Testosterone and Heart Attacks: Q&A
What have the major studies found about testosterone therapy and heart attack? continued...
In the University of Texas study, researchers looked at more than 6,000 men ages 66 and older who were treated with testosterone. The researchers compared them to more than 19,000 men 66 and older who did not get testosterone.
They found no difference in the risk of heart attack in the two groups, says study leader Jacques Baillargeon, PhD, director of research in the division of epidemiology and outcomes at the University of Texas Medical Branch, Galveston. Baillargeon says he even found testosterone may offer some protection for men at the highest risk of heart attack. But he says that finding should be duplicated by other researchers to see if it holds up.
Why are the findings at odds?
"The studies are quite different in the way they are being conducted," Anawalt says.
The studies look at men of different ages and at different time periods. The Texas study focused only on men 66 or older who were on Medicare. The UCLA study looked at a wider age range of men.
Researchers have looked at different time periods to see if testosterone raises heart attack risk, says Sander Greenland, PhD, professor emeritus of epidemiology and statistics at UCLA. He was a researcher on the UCLA study and reports consultant work in various testosterone lawsuits.
His team tracked heart attacks soon after beginning the treatment. "We were looking at the first 90 days," he says.
The Texas researchers followed men between 1997 and 2005.
The men who are studied may differ in health habits, and that could affect results, Baillargeon says.
How might testosterone raise or lower heart attack risk?
The link between testosterone therapy and heart attack is complicated, Baillargeon says. Testosterone may help the heart by improving cholesterol and decreasing body fat and inflammation.
It could also raise heart disease risk in a number of ways, Baillargeon says. Men on testosterone therapy might retain more salt and water while using it, which could lead to high blood pressure and other problems, he says.