By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) – Advertising has been so intense that few have not heard of so-called “low t,” as a result of this marketing. A growing number of American men take testosterone to combat weakness and other physical effects.

Now there is a report that reinforces findings in previous reports that taking testosterone could more than double the risk of heart attack in men 65 and older. Supplementation may also raise the risk of these heart attacks in younger men with pre-existing heart problems. Those younger men had a two- to three-fold increase in heart attack risk after they received a testosterone prescription.

This is according to a new NIH study that looked at more than 55,000 men who began taking prescription testosterone.

While for most men no significant increase in risk of heart attack was seen, in men 65 and older the risk of a heart attack went up. Once these men stopped taking testosterone treatment, their risk of heart attack appeared to go back to the risk that they had before they started taking the drugs.