Abstract

Background: Sarcopenia, the loss of muscle mass due to aging, results in falls, fractures, and the onset of frailty. Calf circumference is positively associated with appendicular muscle mass and lower muscle mass is useful for determining the existence and extent of sarcopenia. Circumference is easily and quickly determined with a tape measure, although it has been reported that the length of circumference is affected by subcutaneous fat. Till date, not many studies have studied the effect of limb circumference on appendicular muscle and fat mass using bioelectrical impedance analysis. This study aimed to clarify the relationship between circumference of upper arm, forearm, thigh, and calf and appendicular muscle and fat mass using bioelectrical impedance analysis.
Methods: We recruited seventy-four healthy young men and women [age: 20–22 years (mean; 21.2 ± 0.6)]. Circumference of the right and left upper arm, forearm, thigh, and calf were measured using a tape measure. Appendicular muscle and fat mass were estimated using segmental multifrequency bioelectrical impedance analysis. Correlation and regression analysis were used for estimating the association of appendicular muscle and fat mass with limb circumference.
Results: Limb circumference and appendicular muscle mass in men were significantly higher than those in women (P < 0.001), but this was not the case for appendicular fat mass (p > 0.05). Circumference of right and left upper arm, forearm, thigh and calf were significantly related to appendicular muscle mass and the independent explanators of appendicular muscle mass in multiple regression analysis adjusted for sex (P < 0.001). Right and left upper arm, forearm, thigh and calf circumferences were also significantly associated with appendicular fat mass (P < 0.001). Right and left forearm circumferences had the lowest correlation with appendicular fat mass (P <0.001).
Conclusion: These results show that forearm circumference has more power in determining appendicular muscle mass than appendicular fat mass in healthy men and women.