Interactive effect of paraoxonase-1 Q192R polymorphism and smoking history on the lung function decline in grain workers.

PURPOSE: This retrospective longitudinal study investigated the association between the Q192R polymorphism of the high-density lipoprotein-associated multifunctional antioxidant enzyme, paraoxonase-1 (PON1), and lung function decline, while taking into account smoking history.
METHODS: The demographic, occupational, and respiratory symptom information and lung function variables were obtained from 216 male Saskatchewan grain workers.
RESULTS: An interaction between the PON1 genotypes and smoking status was observed. Current smokers with the 192R allele had a lower forced expiratory volume in the first second (FEV(1)) and FEV(1) per forced vital capacity (FVC). The annual decline rate of FEV(1)/FVC in current smokers was greater among 192R allele carriers than noncarriers (0.58+/-0.05 vs. 0.35+/-0.04 %/yr, p<0.0001). A similar result was observed with FEV(1) (40.9+/-6.4 vs. -33.0+/-7.0 mL/yr, p=0.10). The annual decline rate of FVC was not influenced by the genotypes.
CONCLUSIONS: These results strengthened the previous findings of our cross-sectional study, suggesting that the 192R allele may be a novel genetic risk factor for airway injury among current smokers.