A Small-Scale Clinical Trial to Determine the Safety and Efficacy of Testosterone Replacement Therapy in Hypogonadal Men with Spinal Cord Injury

Men with spinal cord injury are at an increased risk for secondary medical conditions, including metabolic disorders, accelerated musculoskeletal atrophy, and, for some, hypogonadism, a deficiency, which may further adversely affect metabolism and body composition. A prospective, open label, controlled drug intervention trial was performed to determine whether 12 months of testosterone replacement therapy increases lean tissue mass and resting energy expenditure in hypogonadal males with spinal cord injury. Healthy eugonadal (n = 11) and hypogonadal (n = 11) outpatients with chronic spinal cord injury were enrolled. Hypogonadal subjects received transdermal testosterone (5 or 10 mg) daily for 12 months. Measurements of body composition and resting energy expenditure were obtained at baseline and 12 months. The testosterone replacement therapy group increased lean tissue mass for total body (49.6 +/- 7.6 vs. 53.1 +/- 6.9 kg; p <0.0005), trunk (24.1 +/- 4.1 vs. 25.8 +/- 3.8 kg; p <0.005), leg (14.5 +/- 2.7 vs. 15.8 +/- 2.6 kg; p = 0.005), and arm (7.6 +/- 2.3 vs. 8.0 +/- 2.2 kg; p <0.005) from baseline to month 12. After testosterone replacement therapy, resting energy expenditure (1328 +/- 262 vs. 1440 +/- 262 kcal/d; p <0.01) and percent predicted basal energy expenditure (73 +/- 9 vs. 79 +/- 10%; p <0.05) were significantly increased. In conclusion, testosterone replacement therapy significantly improved lean tissue mass and energy expenditure in hypogonadal men with spinal cord injury, findings that would be expected to influence the practice of clinical care, if confirmed. Larger, randomized, controlled clinical trials should be performed to confirm and extend our preliminary findings.