Author(s): FICARRA, S., WILSON, R.L., GREER, J., NORRIS, M.K., DIELI-CONWRIGHT, C.M. , Institution: DANA-FARBER CANCER INSTITUTE, Country: UNITED STATES, Abstract-ID: 2674

INTRODUCTION:
Sarcopenia is a condition defined as concurrent lack of strength and muscle mass [1] which has prognostic value among prostate cancer survivors (PCa). Black PCa who are prescribed androgen deprivation therapy (ADT) can experience adverse body composition alterations more than non-Black PCa. However, lack of strength for determining sarcopenia is usually assessed through handgrip strength (HGS) which may not capture overall body strength. Additionally, evidence of sarcopenia incidence with gold standard measurements of strength is scarce among Black PCa. Therefore, the aim of this observational analysis is to report incidence of sarcopenia and compare maximum relative strength levels between sarcopenic (SA) and non-sarcopenic (NS) Black PCa who are prescribed ADT.
METHODS:
Black PCa who are prescribed ADT were recruited within a larger ongoing exercise trial (NCT05327465). Population-specific cut-offs were used to determine sarcopenia: HGS <35.5kg and Appendicular Skeletal Muscle Mass Index (ASMI) <7.26kg/m^2. [2] HGS was tested with a handheld dynamometer and ASMI was assessed with a whole body DEXA scan. Two 10-repetition maximum (RM) strength tests were also performed on a Leg Press (LP) and a Chest Press (CP). The 1-RM values were estimated using the Brzycki formula. Estimated 1-RM was normalized to participants’ weight to determine relative strength. Differences between SA and NS were explored using unpaired t-tests.
RESULTS:
A total of 48 Black PCa were included in this analysis with mean age and BMI of 68.8±9.0 years and 29.7±5.09 kg/m^2, respectively. Overall, HGS was 33.9±8.07 kg and ASMI 8.2±1.13 kg/m^2. Nine (19%) participants were sarcopenic with HGS of 27.9±4.83 kg and ASMI of 6.6±0.45 kg/m^2. Among NS (n=39), significantly higher HGS (Mean diff 7.3, 95%CI 1.64–12.97, p=0.013) and ASMI (1.9, 1.28–2.55, p<0.001) were observed compared to SA. Relative CP 1-RM was significantly higher among NS compared to SA (0.5±0.16 vs 0.4±0.12; Mean diff 0.1, 95%CI 0.01–0.24, p=0.033), while relative LP 1-RM was not (1.1±0.30 vs 0.9±0.24; Mean diff 0.2, 95%CI -0.01–0.43, p=0.062).
CONCLUSION:
Black PCa who underwent ADT may present with sarcopenia, yet only 19% of our sample were sarcopenic. Nevertheless, maximal relative strength of the upper body was significantly lower among those presenting with sarcopenia. This population might benefit from specialized, prescriptive resistance exercise to mitigate ADT side effects on strength and muscle mass. In addition, large scale observational studies are needed to assess sarcopenia among Black PCa.

References
 
1          Kirk, B. et al. The Conceptual Definition of Sarcopenia: Delphi Consensus from the Global Leadership Initiative in Sarcopenia (GLIS). Age and Ageing 53 (2024). https://doi.org/10.1093/ageing/afae052
2          Cawthon, P. M. et al. Putative Cut-Points in Sarcopenia Components and Incident Adverse Health Outcomes: An SDOC Analysis. J Am Geriatr Soc 68, 1429–1437 (2020). https://doi.org/10.1111/jgs.16517