Table 1 Baseline characteristics of study participants
Parameters (unit) | Toner-handling group | Non-toner-handling group | P-value | ||
|---|---|---|---|---|---|
n = 887 | n = 581 | ||||
M (SD)/% | M (SD)/% | ||||
Age (years) | 38.7 | (7.1) | 38.5 | (6.5) | 0.678 |
BMI (kg/m2) | 23.3 | (2.9) | 23.7 | (2.9) | 0.023 |
Current smoker | 51.2% | 46.8% | 0.109 | ||
Prevalence of respiratory diseases (%) | |||||
 Asthma | 9.5% | 10.3% | 0.591 | ||
 Allergic rhinitis | 51.1% | 48.2% | 0.286 | ||
 Allergic dermatitis | 20.9% | 22.2% | 0.558 | ||
 Pneumonia | 0.5% | 0.3% | 1.000 | ||
 Sinusitis | 2.7% | 1.9% | 0.383 | ||
Ratio of workers handling harmful substances (%) | |||||
 Workers handling dust other than toner | 2.9% | 0.3% | < 0.001 | ||
 Workers handling organic solvent | 26.3% | 2.9% | < 0.001 | ||
Respiratory function test indicators | |||||
 VC (l) | 4.2 | (0.6) | 4.2 | (0.6) | 0.390 |
 %VC (%) | 92.4 | (10.7) | 91.8 | (9.8) | 0.307 |
 FEV1 (l) | 3.5 | (0.5) | 3.5 | (0.5) | 0.521 |
 %FEV1 (%) | 95.0 | (11.2) | 94.5 | (10.8) | 0.412 |
 FEV1/FVC (%) | 83.1 | (5.9) | 82.9 | (6.0) | 0.655 |
 %FEV1/FVC (%) | 100.1 | (6.9) | 100.1 | (7.1) | 0.938 |
 V25 (l/s) | 1.6 | (0.5) | 1.6 | (0.5) | 0.940 |
 %V25 (%) | 68.2 | (19.9) | 67.4 | (18.7) | 0.413 |
Biomarkers | |||||
 CRP (mg/dl) | 0.09 | (0.18) | 0.10 | (0.21) | 0.455 |
 IgE (IU/ml) | 201.6 | (380.3) | 219.9 | (436.6) | 0.424 |
 IL-4 (pg/ml) | 19.2 | (29.4) | 10.8 | (31.1) | < 0.001 |
 IL-6 (pg/ml) | 1.40 | (3.20) | 1.20 | (4.70) | 0.412 |
 IL-8 (pg/ml) | 2.90 | (19.90) | 1.10 | (0.80) | 0.017 |
 IFN-γ (IU/ml) | 0.11 | (0.01) | 0.07 | (0.07) | < 0.001 |
 8-OHdG/Creatinine (ng/mg) | 3.90 | (1.50) | 3.80 | (1.4) | 0.357 |