Testosterone therapy, often simply called “T,” is associated with cardiovascular risk factors like high blood pressure, elevated levels of “bad” (LDL) cholesterol that clogs arteries, and lower levels of “good” (HDL) cholesterol that helps keep arteries free of debris, says Nina Stachenfeld, PhD, director of the Laboratory for Metabolic Testing and Performance at the Yale School of Medicine in New Haven, Connecticut. Over time, transgender men and transmasculine people taking testosterone may also have an increased risk of blood clots compared with cisgender women, as well as endothelial dysfunction, a condition that develops when the inner lining of small arteries no longer expands and contracts efficiently, says Dr. Stachenfeld. Endothelial dysfunction can then lead to atherosclerosis, a hardening and stiffening of the arteries that can cause heart attacks and strokes.
What Is Masculinizing Hormone Therapy
When trans people take testosterone as part of a medical gender transition, they can experience physical changes similar to what cisgender men undergo during puberty, including the deepening of their voice and hair growth on their chest or face, according to the Gender Affirming Health Program at the University of California San Francisco (UCSF). Testosterone can also suppress menstrual cycles. Masculinizing hormone therapy has clear benefits. It’s associated with improved mental health and reduced gender dysphoria (psychological distress caused when your gender identity doesn’t match your sex assigned at birth). Other benefits can be an improved social life and more sexual satisfaction. But there are downsides, too. Testosterone therapy can increase the likelihood of developing obesity, high blood pressure, elevated cholesterol levels, and type 2 diabetes — all risk factors for cardiovascular disease. That being said, cisgender men have higher rates of heart disease and cholesterol-related disorders than cisgender women, according to the UCSF, and higher rates of diabetes, according to the Centers for Disease Control and Prevention (CDC). Still, for most trans people who want gender-affirming hormone therapy, the benefits outweigh the risks. For many, in fact, it’s medically necessary to avoid serious psychological harm from gender dysphoria, Stachenfeld says.
Heart Risks of Testosterone
Trans men are 2.5 times more likely to have heart attacks than cisgender men, according a study published in April 2019 in the journal Circulation. Another study, published in September 2019 in the journal JSRM Cardiovascular Disease, showed they’re also 2.5 times more likely to experience a stroke than cis men. Heart attack risk is elevated in part because transgender men are less likely than their cisgender counterparts to follow heart-healthy lifestyles that include regular exercise, plenty of sleep, and good eating habits, according to a scientific statement on transgender heart health by the American Heart Association (AHA), published in August 2021 in Circulation. Experts believe these deficits are driven in part by discrimination and lack of access to housing and healthcare. However, testosterone also plays a role. Masculinizing hormone therapy is associated with an increase in systolic blood pressure, the “top number” that indicates the pressure against artery walls when the heart beats, according to a study published in April 2021 in Hypertension. Within two to four months of starting testosterone, transgender men experience an average increase of 2.6 mmHg (millimeters of mercury) in systolic blood pressure. Left untreated, this can contribute to an increased stroke risk over time. In addition, testosterone therapy can negatively impact cholesterol levels. According to a meta-analysis published in September 2017 in The Journal of Clinical Endocrinology & Metabolism, which included 1,500 trans men in 20 studies, two years on T had no effect on total cholesterol, but led to significantly higher levels of LDL cholesterol (a risk factor for heart disease) and significantly lower levels of heart-protective HDL cholesterol. By comparison, evidence does not currently suggest that testosterone therapy for cis men with hypogonadism increases (or decreases) the risk of cardiovascular disease, according to a review published in January 2018 in the journal Mayo Clinic Proceedings — although it noted that further research was needed due to previous weak and contradictory findings.
Heart-Healthy Lifestyle Choices
Like cisgender men, transgender men can minimize their risk of developing or dying from heart disease by adopting a lifestyle that supports cardiovascular health, says Lauren Beach, PhD, of the Institute for Sexual and Gender Minority Research and Wellbeing at the Northwestern Feinberg School of Medicine in Chicago. Dr. Beach advises trans men to focus on seven strategies recommended by the AHA:
Manage blood pressureControl cholesterolReduce blood sugarIncrease physical activityFollow a healthy dietMaintain a healthy weightAvoid smoking
Focusing on these things is crucial because trans men face other heart risks beyond their control that are related to their gender identity, says Beach. In particular, they may experience stigma, stress, discrimination, and marginalization related to their gender identity and gender expression that can limit their ability to afford or access necessary healthcare and make it harder for them to focus on many of these strategies for heart health.
Research Still Needed
There are still a lot of medical unknowns when it comes to lifelong health for transgender men, a group that hasn’t been studied as extensively as trans women or cisgender individuals, says Carl Streed Jr., MD, MPH, a researcher at the Center for Transgender Medicine and Surgery at Boston Medical Center in Massachusetts. Unfortunately for gender-diverse people, many calculators for cardiovascular disease risk are currently based on cis male or female identities, and have yet to be updated to account for the unique medical issues encountered by transgender individuals, Dr. Streed says. This means there aren’t good tools right now to easily determine whether trans men and women (who also face additional risks to heart health as they age) should manage risk factors like high blood pressure or elevated cholesterol in the same way as cisgender people. “These risk calculators need to be updated,” Streed says. “Until these are properly calibrated to meet everyone’s heart health needs, there isn’t the clearest guidance on how to utilize them for transgender persons.” Until there are better treatment guidelines tailored specifically to trans people on T, it’s reasonable for them to follow advice that doctors typically offer patients of all genders, Streed says. “Transgender men need to be offered screening and prevention for heart disease like any other patient, with special attention to modifiable risk factors such as smoking, blood pressure, and lipids,” Streed says. “Much of the guidance for heart health is agnostic of sex and gender issues: stop smoking, engage in physical activity, screen for modifiable factors.”
