Table S2.
Mean and mean differences in FEV1, FVC, and FEV1/FVC (%) according to age, sex, BMI, and smoking, adjusted for all other variables including blood cadmium level*
| Variable | n | FEV1(L)
|
P-value | FVC (L)
|
P-value | FEV1/FVC (%)
|
P-value | |||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean (SE) | Mean difference (SE) | Mean (SE) | Mean difference (SE) | Mean (SE) | Mean difference (SE) | |||||
| Age, years** | ||||||||||
| ≤41 | 1,400 | 3.39 (0.01) | Ref | 4.08 (0.02) | Ref | 83.2 (0.2) | Ref | |||
| 42–50 | 1,447 | 3.07 (0.01) | −0.32 (0.02) | <0.001 | 3.83 (0.01) | −0.25 (0.02) | <0.001 | 80.4 (0.2) | −2.8 (0.3) | <0.001 |
| 51–59 | 1,552 | 2.77 (0.01) | −0.61 (0.02) | <0.001 | 3.59 (0.01) | −0.49 (0.02) | <0.001 | 77.8 (0.2) | −5.5 (0.3) | <0.001 |
| ≥60 | 1,516 | 2.36 (0.01) | −1.02 (0.02) | <0.001 | 3.21 (0.01) | −0.87 (0.02) | <0.001 | 74.3 (0.2) | −8.9 (0.3) | <0.001 |
| P-value for Wald F statistic | <0.001 | <0.001 | <0.001 | |||||||
| Sex | ||||||||||
| Male | 3,018 | 3.31 (0.01) | Ref | 4.27 (0.01) | Ref | 77.5 (0.1) | Ref | |||
| Female | 2,897 | 2.44 (0.01) | −0.87 (0.02) | <0.001 | 3.04 (0.01) | −1.22 (0.02) | <0.001 | 80.2 (0.2) | 2.7 (0.2) | <0.001 |
| P-value for Wald F statistic | <0.001 | <0.001 | <0.001 | |||||||
| BMI, kg/m2** | ||||||||||
| ≤22.06 | 1,487 | 2.83 (0.01) | Ref | 3.63 (0.01) | Ref | 78.0 (0.2) | Ref | |||
| 22.07–24.02 | 1,481 | 2.92 (0.01) | 0.09 (0.02) | <0.001 | 3.73 (0.01) | 0.09 (0.02) | <0.001 | 78.3 (0.2) | 0.3 (0.2) | 0.274 |
| 24.03–26.05 | 1,475 | 2.90 (0.01) | 0.07 (0.02) | <0.001 | 3.68 (0.01) | 0.05 (0.02) | 0.023 | 79.0 (0.2) | 1.0 (0.2) | <0.001 |
| ≥26.06 | 1,480 | 2.89 (0.01) | 0.06 (0.02) | <0.001 | 3.62 (0.01) | −0.01 (0.02) | 0.625 | 79.9 (0.2) | 1.9 (0.2) | <0.001 |
| P-value for Wald F statistic | <0.001 | <0.001 | <0.001 | |||||||
| Smoking | ||||||||||
| Current | 1,438 | 2.85 (0.02) | Ref | 3.70 (0.02) | Ref | 77.3 (0.2) | Ref | |||
| Former | 1,225 | 2.86 (0.02) | 0.01 (0.02) | 0.624 | 3.68 (0.02) | −0.02 (0.02) | 0.492 | 77.9 (0.2) | 0.6 (0.3) | 0.022 |
| Never | 3,252 | 2.91 (0.01) | 0.05 (0.02) | 0.007 | 3.64 (0.01) | −0.06 (0.02) | 0.018 | 79.9 (0.1) | 2.6 (0.3) | <0.001 |
| P-value for Wald F statistic | 0.019 | 0.056 | <0.001 | |||||||
Notes
*
Data are presented as the adjusted mean (SE) and mean difference (SE) unless otherwise indicated;
**
subjects were categorized into four groups for age, BMI, and blood cadmium level as the 25th percentile, the 50th percentile, the 75th percentile, and the 100th percentile.
Abbreviations: BMI, body mass index; SE, standard error; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; Ref, reference.