Superoxide dismutases, lung function and bronchial responsiveness in a general population.
1Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands.
Oxidative stress is an important causative factor in the onset and progression of smoking-related lung diseases, such as chronic obstructive pulmonary disease (COPD). Superoxide dismutases (SODs) can prevent an increase in oxidative burden. A total of 1,390 subjects from the prospective Vlagtwedde-Vlaardingen cohort were genotyped for two single nucleotide polymorphisms (SNPs) in SOD2 and four SNPs in SOD3, which were further analysed for associations with the presence of bronchial hyperresponsiveness (BHR; provocative concentration causing a 10% fall in the forced expiratory volume in one second (FEV(1); PC(10) <or=8 mg mL(-1) of histamine), COPD (defined as Global Initiative for Chronic Obstructive Lung Disease stage II or higher), lung function level and the longitudinal course of FEV(1). The intronic C5774T SNP of SOD2 was significantly associated with the presence of COPD and BHR in the total population. The T/T genotype for this polymorphism and the Val/Val genotype for the SOD2 Ala16Val substitution were risk factors for BHR in individuals without COPD. The SOD3 Arg213Gly substitution was associated with slower FEV(1) decline in never-smokers exclusively, and the SOD3 G(-4466)T SNP was associated with a lower vital capacity level. Both SOD2 polymorphisms are associated with bronchial hyperresponsiveness, a risk factor for chronic obstructive pulmonary disease, while SOD2 C5774T additionally confers a risk for chronic obstructive pulmonary disease in the total population. The current authors furthermore confirm previously reported associations of SOD3 single nucleotide polymorphisms with lung function in the general population.