Lower limb muscle quality and phase angle contribute to the reduced walking speed among older adults

This cross-sectional study aimed to determine the predictors of a walking speed <1 m/s. Factors associated with the health of muscle cells, including the phase angle analyzed using bioimpedance analysis, answers to the mini-nutritional assessment-short form, albumin levels, leg muscle quality and vitamin D levels, were assessed.

The study participants were outpatients from the Locomotor Frailty Outpatient Clinic which was established at our center in 2016 (231 women, 76.5 ± 7.6 years; 137 men, 78.0 ± 6.3 years). Participants were classified into two groups, with 1 m/s walking speed as the cutoff value. Binominal logistic regression analysis was performed with walking speed as the dependent variable, and age, leg muscle quality, mini-nutritional assessment-short form answers, albumin levels, vitamin D levels and the phase angle as explanatory variables. Leg muscle quality was defined as the mean value of both lower limbs' isometric knee extensor strength, divided by the mean value of both lower limbs' muscle mass through bioimpedance analysis.

The explanatory variables associated with decreased walking speed among women were leg muscle quality (P = 0.004, odds ratio: 0.57) and phase angle (P = 0.017, odds ratio: 0.42). Men were also more likely to have leg muscle quality (P = 0.004, odds ratio: 0.43).

Leg muscle quality and the phase angle of lower extremities were independently associated with low walking speeds (<1 m/s) among older outpatients. Geriatr Gerontol Int 2022; 22: 603-609.