Effect of Cigarette Smoking on fractional exhaled nitric oxide in Saudi medical college students

Objective: To see the levels of fractional exhaled nitric oxide (FENO) in young adult smokers and its relationship with duration and dose of smoking.Methods: This study was conducted at the department of Physiology of College of Medicine and King Khalid University Hospital, Riyadh, Saudi Arabia from January 2009 to June 2009. A total of 60 medical students were initially recruited and 48 were finally selected for the study after fulfilling our selection criteria. FENO measurements were performed online according to the recent American Thoracic Society (ATS) guidelines and ventilatory functions were recorded.Results: The difference in age, Body mass index (BMI), Systolic blood pressure (SBP) and Diastolic blood pressure (DBP) between the two groups was non significant. Lung function parameters included FEV1, FVC and FEV1/ FVC ratio and the difference was non significant between the two groups. It was observed that FENO was significantly lower in smokers than non smokers (16.62±5.13 verses 24.35±6.17, p=0.0001). No relationship of FENO was observed with duration and dose of smoking.Conclusion: Young adult smokers exhibit lower levels of fractional exhaled nitric oxide compared to non smokers. This could be an early indicator of effects of smoking on lungs.