Effects of Testosterone+Finasteride On Muscle After Spinal Cord Injury: A Randomized Double-Blind, Placebo-Controlled Pilot Study

Research Objectives To evaluate the influence of high-dose testosterone plus finasteride (T+F) on voluntary knee extensor (KE) strength and KE cross-sectional area (CSA) in men with impaired gait and low to low-normal testosterone after chronic incomplete spinal cord injury (SCI). Design Randomized, double-blind, placebo-controlled pilot study. Setting North Florida/South Georgia Veterans Healthcare System. Participants Men (n=10), age 59.6±8.1 years, 2-46 years after SCI (AIS C/D), injury level (C3-L3), serum testosterone (294±134ng/dL), bioavailable testosterone (54±9ng/dL) who demonstrated impaired gait (0.20-1.30m/s). Interventions T+F: Testosterone-enanthate (Delatestryl®, 125-mg/week, i.m.) plus Finasteride (Proscar®, 5-mg/day, p.o.); or vehicle (sesame oil, i.m.) plus placebo (p.o) for 6-12 months. Main Outcome Measures Changes in non-dominant KE peak isometric torque and mean isokinetic torque at 60°/sec and 180°/sec and KE CSA at 6-months and 12-months. Results At baseline, total and bioavailable testosterone were similar between T+F and placebo groups. Nadir serum testosterone was 130-175% higher in response to T+F while no change was observed in the placebo group throughout the treatment phase. Within the full cohort, the percentage changes in KE torque and KE CSA at 6-months were as follows in T+F vs. placebo groups, respectively: isometric (+14.7% vs. -6.1%, Hedges’ g=0.82), isokinetic 60°/sec (+13.0% vs -5.9%, g=1.07), isokinetic 180°/sec (+26.5% vs -16.7%, g=0.78), and CSA (+9.2 vs -1.1, g=2.73). In a subgroup of men who completed 12-months, the percentage changes in KE torque and CSA were: isometric (+12.8% vs -6.7%, g=1.0), isokinetic 60°/sec (+25.3% vs. -5.2%, g=0.65), isokinetic 180°/sec (+29.8% vs. -0.7%, g=0.65), and CSA (+13.9 vs +0.6, g=1.90). Conclusions This controlled pilot study suggests that T+F increased KE strength and CSA in men with impaired gait and low to low-normal testosterone after chronic incomplete SCI. A larger clinical trial is warranted to validate our findings. Author(s) Disclosures No conflicts of interests. To evaluate the influence of high-dose testosterone plus finasteride (T+F) on voluntary knee extensor (KE) strength and KE cross-sectional area (CSA) in men with impaired gait and low to low-normal testosterone after chronic incomplete spinal cord injury (SCI). Randomized, double-blind, placebo-controlled pilot study. North Florida/South Georgia Veterans Healthcare System. Men (n=10), age 59.6±8.1 years, 2-46 years after SCI (AIS C/D), injury level (C3-L3), serum testosterone (294±134ng/dL), bioavailable testosterone (54±9ng/dL) who demonstrated impaired gait (0.20-1.30m/s). T+F: Testosterone-enanthate (Delatestryl®, 125-mg/week, i.m.) plus Finasteride (Proscar®, 5-mg/day, p.o.); or vehicle (sesame oil, i.m.) plus placebo (p.o) for 6-12 months. Changes in non-dominant KE peak isometric torque and mean isokinetic torque at 60°/sec and 180°/sec and KE CSA at 6-months and 12-months. At baseline, total and bioavailable testosterone were similar between T+F and placebo groups. Nadir serum testosterone was 130-175% higher in response to T+F while no change was observed in the placebo group throughout the treatment phase. Within the full cohort, the percentage changes in KE torque and KE CSA at 6-months were as follows in T+F vs. placebo groups, respectively: isometric (+14.7% vs. -6.1%, Hedges’ g=0.82), isokinetic 60°/sec (+13.0% vs -5.9%, g=1.07), isokinetic 180°/sec (+26.5% vs -16.7%, g=0.78), and CSA (+9.2 vs -1.1, g=2.73). In a subgroup of men who completed 12-months, the percentage changes in KE torque and CSA were: isometric (+12.8% vs -6.7%, g=1.0), isokinetic 60°/sec (+25.3% vs. -5.2%, g=0.65), isokinetic 180°/sec (+29.8% vs. -0.7%, g=0.65), and CSA (+13.9 vs +0.6, g=1.90). This controlled pilot study suggests that T+F increased KE strength and CSA in men with impaired gait and low to low-normal testosterone after chronic incomplete SCI. A larger clinical trial is warranted to validate our findings.