Association of smokeless tobacco and cerebrovascular accident: a systematic review and meta-analysis of global data.

The association of smokeless tobacco (SLT) with stroke has been dealt with in only a few reviews. The present meta-analysis aims to present the updated comprehensive summary risk of stroke in adult SLT users along with sub group analysis.A systematic literature search for articles evaluating risk of stroke in SLT users was conducted. The study characteristics and risk estimates were extracted independently by two authors (RG and SG). Random-effect model was used to estimate the summary relative risks.The overall risk of stroke in SLT users was found to be significantly higher (1.17, 95% CI 1.04-1.30) compared to non-users, especially for users in Southeast Asian region. The results remained unchanged even after strict adjustment for smoking (1.18, 95% CI 1.04-1.32). SLT users had 13.4 times higher risk of fatal stroke, though risk of nonfatal stroke was not enhanced. Significantly higher risk of stroke was seen in users of chewing tobacco (1.35, 95% CI 1.20-1.50) in comparison to non-chewers. Gender-based analysis showed enhanced risk of fatal stroke in both male and female users. SLT-attributable fraction of fatal stroke was highest for India at 14.8%.The significant higher risk of stroke with SLT use, even after adjustment for smoking, emphasizes the imperative need to include SLT cessation advice for control and prevention of stroke.