The Association of Genetically-Predicted Testosterone with Thromboembolism, Heart Failure and Myocardial Infarction
Objective: To determine whether endogenous testosterone has a causal role in thromboembolism, heart failure, and myocardial infarction.
Design: Two sample Mendelian randomization study to test for causal effects of endogenous testosterone on thromboembolism, heart failure, and myocardial infarction. Mendelian randomization exploits genetic variants as instrumental variables, randomly allocated at conception, to infer causality as additional randomized evidence.
Settings: Reduction by DUtasteride of Prostate Cancer Events randomized controlled trial (REDUCE), UK Biobank and CARDIoGRAMplusC4D 1000 Genomes-based GWAS.
Participants: 3,225 men of European ancestry aged 50 to 75 years in REDUCE, 392,038 men and women of White British ethnicity, aged 40 to 69 years, from the UK Biobank, and 171,875 participants, 77% of European descent, from CARDIoGRAMplusC4D 1000 Genomes-based GWAS in the validation study.
Main outcome measures: Thromboembolism, heart failure and myocardial infarction based on self-reports, hospital episodes and death
Results: In the UK Biobank among 392,038 genetically verified White British participants were 13,691 cases of thromboembolism (6,208 men, 7,483 women), 1,688 of heart failure (1186 men, 502 women) and 12,882 of myocardial infarction (10,136 men and 2,746 women).
In men endogenous testosterone genetically predicted by variants in the JMJD1C gene region was positively associated with thromboembolism (odds ratio (OR) 2.09 per unit increase in log-transformed nmol/L testosterone, 95% confidence intervals (CI) 1.27 to 3.46) and heart failure (OR 7.81, 95% CIs 2.56 to 23.8) but not MI (OR 1.17, 95% CIs 0.78 to 1.75); associations were less obvious in women.
In the validation study, genetically-predicted testosterone in JMJD1C gene region was positively associated with MI (OR 1.37, 95% CIs 1.03 to 1.82). No excess heterogeneity was observed between genetic variants in their associations with the outcomes. However, testosterone genetically predicted by potentially pleiotropic variants in the SHBG gene region had no association with the outcomes.
Conclusions: Endogenous testosterone was positively associated with thromboembolism, heart failure and MI in men, rates of these conditions are higher in men than women. Whether existing treatments that modulate endogenous testosterone could be relevant in thromboembolism and heart failure might be worth considering.
Burgess S. The association of genetically-predicted testosterone with thromboembolism, heart failure and myocardial infarction: a Mendelian randomization study using UK Biobank. BMJ. The association of genetically-predicted testosterone with thromboembolism, heart failure and myocardial infarction: a Mendelian randomization study using UK Biobank