Association between Serum Interleukin-6 Concentration and Mortality in Patients with Coronary Artery Disease
Table 1
Baseline clinical characteristics according to total and quartiles of serum interleukin-6.
Total
Quartile 1
Quartile 2
Quartile 3
Quartile 4
P trend
P
*
Range, pg/mL
0.10–101.63
≤1.31
1.32–2.39
2.40–4.26
4.27–101.63
—
—
No. of patients
718
180
179
180
179
—
—
Time of followup, y
2.32 ± 0.81
2.26 ± 0.63
2.47 ± 0.72
2.37 ± 0.86
2.19 ± 0.80
0.006
0.429
Age, y
64 ± 11
63 ± 11
64 ± 11
63 ± 11
65 ± 11
0.114
0.022
Male sex (, %)
454 (63)
108 (59)
113 (62)
111 (60)
122 (67)
0.431
0.114
Hypertension (, %)
673 (93)
167 (91)
167 (91)
170 (92)
169 (92)
0.924
0.708
Diabetes mellitus (, %)
158 (22)
25 (14)
40 (22)
43 (23)
50 (27)
0.012
0.001
Current smoker (, %)
200 (28)
38 (21)
58 (32)
50 (28)
54 (30)
0.094
0.032
Current drinker (, %)
79 (11)
21 (12)
21 (12)
15 ( 8)
22 (12)
0.626
0.500
Education
Middle school and below (, %)
344 (48)
90 (50)
81 (45)
79 (44)
94 (53)
0.320
0.355
High school (, %)
195 (27)
46 (26)
50 (28)
46 (26)
53 (30)
0.785
0.229
Above high school (, %)
170 (24)
42 (23)
45 (25)
53 (29)
30 (17)
0.038
0.073
Missing (, %)
9 (1)
2 (1)
3 (2)
2 (1)
2 (1)
0.952
0.686
Marriage
Single (, %)
119 (17)
19 (11)
30 (17)
40 (22)
30 (17)
0.031
0.059
Married (, %)
447 (62)
131 (73)
111 (62)
101 (56)
104 (58)
0.005
0.002
Separated (, %)
138 (19)
27 (15)
33 (18)
37 (21)
41 (23)
0.272
0.038
Missing (, %)
14 (2)
3 (2)
5 (3)
2 (1)
4 (2)
0.687
0.497
Body mass index, kg/m2
23.91 ± 3.58
23.92 ± 4.03
24.07 ± 3.18
23.71 ± 3.50
23.92 ± 3.60
0.822
0.985
Total cholesterol (mmol/L)
4.75 ± 1.13
4.74 ± 1.16
4.77 ± 1.06
4.85 ± 1.22
4.63 ± 1.06
0.290
0.334
Triglyceride (mmol/L)
1.82 ± 1.26
1.72 ± 1.00
2.07 ± 1.76
1.79 ± 1.17
1.69 ± 0.92
0.018
0.812
LDL-c (mmol/L)
3.01 ± 0.97
3.03 ± 0.97
2.95 ± 0.91
3.10 ± 1.05
2.94 ± 0.94
0.313
0.358
HDL-c (mmol/L)
1.09 ± 0.30
1.13 ± 0.30
1.08 ± 0.28
1.06 ± 0.35
1.06 ± 0.29
0.097
0.024
C-reactive protein
3.15 (0.74–10.27)
1.21 (0.33–5.11)
2.16 (0.55–8.38)
3.39 (1.01–12.07)
6.37 (2.89–16.90)
<0.0001
<0.0001
Interleukin-6
2.39 (1.31–4.26)
0.85 (0.56–1.11)
1.82 (1.55–2.07)
3.25 (2.77–3.74)
6.93 (5.36–11.42)
<0.0001
<0.0001
The values are the mean ± SD for the continuous variable if normally distributed, the median (25th, 75th) for nonnormally distributed variables, and n (%) for the categorical variables. *Quartile 4 versus quartile 1. LDL-c: low-density lipoprotein cholesterol; HDL-c: high-density lipoprotein cholesterol.
