Cardiovascular effects of waterpipe smoking: a systematic review and meta-analysis

Waterpipe smoking has developed into a major and rapidly growing global tobacco epidemic affecting more than 100 million people worldwide. This study identifies and analyzes comprehensively all available data on the cardiovascular effects of waterpipe smoking. Databases PubMed, EMBASE, Web of Science, and the Cochrane Library were searched for studies published until December 2019 assessing cardiovascular effects of waterpipe smoking. We included experimental, cohort, cross-sectional and case-control studies and excluded systematic reviews, case reports/series and qualitative studies. Studies not conducted in humans or not distinguishing waterpipe smoking from other forms of smoking were also excluded. A total of 42 studies with 46 cardiovascular parameters were eligible for analysis. The meta-analysis included 31 studies with 38,037 individuals. Results showed that one waterpipe smoking session leads to immediate increases in heart rate and blood pressure (P < 0.001). Compared to non-smokers, waterpipe smokers had significantly lower high-density lipoprotein levels (P < 0.001), higher levels of low-density lipoprotein (P = 0.04), triglyceride (P < 0.001) and fasting blood glucose (P = 0.03) and higher heart rate (P = 0.04) with a tendency to have higher blood pressure. Mean heart rate, blood pressure and lipids levels did not differ between waterpipe and cigarette smokers, except for total cholesterol, being higher among waterpipe smokers (P < 0.001). Current level of evidence suggests that waterpipe smoking is associated with substantial adverse effects on cardiovascular system, which seem to be similar to those of cigarette smoking. Longitudinal studies are required to scrutinize the magnitude of these effects.