By David Liu, PHD

Saturday Aug 25, 2012 (foodconsumer.org) -- Low testosterone is linked to reduced exercise capacity and poor clinical outcomes in patients with heart failure.  A new study in circulation: Heart Failure, suggest that taking testosterone supplements may help those patients with stable chronic heart failure.

The review study of previous trials found testosterone therapy was associated with a significant increase in exercise capacity as measured by units of pooled standard deviation score (SDs) while no significant adverse cardiovascular events were observed.

Mustafa Toma of the St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada and colleagues searched a number of medical databases including medline Embase, web of science, and Cochrance Central Register of Controlled Trials between 1980 and 2010 and identified four studies on the effects of testosterone on exercise capacity in patients with heart failure.

In the four trials, 198 heart failure patients with a mean age of 67 years reported the 6-minute walk test, incremental shuttle walk test, or peak oxygen consumption to determine the exercise capacity after up to 52 weeks of testosterone supplementation.

Heart failure patients treated with testosterone supplementation improved 6-minute walks test, incremental shuttle walk test and peak oxygen consumption by 54.0 meters, 46.7 meters and 2.70 ml/kg per min, respectively, compared with those treated with the placebo.

The researchers concluded "Given the unmet clinical needs, testosterone appears to be a promising therapy to improve functional capacity in patients with HF (heart failure). Adequately powered RCTs (randomized, controlled trials) are required to assess the benefits of testosterone in this high-risk population with regard to quality of life, clinical events, and safety."

Heart failure is an often chronic or long term medical condition in which the heart cannot pump enough blood to the rest of the body.