Coronary Artery Disease Genetics Consortium Research Articles

Genetically Determined Lifestyle and Cardiometabolic Risk Factors Mediate the Association of Genetically Predicted Age at Menarche With Genetic Predisposition to Myocardial Infarction: A Two-Step, Two-Sample Mendelian Randomization Study.

BackgroundObservational studies have shown an association between early age at menarche (AAM) and myocardial infarction (MI) with recorded cases. In this Mendelian randomization (MR) study, we used large amounts of summary data from genome-wide association studies (GWASs) to further estimate the association of genetically predicted AAM with genetically predicated risk of MI and investigate to what extent this association is mediated by genetically determined lifestyles, cardiometabolic factors, and estrogen exposure.MethodsA two-step, two-sample MR study was performed by mediation analysis. Genetic variants identified by GWAS meta-analysis of reproductive genetics consortium (n = 182,416) were selected for genetically predicted AAM. Genetic variants identified by the Coronary ARtery DIsease Genome-wide Replication and Meta-analysis plus The Coronary Artery Disease Genetics Consortium (n = 184,305) were selected for genetically predicted risk of MI. Genetic variants from other international GWAS summary data were selected for genetically determined mediators.ResultsThis MR study showed that increase in genetically predicted AAM was associated with lower risk of genetically predicted MI (odds ratio 0.91, 95% confidence interval 0.84–0.98). Inverse variance weighted (IVW) MR analysis also showed that decrease in genetically predicted AAM was associated with higher genetically predicted alcohol intake frequency, current smoking behavior, higher waist-to-hip ratio, and higher levels of systolic blood pressure (SBP), fasting blood glucose, hemoglobin A1c (HbA1c), and triglycerides (TGs). Furthermore, increase in genetically predicted AAM was associated with genetically predicted longer sleep duration, higher levels of high-density lipoproteins, and older age at which hormone replacement therapy was started. The most essential mediators identified were genetically predicted current smoking behavior and levels of HbA1c, SBP, and TGs, which were estimated to genetically mediate 13.9, 12.2, 10.5, and 9.2%, respectively, with a combined mediation proportion of 37.5% in the association of genetically predicted AAM with genetically predicted increased risk of MI in an MR framework.ConclusionOur MR analysis showed that increase in genetically predicted AAM was associated with lower genetically predicted risk of MI, which was substantially mediated by genetically determined current smoking behavior and levels of HbA1c, SBP, and TGs. Intervening on the above mediators may reduce the risk of MI.

Genetically determined risk of mood swings and cardiometabolic diseases: mendelian randomization study

Abstract Background Mood swings is believed to associated with increased risk of Cardiometabolic Diseases (CMD). However, the roles of mood swings on CMD are controversial because of the bias of reverse causation and/or confounding in epidemiological studies. Hence, we use a two-sample MR approach to identify the causal association between genetically determined mood swings and CMD. Methods We obtained 33 independent single-nucleotide polymorphisms (SNPs) with genome-wide significant (P<5×10–8) associated with mood swings as instrumental variable in UK Biobank. Summary data of outcomes were extracted from the Coronary Artery Disease Genome-wide Replication and Meta-analysis plus the Coronary Artery Disease Genetics consortium, the Diabetes Genetics Replication and Meta-analysis consortium, the CKDGen consortium, and the International Stroke Genetics Consortium. Results The genetic instrument of 33 SNPs explained 4.8% of the variance in mood swings. Genetically determined mood swings was associated with an increased risk of coronary artery disease (CAD) (odds ratio 3.12, 95% confidence interval 1.92 to 5.08; P=4.32×10–6). However, mood swings had no effect on the other cardiometabolic outcomes. The above estimates were consistent across all three MR methods without significant heterogeneity. Also, there was no evidence of directional pleiotropy for each outcome except for large artery stroke. Conclusions Using MR approaches that are able draw causal inference, our results suggest that interventions aimed at improving mood swings in the population would lead to a reduction risk of CAD, which highlights the importance of mood management in high-risk CAD population. Funding Acknowledgement Type of funding sources: None.

Sleep Duration and Myocardial Infarction

BackgroundObservational studies suggest associations between extremes of sleep duration and myocardial infarction (MI), but the causal contribution of sleep to MI and its potential to mitigate genetic predisposition to coronary disease is unclear. ObjectivesThis study sought to investigate associations between sleep duration and incident MI, accounting for joint effects with other sleep traits and genetic risk of coronary artery disease, and to assess causality using Mendelian randomization (MR). MethodsIn 461,347 UK Biobank (UKB) participants free of relevant cardiovascular disease, the authors estimated multivariable adjusted hazard ratios (HR) for MI (5,128 incident cases) across habitual self-reported short (<6 h) and long (>9 h) sleep duration, and examined joint effects with sleep disturbance traits and a coronary artery disease genetic risk score. The authors conducted 2-sample MR for short (24 single nucleotide polymorphisms) and continuous (71 single nucleotide polymorphisms) sleep duration with MI (n = 43,676 cases/128,199 controls), and replicated results in UKB (n = 12,111/325,421). ResultsCompared with sleeping 6 to 9 h/night, short sleepers had a 20% higher multivariable-adjusted risk of incident MI (HR: 1.20; 95% confidence interval [CI]: 1.07 to 1.33), and long sleepers had a 34% higher risk (HR: 1.34; 95% CI: 1.13 to 1.58); associations were independent of other sleep traits. Healthy sleep duration mitigated MI risk even among individuals with high genetic liability (HR: 0.82; 95% CI: 0.68 to 0.998). MR was consistent with a causal effect of short sleep duration on MI in CARDIoGRAMplusC4D (Coronary ARtery DIsease Genome wide Replication and Meta-analysis plus Coronary Artery Disease Genetics Consortium) (HR: 1.19; 95% CI: 1.09 to 1.29) and UKB (HR: 1.21; 95% CI: 1.08 to 1.37). ConclusionsProspective observational and MR analyses support short sleep duration as a potentially causal risk factor for MI. Investigation of sleep extension to prevent MI may be warranted.

Genetic Association of Finger Photoplethysmography-Derived Arterial Stiffness Index With Blood Pressure and Coronary Artery Disease.

Objective- Arterial stiffness index (ASI) is independently associated with blood pressure (BP) and coronary artery disease (CAD) epidemiologically. However, it is unknown whether these associations represent causal relationships. Here, we assess whether genetic predisposition to increased ASI is associated with elevated BP and CAD risk. Approach and Results- We first performed a large-scale epidemiological association of finger photoplethysmography-derived ASI in the UK Biobank, finding significant associations with systolic BP (β=0.55 mm Hg; [95% CI, 0.45-0.65]; P=5.77×10-24; N=137 858), diastolic BP (β=1.05 mm Hg; [95% CI, 0.99-1.11]; P=7.27×10-272; N=137 862), and incident CAD (hazard ratio, 1.08; [95% CI, 1.04-1.11]; P=1.5×10-6; N=3692 cases, 126 615 controls) in multivariable models. We then performed an ASI genome-wide association study analysis in 131 686 participants from the UK Biobank. Across participants not in the ASI genome-wide association study, a 6-variant ASI polygenic risk score was calculated. Each SD increase in genetic ASI was associated with systolic BP (β=4.63 mm Hg; [95% CI, 2.1-7.2]; P=3.37×10-4; N=208 897), and diastolic BP (β=2.61 mm Hg; [95% CI, 1.2-4.0]; P=2.85×10-4; N=208 897); however, no association was observed with incident CAD (hazard ratio, 1.12; [95% CI, 0.55-2.3]; P=0.75; N=223 061; 7534 cases). The lack of CAD association observed was replicated among 184 305 participants (60 810 cases) from the CARDIOGRAMplusC4D (Coronary Artery Disease Genetics Consortium; odds ratio, 0.56; [95% CI, 0.26-1.24]; P=0.15). Conclusions- Our data support the conclusion that finger photoplethysmography-derived ASI is an independent, genetically causal risk factor for BP, but do not support the notion that ASI is a suitable surrogate for CAD risk.