Association of coffee and caffeine consumption with risk of ischemic stroke: a Mendelian randomization study

Abstract Background Previous research has not elucidated a causal relationship between coffee and caffeine intake and ischemic stroke. Methods Mendelian randomization (MR) studies were used to assess the causal relationship between coffee and caffeine consumption and the risk of ischemic stroke. Genetic statistically significant single nucleotide polymorphisms (SNPs) for coffee and caffeine intake served as instrumental variables (IVs). Ischemic stroke was used as the outcome, and the IVW, MR-Egger, simple mode, weighted mode, and weighted median methods were used for analysis, and the inverse variance weighting (IVW) method was used as the main method for MR analysis. Further sensitivity analysis was performed using MR-Egger and IVW to assess robustness. Results MR analysis results showed that coffee and caffeine intake were not associated with the risk of ischemic stroke. Twenty-three SNPs of coffee and 19 SNPs of caffeine were selected as IVs, and the F values of all SNPs were greater than 10. The study results show that genetic susceptibility to coffee intake is associated with IS (OR = 1.147, 95% CI: 0.704– 1.869, P = 0.583), and caffeine intake is associated with IS (OR = 0.93, 95% CI: 0.846– 1.021, P = 0.126) had no effect. After excluding SNPs with confounding factors, a sensitivity analysis was performed in this study, and the results were consistent. Conclusion The findings suggest there is insufficient evidence to support an association between coffee and caffeine intake and the risk of ischemic stroke. More research is needed to verify this in the future.