Abstract 18671: Exercise Training Associated With Testosterone Replacement Decreases Muscle Sympathetic Nerve Activity in Heart Failure Patients With Hypogonadism
Purpose: Heart failure (HF) is characterized by increase in muscle sympathetic nerve activity (MSNA). Advanced HF can be associated to testosterone deficiency. Study with HF patients and testosterone therapy showed improvement in VO2 and baroreflex sensitivity. The role of exercise with or without testosterone is unknown. Therefore, the aim of the study was to investigate if aerobic exercise with or without testosterone replacement decreases MSNA.
Methods: 24 HF patients (52±2 yr) with low testosterone, FC III (NYHA) and LVEF 26±2%, were divided: Exercise Training (ET,n=9) Testosterone (Testo,n=8) and Exercise Training+Testosterone (ET+Testo,n=7). Total (TT) and free (FT) testosterone and SHBG were measured. Testosterone deficiency was characterized as TT <350 ng/dL and FT <131 pmol/L. Cardiopulmonary exercise was performed on bike. MSNA was measured by microneurography. Both groups Testo and ET+Testo were treated with undecilate of testosterone (intramuscular) at the beginning of the protocol and were monitored monthly. The exercise consisted in three 40-minutes sessions per week on an ergometer bike. Exercise intensity was between anaerobic threshold and respiratory compensation point.
Results: After 4 months, TT and FT were restored in ET (307±40 to 429±93 ng/dL; p<.001 and 160±26 to 246±50 pmol/L; p<.001), Testo (279±33 to 575±66 ng/dL; p<.001 and 137±18 to 381±55 pmol/L; p<.001) and ET+Testo (223±18 to 497±82 ng/dL; p<.001 and 135±22 to 353±49 pmol/L; p<.001) groups. Peak VO2 increased in ET (14.76±1.60 to 18.06±2.26 ml/kg/min; p=.01), Testo (19.33±1.87 to 20.34±2.08 ml/kg/min; p=.01) and ET+Testo (17.61±1.37 to 20.63±2.72 ml/kg/min; p=.01). Maximal power (watts) was increased only within ET+Testo (75±8 to 129±21 watts; p<.001). MSNA decreased in ET (49±4 to 34±1 bursts/min; p=.02) and ET+Testo (61±4 to 32±2 bursts/min; p<.001) but was not different within Testo (39±4 to 34±3 bursts/min; p=.89).
Conclusion: Functional capacity increased in all groups, but only ET+Testo improved muscle strength. Interestingly, exercise alone was able to restore testosterone. In addition, ET and ET+Testo reduced MSNA. These findings emphasize that ET and testosterone together should be included in the treatment of HF patients with hypogonadism.
- © 2013 by American Heart Association, Inc.