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

Background: 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.

Methods: 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.

Results: 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 1.34 times or 13.4% 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%.

Conclusion: 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.