The Relationship Between Serum YKL-40 Levels on Admission and Stroke-Associated Pneumonia in Patients with Acute Ischemic Stroke

Figures & data

Figure 1 Patient flowchart.

Table 1 Characteristics of Subgroups Based on the Quartiles of YKL-40

Variable	First Quartile (n = 128)	Second Quartile (n = 128)	Third Quartile (n = 128)	Fourth Quartile (n = 127)	P
Demographic characteristics
Age (years)	68 (58, 74)	69 (60, 78)	69.0 (60, 78)	74 (63, 82)	0.003
Male (%)	90 (70.3)	83 (64.8)	80 (62.5)	75 (59.1)	0.293
Past medical history (%)
Hypertension	89 (69.5)	91 (71.1)	89 (69.5)	88 (69.3)	0.989
Diabetes mellitus	29 (22.7)	29 (22.7)	23 (18.0)	32 (25.2)	0.568
Dyslipidemia	14 (10.9)	17 (13.3)	23 (18.0)	16 (12.6)	0.400
Atrial fibrillation	19 (14.8)	12 (9.4)	25 (19.5)	31 (24.4)	0.011
Previous stroke	21 (16.4)	24 (18.9)	18 (14.1)	28 (22.0)	0.383
Coronary artery disease	12 (9.4)	15 (11.8)	17 (13.3)	28 (22.5)	0.022
COPD	1 (0.8)	3 (2.3)	7 (5.5)	2 (1.6)	0.089
Smoking					0.107
Never	66 (51.6)	74 (57.8)	74 (57.8)	80 (63.0)
Ever smoking	40 (31.3)	41 (32.0)	46 (35.9)	35 (27.6)
Currently smoking	22 (17.2)	13 (10.2)	8 (6.3)	12 (9.4)
Drinking alcohol					0.043
Never	78 (60.9)	86 (67.2)	81 (63.3)	86(67.7)
Ever drinking alcohol	29 (22.7)	29 (22.7)	40 (31.3)	33(26.0)
Currently drinking alcohol	21 (16.4)	13 (10.2)	7 (5.5)	8(6.3)
Clinical assessment
Systolic blood pressure (mmHg)	155 (138, 166)	150 (140, 162)	147 (133, 160)	147 (134, 166)	0.215
Diastolic blood pressure (mmHg)	89 (80, 99)	87 (80, 98)	87 (79, 99)	84 (76, 92)	0.101
Baseline NIHSS	3 (2, 5)	4 (2, 6)	6 (3, 12)	11 (4, 15)	0.001
Dysphagia (%)	32 (25.0)	32 (25.0)	38 (29.7)	54(42.5)	0.006
Previous antiplatelet (%)	14 (10.9)	22 (17.2)	13 (10.2)	26 (20.5)	0.056
Previous statin (%)	8 (6.3)	19 (14.8)	12 (9.4)	19 (15.0)	0.072
Intravenous thrombolysis (%)	40 (31.3)	42 (32.8)	46 (36.0)	44(34.6)	0.867
SAP (%)	13 (10.2)	22 (17.2)	37 (28.9)	77 (60.6)	0.001
Tracheal intubation or ventilator (%)	0 (0.0)	4 (3.1)	3 (2.3)	11 (8.7)	0.020
TOAST subtype					0.005
LAA	53 (41.4)	61 (47.7)	60 (46.9)	66 (52.0)
CE	21 (16.4)	16 (12.5)	31 (24.2)	34 (26.8)
SAO	49 (38.23)	44 (34.4)	32 (25.0)	18 (14.2)
SOE	2 (1.6)	0 (0.0)	2 (1.6)	3 (2.4)
SUE	3 (2.3)	7 (5.5)	3 (2.3)	6 (4.7)
Laboratory data
Leukocyte (10^^9/L)	7.37 (5.83, 9.10)	7.14 (5.78, 8.55)	8.01 (6.21, 9.79)	8.3 (6.47, 10.39)	0.002
TC (mmol/L)	4.70 (4.10, 5.26)	4.35 (3.89, 5.21)	4.46 (3.84, 5.17)	4.33 (3.79, 5.16)	0.273
TG (mmol/L)	1.37 (0.89, 1.89)	1.30 (0.91, 1.94)	1.19 (0.88, 1.65)	1.05 (0.77, 1.54)	0.007
HDL (mmol/L)	1.07 (0.91, 1.32)	1.13 (0.91, 1.32)	1.14 (0.99, 1.40)	1.18 (0.99, 1.40)	0.093
LDL (mmol/L)	2.75 (2.1, 3.14)	2.58 (2.01, 3.19)	2.59 (2.12, 3.23)	2.44 (1.94, 3.28)	0.706
FBG (mmol/L)	5.69 (5.01, 6.71)	5.66 (4.93, 7.04)	5.64 (4.82, 6.97)	6.56 (5.37, 8.15)	0.001
Hs-CRP (mg/L)	2.15 (0.89, 5.50)	2.48 (1.14, 6.28)	4.15 (1.7, 9.38)	6.45 (3.19, 13.52)	0.001

Abbreviations: COPD, chronic obstructive pulmonary disease; NIHSS, National Institute of Health Stroke Scale; SAP, stroke-associated pneumonia; TOAST, Trial of Org 10172 in Acute Stroke Treatment; LAA, large-artery atherosclerosis; CE, cardioembolism; SAO, small-artery occlusion; SOE, stroke of other determined etiology; SUE, stroke of undetermined etiology; TC, total cholesterol; TG, triglyceride; HDL, high-density lipoprotein; LDL, low-density lipoprotein; FBG, fasting blood glucose; Hs-CRP, hyper-sensitive C-reactive protein.

Figure 2 Violin plot in the distribution of YKL-40 between SAP group and non-SAP group.

Table 2 Logistic Regression Analyses for the Related Factors Associated with SAP Including YKL-40 as a Continuous Variable

Variable	Unadjusted OR (95% CI)	P	Adjusted OR (95% CI)	P
Demographic characteristics
Age	1.032 (1.016–1.049)	0.001	1.004 (0.979–1.030)	0.755
Male	0.763 (0.516–1.133)	0.178
Past medical history
Hypertension	0.871 (0.579–1.321)	0.512
Diabetes mellitus	0.897 (0.557–1.418)	0.648
Dyslipidemia	0.891 (0.496–1.545)	0.690
Atrial fibrillation	2.608 (1.620–4.193)	0.001	0.694 (0.263–1.809)	0.457
Coronary heart disease	1.448 (0.848–2.429)	0.167
Chronic obstructive pulmonary disease	2.128 (0.674–6.512)	0.181
Previous stroke	1.486 (0.915–2.385)	0.104
Smoking
Never	Reference		Reference
Ever smoking	0.856 (0.561–1.296)	0.467	1.289 (0.591–2.795)	0.521
Currently smoking	0.305 (0.122–0.659)	0.005	0.894 (0.171–3.965)	0.888
Drinking alcohol
Never	Reference		Reference
Ever drinking alcohol	0.879 (0.561–1.362)	0.570	0.897 (0.409–1.954)	0.785
Currently drinking alcohol	0.300 (0.112–0.677)	0.008	0.349 (0.062–1.897)	0.222
Clinical assessment
Systolic blood pressure	1.001 (0.999–1.003)	0.342
Diastolic blood pressure	0.969 (0.954–0.983)	0.001	0.978 (0.957–0.998)	0.033
Baseline NIHSS	1.211 (1.167–1.260)	0.001	1.146 (1.085–1.214)	0.001
Dysphagia	4.000 (2.667–6.032)	0.001	4.422 (2.602–7.650)	0.001
Previous antiplatelet	1.088 (0.629–1.834)	0.756
Previous statin	0.917 (0.485–1.657)	0.780
Intravenous thrombolysis	1.225 (0.820–1.822)	0.318
Tracheal intubation or ventilator	9.281 (3.264–33.188)	0.001	0.408 (0.082–2.339)	0.288
TOAST subtype
LAA	Reference		Reference
CE	2.379 (1.480–3.839)	0.001	2.072 (0.814–5.323)	0.127
SAO	0.210 (0.104–0.389)	0.001	0.812 (0.355–1.786)	0.611
SOE	0.915 (0.129–4.353)	0.917	0.439 (0.035–3.401)	0.469
SUE	2.542 (0.985–6.653)	0.052	2.249 (0.550–9.306)	0.259
Laboratory data
Leucocyte	1.208 (1.128–1.299)	0.001	1.135 (1.029–1.258)	0.013
TC	0.847 (0.706–1.009)	0.068
TG	0.871 (0.719–1.006)	0.130
HDL	1.422 (0.803–2.505)	0.223
LDL	0.859 (0.689–0.987)	0.169
FBG	0.999 (0.979–1.009)	0.890
Hs-CRP	1.078 (1.054–1.105)	0.001	1.030 (1.003–1.060)	0.037
YKL-40	1.010 (1.008–1.012)	0.001	1.007 (1.004–1.009)	0.001

Abbreviations: SAP, stroke-associated pneumonia; NIHSS, National Institute of Health Stroke Scale; TOAST, Trial of Org 10172 in Acute Stroke Treatment; LAA, large-artery atherosclerosis; CE, cardioembolism; SAO, small-artery occlusion; SOE, stroke of other determined etiology; SUE, stroke of undetermined etiology; TC, total cholesterol; TG, triglyceride; HDL, high-density lipoprotein; LDL, low-density lipoprotein; FBG, fasting blood glucose; Hs-CRP, hyper-sensitive C-reactive protein.

Table 3 Multivariable Logistic Analyses for the Related Factors Associated with SAP Including YKL-40 as Quartiles

Variable	Adjusted OR (95% CI)	P
Age	1.004 (0.980–1.029)	0.733
Atrial fibrillation	0.738 (0.282–1.903)	0.532
Smoking
Never	Reference	Reference
Ever smoking	1.322 (0.608–2.859)	0.478
Currently smoking	0.954 (0.188–4.214)	0.952
Drinking alcohol
Never	Reference	Reference
Ever drinking alcohol	0.876 (0.399–1.908)	0.740
Currently drinking alcohol	0.448 (0.085–2.319)	0.335
Diastolic blood pressure	0.976 (0.955–0.995)	0.017
Baseline NIHSS	1.149 (1.088–1.217)	0.001
Dysphagia	4.253 (2.516–7.308)	0.001
Tracheal intubation or ventilator	0.419 (0.087–2.305)	0.293
TOAST subtype
LAA	Reference	Reference
CE	2.011 (0.802–5.081)	0.136
SAO	0.704 (0.307–1.544)	0.391
SOE	0.416 (0.035–3.230)	0.437
SUE	1.976 (0.478–8.269)	0.348
Leucocyte	1.140 (1.034–1.261)	0.010
Hs-CRP	1.029 (1.003–1.058)	0.033
YKL-40
First quartile	Reference	Reference
Second quartile	1.574 (0.671–3.812)	0.303
Third quartile	1.620 (0.701–3.866)	0.265
Fourth quartile	5.819 (2.652–13.493)	0.001

Abbreviations: SAP, stroke-associated pneumonia; NIHSS, National Institute of Health Stroke Scale; TOAST, Trial of Org 10172 in Acute Stroke Treatment; LAA, large-artery atherosclerosis; CE, cardioembolism; SAO, small-artery occlusion; SOE, stroke of other determined etiology; SUE, stroke of undetermined etiology; Hs-CRP, hyper-sensitive C-reactive protein.

Figure 3 ROC curve for values of YKL-40 to predict SAP.