Abstract :
to correlate thigh muscle volume measured by magnetic resonance image (MRI) with
anthropometric measurements and physical function in elderly subjects; 2) to predict MRI-measured thigh muscle
volume using anthropometric measurements and physical functional status in elderly subjects. Design: Crosssectional,
nonrandomized study. Setting: Outpatient clinic in Taiwan. Participants: Sixty-nine elderly subjects
(33 men and 36 women) aged 65 and older. Measurments: The anthropometric data (including body height, body
weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral
quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance
analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRImeasured
muscle volume of both thighs was used as the reference standard. Results: The MRI-measured thigh
volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as
well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time.
In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were
significant predictors in the linear regression model: Muscle volume(cm3) =4226.3－42.5×Age(year)－955.7×
gender(male=1, female=2)+45.9×body weight(kg) +60.0×thighcircumference (cm) (r2 = 0.745, P < 0.001;
Standard Error of the Estimate = 581.6cm3). Conclusion: The current work provides evidence of a strong
relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction
equation model using anthropometric measurements. This model is a simple and noninvasive method for
everyday clinical practice and follow-up.
