Medical Research: What is the background for this study? What are the main findings?
Dr. Yu: It is well known that cardiovascular disease is more common in men than in women. The exact reasons for this are unknown, but may be related to gender differences in levels of sex hormones such as testosterone and estrogen. As compared to premenopausal women, men have higher testosterone and lower estrogen levels. It is currently unclear whether the actions of testosterone and/or estrogen affect cardiovascular risk factors.
In this study, we explored the regulation of cardiovascular risk factors by testosterone and estrogen in men. We found that higher levels of testosterone led to lower HDL levels (“good” cholesterol), whereas estrogen did not regulate HDL. In contrast, low levels of estrogen led to worsening insulin resistance and increased muscle fat, markers for developing diabetes. Importantly, LDL cholesterol (“bad” cholesterol”) was not affected by either testosterone or estrogen in men.
Medical Research: What should clinicians and patients take away from your report?
Dr. Yu: This study of adult men revealed that HDL levels are regulated by testosterone and unaffected by estrogen, whereas insulin resistance and muscle fat are regulated by estrogen but not testosterone. These observations may help explain why men have a higher risk of cardiovascular disease than women.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Yu: It will be important to evaluate whether other cardiovascular risk factors are similarly regulated by gonadal steroids in men. For example, we plan to study effects of testosterone and estrogen on inflammatory markers as well as hormones related to fat metabolism and cardiovascular function. An improved understanding of these effects may help to explain sex differences in cardiovascular disease.
Men’s heart disease risk linked to high testosterone and low estrogen
MedicalResearch.com Interview with:Elaine W. Yu, MD, MMSc Assistant Professor of Medicine Harvard Medical School (2015). High Testosterone Low Estrogen Linked To Men’s Cardiovascular Health