Effect of androgen deprivation therapy on muscle attenuation in men with prostate cancer

Introduction Aging skeletal muscle is associated with not only a reduction in muscle size and strength but also in muscle quality which reflects an increase in fatty infiltration of muscle. In men with prostate cancer, androgen deprivation therapy (ADT) accelerates this loss of muscle size and strength, but it is unknown if muscle quality is also adversely affected. Therefore, we examined the effects of ADT on muscle attenuation, an indirect measure of intramuscular lipid content, as well as the muscle cross-sectional area (CSA) in men with prostate cancer. Methods Pre- and post-CT scans of the pelvis in 39 men aged 49-78 years receiving leuprorelin were examined. The time between baseline and follow-up scans was 14.6-20 weeks after the commencement of ADT. Changes in skeletal muscle attenuation in Hounsfield units of the rectus femoris and the CSA of the rectus femoris, sartorius and quadricep muscles were assessed. Results Muscle attenuation of the rectus femoris muscle was significantly reduced following the initiation of ADT by 18.9% (P < 0.001). In addition, there was a significant decrease (P < 0.001) in the CSA for the sartorius, quadriceps and rectus femoris muscles. There was no effect of Zometa on muscle attenuation or muscle CSA. Conclusions Our results indicate that not only muscle size but also muscle quality may be adversely affected by the undertaking of ADT in men with prostate cancer. Consequently, interventions to counteract deteriorations to both muscle mass and possibly muscle quality should be considered in men receiving ADT.