Background and objectives: To develop and validate the prediction equations for lean body mass (LBM) and appendicular skeletal muscle mass (ASM) using body circumference measurements of community-dwelling adults older than 50 years old.
Methods and study design: Four hundred and ninety-eight community-dwelling adults older than 50 years old were recruited for this study. Participants were randomly assigned to a development group (DG, n=332) and validation group (VG, n=166). Lean body mass and ASM were assessed using dualenergy x-ray absorptiometry along with the anthropometric parameters. The Pearson correlation coefficient was used to examine the associations between ASM, LBM and anthropometric parameters in the DG. Prediction equations for LBM and ASM were established from DG data using multiple regression analyses. Paired t-test and Bland-Altman test were used to validate the equations in the VG.
Results: Forearm circumference had the highest correlation with LBM and ASM. The developed prediction models were: LBM (kg) = 27.479 + 0.726 * weight (kg) - 3.383 * gender (male = 1, female = 2) - 0.672 * BMI + 0.514 * forearm circumference (cm) - 0.245 * hip circumference (cm)(r2=0.90); ASM (kg) = -4.287 + 0.202 * weight (kg) - 0.166 * hip circumference (cm) - 1.484 * gender (male = 1, female = 2) + 0.173 * calf circumference (cm) + 0.096 * height + 0.243 * forearm circumference (cm)(r2=0.85).
Conclusions: Prediction equations using only a measuring tape provide accurate, inexpensive, practical methods to assess LBM and ASM in Asians older than 50 years old.