Surfactant protein B polymorphisms, pulmonary function and COPD in 10,231 individuals

The surfactant protein (SP)-B gene may influence chronic obstructive pulmonary disease (COPD) and, thus, personalised medicine. We tested whether functional polymorphisms in SP-B (rs1130866 (1580T > C), rs2077079 (-18A > C) and rs3024791 (-384G > A)) associate with reduced lung function and risk of COPD in the general population. We genotyped 10,231 individuals from the general adult Danish population, and recorded spirometry and hospital admissions due to COPD. Because we previously found an association between the rare SP-B 121ins2 mutation and COPD among smokers, we stratified the analyses for smoking status. None of the individual SP-B genotypes or genotype combinations were associated with reduced forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % pred and FEV1/FVC overall or among smokers (p=0.25-0.99). The odds ratio for spirometrically defined COPD did not differ from 1.0 for any of the SP-B genotypes or genotype combinations overall or among smokers (p=0.17-0.78). Similar results were obtained for hospitalisation due to COPD (p=0.07-0.93); we could exclude overall hazard ratios for heterozygotes of 1.18-1.21 and for homozygotes of 1.25-1.57 or larger for all three polymorphisms. In conclusion, the functional rs1130866, rs2077079 and rs3024791 polymorphisms in the SP-B gene are not associated with reduced lung function or risk of COPD, making it unlikely that these variants will be useful in personalised medicine.