Effects of Hormonal Anabolic Deficiency and Neurovascular Alterations on Mortality in Male Patients With Heart Failure

Oxygen consumption (VO2) and carbon dioxide output (VCO2) were measured by means of gas exchange on a breath-by-breath basis. The patients were initially monitored for 2 minutes at rest when seated on the ergometer, after that they were instructed to pedal at a pace of 60-70 rpm and the completion of the test occurred when, in spite of verbal encouragement, the patient reached maximal volitional fatigue.

Multiunit post-ganglionic muscle sympathetic nerve recordings were made using a tungsten microelectrode placed in the peroneal nerve near the fibular head. Nerve signals were amplified by a factor of 50,000 to 100,000 and band-pass filtered (700 to 2000 Hz). For recording and analysis, nerve activity was rectified and integrated (time constant 0.1 seconds) to obtain a mean voltage display of sympathetic nerve activity.

Dual-energy X-ray absorptiometry (DXA) scan was used to measure total lean mass, body fat and bone mineral content.

Venous occlusion plethysmography was used to assess non-invasively blood flow.

Blood samples were drawn in the morning after 12h overnight fasting.

Muscle strength was assessed by handgrip dynamometer using the mean value of three attempts.