In a study of 70 elderly men with moderately severe CHF, testosterone therapy for 12 weeks improved exercise capacity, muscle strength, glucose metabolism, and baroreflex sensitivty. Testosterone had no effect on LV function, however. The results of the Italian study appear in the Journal of the American College of Cardiology.
In an accompanying editorial, Pâl Aukrust writes that:
Testosterone treatment represents a new therapeutic approach in chronic HF that might have some potential. Studies performed thus far primarily demonstrate improved functional capacity and quality of life, with little or no effects on cardiac function, representing a more “palliative” therapeutic concept. However, it is not inconceivable, on the basis of the dynamic interaction between HF comorbidities and the myocardium, that these extra-cardiac effects, at least in the long-term, might translate into not only reduced morbidity but also into improved myocardial performance and reduced mortality. This aspect should be addressed in forthcoming studies.
Here is the ACC press release:
A Boost of Testosterone Benefits Elderly Patients with Heart Failure
Hormone improves cardiac function, large muscle strength and blood sugar metabolism—key factors for prognosis and survival
Boosting dwindling testosterone levels appears to provide important therapeutic benefits for elderly men with heart failure—a condition in which the heart lacks the ability to pump enough blood through the body.
Patients receiving testosterone therapy had improved exercise capacity, muscle strength and performance, as well as blood sugar metabolism, according to new data published in the September 1, 2009, issue of the Journal of the American College of Cardiology. Unlike previous studies using testosterone, researchers found that increases in functional capacity and muscle strength were due to higher plasma levels of testosterone and not to changes in left ventricular function, suggesting that testosterone could have direct beneficial effects on muscle performance in heart failure patients.
“Our study shows that testosterone therapy may be an important addition to the treatment of chronic heart failure,” said Ferdinando Iellamo, M.D., Department of Internal Medicine, University of Rome Tor Vergata, and IRCCS San Raffaele Pisana, Rome, Italy. “It is well tolerated and appears to improve cardiovascular parameters that play a role in determining the prognosis and survival of these patients.”
Approximately one in four men with chronic heart failure has evidence of testosterone deficiency. Low plasma levels of this hormone have been related to the progression of heart failure at least partly because it may impair muscle function and exercise tolerance. Testosterone is believed to play a protective role, in part, by improving the capacity of the cardiovascular and respiratory systems to deliver oxygen to exercising muscles. Supplementing testosterone levels also appears to improve other disturbances in heart failure patients such as impaired effects of insulin with subsequent increased glucose levels, as well as increased levels of inflammatory mediators that can contribute to an inappropriate weight loss.
Experts say it is becoming increasingly apparent that heart failure is a disease that involves not only the heart and circulation, but also other organs and systems such as the skeletal muscle.
“Despite state-of-the-art cardiovascular treatment, chronic heart failure is a progressive disease with high morbidity and mortality, suggesting that important pathogenic mechanisms remain unmodified by the present treatment modalities,” said Pal Aukrust, M.D., Ph.D., Research Institute for Internal Medicine, University of Oslo, Norway and lead author of the accompanying editorial. “Accordingly, there is an urgent need for new treatment options, and testosterone substitution may well be an interesting approach.”
Seventy elderly male patients with stable chronic heart failure were randomly assigned to receive long-acting testosterone therapy by intramuscular injection (n=35) or placebo (saline injection, n=35)—both in addition to standard medical treatment. Patients had to have stable heart failure to be enrolled in this double-blind, placebo-controlled trial. Each received an injection at baseline, 6 weeks and 12 weeks. All patients received a series of tests including electrocardiogram, cardiopulmonary exercise test, 6-minute walk test, and an assessment of muscle strength, among other measures at the start and conclusion of the study.
Although there have been several other studies examining the therapeutic value of testosterone on chronic heart failure, the present study builds upon the existing data in several important ways. First, in contrast to previous studies, researchers found that the effect of testosterone on muscle performance was not secondary to improved heart function, suggesting a more direct effect on the muscles, according to Dr. Aukrust. Second, while it has previously been reported that testosterone therapy may increase forearm muscle strength, the present study shows better performance in larger, weight-bearing muscles. Finally, the improvement in muscle performance and functional capacity was accompanied by an increase in insulin sensitivity even in patients with normal blood sugar levels, which may counteract the development of type II diabetes mellitus.
“These are exciting results, but we need large scale clinical trials to determine how best to prescribe testosterone supplementation and identify sub-groups of heart failure patients likely to benefit. This includes evaluating its use in women,” added Dr. Iellamo.
He says preliminary results from an ongoing study in women with chronic heart failure by his group seem promising.
Dr. Iellamo reports no conflicts of interest.