J. Wouter Jukema (Netherlands)
Leiden University Medical Center Department of CardiologyAuthor Of 3 Presentations
Which patient needs the PCSK9 inhibitors most? (ID 1376)
Live Q&A (ID 1378)
O038 - Dietary-derived antioxidants do not decrease the risk of ischemic stroke: a Mendelian Randomization study (ID 488)
Abstract
Background and Aims
In observational studies, dietary intake, as dietary components or supplements, and blood concentrations of vitamin E, C, lycopene and carotenoids were associated with a lower risk of ischemic stroke. However, these studies were prone to residual confounding and reverse causation, and thereby limit the ability for causal inference. We investigated the associations between genetically-determined antioxidant concentrations and ischemic stroke using Mendelian Randomization.
Methods
For each circulating antioxidant (vitamin E, C, lycopene, β-carotene and retinol), which were assessed as absolute levels and/or metabolites, single-nucleotide polymorphisms (SNPs) were retrieved from earlier genomics studies and used as genetic instrument variables. We obtained summary statistics for gene-stroke associations from three European-ancestry cohorts (cases/controls): MEGASTROKE (67 162/454 450), UK Biobank (2404/368771) and FinnGen study (4026/90211). MR analyses were performed on each exposure per outcome database using inverse-variance weighted analyses, and subsequently meta-analyzed.
Results
In a combined sample of 986 964 individuals (73 592 cases), none of the genetically-determined absolute antioxidants or antioxidant metabolite concentrations were causally associated with the risk of ischemic stroke. For absolute antioxidants, the odds ratios (95% CI) ranged between 1.00 (95% CI: 0.99 to 1.01) for vitamin C and 1.06 (95% CI: 0.74 to 1.52) for retinol. For metabolites, they ranged between 1.00 (95% CI: 0.98 to 1.03) for vitamin C and 1.17 (95% CI: 0.92 to 1.49) for vitamin E.
Conclusions
Our study did not provide evidence supporting a causal association between dietary-derived antioxidant levels and ischemic stroke. Therefore, taking antioxidant supplementation seems unlikely to be of clinical benefit to prevent ischemic stroke.