Body composition and risk for sarcopenia in transgender women

Abstract

Objectives: Body composition and strength of cisgender (cis) individuals are well established. However, those for transgender women (trans women) undergoing gender-affirming hormone therapy remain unclear. This study aimed to detect possible body composition and strength variations related to sarcopenia.

Methods: This was a cross-sectional comparative study of 37 trans women, 34 cis men, and 34 cis women. Body composition was measured in all individuals by bioelectrical impedance analysis; prehensile strength by dynamometry was studied in trans women.

Results: In this study, trans women had higher body mass index values than cis individuals (P < 0.01). Fat mass was 41% higher for trans women than cis men. Muscle mass (MM) was lower in trans women than cis men (-10%), and higher than cis women (24%). Bone mass was lower in trans women than cis men and higher in cis women (P < 0.01). Trans women's prehensile strengths were 25.26 kg for the right hand and 24.8 kg for the left. Appendicular skeletal muscle mass was 23.63 kg, and appendicular skeletal muscle mass index was 8.14 kg.

Conclusion: Trans women undergoing gender-affirming hormone therapy show a tendency to adapt body compartments to those of cis women with increased fat mass and reduced muscle mass. Prehensile strength in trans women was close to the cutoff points for sarcopenia risk. Nutrition, physical activity, strength, and body composition are important to avoid the possible risk for sarcopenia. More studies along these lines are necessary, especially in older adults.

Keywords: Body composition; Muscle mass; Sarcopenia; Strength; Trans women.