1 The Faculty of Medicine, Aalborg University, VBN2 Aalborg University Hospital, The Faculty of Medicine, Aalborg University, VBN3 Klinik Diagnostik, The Faculty of Medicine, Aalborg University, VBN4 Arvelige Sygdomme (Klinisk Genetik), The Faculty of Medicine, Aalborg University, VBN5 Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark6 The Danish Twin Registry, Epidemiology, Institute of Public Health, University of Southern Denmark7 Institute of Regional Health Research, Department of Biostatistics, University of Southern Denmark8 Department of Respiratory Medicine, Odense University Hospital, Odense
Variation in Surfactant Protein D (SP-D) is associated with lung function in tobacco smoke-induced chronic respiratory disease. We hypothesized that the same association exists in the general population and could be used to identify individuals sensitive to smoke-induced lung damage. The association between serum SP-D (sSP-D) and expiratory lung function was assessed in a cross-sectional design in a Danish twin population (N=1,512, 18-72 years old). The adjusted heritability estimates for expiratory lung function, associations between SP-D gene (SFTPD) single-nucleotide polymorphisms or haplotypes, and expiratory lung function were assessed using twin study methodology and mixed-effects models. Significant inverse associations were evident between sSP-D and the forced expiratory volume in 1 second and forced vital capacity in the presence of current tobacco smoking but not in non-smokers. The two SFTPD single-nucleotide polymorphisms, rs1923536 and rs721917, and haplotypes including these single-nucleotide polymorphisms or rs2243539, were inversely associated with expiratory lung function in interaction with smoking. In conclusion, SP-D is phenotypically and genetically associated with lung function measures in interaction with tobacco smoking. The obtained data suggest sSP-D as a candidate biomarker in risk assessments for subclinical tobacco smoke-induced lung damage. The data and derived conclusion warrant confirmation in a longitudinal population following chronic obstructive pulmonary disease initiation and development.
American Journal of Physiology: Lung Cellular and Molecular Physiology, 2014, Vol 306, Issue 9
Forced expiratory volume in one second; Lung injury; Single-nucleotide polymorphisms; Surfactant protein D; Tobacco smoking; Single-nucleotide polymorphism; surfactant protein D