Does High Testosterone Cause Heart Disease?

A combination of high testosterone and low estrogen in men may explain why males have more heart disease than premenopausal women. A new study shows that these sex hormones in men have an impact on cardiovascular risk factors that in turn increase a man’s risk of heart disease.

Testosterone and heart disease

Prior to this new study, which was presented at the Endocrine Society’s 97^th annual meeting in San Diego on March 7, 2015, experts had investigated a link between testosterone and heart disease. The 2014 study, which appeared in The Journal of the American Medical Association, evaluated data from 8,700 older men (average age, early 60s) who had low T levels.

The researchers found that men who were placed on testosterone replacement therapy had a 30 percent higher risk of stroke, heart attack, or death over a three-year period than did men who did not take testosterone.

According to the Harvard team, it was possible the hormone prompted the formation of blood clots, which placed the men at risk of these cardiovascular events.

New study of testosterone and heart disease

In the new study, which was headed by Elaine Yu, MD, MSc, an assistant professor at Harvard Medical School, 400 healthy men (ages 20-50) were evaluated. Here’s how the research was conducted:

All the men were given a drug (goserelin) that suppressed their natural production of testosterone and estrogen
Then the men were divided into two groups. In one group, 198 men were treated daily for four months with a placebo or one of four doses of testosterone gel. The men who received testosterone achieved levels of the hormone ranging from very low testosterone to high-normal testosterone.
In the second group, 202 men were treated the same way as those in group 1, but they also received a drug (anastrozole) that blocks conversion of testosterone to estrogen, resulting in very low levels of estrogen.

Here’s what the investigators found:

Higher levels of testosterone were associated with lower levels of good (high-density lipoprotein,HDL) cholesterol
Estrogen had no impact on HDL cholesterol
Low levels of estrogen resulted in higher fasting blood sugar levels, worsening insulin resistance, and accumulation of fat in the muscles, all of which are factors involved in diabetes, which in turn is a risk factor for heart disease.
Changes in low-density lipoprotein (LDL) cholesterol (bad cholesterol), body weight, and blood pressure (also risk factors associated with heart disease) were not significantly associated with testosterone or estrogen levels

Yu commented that their observations “may help explain why men have a higher risk of cardiovascular disease.”