosis and prognosis in patients with acute stroke is not well known.

Methods—In 1034 patients with first-ever acute cerebral infarction, levels of ALP and phosphate were compared with (1) cerebral atherosclerosis and (2) poor long-term functional outcomes as defined by the modified Rankin Scale >2 at 3 months after stroke onset.

Results—ALP levels were not associated with cerebral atherosclerosis. However, higher levels of ALP were associated with a poor functional outcome (adjusted odds ratio per 1 SD, 1.25; 95% confidence interval, 1.04–1.50). Phosphate was associated with neither cerebral atherosclerosis nor functional outcome.

Conclusions—A higher level of ALP was not associated with cerebral atherosclerosis but was an independent prognostic factor for long-term functional outcome after acute cerebral infarction. (Stroke. 2013;44:3547-3549.)

Key Words: alkaline phosphatase ◼ atherosclerosis ◼ phosphate ◼ stroke

Serum Alkaline Phosphatase and Phosphate in Cerebral Atherosclerosis and Functional Outcomes

After Cerebral InfarctionJinkwon Kim, MD; Tae-Jin Song, MD; Dongbeom Song, MD; Hye Sun Lee, MS;

Chung Mo Nam, PhD; Hyo Suk Nam, MD, PhD; Young Dae Kim, MD, PhD; Ji Hoe Heo, MD, PhD

Received July 23, 2013; accepted August 15, 2013.From the Department of Neurology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea (J.K.); Department of Neurology,

Ewha Womans University, Seoul, Republic of Korea (T.-J.S.); and Departments of Neurology (J.K., D.S., H.S.N., Y.D.K., J.H.H.) and Biostatistics (H.S.L., C.M.N.), Yonsei University College of Medicine, Seoul, Republic of Korea.

The online-only Data Supplement is available with this article at http://stroke.ahajournals.org/lookup/suppl/doi:10.1161/STROKEAHA. 113.002959/-/DC1.

Correspondence to Ji Hoe Heo, MD, PhD, Department of Neurology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemoon-ku, 120–752 Seoul, Republic of Korea. E-mail jhheo@yuhs.ac

© 2013 American Heart Association, Inc.

Stroke is available at http://stroke.ahajournals.org DOI: 10.1161/STROKEAHA.113.002959

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3548 Stroke December 2013

shown in Tables I and II in the online-only Data Supplement. ALP was associated with old age, higher frequency of hyper-cholesterolemia, and higher hemoglobin, cholesterol, alanine aminotransferase, and glucose. Phosphate was associated with female sex, lower National Institutes of Health Stroke Scale score at admission, higher cholesterol, triglyceride, and calcium, and lower hemoglobin and high-sensitivity C-reactive protein.

There were 623 patients (59.73%) with cerebral atheroscle-rosis. The levels of ALP/phosphate were not associated with intracranial or extracranial cerebral atherosclerosis (Table 1). When we subdivided patients according to the degree of cere-bral atherosclerosis (no atherosclerosis, <50%, 50%–75%, and ≥75% or occlusion), there was no significant difference of ALP/phosphate among them (Table III in the online-only Data Supplement).

At 3 months, 243 patients (23.3%) showed poor functional outcomes. Elevated ALP levels were associated with a poor functional outcome (61.17±17.24 versus 66.66±25.51 U/L; P=0.002), but phosphate levels were not (1.07±0.20 versus 1.07±0.22 mmol/L; P=0.826). After adjustment for sex, age, and other covariates that had a P<0.05 on univariate analysis (Table IV in the online-only Data Supplement), odds ratio for 1 increase of SD in ALP (19.61 U/L) was 1.25 (95% confidence interval, 1.04–1.50; P=0.017; Table 2). Penalized-spline curve demonstrated a positive relationship between levels of ALP and an increased risk for poor functional outcomes (Figure).

DiscussionIn this study, we tested the hypothesis that elevated ALP/phosphate levels are associated with cerebral atheroscle-rosis, which was based on previous reports that showed a higher prevalence of coronary artery disease and peripheral artery disease in patients with elevated ALP/phosphate levels. However, such a relationship between serum ALP/phosphate

levels and cerebral atherosclerosis was not found in our study. The action of ALP/phosphate might differ in each vascular bed. Susceptibility to atherosclerosis is strongly influenced by intrinsic differences in the cells composing each vascular system.6 Associated risk factors and pathological findings, including calcification, differ according to the location of the atherosclerosis. Although we defined atherosclerosis as sig-nificant stenosis (≥ 50%) on angiographic studies, most previ-ous studies used definitions based on coronary artery calcium score, ankle-brachial index, and carotid intima thickness. ALP and phosphate are suggested to enhance medial calcifica-tion and stiffening of the vessel and further atherosclerosis.5,7 Medial calcification has a longitudinal, uniform distribution (pipeline-like) without focal luminal narrowing.6 Thus, ALP-/phosphate-related medial calcification and atherosclerosis might be undetected in angiographic studies.

Inflammation may be a link between elevated ALP levels and poor clinical outcomes.3,4 ALP is increased in inflamma-tory conditions, poor nutrition, and infections, which could lead to worse functional outcomes after stroke.3,8 In contrast to ALP, phosphate is not associated with functional outcomes in this study. Although there are reports for increased mortality with high levels of serum phosphate, low levels of phosphate are also associated with malnutrition, low physical activ-ity, hypertension, and metabolic syndrome.3,9 Racial differ-ences and genetic polymorphisms among Western and Asian individuals might be present.5 Compared with Asian diets, Western diets are relatively high in bioavailable phosphate.5 The lack of an association in this study between phosphate and functional outcomes in Asian patients with stroke may be partly ascribed to the complex nature of phosphate.

This study has some limitations. Selection bias might be present because this was a retrospective observational study in a single center, and many patients were excluded because of missing data. The mechanism behind the association between

Table 1. Level of Alkaline Phosphatase and Phosphate According to the Cerebral Atherosclerosis

Location of Cerebral Atherosclerosis Number (%) Alkaline Phosphatase, U/L P Value Phosphate, mmol/L P Value

No atherosclerosis 420 (40.3) 62.82±19.81 0.083 3.32±0.65 0.294

Only intracranial 374 (35.9) 61.32±18.35 3.33±0.62

Only extracranial 135 (12.9) 65.01±19.81 3.25±0.64

Both intracranial and extracranial

114 (10.9) 65.45±19.61 3.22±0.62

P value is derived from 1-way ANOVA.

Table 2. Prognostic Value of Alkaline Phosphatase and Phosphate for Functional Outcomes at 3 Months After Stroke Onset

Alkaline Phosphatase Phosphate

OR (95% CI)* P Value OR (95% CI)* P Value

Unadjusted 1.30 (1.13–1.49) <0.001 1.02 (0.88–1.17) 0.826

Adjusted† 1.25 (1.04–1.50) 0.017 … …

CI indicates confidence interval; and OR, odds ratio.*OR for poor functional outcome per 1 SD increase in alkaline phosphatase (19.61 U/L) or phosphate (0.21 mmol/L). †Adjusted for sex,

age, National Institute of Health Stroke Scale, thrombolysis, hypertension, current smoking, atrial fibrillation, peripheral artery disease, cerebral atherosclerosis, hemoglobin, high-sensitivity C-reactive protein, cholesterol, triglyceride, albumin, total bilirubin, calcium, and estimated glomerular filtration rate.

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Kim et al ALP/Phosphate and Functional Outcomes After Stroke 3549

elevated ALP and poor functional outcomes is unclear. We could not conclude whether elevated ALP caused poor out-comes or was only a marker for stroke prognosis. Other poten-tial factors, such as alcohol consumption, not collected in this study might act as confounders.

ConclusionsWe did not find a significant association between serum ALP/phosphate and cerebral atherosclerosis. Patients with elevated ALP levels had poor functional outcomes after acute cerebral infarction.

Sources of FundingThis work was supported by a grant from the Korea Healthcare Technology Research and Development Project, Ministry for Health and Welfare, Republic of Korea (HI10C2020).

DisclosuresNone.

References 1. Tonelli M, Curhan G, Pfeffer M, Sacks F, Thadhani R, Melamed ML,

et al. Relation between alkaline phosphatase, serum phosphate, and all-cause or cardiovascular mortality. Circulation. 2009;120:1784–1792.

2. Tonelli M, Sacks F, Pfeffer M, Gao Z, Curhan G; Cholesterol And Recurrent Events Trial Investigators. Relation between serum phosphate level and cardiovascular event rate in people with coronary disease. Circulation. 2005;112:2627–2633.

3. Wannamethee SG, Sattar N, Papcosta O, Lennon L, Whincup PH. Alkaline phosphatase, serum phosphate, and incident cardiovascular disease and total mortality in older men. Arterioscler Thromb Vasc Biol. 2013;33:1070–1076.

4. Park JB, Kang DY, Yang HM, Cho HJ, Park KW, Lee HY, et al. Serum alkaline phosphatase is a predictor of mortality, myocardial infarction, or stent thrombosis after implantation of coronary drug-eluting stent. Eur Heart J. 2013;34:920–931.

5. Ellam TJ, Chico TJ. Phosphate: the new cholesterol? The role of the phosphate axis in non-uremic vascular disease. Atherosclerosis. 2012;220:310–318.

6. Drüeke TB. Arterial intima and media calcification: distinct entities with different pathogenesis or all the same? Clin J Am Soc Nephrol. 2008;3:1583–1584.

7. Demer LL, Tintut Y. Vascular calcification: pathobiology of a multifac-eted disease. Circulation. 2008;117:2938–2948.

8. Ryu WS, Lee SH, Kim CK, Kim BJ, Yoon BW. Increased serum alka-line phosphatase as a predictor of long-term mortality after stroke. Neurology. 2010;75:1995–2002.

9. Park W, Kim BS, Lee JE, Huh JK, Kim BJ, Sung KC, et al. Serum phos-phate levels and the risk of cardiovascular disease and metabolic syn-drome: a double-edged sword. Diabetes Res Clin Pract. 2009;83:119–125.

Figure. Relationship between alkaline phosphatase levels and risk for poor functional outcomes. The solid line represents the log odds ratio, and the dotted lines represent 95% confidence intervals. The odds ratio was adjusted for the same variables listed in Table 2. Bars represent the alkaline phosphatase distri-bution. mRS indicates modified Rankin Scale.

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Young Dae Kim and Ji Hoe HeoJinkwon Kim, Tae-Jin Song, Dongbeom Song, Hye Sun Lee, Chung Mo Nam, Hyo Suk Nam,

Outcomes After Cerebral InfarctionSerum Alkaline Phosphatase and Phosphate in Cerebral Atherosclerosis and Functional

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SUPPLEMENT MATERIAL

Title: Serum alkaline phosphatase and phosphate in cerebral atherosclerosis and functional

outcomes after cerebral infarction

Authors: Jinkwon Kim, MD; Tae-Jin Song, MD; Dongbeom Song, MD; Hye Sun Lee, MS;

Chung Mo Nam, PhD; Hyo Suk Nam, MD, PhD; Young Dae Kim, MD, PhD; Ji Hoe Heo,

MD, PhD

Supplementary Method

Supplementary Figure I. Flow of participants according to the inclusion and exclusion

criteria in this study

Supplementary Table I. Clinical characteristics according to quartiles of serum alkaline

phosphatase

Supplementary Table II. Clinical characteristics according to quartiles of serum phosphate

Supplementary Table III. The levels of alkaline phosphatase and phosphate in subgroups

according to the degree of cerebral atherosclerosis

Supplementary Table IV. Comparison between patients with and without poor functional

outcomes after 3 months.

Supplementary References

Supplementary Method

Collection of clinical data

We collected clinical data including sex, age, time from stroke onset to hospital arrival, and

National Institute of Health Stroke Scale (NIHSS) score at admission. Data for the presence

of hypertension, diabetes mellitus, hypercholesterolemia, current smoking, atrial fibrillation,

coronary artery disease (CAD), peripheral artery disease (PAD), and use of thrombolysis

(intravenous, intra-arterial or combined) were obtained. We collected other laboratory results

that might act as confounders, including total white blood cell count, hemoglobin, high-

sensitivity C-reactive protein, total cholesterol, triglyceride, albumin, total bilirubin, aspartate

aminotransferase, alanine aminotransferase, calcium, glucose, and estimated glomerular

filtration rate (eGFR). eGFR was calculated using the abbreviated Modification of Diet in

Renal Disease Study Equation [186 x Serum Creatinine-1.154 x Age-0.203 x (0.742 if female)].1

Definition of risk factors

Hypertension was diagnosed when a patient was on anti-hypertensive medication or had

systolic blood pressures ≥ 140 mmHg or diastolic blood pressures ≥ 90 mmHg on repeated

measurements during admission. Diabetes mellitus was diagnosed if the patient had a fasting

plasma glucose level ≥ 7.0 mmol/L or was being treated with anti-diabetic medications or

insulin. Hypercholesterolemia was diagnosed if the patient had low-density lipoprotein

cholesterol ≥ 4.1 mmol/L, total cholesterol ≥ 6.2 mmol/L, or the patient was treated with lipid

lowering agents after diagnosis of hypercholesterolemia. Current smoking was defined as

having smoked a cigarette in the year prior to admission. The presence of CAD was identified

when a patient had a history of acute myocardial infarction, unstable angina, angiographically

confirmed coronary artery occlusive disease, or a coronary artery bypass graft or

percutaneous coronary artery stent/angioplasty. The presence of PAD was determined if a

patient had an ankle-brachial index < 0.9 on either the right or left side measured during

admission, or a previous history of angiographically-confirmed PAD.

Assessment for cerebral atherosclerosis

MRA was conducted using a 3.0-T system (Achieva, Philips, Best, the Netherlands, or Trio,

Siemens, Erlangen, Germany). CTA was performed using a 64-slice CT scanner (Siemens

Sensation 64, Siemens Medical Solutions, Forchheim, Germany). For those patients who

received both DSA and MRA or CTA, the results of the DSA were used for analysis. The

degree of stenosis in the extracranial cerebral artery was measured using the method in the

North American Symptomatic Carotid Endarterectomy Trial,2 and that in the intracranial

cerebral artery was measured using the method in the Warfarin vs. Aspirin for Symptomatic

Intracranial Disease Trial.3 All angiographic findings were evaluated and determined during

the weekly stroke conference based on the consensus of stroke specialists and on the

radiology report, and were prospectively registered in the Yonsei stroke registry.4

Patient management and determination of functional outcome

Patients were treated with the standard stroke treatment protocols of our hospital, which are

based on the guidelines for ischemic stroke.5,6 Patients admitted within 6 hours of stroke

onset were considered for intravenous tissue-type plasminogen activator, intra-arterial

thrombolysis, or combined thrombolysis.7 Patients with high-risk potential cardioembolic

sources such as atrial fibrillation, intracardiac thrombus, or a mechanical prosthetic valve

received an oral anticoagulant. Others received antiplatelet agents unless the patient had a

contraindication to antithrombotic medication. All patients except those with

contraindications were given a statin. Early rehabilitation was strongly encouraged in patients

with neurological deficits. Long-term functional outcome was assessed using the modified

Rankin Scale (mRS) via a direct interview performed by a clinician or a telephone interview

conducted by a well-trained research nurse.

Statistical analyses

All statistical analyses were performed using the R package for Windows (version 3.0.1, R

Foundation for Statistical Computing, Vienna, Austria) and the Statistical Package for the

Social Sciences for Windows (SPSS version 18.0, SPSS Inc., Chicago, IL, USA). NIHSS

score was considered a continuous variable. Continuous variables were expressed as mean

standard deviation or median [interquartile range].

To evaluate the association between clinical characteristics and ALP/phosphate, patients were

subdivided into quartile groups according to the levels of ALP and phosphate. The difference

across the quartile groups were evaluated using Fisher’s exact test, one-way analysis of

variance or the Kruskal-Wallis test, appropriately. In subgroups of patients, levels of

ALP/phosphate were compared using independent t-test or one-way analysis of variance.

Univariate logistic regression was performed to identify potential variables associated with a

poor functional outcome (mRS >2). The levels of ALP and phosphate were treated as

continuous variables in the regression analysis. If there was a significant association between

ALP/phosphate and a poor functional outcome, we performed multivariate logistic regression

adjusted for sex, age, and those variables which had p<0.05 in univariate analysis.

Additionally, penalized regression smoothing splines (P-spline) were performed to exam

dose-response relation and to illustrate the likelihood of poor functional outcome across the

levels of ALP/phosphate. The P-spline curve was fitted via the “gam” function in the “mgcv”

package of R software. All statistical tests were two-tailed, and p<0.05 was considered

statistically significant.

Supplementary Figure I. Flowchart of patient inclusion and exclusion criteria.

mRS indicates modified Rankin Scale.

Supplementary Table I. Clinical characteristics according to quartiles of serum alkaline

phosphatase

ALP Q1:

<49 U/L

ALP Q2:

49-59 U/L

ALP Q3:

60-71 U/L

ALP Q4:

>71 U/L P-value

(N=248) (N=270) (N=259) (N=266)

Baseline characteristics

Sex, male 149 (60.1) 175 (64.8) 170 (65.6) 158 (59.4) 0.332

Age, year 64.73 ± 14.17 64.76 ± 12.07 64.78 ± 12.13 68.93 ± 12.32 <0.001

Time from stroke onset to

hospital arrival, hour 11 [3-25] 13 [4-30] 13 [4-27] 12 [4-26] 0.167

NIHSS score at admission 3 [1-10] 3 [1-6] 3 [1-7] 4 [1-9] 0.216

Risk factors

Hypertension 166 (66.9) 206 (76.3) 182 (70.3) 198 (74.4) 0.078

Diabetes mellitus 70 (28.2) 73 (27.0) 84 (32.4) 87 (32.7) 0.370

Hypercholesterolemia 50 (20.2) 57 (21.1) 78 (30.1) 78 (29.3) 0.009

Current smoking 57 (23.0) 72 (26.7) 65 (25.1) 75 (28.2) 0.573

Atrial fibrillation 69 (27.8) 54 (20.0) 60 (23.2) 65 (24.4) 0.215

Coronary artery disease 49 (19.8) 61 (22.6) 59 (22.8) 63 (23.7) 0.737

Peripheral artery disease 17 (6.9) 17 (6.3) 22 (8.5) 31 (11.7) 0.111

Laboratory findings

Phosphate, mmol/L 1.05 ± 0.22 1.07 ± 0.21 1.07 ± 0.18 1.06 ± 0.20 0.631

Hemoglobin, g/dL 13.75 ± 1.59 14.04 ± 1.81 14.30 ± 1.80 14.21 ± 1.89 0.003

hs-CRP, nmol/L 75.14 ± 179.76 90.56 ± 283.06 82.55 ± 206.31 104.22 ± 246.26 0.530

Cholesterol, mmol/L 4.71 ± 0.95 4.92 ± 1.09 4.89 ± 1.07 5.15 ± 1.23 <0.001

Triglyceride, mmol/L 1.33 ± 1.14 1.40 ± 0.92 1.40 ± 0.84 1.36 ± 0.82 0.820

Albumin, g/dL 4.21 ± 0.40 4.24 ± 0.45 4.26 ± 0.40 4.27 ± 0.45 0.388

Total bilirubin, μmol/L 11.36 ± 5.00 11.96 ± 6.66 11.49 ± 5.07 12.03 ± 7.10 0.498

AST, U/L 24.43 ± 13.33 25.19 ± 19.15 24.96 ± 14.51 27.33 ± 24.41 0.293

ALT, U/L 20.53 ± 12.45 21.11 ± 15.26 22.42 ± 15.13 24.59 ± 23.07 0.033

Calcium, mmol/L 2.24 ± 0.12 2.26 ± 0.12 2.26 ± 0.11 2.26 ± 0.12 0.179

Glucose, mmol/L 7.62 ± 2.53 7.79 ± 3.27 7.94 ± 3.27 8.76 ± 4.21 0.001

eGFR, mL/min/1.73m2 83.83 ± 26.97 82.31 ± 25.62 85.02 ± 25.91 79.90 ± 26.02 0.132

Values are mean ± standard deviation, median [interquartile range] or number (%).

P-value is derived from Fisher`s exact test, Kruskal-Wallis test or one-way analysis of variance.

NIHSS indicates National Institute of Health Stroke Scale; hs-CRP, high-sensitivity C-reactive protein; ALP,

alkaline phosphatase; AST, aspartate aminotransferase; ALT, alanine aminotransferase; eGFR, estimated

glomerular filtration rate.

Supplementary Table II. Clinical characteristics according to quartiles of serum phosphate

Phosphate Q1:

<0.93 mmol/L

Phosphate Q2:

0.93-1.05

mmol/L

Phosphate Q3:

1.06-1.17

mmol/L

Phosphate Q4:

>1.17 mmol/L P-value

(N=223) (N=270) (N=260) (N=290)

Baseline characteristics

Sex, male 171 (76.7) 176 (65.2) 166 (63.8) 139 (47.9) <0.001

Age, year 66.87 ± 12.37 66.04 ± 13.48 65.04 ± 12.98 65.51 ± 12.26 0.436

Time from stroke onset to

hospital arrival, hour 11 [3-24] 12 [3-29] 14 [4-26] 14 [5-27] 0.191

NIHSS score at admission 3 [1-10] 4 [2-9] 3 [1-7] 3 [1-7] 0.041

Risk factors

Hypertension 160 (71.7) 201 (74.4) 191 (73.5) 200 (69.0) 0.494

Diabetes mellitus 62 (27.8) 81 (30.0) 81 (31.2) 90 (31.0) 0.846

Hypercholesterolemia 56 (25.1) 58 (21.5) 70 (26.9) 79 (27.2) 0.389

Current smoking 50 (22.4) 73 (27.0) 70 (26.9) 76 (26.2) 0.629

Atrial fibrillation 60 (26.9) 70 (25.9) 62 (23.9) 56 (19.3) 0.165

Coronary artery disease 46 (20.6) 65 (24.1) 48 (18.5) 73 (25.2) 0.218

Peripheral artery disease 21 (9.4) 26 (9.6) 23 (8.9) 17 (5.9) 0.343

Laboratory findings

Alkaline phosphatase, U/L 61.52 ± 18.43 62.41 ± 18.42 63.07 ± 20.17 62.65 ± 21.05 0.851

Hemoglobin, g/dL 14.34 ± 1.59 14.01 ± 1.77 14.24 ± 1.91 13.81 ± 1.80 0.003

hs-CRP, nmol/L 136.20 ± 328.82 93.84 ± 243.60 78.01 ± 197.23 55.84 ± 141.81 0.001

Cholesterol, mmol/L 4.81 ± 1.06 4.75 ± 0.99 5.09 ± 1.12 5.02 ± 1.19 0.001

Triglyceride, mmol/L 1.29 ± 0.70 1.27 ± 0.78 1.43 ± 0.94 1.47 ± 1.18 0.023

Albumin, g/dL 4.20 ± 0.43 4.24 ± 0.40 4.25 ± 0.42 4.28 ± 0.44 0.237

Total bilirubin, μmol/L 11.82 ± 6.21 12.08 ± 6.37 11.93 ± 5.94 11.10 ± 5.70 0.225

AST, U/L 26.31 ± 19.04 26.13 ± 22.86 24.92 ± 15.54 24.80 ± 15.77 0.702

ALT, U/L 23.17 ± 21.05 21.55 ± 17.09 22.52 ± 15.43 21.72 ± 14.95 0.698

Calcium, mmol/L 2.23 ± 0.12 2.25 ± 0.11 2.26 ± 0.11 2.27 ± 0.12 <0.001

Glucose, mmol/L 8.08 ± 2.65 7.91 ± 2.90 8.19 ± 3.99 7.96 ± 3.80 0.774

eGFR, mL/min/1.73m2 83.01 ± 24.42 84.79 ± 25.92 82.56 ± 24.78 80.75 ± 28.72 0.338

Values are mean ± standard deviation, median [interquartile range] or number (%).

P-value is derived from Fisher`s exact test, Kruskal-Wallis test or one-way analysis of variance.

NIHSS indicates National Institute of Health Stroke Scale; hs-CRP, high-sensitivity C-reactive protein; ALP,

alkaline phosphatase; AST, aspartate aminotransferase; ALT, alanine aminotransferase; eGFR, estimated

glomerular filtration rate.

Supplementary Table III. The levels of alkaline phosphatase and phosphate in subgroups

according to the degree of cerebral atherosclerosis

Number

(%)

Alkaline

phosphatase

(IU/L)

P-value Phosphate

(mmol/L)

P-value

Degree of cerebral

atherosclerosis

0.679 0.833

no atherosclerosis 248 (23.8) 62.52 ± 21.56 3.31 ± 0.66

<50% 172 (16.5) 60.81 ± 16.97 3.32 ± 0.63

50~75% 211 (20.2) 63.00 ± 18.79 3.31 ± 0.68

≥75% or occlusion 412 (39.5) 62.81 ± 19.84 3.28 ± 0.59

Values are mean ± standard deviation.

P-value is derived from one-way analysis of variance test.

Supplementary Table IV. Comparison between patients with and without poor functional

outcomes after 3 months

Variables OR [95% CI] P-value

Baseline characteristics at admission

Sex, male 0.561 [0.419-0.751] <0.001

Age, year 1.066 [1.051-1.082] <0.001

Time from stroke onset to hospital arrival, hour 0.992 [0.983-1.000] 0.055

NIHSS score at admission, per 1 point 1.243 [1.207-1.281] <0.001

Thrombolysis at admission 2.406 [1.617-3.556] <0.001

Risk factors

Hypertension 1.713 [1.218-2.447] 0.002

Diabetes mellitus 1.217 [0.892-1.652] 0.213

Hypercholesterolemia 0.809 [0.571-1.132] 0.220

Current smoking 0.493 [0.336-0.709] <0.001

Atrial fibrillation 2.513 [1.835-3.435] <0.001

Coronary artery disease 1.198 [0.851-1.672] 0.297

Peripheral artery disease 2.294 [1.440-3.613] 0.001

Cerebral atherosclerosis

no atherosclerosis Reference

only intracranial 3.517 [2.404-5.146] <0.001

only extracranial 3.509 [2.167-5.680] <0.001

both intracranial and extracranial 5.846 [3.601-9.489] <0.001

Laboratory findings

Alkaline phosphatase, U/L 1.013 [1.006-1.020] <0.001

Phosphate, mmol/L 1.082 [0.537-2.178] 0.826

Hemoglobin, g/dL 0.829 [0.765-0.898] <0.001

hs-CRP, nmol/L 1.002 [1.002-1.003] <0.001

Cholesterol, mmol/L 0.846 [0.739-0.968] 0.015

Triglyceride, mmol/L 0.639 [0.506-0.806] <0.001

Albumin, g/dL 0.288 [0.204-0.407] <0.001

Total bilirubin, μmol/L 1.027 [1.005-1.050] 0.018

AST, U/L 1.004 [0.997-1.011] 0.250

ALT, U/L 0.991 [0.981-1.001] 0.085

Calcium, mmol/L 0.011 [0.003-0.042] <0.001

Glucose, mmol/L 1.016 [0.975-1.058] 0.451

eGFR, mL/min/1.73m2 0.988 [0.983-0.994] <0.001

OR and P-value are derived from univariate logistic regression using modified Rankin Scale >2 as the

dependent variable. NIHSS indicates National Institute of Health Stroke Scale; hs-CRP, high-sensitivity C-

reactive protein; ALP, alkaline phosphatase; AST, aspartate aminotransferase; ALT, alanine aminotransferase;

eGFR, estimated glomerular filtration rate; OR, odds ratio; CI, confidence intervals.

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