Journal of Cachexia, Sarcopenia and Muscle (JCSM) - Online First - Abstract
Article first published online: 2 AUG 2016
Androgen deprivation causes selective deficits in the biomechanical leg muscle function of men during walking: a prospective case–control study
Ada S. Cheung, Hans Gray, Anthony G. Schache, Rudolf Hoermann, Daryl Lim Joon, Jeffrey D. Zajac, Marcus G. Pandy, Mathis Grossmann
We conducted a 12-month prospective, observational case–control study of 34 men newly commencing androgen deprivation treatment (ADT) for prostate cancer and 29 age-matched prostate cancer controls. Participants were assessed at 0, 6, and 12 months while walking in a biomechanics laboratory. We combined video-based motion capture and ground reaction force data with computerized musculoskeletal modelling to assess the following primary outcomes: (i) peak joint torques at the hip, knee and ankle, and corresponding individual muscle forces; (ii) individual muscle contributions to acceleration of the body's centre of mass; and (iii) walking speed, stride length, and step width. A linear mixed model was used to compare mean differences between groups.
Compared with controls over 12 months, men receiving ADT had a mean reduction in total testosterone level from 14.1 to 0.4 nmol/L, and demonstrated more marked decreases in peak hip flexor torque by 14% [mean difference −0.11 N/kg (−0.19, −0.03), P = 0.01] and peak knee extensor torque by 16% [−0.11 N/kg (−0.20, −0.02), P = 0.02] of the initial mean value. Correspondingly, iliopsoas force decreased by 14% (P = 0.006), and quadriceps force decreased by 11%, although this narrowly missed statistical significance (P = 0.07). Soleus decreased contribution to forward acceleration of the body's centre of mass by 17% [mean difference −0.17 m/s2 (−0.29, −0.05), P < 0.01]. No significant changes between groups were observed in other joint torques or individual muscle contributions to acceleration of the body. Step width increased by 18% [mean adjusted difference 1.4 cm (0.6, 27.4), P = 0.042] in the ADT group compared with controls, with no change in stride length or walking speed.
Testosterone deprivation selectively decreases lower-limb muscle function, predominantly affecting muscles that support body weight, accelerate the body forwards during walking, and mediate balance. Future exercise and pro-myogenic interventional studies to mitigate ADT-associated sarcopenia should target these deficits.