Effects of testosterone+finasteride on bone after spinal cord injury: A randomized, double-blind, placebo-controlled pilot study

Research Objectives: To assess the influence of high-dose testosterone plus finasteride (T+F) on bone mineral density (BMD) in men with impaired gait and low to low-normal testosterone subsequent to 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), 59.6±8.1 years old, 2-46 years after SCI (AIS C/D) ranging from C3-L3, serum testosterone (294±134ng/dL) and bioavailable testosterone (54±9ng/dL), and gait speeds of 0.20-1.30m/s with impaired gait.

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 total serum testosterone and total hip, femoral neck, and distal femur BMD at 6-months and 12-months.

Results: At baseline, total and bioavailable testosterone were similar between T+F and placebo groups, as were total hip, femoral neck, and distal femur BMD. At subsequent timepoints, nadir total testosterone was 130-175% higher in the T+F group, with no obvious change in the placebo group. In the full cohort, the percentage changes in BMD at 6-months were as follows in T+F vs. placebo groups, respectively: total hip (+2.4% vs. -0.8%, Hedges’ g=0.78), femoral neck (+1.4% vs +0.9%, g=0.20), and distal femur (+6.4% vs -5.5%, g=1.14). In a subgroup of men who completed 12-months, the percentage changes in BMD were: total hip (+1.3% vs +0.4%, g=0.18), femoral neck (+4.3% vs. -2.1%, g=2.67), distal femur (+9.2% vs. +1.1%, g=0.61).

Conclusions: This controlled pilot study suggests that T+F increased lower-extremity BMD in men with impaired gait and low to low-normal testosterone after chronic incomplete SCI. These results provide rationale to validate our findings in a larger clinical trial.

Author(s) Disclosures: No conflicts of interests.