A Bidirectional Mendelian Randomization Study of Selenium Levels and Ischemic Stroke.

Area of Science:

• Nutritional Epidemiology
• Genetic Epidemiology
• Cardiovascular Disease Research

Background:

• Observational studies suggest an inverse association between selenium levels and ischemic stroke (IS).
• Causal relationships between selenium and IS remain unclear.
• Genetic epidemiology offers tools to investigate causality.

Purpose of the Study:

• To evaluate the causal links between circulating selenium levels and ischemic stroke (IS) and its subtypes.
• To utilize Mendelian randomization (MR) analysis for assessing causality.
• To determine if genetic predisposition to selenium levels influences IS risk.

Main Methods:

• Two-sample Mendelian randomization (MR) analysis was employed.
• Genetic variants (SNPs) associated with selenium levels were identified from a large genome-wide association study (GWAS) meta-analysis.
• The inverse variance-weighted (IVW) method was used to estimate causal effects.

Main Results:

• Four single nucleotide polymorphisms (SNPs) significantly associated with selenium levels were identified.
• MR analysis revealed no causal effect of selenium levels on ischemic stroke (IS) (OR = 0.968, P = 0.269).
• No evidence of a causal link was found for IS subtypes.

Conclusions:

• Genetically predicted selenium levels do not appear to causally influence ischemic stroke risk.
• The study provides no genetic evidence to support selenium supplementation for IS prevention.
• Further research may explore other mechanisms or populations.