Spirometric Parameters in Waterpipe Smokers, Cigarette Smokers, and Non-smokers of Shahedieh Cohort Study

Background: Different kinds of smoking tobacco may affect pulmonary function and reduce some spirometric parameters. This study aimed to assess the relationship between smoking cigarettes and waterpipe and spirometric parameters. Methods: This was a cross-sectional study on 1543 middle-aged individuals, as a sub-study of the Shahedieh cohort study in Yazd. The participants were randomly selected from the Shahedieh cohort population and were divided into 6 groups according to their smoking habits: non-smokers (n=455), cigarette smokers (n=139), waterpipe smokers (n=287), ex-cigarette smokers (n=131), concurrent waterpipe and cigarette smokers (n=121), and cigarette or waterpipe passive smokers (n=410). Spirometry was performed on all participants and spirometric parameters were compared between different groups. The data were analyzed by SPSS (version 20) using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests. Findings: FEV1 %, FEV1/FVC, and PEF25-75% were significantly lower in cigarette smokers, compared to waterpipe smokers and non-smokers. The measures were not significantly lower in waterpipe smokers in comparison to non-smokers. The frequency of obstructive pattern and small airway diseases was significantly higher in cigarette smokers compared to waterpipe smokers and non-smokers. Conclusion: The results of this study showed that in the middle-aged population, spirometric parameters related to airway obstruction (FEV1, FEV1/FVC, and FEF25-75%) were significantly lower in cigarette smokers than in non-smokers and waterpipe smokers, but these parameters were not significantly different between waterpipe smokers and non-smokers.