The genetic effects of hormones modulated by the Pituitary-Thyroid/Adrenal/Gonadal axis on the risk of developing venous thromboembolism: a mendelian randomization study.

BACKGROUND

The aim of this study was to explore the genetic effects of hormones modulated through the pituitary-thyroid/adrenal/gonadal axis on the risk of developing venous thromboembolism (VTE) and to investigate the potentially causal relationships between them.

METHODS

A two-sample Mendelian randomization (MR) design was used. The single-nucleotide polymorphisms (SNPs) used as instrumental variables for various hormones and hormone-mediated diseases were derived from published genome-wide association studies (GWASs). Summary statistics for the risk of developing VTE (including deep venous thrombosis [DVT] and pulmonary embolism [PE]) were obtained from the UK Biobank and the FinnGen consortium. Inverse-variance weighting (IVW) was applied as the primary method to analyse causal associations. Other MR methods were used for supplementary estimates and sensitivity analysis.

RESULTS

A genetic predisposition to greater free thyroxine (FT4) concentrations was associated with a greater risk of developing DVT (OR = 1.0007, 95%CI [1.0001-1.0013], p = 0.0174) and VTE (OR = 1.0008, 95%CI [1.0002-1.0013], p = 0.0123). Genetically predicted hyperthyroidism was significantly associated with an increased risk of developing DVT (OR = 1.0685, 95%CI [1.0139-1.1261], p = 0.0134) and VTE (OR = 1.0740, 95%CI [1.0165-1.1348], p = 0.0110). According to the initial MR analysis, testosterone concentrations were positively associated with the risk of developing VTE (OR = 1.0038, 95%CI [1.004-1.0072], p = 0.0285). After sex stratification, estradiol concentrations were positively associated with the risk of developing DVT (OR = 1.0143, 95%CI [1.0020-1.0267], p = 0.0226) and VTE (OR = 1.0156, 95%CI [1.0029-1.0285], p = 0.0158) in females, while the significant relationship between testosterone and VTE did not persist. SHBG rs858518 was identified as the only SNP that was associated with an increased risk of developing VTE, mediated by estradiol, in females.

CONCLUSIONS

Genetically predicted hyperthyroidism and increased FT4 concentrations were positively associated with the risk of developing VTE. The effects of genetically predicted sex hormones on the risk of developing VTE differed between males and females. Greater genetically predicted estradiol concentrations were associated with an increased risk of developing VTE in females, while the SHBG rs858518 variant may become a potential prevention and treatment target for female VTE.