VA Office of Research and Development
Spinal cord injury (SCI) results in lower limb muscle loss, bone loss, and high fat mass that impede the recovery of physical function, increase bone fracture risk, and worsen health and quality of life. These deficits result from reduced activity after SCI and may be worsened by low testosterone, which is present in many men with SCI. In older men with low testosterone who do not have SCI, testosterone therapy (TRT) is known to increase muscle mass, muscle strength, and bone mineral density, and to reduce body fat. However, it is not known if TRT is effective in men with SCI. The purposes of this study are to determine the effectiveness of TRT in men who have low testosterone and difficulty walking after chronic motor incomplete SCI and to assess whether a process in the body that changes testosterone to dihydrotestosterone (DHT; another hormone that is stronger than testosterone) impacts the effectiveness of TRT in the impaired lower limbs and in other tissues after SCI. The researchers hypothesize that TRT will improve muscle and bone in the impaired limbs of men with chronic incomplete SCI and reduce fat mass, and that finasteride (a drug that blocks that blocks a process that changes testosterone to DHT) will influence prostate symptoms but not the musculoskeletal or body composition benefits produced by TRT.
There is no known cure for spinal cord injury (SCI) nor for the muscle, bone, or metabolic deficits that impair physical function, increase fracture risk, and worsen health after SCI. These deficits are preceded by the neural insult and impaired motor function and may be impacted by low testosterone, present in many men with SCI. Testosterone therapy (TRT) is known to improve musculoskeletal health, body composition, and physical function in older men with low testosterone who do not have SCI and some of the effects of TRT are known to be mediated by the 5-alpha reductase type II (5AR2) enzyme…
Inclusion Criteria: * Veterans eligible for care within the Veterans Health Administration (VHA) * Diagnosis of motor incomplete SCI (AIS C-D) for \>24-months involving spinal segment lumbar (L)1 or above from trauma, vascular, or orthopedic pathology * Low total testosterone (\<300 nanograms/decilliter \[ng/dL\]) and/or low free testosterone (\<4.6 ng/dL) * Presence of one or more sign of low testosterone, defined as: * decreased energy * motivation * initiative or self-confidence * increased fatigue or tiredness * reduced sexual desire or activity * decreased spontaneous (e.g.,…
Participants receive testosterone (200 mg/q2wk) by intramuscular injection
Participants receive finasteride (5 mg/day) orally
Participants receive placebo (weekly) by intramuscular injection
Participants receive placebo pill (daily) orally