Table 1.
Demographics of the subset of study participants who provided urine for TCB analyses by asthma severity
| Characteristics | Nonsevere Asthma |
Severe Asthma |
P Value | ||
|---|---|---|---|---|---|
| No. | Mean ± SD | No. | Mean ± SD | ||
| Age at enrollment, yr | 178 | 45.4 ± 14.6 | 253 | 50.0 ± 13.3 | 0.001 |
| Age when first diagnosed, yr | 178 | 19.2 ± 15.4 | 253 | 20.1 ± 16.6 | 0.56 |
| Female sex, % | 122/178 | 68.5 | 169/253 | 66.8 | 0.70 |
| Race, % | |||||
| European ancestry | 121/178 | 68.0 | 161/253 | 63.6 | 0.29 |
| African ancestry | 37/178 | 20.8 | 65/253 | 25.7 | 0.24 |
| Body mass index, kg/m2 | 178 | 30.8 ± 7.7 | 253 | 33.2 ± 8.7 | 0.004 |
| Blood pressure, mmHg | |||||
| Systolic | 178 | 120 ± 13 | 253 | 127 ± 14 | <0.001 |
| Diastolic | 178 | 75 ± 11 | 253 | 78 ± 10 | 0.005 |
| Lung functions | |||||
| Forced expiratory volume in 1 s, %predicted | 178 | 81.8 ± 16.9 | 253 | 67.5 ± 19.6 | <0.001 |
| Forced vital capacity, %predicted | 178 | 92.1 ± 15.8 | 253 | 80.0 ± 17.1 | <0.001 |
| FEV1/FVC | 178 | 0.72 ± 0.09 | 253 | 0.67 ± 0.10 | <0.001 |
| Provocative concentration of methacholine causing a 20% fall in FEV1, mg/mL | 63 | 3.4 ± 4.1 | 52 | 3.4 ± 4.2 | 0.94 |
| White blood cells, ×109/L | 178 | 6.7 ± 2.1 | 252 | 8.0 ± 2.8 | <0.001 |
| Neutrophils | 178 | 3.9 ± 1.8 | 252 | 4.8 ± 2.4 | <0.001 |
| Eosinophils | 178 | 0.25 ± 0.21 | 252 | 0.31 ± 0.30 | 0.008 |
| Platelets, ×109/L | 176 | 250 ± 69 | 250 | 261 ± 63 | 0.08 |
| IgE, IU/mL | 177 | 348 ± 655 | 251 | 346 ± 600 | 0.8 |
| Sputum eosinophils, ×106/L | 136 | 59 ± 248 | 193 | 100 ± 263 | 0.15 |
| Asthma quality of life questionnaire | 178 | 5.8 ± 1.0 | 253 | 4.8 ± 1.3 | <0.001 |
| Asthma control test score | 178 | 19.1 ± 3.8 | 253 | 15.7 ± 4.6 | <0.001 |
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; TCB, total conjugated bromotyrosine.