Waterpipe Smoking and Dependence are Associated with Chronic Obstructive Pulmonary Disease: A Case-Control Study

Introduction: Waterpipe smoking gained popularity during recent years. Although waterpipe smoking exposes people to the same noxious substances found in cigarettes, popular belief considers it harmless. Our objective was to evaluate the association between waterpipe smoking and dependence, and COPD. Methods: We conducted a case-control study in two tertiary care hospitals. Cases were included if diagnosed as COPD by a pulmonologist and confirmed by post-bronchodilator FEV1/FVC<0.7; controls were included if free of any respiratory disease or symptom. After oral consent, a standardized questionnaire was administered and spirometry results were collected. Results: 211 COPD cases and 527 controls were studied. In previous smokers, any smoking type was associated with COPD. The ORs were 29.0[14.3-58.8] (p<0.001) for previous cigarette smoking, 11.7[4.4-31.2] (p<0.001) for previous waterpipe smoking, and 44.1[16.3-4.4] (p<0.001) for previous mixed smoking. In current smokers, the ORs were 20.5[10.2-41.2] (p<0.001) for cigarette smoking, 1.8[0.5-5.9] (p=0.299) for waterpipe smoking, and 9.4[3.81-23.0] (p<0.001) for mixed smoking. Nevertheless, we found in waterpipe current smokers, an OR=8.9[3.9-20.7] (p<0.001) for the association between dependence evaluated by LWDS-11 scale, and COPD. These results were confirmed by stratified and multivariate analysis, after adjustment for cigarette smoking and confounding variables. A cumulative smoking of one waterpipe per week for 20years (or its equivalent) was predictive of higher risk of COPD. Discussion: Whereas evidence showing harmful effects of waterpipe smoking is sparse, this study showed a high OR between the risk of developing COPD and being an ex-smoker of waterpipe, or a current waterpipe dependent individual. Additional studies are necessary to confirm our results.