Water Pipe Tobacco Smoking and Risk of Coronary Artery Disease: A Systematic Review and Meta-Analysis

Background: Waterpipe smoking has become a vitally important public health issue in the world with a false assumption that it has a less harmful effect. Objective: The aim of this study was to systematically review the association between waterpipe tobacco smoking and the risk of coronary artery disease (CAD). Methods: Up to September 25, 2018, we electronically searched the PubMed, Embase, and ISI Web of Science with no time restriction. We included observational studies and excluded conference abstracts, editorials, case reports, case series, and reviews. With the fixed model effect, we conducted a meta-analysis to evaluate the association between waterpipe smoking and coronary artery disease. Heterogeneity among studies was assessed by the I2 square test. Publication bias was assessed by Egger test. P<0.05 was set as significant level. Results: Among 248 paper records identified through a database search, 52 full texts were eligible for full text assessment whereas 49 papers were excluded. Additionally, three studies were eligible for meta-analysis, which involved 58,960 adults with 1334 in the water pipe smoker group. Risk of CAD was increased in water pipe smokers compared to individuals who had never smoked water pipe but the result did not reach a statistical significance (OR=1.18, 95% CI: 0.98-1.38, p=0.06). We found that heavy water pipe smoking (40 to 50 sessions of waterpipe smoking/year) was associated with CAD compared to lower smokers defined as less than 40 to 50 water pipe/year (OR=2.001, 95% CI: 1.13-2.87). Conclusion: Heavy Water pipe smoking was associated with coronary artery disease based on clinical findings. It seems very crucial to increase public awareness on adverse effects of water pipe smoking and its cessation in clinical setting.