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 (n, %) | 454 (63) | 108 (59) | 113 (62) | 111 (60) | 122 (67) | 0.431 | 0.114 |
| Hypertension (n, %) | 673 (93) | 167 (91) | 167 (91) | 170 (92) | 169 (92) | 0.924 | 0.708 |
| Diabetes mellitus (n, %) | 158 (22) | 25 (14) | 40 (22) | 43 (23) | 50 (27) | 0.012 | 0.001 |
| Current smoker (n, %) | 200 (28) | 38 (21) | 58 (32) | 50 (28) | 54 (30) | 0.094 | 0.032 |
| Current drinker (n, %) | 79 (11) | 21 (12) | 21 (12) | 15 ( 8) | 22 (12) | 0.626 | 0.500 |
| Education | |||||||
| Middle school and below (n, %) | 344 (48) | 90 (50) | 81 (45) | 79 (44) | 94 (53) | 0.320 | 0.355 |
| High school (n, %) | 195 (27) | 46 (26) | 50 (28) | 46 (26) | 53 (30) | 0.785 | 0.229 |
| Above high school (n, %) | 170 (24) | 42 (23) | 45 (25) | 53 (29) | 30 (17) | 0.038 | 0.073 |
| Missing (n, %) | 9 (1) | 2 (1) | 3 (2) | 2 (1) | 2 (1) | 0.952 | 0.686 |
| Marriage | |||||||
| Single (n, %) | 119 (17) | 19 (11) | 30 (17) | 40 (22) | 30 (17) | 0.031 | 0.059 |
| Married (n, %) | 447 (62) | 131 (73) | 111 (62) | 101 (56) | 104 (58) | 0.005 | 0.002 |
| Separated (n, %) | 138 (19) | 27 (15) | 33 (18) | 37 (21) | 41 (23) | 0.272 | 0.038 |
| Missing (n, %) | 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.