Smoking Effects on Clinical Manifestations and Drug Resistance Patterns in Pulmonary TB Patients

Background: Considering the rising trend of tuberculosis (TB) and cigarette smoking, an evaluation of the clinical manifestations and drug resistance patterns in TB patients with regard to smoking status seemed beneficial. Materials and Methods: Clinical manifestations and drug resistance patterns were studied in 872 new pulmonary TB patients classified as non-smokers, ever-smokers, and passive smokers during 3 years at the National Research Institute of Tuberculosis and Lung Disease. Both univariate and multivariate analyses were performed. Results: Ever-smokers were mostly male (p < 0.001), Iranian (p < 0.001), and drug and alcohol users (p < 0.001). They were found to have a longer patient delay (15.9 versus 8.7 and 6.3 days, p=0.008), shorter diagnostic delay (106.8 versus 132.6 and 156 days, p=0.01), greater weight loss (p=0.01), and higher sputum expectoration (p < 0.001). Notably, the degree of smear positivity was associated with smoking (p < 0.001) in both univariate and multivariate analyses. No statistical significance was found for the aforementioned factors among non-smokers and passive smokers. Conclusion: Some of the clinical manifestations of TB are significantly different with regard to the patientsʹ smoking status. The degree of sputum smear positivity for acid fast bacilli was higher and patient delay was longer in ever-smoker patients.