[The effect of cigarette smoking on pulmonary diffusing capacity in asymptomatic smokers]

Ninety-seven subjects of which 72 smokers and 25 nonsmokers attending the Laboratory for Respiratory Functional Diagnostics of the University Hospital for Lung Diseases, Jordanovac, Zagreb were examined. The selection criteria were normal standard spirometric test values (FEV1, FVC, FEV1/FVC) in asymptomatic healthy, young smokers/nonsmokers who showed no signs of hematological, cardiovascular and chronic or acute pulmonary symptoms or diseases (according to a standardized questionnaire), and were not exposed to harmful environmental factors. The single-breath carbon monoxide diffusing capacity was measured in all patients. The results of our study confirm the findings of those authors who report reduced values of DLCO and DL/VA in smokers in comparison with the nonsmokers. A linear value diminution has been noticed in smokers and nonsmokers with increasing age, with the values being much lower in smokers. Our results also demonstrate a significant correlation between DLCO and DL/VA in young healthy smokers vs the duration of smoking and the number of cigarettes smoked per day (p < 0.01). The possibility to detect early reversible damages of lung function in young healthy smokers is an important contribution to the prevention of all diseases in which causal consecutive relation with cigarette smoking is confirmed.