Cortisol is the hormone most directly tied to stress and HRV. If you suspect hormonal issues, work with a healthcare provider. Understanding these patterns helps interpret HRV data accurately. While acute cortisol spikes are normal and healthy, chronic elevation suppresses HRV. In addition, there have been two large long-term peer-reviewed studies showing a significant reduction in the incidence of invasive breast cancer in women on testosterone therapy. In summary, TRT may raise heart rate in some people, but this effect is not the same for everyone. Adjusting the dose or changing the type of TRT may help control side effects like a fast heart rate. The longitudinal Cardiovascular Health Study failed to find an association between total and free testosterone levels and either incident CVD or mortality in older men. In contrast, other studies have found no statistically significant association between testosterone level and cardiovascular mortality. Speculation on the hormone's effects has led to decades of observational studies and reviews. ARE, androgen response element; CR, coregulator; ER, estrogen receptor; H, hydrogen; HSP, heat shock protein; O, oxygen; OH, hydroxide; SHBG, sex-hormone binding globulin; T, testosterone. The effect of testosterone on specific cardiovascular risk factors is also assessed. Nonetheless, despite conflicting results, these hormones may influence arrhythmia occurrence both in the presence or absence of underlying structural heart disease. However, the link between the sex hormones and susceptibility to arrhythmias is still a matter of debate. A study on hormone replacement for 1 year confirmed that the use of ERT increases the QTc interval (73). Concerning hormone replacement in females, there are several studies in post-menopausal women showing that estrogen replacement therapy (ERT) prolongs the QTc interval. This has led to multiple pharmacovigilance studies assessing the link between hormone replacement therapy (HRT) and the incidence of ventricular arrhythmias. This most likely relates to the significant decrease in testosterone in surgically induced menopausal women . Menopausal status has a significant impact on the prevalence of HSDD, with several studies showing that the prevalence of HSDD is greatest in younger, surgically menopausal women (16–26%) compared with naturally pre-menopausal women (7–14%). HSDD is a sexual disorder characterized by distress related to a loss of or decline in sexual interest.