Resistance exercise prevents ADT-induced muscle loss in patients with prostate cancer

Resistance exercise training counters the negative effects of androgen deprivation therapy (ADT) and improves muscle fibre size, as well as capillarization, in patients with prostate cancer, reports a study.

“[ADT] reduces both type I and II muscle fibre size and capillarization in PCa patients,” the researchers said. “Supervised resistance exercise training prevents this decline and effectively increases muscle fibre size and capillarization in prostate cancer patients following the onset of ADT.”

Twenty-one prostate cancer patients (mean age 72 years) who initiated ADT were included in this study, which identified the impact of ADT with and without resistance training on muscle fibre characteristics.

The research team evaluated tissue samples from the vastus lateralis muscle at baseline and after 20 weeks of usual care (n=11) or resistance training (n=10). Using immunohistochemistry, they then determined the type I and II muscle fibre distribution, fibre size, and myonuclear and capillary contents.

Patients in the usual care group had significant reductions in type I (from 7,401 to 6,489 μm²; p<0.05) and type II (from 6,225 to 5,015 μm²; p<0.05) muscle fibre size. They also showed decline in type I and II individual capillary-to-fibre ratio (C/Fi; ‒12 percent and ‒20 percent, respectively; p<0.05). [J Clin Endoc Metab 2023;108:e907-e915]

On the other hand, patients who underwent resistance training achieved significant increases in type I (from 6,700 to 7,772 μm²; p<0.05) and type II (from 5,248 to 6,302 μm²; p<0.05) muscle fibre size, as well as improvements in type I and II muscle fibre myonuclear contents (24 percent and 21 percent, respectively; p<0.05) and type I C/Fi (18 percent; p<0.05).

“Prolonged resistance exercise training is an effective intervention strategy to counteract ADT-induced loss of muscle mass in older prostate cancer patients,” the researchers said. [Scand J Med Sci Sports 2016;26:1026‐1035; J Gerontol A Biol Sci Med Sci 2013;68:490‐498; Med Sci Sports Exerc 2006;38:2045‐2052]

“As such, we show a significant increase in quadriceps muscle cross-sectional area following 20 weeks of resistance exercise training in prostate cancer patients,” they added.

Muscle loss

One of the hallmarks of ADT initiation is skeletal muscle mass loss. ADT also speeds up the age-related muscle loss in older patients with prostate cancer, according to the researchers.

Loss of type II muscle fibre size, myonuclear content, and capillarization are the main characteristics of age-related muscle loss. [J Gerontol A Biol Sci Med Sci 1995;50A:17‐22; J Neurol Sci 1988;84:275‐294; J Appl Physiol (1985) 2014;116:998‐1005; J Appl Physiol (1985) 2006;100:178‐185]

“The current study is the first to show that ADT initiation in patients [with prostate cancer] results in a decline in both type I and type II muscle fibre size, as well as a decline in capillarization,” said the researchers.

“Although the gradual age-related lowering in testosterone levels may contribute to the age-related muscle loss, the severe decline in testosterone levels following ADT in prostate cancer patients clearly has a larger and more acute impact on muscle tissue health,” they added. [Am J Med 2014;127:554‐561]