Table 3.
Demographic, ECG, Laboratory, and Clinical Findings in Subjects of the Study Population Stratified by IL‐6 Level
| IL‐6, pg/mL | ||||
|---|---|---|---|---|
| Characteristic | <5 | 5–25 | >25 | P value |
| Total, n | 306 | 376 | 403 | … |
| Demographics | ||||
| Age, y | 68 [61–74] | 71 [63–76] * | 72 [64–77] * , † | <0.001 |
| Male sex, n | 277 (90.5%) | 343 (91.2%) | 378 (93.8%) | 0.226 |
| Race, n | ||||
| White | 200 (65.4%) | 262 (69.7%) | 254 (63.0%) | 0.406 |
| Black | 83 (27.1%) | 91 (24.2%) | 117 (29.0%) | |
| Others‡ | 23 (7.5%) | 23 (6.1%) | 32 (7.9%) | |
| ECG findings | ||||
| Heart rate, bpm | 73 [66–85] | 79 [70–88] * | 83 [73–94] * , † | <0.001 |
| QRS interval, ms | 90 [82–96] | 90 [84–98] | 88 [82–96] | 0.161 |
| Laboratory data | ||||
| IL‐6, pg/mL | 2.9 [2.1–3.7] | 10.7 [7.3–15.8] * | 64.8 [40.7–135.6] * , † | <0.001 |
| Potassium <4.0 mEq/L, n | 63 (25.7%) | 95 (29.3%) | 78 (21.3%) | 0.053 |
| Calcium <8.5 mg/dL, n | 4 (1.6%) | 10 (3.1%) | 37 (10.1%) * , † | <0.001 |
| Magnesium <1.8 mg/dL, n | 34 (13.9%) | 40 (12.3%) | 33 (9.0%) | 0.144 |
| Cardiovascular risk factors/diseases | ||||
| Smoking, n | 138 (45.1%) | 171 (45.5%) | 162 (40.2%) | 0.259 |
| Hypertension, n | 47 (15.4%) | 101 (26.9%) * | 108 (26.8%) * | <0.001 |
| Diabetes mellitus, n | 138 (45.1%) | 235 (62.5%) * | 241 (59.8%) * | <0.001 |
| Myocardial infarction, n | 45 (14.7%) | 87 (23.1%) * | 120 (29.8%) * , † | <0.001 |
| Angina pectoris, n | 62 (20.3%) | 67 (17.8%) | 75 (18.6%) | 0.714 |
| Left ventricular hypertrophy/heart failure, n | 30 (9.8%) | 52 (13.8%) | 52 (12.9%) | 0.258 |
| Autoimmune rheumatic diseases, n | 25 (8.2%) | 36 (9.6%) | 31 (7.7%) | 0.625 |
| Drugs | ||||
| Alpha blockers, n | 186 (60.8%) | 233 (62.0%) | 256 (63.5%) | 0.752 |
| Anesthetics, n | 9 (2.9%) | 19 (5.1%) | 66 (16.4%) * , † | <0.001 |
| Antianginal, n | 93 (30.4%) | 112 (29.8%) | 130 (32.3%) | 0.740 |
| Antiarrhythmics, n | 26 (8.5%) | 38 (10.1%) | 57 (14.1%) | 0.044 |
| Antibiotics, n | 291 (95.1%) | 363 (96.5%) | 400 (99.3%) * , † | 0.003 |
| Anticonvulsants, n | 241 (78.8%) | 273 (72.6%) | 260 (64.5%) * , † | <0.001 |
| Antidepressants, n | 257 (84.0%) | 302 (80.3%) | 292 (72.5%) * , † | 0.001 |
| Antiemetics, n | 169 (55.2%) | 206 (54.8%) | 228 (56.6%) | 0.872 |
| Antifungals, n | 93 (30.4%) | 132 (35.1%) | 150 (37.2%) | 0.160 |
| Antihistamines, n | 246 (80.4%) | 304 (80.9%) | 318 (78.9%) | 0.779 |
| Antihypertensives, n | 113 (36.9%) | 172 (45.7%) | 173 (42.9%) | 0.064 |
| Antimalarials, n | 38 (12.4%) | 49 (13.0%) | 73 (18.1%) | 0.054 |
| Antipsychotics, n | 102 (33.3%) | 131 (34.8%) | 176 (43.7%) * , † | 0.007 |
| Antivirals, n | 102 (33.3%) | 165 (43.9%) * | 186 (46.2%) * | 0.002 |
| Beta blockers, n | 191 (62.4%) | 253 (67.3%) | 290 (72.0%) * | 0.026 |
| Bronchodilators, n | 189 (61.8%) | 264 (70.2%) | 279 (69.2%) | 0.041 |
| Calcium blockers, n | 178 (58.2%) | 229 (60.9%) | 274 (68.0%) * | 0.018 |
| Diuretics, n | 195 (63.7%) | 275 (73.1%)* | 317 (78.7%) * | <0.001 |
| Muscle relaxants, n | 226 (73.9%) | 250 (66.5%) | 250 (62.0%) * | 0.004 |
| Sedatives, n | 207 (67.6%) | 256 (68.1%) | 288 (71.5%) | 0.464 |
IL‐6 indicates interleukin‐6. Values are expressed as median [interquartile range], or frequency count (percentage). Differences between the groups were evaluated by the Kruskal–Wallis test or chi‐squard test.
*
Statistically different from IL‐6 <5 pg/mL group.
†
Statistically different from IL‐6 5–25 pg/mL group (post hoc tests: multiple Mann–Whitney U test or chi‐square test with Holm correction).
‡
Other includes: Asian, American Indian, Alaska native, Hawaiian or other Pacific Islander, and unknown.