Comparison of Pulmonary Function Test between Smokers and Nonsmokers at Hawler Medical University, Erbil, Iraq


Introduction: Cigarette smoking has extensive effects on pulmonary function. Pulmonary function testing is a routine procedure for theassessment and monitoring of respiratory diseases. The pulmonary functions were compared between apparently healthy smoker and nonsmokerpersons in this study. Materials and Methods: This case–control study was conducted among apparently healthy smoker and nonsmokerstudents and staff of the university between the first of April and the end of June 2018. A total number of 131 persons were taken, in which71 of them were nonsmokers (controls) and 60 were smokers (cases). The reference ranges for the pulmonary functions were used followingthe below criteria: forced vital capacity (FVC): normal (80%–120%) and reduced (<80%); FEV1 (forced expiratory volume in one second):normal (≥75) and reduced (<75); FEV1/FVC: normal ≥80 and reduced <80. Results: The study showed that smoker persons had a lower levelof FVC (84.38 vs. 94.75; P = 0.026) and peak expiratory flow rate (PEFR) (67.08 vs. 84.18; P < 0.0001) compared to nonsmoker persons.Whereas, there was no significant difference in FEV1 (the first second of forced expiration) (80.42 vs. 86.86; P = 0.139) and the FEV1/FVCratio (96.13 vs. 94.48; P = 0.589) between smokers and nonsmokers, respectively. The mean pack‑year smoked by the smokers was 34.89.Conclusions: Cigarette smoking has a significant adverse effect on FVC and peak expiratory flow rate, while it was not confirmed to have anadverse effect on other pulmonary function tests.