Men who undergo testosterone replacement therapy (TRT) may get an unexpected benefit: They may be at lower risk for heart attack and stroke.

Testosterone is used to treat men who have been diagnosed with low-T, or low levels of the male sex hormone testosterone. Men with low-T report increases in energy, sex drive, and mood after testosterone replacement therapy.

The number of middle-aged men taking TRT has tripled in 10 years, according to a 2011 study published in the journal JAMA Internal Medicine.

A study conducted at the Kansas City VA Medical Center examined data from 83,010 healthy men who underwent TRT. Only 63 percent of patients achieved normal testosterone levels after treatment, but heart attacks and strokes were significantly lower in that group.

"With such widespread and ever increasing use of TRT, there has been growing concern regarding its effect on mortality, as well as conflicting results," said cardiologist Rajat S. Barua. "Our aim was to address the knowledge gap.

"In this study of men, without previous history MI [myocardial infarction or heart attack] or stroke, with low testosterone levels, normalization of testosterone levels using TRT is associated with lower mortality, fewer MIs, and strokes," said Barua. "This is the first study to demonstrate that significant benefit is observed only if the dose is adequate to normalize the testosterone levels."

Dr. Aaron Michelfelder, a family physician at Loyola University Health System, said that TRT may not be the best choice for all men.

"Asymptomatic men should not be screened for low testosterone levels, because there is no evidence that supplementing testosterone in men without symptoms makes any difference in their lives," Michelfelder told dailyRx News. "Aging is a normal process, and many men do not develop sexual issues or significant fatigue as they age, which would be symptoms of low testosterone.

Dr. Barua's study was published in the European Heart Journal.