Abstract
Background: Low intelligence has been shown to be associated with a high risk of cardiovascular disease in observational studies. It remains unclear whether the association is causal. This study aimed to explore the causal association of intelligence with coronary artery disease (CAD) and myocardial infarction (MI). Methods: A two-sample Mendelian randomization study was designed to infer the causality. A total of 121 single nucleotide polymorphisms were selected as a genetic instrumental variable for intelligence. Summary data on CAD (n = 184,305) and MI (n = 171,875) were obtained from the Coronary ARtery DIsease Genome-wide Replication and Meta-analysis (CARDIoGRAM) plus The Coronary Artery Disease (C4D) Genetics (CARDIoGRAMplusC4D) consortium and the FinnGen study. Inverse variance weighting method was used to calculate the effect estimates. Sensitivity analyses including other statistical models and leave-one-out analysis were conducted to verify the robustness of results. MR-Egger test was performed to assess the pleiotropy. Results: Genetically predicted higher intelligence was significantly associated with lower risk of CAD (OR, .76; 95%CI, .69–.85; p = 1.5 × 10–7) and MI (OR, .78; 95%CI, .70–.87; p = 7.9 × 10–6). The results remained consistent in the majority of the sensitivity analyses and were repeated in the FinnGen datasets. MR-Egger test suggested no evidence of directional pleiotropy for the association with coronary artery disease (intercept = −.01, p = .19) and myocardial infarction (intercept = −.01, p = .06). Conclusion: This Mendelian randomization analysis provided genetic evidence for the causal association between low intelligence and increased risks of CAD and MI.
Highlights
Cardiovascular diseases (CVD) have represented a major cause of death and disability in the past few decades (Joseph et al, 2017)
Genetically predicted higher intelligence was significantly associated with lower risk of coronary artery disease (CAD) (OR, .76; 95%CI, .69–.85; p = 1.5 × 10–7) and myocardial infarction (MI) (OR, .78; 95%CI, .70–.87; p = 7.9 × 10–6)
Mendelian randomization (MR)-Egger test suggested no evidence of directional pleiotropy for the association with coronary artery disease and myocardial infarction
Summary
Cardiovascular diseases (CVD) have represented a major cause of death and disability in the past few decades (Joseph et al, 2017). The burden of CVD remains a great challenge, though great efforts have been made to manage this disease (GBD 2013 Mortality and Causes of Death Collaborators, 2015). Several observational studies demonstrated that low intelligence is associated with a high risk of CVD (Roberts et al, 2013; Dobson et al, 2017). It is unclear whether this association is causal or spurious. Low intelligence has been shown to be associated with a high risk of cardiovascular disease in observational studies. It remains unclear whether the association is causal. This study aimed to explore the causal association of intelligence with coronary artery disease (CAD) and myocardial infarction (MI)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
