NEW YORK (Reuters Health) - In a small study of men with chronic heart failure (CHF), 12 weeks of testosterone therapy appeared to safely improve exercise tolerance and CHF symptoms. Larger studies are needed to verify this effect and to elucidate the mechanisms involved.

The findings, which are reported in the April issue of Heart, are based on a study of 20 men with CHF who were randomized to receive testosterone or placebo injections every 2 weeks for 12 weeks. All of the men had CHF for at least 6 months and no malignant or other debilitating diseases.

Testosterone therapy was associated with a significant improvement in the distance walked in the shuttle walk test, Dr. K. S. Channer, from Royal Hallamshire Hospital in Sheffield, UK, and colleagues note.

Testosterone therapy also led to significant improvements in CHF symptoms and may have had a beneficial effect on depression. None of these effects was seen with placebo. Treatment with the hormone had no significant effect on muscle bulk and strength or on any hemodynamic parameters.

Treatment with testosterone appeared to be safe and well tolerated, the authors note. However, one patient in the testosterone group did experience breathlessness after 8 weeks of therapy. Exactly how testosterone produced these benefits in CHF patients is unclear, the researchers state. "The small sample size limited our ability to detect any significant impact of treatment on myocardial contractility, physical strength, or humoral factors," they add.

Heart 2004;90:446-447.

Copyright © 2003 Reuters Limited. All rights reserved. Republication or redistribution of Reuters Limited content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters Limited. Reuters Limited shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.