C-reactive protein and cognitive impairment: A bidirectional Mendelian randomization study

Wenhuo Xie1, Chenghua Kong1, Wei Luo2

  • 1Department of Clinical Pharmacy and Pharmacy Administration, School of Pharmacy, Fujian Medical University, Fuzhou, China.

Insights

Genetically proxied C-reactive protein (CRP) is linked to prospective memory decline. Reverse analysis suggests cognitive performance and fluid intelligence may influence CRP levels, indicating a complex relationship between inflammation and cognition.

Area of Science:

  • Neuroscience
  • Genetics
  • Inflammation Research

Background:

  • C-reactive protein (CRP) is a known risk factor for cognitive impairment.
  • Observational studies suggest a link, but causal relationships remain unclear.
  • Mendelian randomization (MR) can investigate genetic associations to infer causality.

Purpose of the Study:

  • To determine the causal association between C-reactive protein (CRP) and cognitive impairment using bidirectional Mendelian randomization (MR).
  • To investigate the genetic link between CRP levels and various cognitive functions.

Main Methods:

  • Utilized genome-wide association studies (GWAS) summary statistics for CRP and cognitive traits (performance, fluid intelligence, prospective memory, reaction time).
  • Employed bidirectional MR analysis with multiple methods (IVW, MR Egger, weighted median, etc.).
  • Conducted MR sensitivity analyses to assess pleiotropy and heterogeneity.

Main Results:

  • Forward MR indicated a significant association between genetically proxied CRP and prospective memory (P=0.009).
  • Little evidence supported CRP's association with other cognitive tests.
  • Reverse MR suggested potential associations between genetically proxied cognitive performance/fluid intelligence and CRP levels (P=0.002, P=0.019).

Conclusions:

  • Genetically proxied CRP impacts prospective memory, but not other cognitive measures.
  • Evidence suggests a bidirectional relationship, with cognition potentially influencing CRP levels.
  • MR sensitivity analyses confirmed the robustness of the CRP-prospective memory association.
Abstract