Comparison of lower-limb muscle quantity, quality, and physical functions between older adults with and without certified for long-term care and/or support

Abstract

Echo intensity（EI）of skeletal muscle obtained by ultrasonography is considered to reflect muscle quality. This study aimed to compare lower-limb muscle quantity, quality, and physical function between independent older adults and those certified for long-term care and/or support.

A total of 98 older adults participated in this study, and then 40 were independent group, whereas 58 were certified group. Muscle thickness（MT）, subcutaneous fat thickness（FT）, and EI of the right front-thigh were evaluated using ultrasonography imaging method. Six physical functions were measured by tests including knee extension strength, and fitness age score（FAS）was calculated from the values obtained.

In both sexes, independent group had significantly higher MT and lower EI than certified group. All physical functions in independent group were significantly higher than those in certified group. When multiple regression analysis was performed, after adjusting sex, group, age, body mass index, and FT, MT and EI were still significantly correlated with knee extension strength. However, EI was not significantly correlated with FAS. This study indicates that lower-limb muscle quantity is more strongly associated with physical functions than muscle quality in older people.