Causal relationship between C-reactive protein and ischemic stroke caused by atherosclerosis: A Mendelian...

This study investigates the association between C-reactive protein (CRP) and ischemic stroke caused by large artery atherosclerosis (LAA).

Five Mendelian Randomization (MR) methodologies were used for two-sample analyses: Inverse Variance Weighting (IVW), MR-Egger regression, Weighted Median (WM), Simple Mode, and Weighted Mode. CRP exposure data were obtained from aggregated summary statistics from a meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry (n = 343,524; UK Biobank). Stroke data were used as the outcome, with specific dataset details for relevant subtypes (cases = 40,585, controls = 406,111).

In the CRP GWAS dataset, selected single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) showed genome-wide significance and a causal relationship with CRP, particularly in relation to LAA stroke. IVW indicated a robust causal connection between CRP and LAA stroke (Beta = 0.151, SE = 0.055, P = 0.006). The WM approach supported this relationship (Beta = 0.176, SE = 0.082, P = 0.033). However, MR-Egger regression suggested a potential absence of a causal link (Beta = 0.098, SE = 0.077, P = 0.206), with minimal influence from horizontal pleiotropy (Intercept = 0.0029; P = 0.317). The Simple mode found no significant association (Beta = 0.046, SE = 0.217, P = 0.834), while the Weighted mode revealed a significant causal association (Beta = 0.138, SE = 0.059, P = 0.020) between CRP and LAA stroke.

MR analysis provides evidence for a potential causal relationship between CRP and an increased risk of LAA stroke.