Medical Research: What is the background for this study? What are the main findings?
Response: Heart rate variability (HRV) has emerged as a valuable non-invasive test to assess autonomic nervous system (ANS) activity. Several studies have linked low resting Heart rate variability to mental health conditions including depression, anxiety, and alcohol dependence, indicating these disorders may be related to an imbalance in autonomic activity. As Heart rate variability is an index of the balance of sympathetic nervous system (SNS) and parasympathetic nervous system activity (PNS), it has proven a useful tool for examining the relative role of SNS activity in female sexual arousal. Moderate SNS dominance (relative to PNS activity) has been shown to predict women’s genital arousal in the laboratory, while high levels of SNS activation have been shown to inhibit genital arousal. Based on this background evidence and on a growing clinical literature indicating that low HRV (generally indicative of high SNS) is associated with negative health outcomes, we predicted a positive linear relationship between Heart rate variability and sexual arousal function. That is, we predicted that women with autonomic balance indicating moderate or low resting SNS activity (relative to PNS activity) would be less likely than women with autonomic balance indicating high resting SNS to report clinically relevant sexual arousal dysfunction. We also predicted that this relationship would hold for overall sexual function.
To test this hypothesis, sexual arousal function, overall sexual function, and resting HRV were assessed in 72 women, aged 18-39. The main finding of the study is that women with below average Heart rate variability were significantly more likely to report sexual arousal dysfunction (p < .001) and overall sexual dysfunction (p < .001) than both women with average HRV and women with above average HRV. Based on these results, we concluded that low HRV may be a risk factor for female sexual arousal dysfunction and overall sexual dysfunction.
Medical Research: What should clinicians and patients take away from your report?
Response: To date, there are no validated physiological markers of sexual dysfunction in women. Based on this study, HRV may be one of the first. Clinicians and patients should be aware that HRV may prove to be a cost effective, easy to administer, and non-intrusive index for both assessing potential sexual dysfunction and for monitoring treatment progress. As potential pharmacological treatments for female sexual dysfunction become increasingly prevalent, HRV may also be used as an index of sexual arousal function in clinical trials of medications developed to treat female sexual arousal disorders.
Furthermore, genital arousal in women is mediated by some of the same mechanisms as genital arousal in men. Given that SNS activity is elevated in both men and women with sexual arousal problems, insights from the literature on HRV and ED may apply to female sexual dysfunction. One such insight that may be relevant to female sexual dysfunction is the relationship between ED and cardiovascular disease (CVD). ED has been shown to be a robust early indicator of CVD. Males who present with erectile dysfunction of vascular rather than psychological origin who are asymptomatic for ischemic heart disease have been shown to be at increased risk for future negative cardiovascular events. It is important to note that CVD is the leading cause of death for both men and women in the United States. More women die each year of CVD than men, and the lifetime risk of developing CVD in women by age 50 is 39%. Because the vascular mechanisms governing male sexual function are similar to those involved in female sexual function, it is possible that arousal dysfunction could be an early prognostic factor for CVD in women.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: Given the difficulties inherent in assessing heart rate variability outside the laboratory, and the necessity of using self-report data to determine participant’s sexual function, the generalizability of these findings may be uncertain. Future research may benefit from a portable device that calculates Heart rate variability, which allows participants to measure their own HRV from home. Also, because we used archival data across studies, we did not have complete data on mental health variables such as depression or anxiety, which may be a mediating pathway between HRV and sexual function. Future research on the relationship between Heart rate variability and sexual function should control for such factors and others that could impact SNS activity, such as smoking, athleticism, and antidepressant medication use.
Amelia Stanton, Graduate Student (2015). Low Heart Rate Variability Linked To Decreased Sexual Arousal In Women