Crude and adjusted quantile regression (50th) analysis of lung function by surfactant composition (lipids and proteins) among healthy groups, ECRHS-III (n=200)
| Explanatory variables | FEV1 (%pred) coefficient (95% CI) | FVC (%pred) coefficient (95% CI) | FEV1/FVC coefficient (95% CI) | |||
| Crude | Adjusted | Crude | Adjusted | Crude | Adjusted | |
| DPPC (wt%) | −0.01 (−0.08 to 0.06) | −0.03 (−0.10 to 0.04) | −0.03 (−0.11 to 0.06) | 0.03 (0.01 to 0.06)* | 0.16 (0.002 to 0.31)* | 0.25 (0.10 to 0.40)* |
| POPC (wt%) | −0.02 (−0.24 to 0.20) | −0.12 (−0.36 to 0.11) | −0.09 (−0.37 to 0.20) | 0.14 (0.06 to 0.22)* | 0.45 (0.06 to 0.95)* | 0.91 (0.42 to 1.42)* |
| PC14:0/16:0 (%) | 0.02 (−0.01 to 0.05) | −0.02 (0.001 to 0.03)* | 0.04 (0.001 to 0.08)* | 0.02 (0.001 to 0.04)* | −0.08 (−0.15 to −0.01)* | −0.04 (−0.08 to 0.001) |
| PC16:0/18:2 (%) | 0.01 (−0.06 to 0.08) | 0.03 (−0.05 to 0.10) | 0.01 (−0.08 to 0.11) | 0.04 (−0.06 to 0.13) | −0.10 (−0.25 to 0.07) | −0.01 (−0.10 to 0.08) |
| SP-A (wt%) | 0.03 (−0.10 to 0.15) | 0.01 (−0.06 to 0.07) | 0.09 (−0.08 to 0.25) | 0.13 (−0.06 to 0.33) | 0.09 (−0.20 to 0.37) | 0.04 (−0.06 to 0.13) |
| Albumin (wt%) | −0.02 (−0.07 to 0.02) | −0.02 (−0.05 to 0.01) | −0.03 (−0.10 to 0.03) | −0.03 (−0.10 to 0.03) | −0.06 (−0.19 to 0.06) | −0.04 (−0.04 to 0.08) |
Significant associations (*) are also marked in bold.
DPPC, di-palmitoyl-di-phosphatidyl-choline; ECRHS-III, European Community Respiratory Health Survey III; FEV1, forced expiratory volume in one second; FVC, forced vital capacity; PC, phosphatidylcholine; SP-A, surfactant protein A.