Objective: To evaluate the effect of tobacco smoking, respiratory symptoms, and asthma on lung function among Mexican adults who were evaluated during a medical exam in a private health clinic.
Material and methods: Reference prediction equations were generated for spirometry parameters [forced vital capacity (FVC), forced expired volume in one second (FEV1) and FEV1/FVC] based on multiple linear regression models. The effect of tobacco smoking, respiratory symptoms and asthma on these equations were explored.
Results: Spirometry tests were performed on 919 subjects from 14 to 86 years of age. Asthma decreased FVC and FEV1 in men with a R2 change <1%. Respiratory symptoms decreased the FEV1/FVC ratio in both sexes. Tobacco smoking was associated with a significant reduction in FEV in women.
Conclusions: Asthma lightly reduced lung function in males while tobacco smoking decreased FEV, particularly in females.