Influence of cigarette smoking on lung function at baseline and at follow-up in 14 years: the Framingham Study.

Cross-sectional and prospective associations between lung function and potential determinants were examined in the Framingham Study. Personal characteristics of interest were body height and weight, hand grip strength, smoking habits, history of respiratory symptoms and disease, and hematocrit. Baseline pulmonary function was the most powerful indicator of future FEV1, and cigarette smoking was the most important correctable influence. In addition to baseline FEV1, FVC and smoking habits, the important predictors of future lung function were age, relative weight, respiratory symptoms and hematocrit. There was a higher follow-up FEV1 in those who quit smoking compared to those who continued even after adjustment for other associated variables. Relative weight and hematocrit were associated with FEV1 measured 14 years after baseline (directly for relative weight and inversely for hematocrit).