Differential association of total and regional muscle mass and quality with physical performance in community-dwelling older adults.

PURPOSE

In this study, we examined the association among total muscle mass, regional muscle mass, muscle quality, and various types of physical performance in community-dwelling older adults.

METHODS

This study included 195 community-dwelling older adults (61 males and 134 females). The muscle thickness and echo intensity of the quadriceps femoris and triceps surae were measured using ultrasound, and the skeletal muscle mass index was evaluated using bioelectrical impedance analysis. Physical performance was measured using the 30-s standing test (CS30), Timed up-and-go test (TUG), 10-m maximum walking speed (10MWT), vertical jump test (VJT), and grip strength.

RESULTS

Partial correlation analysis after controlling for age, sex, and body mass index showed that CS30 was significantly correlated with muscle thickness and echo intensity of the quadriceps femoris. The TUG and VJT were significantly correlated with muscle thickness of the triceps surae, and grip strength was significantly correlated with muscle thickness of the triceps surae and skeletal muscle mass index. Stepwise multiple regression analyses indicated that the echo intensity of the quadriceps femoris was a significant predictor of CS30, and the muscle thickness of the triceps surae was a significant predictor of TUG, VJT, and grip strength, whereas the skeletal muscle mass index was not a significant predictor of any physical performance test.

CONCLUSION

Our results suggest that regional muscle mass and quality are more important than skeletal muscle mass index for predicting physical performance.