| Background:The use of chewing substances, including chewing tobacco and betel quid, though prevailing forms of tobacco consumption, or rather substance abuse in Asia, has been less explored for their effect on cardiovascular system.Objective:To assess whether people who ever use any form of chewing substance in Asia are at increased risk of cardiovascular diseases (CVD).Methods:Systematic review with meta-analysis of observational studies in Asia. PubMed, Web of Science were searched for relevant studies, with no limitation on language or study year. Studies were included if they provided quantitative estimate of the association between ever use of chewing substance and the occurrence of CVD. Two authors independently implemented inclusion criteria, abstracted study characteristics, and performed meta-analysis. Summary relative risks were estimated on the basis of random effects model. We used Q statistic. Egger's test to examine heterogeneity across studies, and potential publication bias, respectively.Results:Eight eligible studies were included. The relative risk (RR) of CVD for ever chewing substances with or without tobacco was 1.26 (95% confidence interval 1.12 to 1.40), which was undiminished when restricted to cohort studies (RR:1.25(1.08 to 1.42)) or cohort studies in Taiwan (RR:1.31(1.12 to 1.51)). The summary relative risk for ischemic heart diseases was 1.27(1.02 to 1.52), and was lowered to 1.26(0.85 to 1.67) after exclusion of a cross-sectional study. The overall relative risk based on three risk estimates for cerebrovascular diseases was 1.32 (1.08 to 1.56). Data on dose-response were limited to betel quid chewing in Taiwan, suggesting a relationship between risk of CVD and cumulative exposure.Conclusions:An association was detected between use of chewing substances with or without tobacco and risk of CVD, which does not seem to be explained by chance. Future studies are needed to further explore the relationship between chewing substances and subtypes of CVD. |
PDF Full Text Request