Biomechanical Leg Muscle Function During Stair Ambulation in Men Receiving Androgen Deprivation Therapy

Abstract

Abstract Background The role of testosterone in maintaining functional performance in older men remains uncertain. Methods We conducted a 12-month prospective, observational case–control study including 34 men newly commencing androgen deprivation therapy for prostate cancer and 29 age-matched prostate cancer controls. Video-based motion capture and ground reaction force data combined with computational musculoskeletal modeling, and data were analyzed with a linear mixed model. Results Compared with controls over 12 months, men receiving androgen deprivation therapy had a mean reduction in circulating testosterone from 14.1 nmol/L to 0.4 nmol/L, associated with reductions in peak knee extension torque, mean adjusted difference (MAD) –0.07 Nm/kg (95% confidence interval [CI]: –0.18, 0.04), p = .009, with a corresponding more marked decrease in quadriceps force MAD –0.11 × body weight (BW) [–0.27, 0.06], p = .045 (equating to a 9 kg force reduction for the mean body weight of 85 kg), and decreased maximal contribution of quadriceps to upward propulsion, MAD –0.47 m/s2 [–0.95, 0.02], p = .009. We observed between-group differences in several other parameters, including increased gluteus maximus force in men receiving androgen deprivation therapy, MAD 0.11 × BW [0.02, 0.20], p = .043, which may be compensatory. Conclusions Severe testosterone deprivation over 12 months is associated with selective deficits in lower-limb function evident with an important task of daily living.