Skeletal Muscle Mass Indices in Healthy Young Mexican Adults Aged 20-40 Years: Implications for Diagnoses of Sarcopenia in the Elderly Population

Background and Objectives. Skeletal muscle and skeletal muscle indices in young adults from developing countries are sparse. Indices and the corresponding cut-off points can be a reference for diagnoses of sarcopenia. This study assessed skeletal muscle using dual-energy X-ray absorptiometry (DXA) in healthy male and female subjects aged 20-40 years and compared their appendicular skeletal muscle mass (ASM) and total-body skeletal muscle (TBSM) indices using certain cut-off points published in the literature. Methods. A sample of 216 healthy adults men and women from northwest Mexico was included. Body composition was assessed by DXA and several published DXA-derived skeletal muscle indices were compared. Results. Both, ASM and TBSM were higher in men compared to the women group (23.0 +/- 3.4 versus 15.9 +/- 1.6 kg; P < 0.05 and 26.5 +/- 4.1 versus 16.9 +/- 1.9 kg; P < 0.05, resp.). These differences were also valid for both indices. When derived cut-off points were compared with the most reported indices, significant differences were found. Interpretation and Conclusion. Published cut-off points from Caucasians are higher than cut-off point derived in this sample of Mexican subjects. The new DXA-derived cut-off points for ASM proposed herein may improve diagnoses of sarcopenia in the geriatric Mexican population.