Table 3. Comparison of biomarkers and pulmonary function tests between the toner–handling group and the non–toner handling group from 2004 to 2008.
| Parameters (Unit) | Groups | n | 2004 | 2005 | 2006 | 2007 | 2008 | F valuea | p value | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | (SD) | Mean | (SD) | Mean | (SD) | Mean | (SD) | Mean | (SD) | |||||
| WBC (/μl) |
Toner–handling group | 32 | 7056.3 | (1447.1) | 7337.5 | (2116.1) | 6696.9 | (1711.3) | 6159.4 | (1267.2) | 6987.5 | (1838.4) | 0.270 | 0.847 |
| Non–toner–handling group | 45 | 6571.1 | (1931.6) | 6500.0 | (2167.2) | 6293.3 | (1829.4) | 6171.1 | (1655.8) | 6386.7 | (1758.0) | |||
| Total | 77 | 6772.7 | (1752.8) | 6848.1 | (2172.2) | 6461.0 | (1781.1) | 6166.2 | (1497.4) | 6636.4 | (1804.7) | |||
| KL–6 (U/ml) |
Toner–handling group | 32 | 235.2 | (84.4) | 247.0 | (79.5) | 244.7 | (82.1) | 226.5 | (83.5) | 222.8 | (82.2) | 0.411 | 0.757 |
| Non–toner–handling group | 45 | 204.6 | (76.6) | 209.4 | (76.0) | 208.6 | (66.7) | 199.4 | (75.2) | 202.9 | (85.1) | |||
| Total | 77 | 217.4 | (80.8) | 225.0 | (79.2) | 223.6 | (75.1) | 210.7 | (79.4) | 211.1 | (84.0) | |||
| SP–D (ng/ml) |
Toner–handling group | 32 | 51.2 | (24.4) | 44.7 | (22.2) | 39.1 | (18.5) | 41.1 | (22.2) | 46.9 | (22.7) | 1.231 | 0.289 |
| Non–toner–handling group | 45 | 58.1 | (30.1) | 53.6 | (27.3) | 49.6 | (28.4) | 49.6 | (26.1) | 52.6 | (28.0) | |||
| Total | 77 | 55.2 | (27.9) | 49.9 | (25.5) | 45.2 | (25.2) | 46.1 | (24.7) | 50.2 | (25.9) | |||
| 8–OHdG (mg/dl) |
Toner–handling group | 27 | 4.3 | (1.7) | 4.8 | (2.3) | 4.3 | (1.7) | 4.2 | (1.7) | 3.9 | (1.4) | 0.145 | 0.941 |
| Non–toner–handling group | 42 | 5.0 | (1.9) | 5.0 | (1.6) | 4.9 | (1.7) | 4.5 | (1.6) | 4.5 | (1.3) | |||
| Total | 69 | 4.7 | (1.9) | 4.9 | (1.9) | 4.7 | (1.7) | 4.4 | (1.6) | 4.2 | (1.4) | |||
| CRPb (mg/dl) |
Toner–handling group | 32 | 0.22 | (0.26) | 0.53 | (1.08) | 0.17 | (0.13) | 0.12 | (0.20) | 0.17 | (0.32) | ||
| Non–toner–handling group | 45 | 0.21 | (0.38) | 0.18 | (0.28) | 0.22 | (0.68) | 0.07 | (0.08) | 0.17 | (0.52) | |||
| Total | 77 | 0.21 | (0.34) | 0.33 | (0.74) | 0.20 | (0.53) | 0.09 | (0.14) | 0.17 | (0.44) | |||
| %VC (%) |
U values / p valuec | 634.5 / 0.274 | 601.0 / 0.110 | 582.5 / 0.064 | 577.5 / 0.139 | 584.5 / 0.160 | ||||||||
| Toner–handling group | 31 | 111.0 | (14.1) | 107.9 | (15.2) | 109.0 | (13.3) | 108.4 | (14.6) | 113.2 | (13.9) | 3.534 | 0.020* | |
| Non–toner–handling group | 39 | 112.7 | (11.3) | 111.6 | (14.8) | 113.4 | (12.4) | 113.8 | (12.2) | 118.3 | (15.4) | |||
| Total | 70 | 112.0 | (12.6) | 109.9 | (15.0) | 111.4 | (12.9) | 111.4 | (13.5) | 116.1 | (14.9) | |||
| FEV1.0% (%) |
Toner–handling group | 31 | 82.1 | (5.8) | 81.1 | (9.1) | 82.8 | (5.5) | 83.0 | (6.0) | 82.0 | (5.2) | 1.588 | 0.201 |
| Non–toner–handling group | 38 | 84.5 | (6.0) | 85.4 | (6.7) | 83.9 | (5.7) | 82.4 | (6.8) | 81.1 | (7.3) | |||
| Total | 69 | 83.4 | (6.0) | 83.5 | (8.1) | 83.4 | (5.6) | 82.7 | (6.4) | 81.5 | (6.4) | |||
SD: standard deviation, WBC: white ball cell, KL–6: Sialylated carbohydrate antigen KL–6, SP–D: surfactant protein D, 8–OHdG: 8–hydroxy–2’–deoxyguanosine, CRP: C–reactive protein, %VC: vital capacity as percent of predicted, FEV1.0%: forced expiratory volume percentile in one second.
a In mixed model repeated ANOVA, the sphericity assumption was violated; to account for this violation, degrees of freedom were Greenhouse–Geisser adjusted.
b The serum level of CRP was measured using turbidimetric immunoassay (TIA) from 2004 to 2006 and latex immunoagglutination assay (LA) from 2007 to 2008. Limits of detection (LOD) for CRP were 0.1 mg/dl in using TIA and 0.01 mg/dl in using LA.
c Mann–Whitney U test was performed on the serum levels of CRP between the toner–handling group and non–toner–handling groups in each year of the survey.
* p<0.05. The levels of %VC in 2008 were significantly more than the level of 2006 to 2007 in the toner–handling group, and the levels in 2008 were significantly more than the levels from 2004 to 2007 in the non–toner–handling group with Bonferroni multiple comparison procedure.