335MO - Prevalence of low muscle mass/sarcopenia in prostate cancer patients undergoing androgen deprivation therapy and association with muscle strength and physical function

Background

Androgen deprivation therapy (ADT) in patients with prostate cancer (PCa) results in a range of treatment-related toxicities including a reduction in muscle mass and an increase in fat mass that may compromise strength and physical functioning. However, the prevalence of low muscle mass or sarcopenia is unclear and varies based on the definition/criteria and technique used. Here we report the prevalence of low muscle mass/sarcopenia and the association with strength and physical function in patients with PCa on hormone therapy assessed in our Institute.

Methods

Two-hundred and eighty-four men with PCa undergoing ADT (43-90 years, BMI 28.8 ± 4.4 kg/m², Gleason score 7.6 ± 1.0, ADT duration 7.1 ± 18.4 months) underwent assessments of body composition by dual X-ray absorptiometry, upper and lower body muscle strength using the 1-RM method, and physical function by a battery of tests. Low muscle mass/sarcopenia was defined as an appendicular lean mass index [ALMI, ALM divided by height (m) squared] < 7.26 and by an ALM/BMI (ALM_BMI) < 0.789, and sarcopenic obesity as sarcopenia co-existing with body fat of ≥ 25%.

Results

Based on ALMI, the prevalence of low muscle mass/sarcopenia was 13.7% and by ALM_BMI 26.4%, while the prevalence of sarcopenic obesity was 12.8%. Those classed as low muscle mass/sarcopenic were older (71.9 ± 9.1 vs. 68.0 ± 7.8 years, p = 0.005) had lower upper (-26%) and lower body (-29%) muscle strength (p < 0.001), and slower (-20%) stair climb performance (p = 0.002). Compared to those on short-term ADT (< 6 months), the odds ratio for low muscle mass/sarcopenia was 2.5 (95% CI, 1.2 – 5.2) for those on longer term ADT (≥ 6 months) after adjustment for age, number of comorbidities and medications.

Conclusions

Given the increased odds of low muscle mass/sarcopenia with duration of ADT and the association with lower muscle strength and poorer physical function, PCa patients initiating and on established ADT regimens should be prescribed exercise medicine, primarily resistance-based exercise, to assist in countering treatment-related adverse effects thereby preserving muscle strength and function.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Exercise Medicine Research Institute, Edith Cowan University.

Funding

NHMRC, Cancer Australia.

Disclosure

All authors have declared no conflicts of interest.