Abstract
The purpose of the work is to investigate the effects of low-dose testosterone replacement therapy (TRT) and evoked resistance training (RT) on body composition and metabolic variables after spinal cord injury (SCI). Twenty-two individuals with chronic motor complete SCI (ages 18–50 years) were randomly assigned to either TRT+RT (
n
= 11) or TRT (
n
= 11) for 16 weeks following a 4 -week delayed entry period. TRT+RT men underwent twice weekly progressive RT using electrical stimulation with ankle weights. TRT was administered via testosterone patches (2–6 mg/day). Body composition was tested using anthropometrics, dual energy x-ray absorptiometry, and magnetic resonance imaging. After an overnight fast, basal metabolic rate (BMR), lipid panel, serum testosterone, adiponectin, inflammatory and anabolic biomarkers (insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 [IGFBP-3]), glucose effectiveness (Sg), and insulin sensitivity (Si) were measured. Total body lean mass (LM; 2.7 kg,
p
< 0.0001), whole muscle (
p
< 0.0001), and whole muscle knee extensor cross-sectional areas (CSAs;
p
< 0.0001) increased in the TRT+RT group, with no changes in the TRT group. Visceral adiposity decreased (
p
= 0.049) in the TRT group, with a trend in the TRT+RT (
p
= 0.07) group. There was a trend (
p
= 0.050) of a 14–17% increase in BMR following TRT+RT. Sg showed a trend (
p
= 0.07) to improvement by 28.5–31.5% following both interventions. IGFBP-3 increased (
p
= 0.0001) while IL-6 decreased (
p
= 0.039) following both interventions, and TRT+RT suppressed adiponectin (
p
= 0.024). TRT+RT resulted in an increase in LM and whole thigh and knee extensor muscle CSAs, with an increase in BMR and suppressed adiponectin. Low-dose TRT may mediate modest effects on visceral adipose tissue, Sg, IGFBP-3, and IL-6, independent of changes in LM.
