Pre‐diagnostic free androgen and estradiol levels influence heart failure risk in both women and men: A prospective cohort study in the UK Biobank

Serum sex hormones have been linked to cardiovascular disease risk. However, their roles in the pathogenesis of heart failure (HF) in both men and women are unclear. We investigated the associations between free androgen, testosterone, and estradiol, and future risk of HF.This prospective cohort study evaluated UK Biobank participants free of prevalent cardiovascular disease and HF at baseline. Unitless free androgen, testosterone, and estradiol indices were generated using serum concentrations of total testosterone (nmol/L), estradiol (pmol/L), sex hormone binding globulin (SHBG, nmol/L), and albumin (g/L) in blood collected at enrolment. Multivariable Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident HF in relation to quartiles (Q) of free androgen (FAI), testosterone (FTI), estradiol (FEI) indices, and potential confounders. There were 180 712 men (including 5585 HF cases with FAI and 571 HF cases with FEI), and 177 324 women (including 2858 HF cases with FAI and 314 HF cases with FEI) with complete data. Increased FAI was associated with decreased HF risk in both men (HRQ4 vs. Q1: 0.86, 95% CI 0.79-0.94, p-trendcontinuous < 0.0001) and post-menopausal women (HRQ4 vs. Q1: 0.83, 95% CI 0.73-0.95). Similar inverse associations were observed for FTI only in men (HRQ4 vs. Q1: 0.91, 95% CI 0.83-0.98). Higher FEI was significantly associated with decreased HF risk among men (HRQ4 vs. Q1: 0.76, 95% CI 0.59-0.98), but was positively associated among pre-menopausal women (HRQ4 vs. Q1: 2.16, 95% CI 1.11-4.18).Sex hormones potentially influence HF pathogenesis and may offer pathways for interventions.