Equations of Yoshida et al for Estimating Appendicular Skeletal Muscle Mass in Older Japanese Adults Using Bioelectrical Impedance Analysis (BIA)

Patient selection: Japanese adults >= 65 years of age

Analysis: bioelectrical impedance analysis (BIA)

Parameters:

(1) sex

(2) height in cm

(3) weight in kilograms

(4) resistance at 50kHz in Ohms

impedance index =

= ((height)^2) / (resistance)

where:

• The impedance index is referred to as the resistance or resistive index by other authors.

appendicular muscle mass for a male in kilograms =

= (0.197 * (impedance index)) + (0.179 * (weight)) - 0.019

appendicular muscle mass for a female in kilograms =

= (0.221 * (impedance index)) + (0.117 * (weight)) + 0.881

Performance:

• The R^2 for males is 0.87 and for females is 0.89.

• The standard error of the estimate for males is 0.98 kg for males and 0.81 kg for females.