Testosterone Benefits Men With Heart Failure

Abstract

Kate Johnson is a freelance writer in Montreal. Long-acting testosterone injections improved exercise capacity and insulin sensitivity in elderly men with heart failure, reported Dr. Giuseppe Caminiti of the Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana in Rome and colleagues. “The increase in functional capacity and muscle strength is related to the increase in plasma levels of testosterone and not related to changes in left ventricular function,” noted the authors (J. Am. Coll. Cardiol. 2009 54: 919-27). The study randomized 70 elderly patients, median age 70 years, with stable chronic heart failure (CHF) to either long-acting testosterone undecanoate (1,000 mg) or placebo intramuscular injections given at baseline, 6, and 12 weeks, in addition to optimal medical therapy. Echocardiographic examination, muscle strength assessment, and cardiopulmonary exercise testing, as well as a 6-minute walk test (6MWT) were performed at the same three time points. Blood samples also were to measure testosterone and insulin, among other parameters. Baroreceptor cardiac reflex sensitivity (BRS) was assessed at the start and end of the study. At baseline, 21 patients in the testosterone group and 9 in the placebo group had total and free testosterone levels below the normal range—a phenomenon that has been well documented in CHF patients. Baseline testosterone levels correlated with peak oxygen consumption (VO2), distance reached in the 6MWT, and isometric strength. As expected, testosterone levels normalized in the treatment group but not the placebo group, and improved testosterone levels correlated with improved VO2 and quadriceps maximal voluntary contraction. Insulin resistance was significantly reduced in the treated group, BRS improved with treatment but not with placebo. There were no significant changes in left ventricular function in either group. The authors suggested that testosterone's ability to improve such extra-cardiac problems of muscle performance and glucose metabolism might not only improve the symptoms but possibly the pathophysiology and worsening of heart failure syndrome.