Men with spinal cord injury (SCI) experience a high prevalence of hypogonadism which influences the neural, muscular, skeletal, and body composition deficits that occur after injury. It remains unknown whether testosterone administration improves bone mineral density, muscle mass and muscle function, and body composition / metabolic health in hypogonadal men who have experienced ambulatory dysfunction subsequent to incomplete spinal cord injury. In addition, it is unknown whether testosterone or the 5-alpha reduced metabolite dihydrotestosterone (an endogenous metabolite of testosterone) mediate effects in these and other tissues.~For this study hypogonadal men with motor incomplete spinal cord injury who present with ambulatory dysfunction will be randomized to receive testosterone plus the 5-alpha reductase inhibitor finasteride or a placebo treatment for 12 months. Testosterone or placebo injection will be administered weekly; finasteride or placebo will be administered daily. Participants will be assessed at study entry and at 1-6 month intervals thereafter. Assessments will include measurements such as a dual energy x-ray absorptiometry (DEXA) scan, MRI scan, and muscle performance tests. Participants will also have several safety tests, including electrocardiogram (EKG) for cardiac electrophysiology, prostate digital rectal exam and prostate ultrasound sizing for prostate health, and blood tests to assess hematocrit, liver enzymes (AST and ALT), prostate specific antigen (PSA), cholesterol, and other health markers.
The purpose of this study is to determine whether testosterone plus finasteride treatment will improve musculoskeletal health, neuromuscular function, body composition, and metabolic health in hypogonadal men who have experienced ambulatory dysfunction subsequent to incomplete spinal cord injury. The investigators hypothesize that this treatment will improve bone mineral density, enhance muscle size and muscle function, and improve body composition, without causing prostate enlargement.