Low testosterone is linked with higher heart and metabolic risk in men, but a link is not a cause. In many men, low testosterone looks more like a sign of poorer overall health, such as excess weight or type 2 diabetes, than a driver of heart disease in its own right.
The largest safety trial so far found that testosterone therapy did not increase major cardiac events in men with confirmed low testosterone. It did not reduce them either. Testosterone therapy is a treatment for testosterone deficiency. It is not a heart treatment.
Key takeaways
- Low testosterone is linked with higher heart risk, but it often looks like a sign of poorer overall health and not a proven cause.
- In the largest trial, testosterone therapy neither raised nor lowered major cardiac events in men with confirmed low testosterone.
- That trial also saw more atrial fibrillation, acute kidney injury and pulmonary embolism in the testosterone group.
- Testosterone therapy treats the symptoms of deficiency and is not a way to prevent heart disease.
- Erectile dysfunction can be an early vascular warning sign and makes a heart risk check reasonable.
What "low testosterone" actually means
Testosterone falls gradually with age, and levels swing through the day. A single low reading does not make a diagnosis.
The Endocrine Society's guideline recommends diagnosing testosterone deficiency, also called hypogonadism, only in men who have both consistent symptoms and unequivocally, consistently low levels. It recommends a fasting morning blood test, repeated to confirm the result.1
This matters for the heart question. Most of the research below is about men who met that stricter definition, not men with a borderline number and no symptoms.
What low testosterone is linked to
The strongest links are metabolic. In a pooled analysis of 43 studies, men with type 2 diabetes had clearly lower testosterone than men without it, and men with higher testosterone had a 42% lower risk of developing type 2 diabetes.2
Low testosterone also travels with excess abdominal fat, raised blood sugar and insulin resistance. Each of these raises heart risk through routes that have nothing to do with hormones.
There is a link with survival as well. A review of community studies found that men with low testosterone had a higher risk of death from any cause and from cardiovascular disease.
Why association is not causation
The same review added an important caution. Results varied widely from study to study, and the authors concluded that the effects were probably driven by differences in the men studied, such as their underlying health.3
That fits what is known about testosterone. Excess body fat, type 2 diabetes, poor sleep and long-term illness can all lower it. So a low level may be the result of the same conditions that damage arteries, with both pointing back to a shared cause.
Observational studies cannot settle this. Only a randomized trial can show whether raising testosterone changes heart outcomes.
What the TRAVERSE trial found
TRAVERSE, published in the New England Journal of Medicine in 2023, is the largest such trial. It enrolled 5,246 men aged 45 to 80 who had symptoms of hypogonadism, two fasting testosterone levels below 300 ng/dL, and either existing cardiovascular disease or a high risk of it. They were randomly assigned to a daily testosterone gel or a placebo gel.
| Outcome | Testosterone | Placebo |
|---|---|---|
| Cardiovascular death, nonfatal heart attack or nonfatal stroke | 7.0% (182 men) | 7.3% (190 men) |
| Atrial fibrillation, acute kidney injury, pulmonary embolism | Higher incidence | Lower incidence |
The trial was designed to test safety, and on its main measure testosterone was found to be noninferior to placebo. In plain terms, it did not raise the rate of major cardiac events. The researchers also reported a higher incidence of atrial fibrillation, acute kidney injury and pulmonary embolism in the testosterone group.4
Three limits are worth knowing:
- The men had confirmed low testosterone with symptoms. The results do not apply to men with normal levels.
- Treatment lasted about 22 months on average, with about 33 months of follow-up. Longer-term effects are less certain.
- The trial tested one form of prescribed therapy, adjusted to keep blood levels in a set range. It says nothing about higher doses or unsupervised use.
Testosterone therapy is not a heart treatment
TRAVERSE answered a safety question. It did not show that testosterone prevents heart attacks or strokes, because the rates in the two groups were about the same.
The Endocrine Society recommends testosterone therapy for men with symptomatic deficiency, to correct those symptoms, after a discussion of benefits and risks. Lowering cardiovascular risk is not among the reasons it gives. It also recommends against starting it in men who have had a heart attack or stroke in the last six months, or who have uncontrolled heart failure, a raised red blood cell level or a tendency to form clots.1
If you have low testosterone and heart risk factors, they are two separate problems to work on. Blood pressure, cholesterol, blood sugar, weight, activity and smoking are still what determine your heart risk.
Erectile dysfunction as an early vascular warning
Men often look into testosterone because of erectile dysfunction, or ED. ED has its own relationship with the heart.
An erection depends on healthy blood vessels. In a pooled analysis of 12 prospective studies with 36,744 participants, men with ED had a 48% higher risk of cardiovascular disease, a 46% higher risk of coronary heart disease and a 35% higher risk of stroke than men without it. The authors judged the increase to be probably independent of standard risk factors.5
An expert panel on sexual function and heart health, known as the Princeton Consensus, highlights this link. It notes that cardiovascular disease in men with ED may be present without symptoms and may benefit from risk reduction.6
ED has many causes, including medicines, stress, nerve problems and hormones, and it does not mean you have heart disease. It does mean a heart risk check is reasonable, especially if ED appears in your 40s or 50s without an obvious reason. Our page on erectile dysfunction explains more.
Your next step
If you have low testosterone, ED or both, the sensible move is to find out where your heart risk stands on its own terms. Our guide to a heart disease risk assessment explains what a preventive evaluation looks at.
You can also answer the three quick questions in the screener on the Cardio Res-Q program page. Low testosterone and erectile dysfunction are both on the list of risk factors the program screens for. No testosterone or other hormone test is part of the first visit.
Are You a Candidate for Cardio Res-Q?
Three quick questions about the risk factors we screen for. Your answers stay between you and the clinic.
Frequently asked questions
Does low testosterone cause heart disease?
That has not been shown. Low testosterone is associated with diabetes, excess weight and higher death rates in population studies, but researchers believe much of this reflects underlying health and not a direct effect of the hormone. It is best treated as a prompt to check your other risk factors.
Is testosterone therapy safe for the heart?
In the TRAVERSE trial, men with confirmed hypogonadism who used testosterone gel had no more major cardiac events than men on placebo over about three years of follow-up. Atrial fibrillation, acute kidney injury and pulmonary embolism were more frequent with testosterone. Whether it is right for you depends on your own history and is a decision for you and your prescriber.
Will raising my testosterone lower my heart risk?
There is no good evidence that it will. The largest trial found similar rates of heart attack, stroke and cardiovascular death with testosterone and with placebo. Testosterone therapy treats the symptoms of deficiency. It is not a way to prevent heart disease.
Should a man with erectile dysfunction have his heart checked?
It is a reasonable step. Pooled studies show men with ED have a higher rate of later cardiovascular disease, and expert guidance notes that heart disease in these men can be silent. Tell your doctor about ED so that blood pressure, cholesterol and blood sugar can be reviewed.
Related reading
This article is for general education and is not medical advice. Decisions about testing and medication should be made with your clinician. If you have chest pain or other symptoms of a heart attack, call 911.
