Quantitative features of intramuscular adipose tissue of the quadriceps and their association with gait independence in older inpatients: A cross-sectional study.

Objective: The aim of this study was to examine the quantitative features of intramuscular adipose tissue of the quadriceps and their association with gait independence in older inpatients.

Methods: This was a cross-sectional study with 216 inpatients ≥65 y of age. We also recruited 40 community-dwelling healthy individuals in the same age group who were able to walk independently for matched-pair analysis to determine the quantitative features of intramuscular adipose tissue in older inpatients. Participants were assigned to total assistance (Functional Independence Measure [FIM] gait score 1 or 2), partial assistance (FIM gait score 3-5), and independent (FIM gait score 6 or 7) groups. Ultrasound images were acquired using B-mode ultrasound imaging. Intramuscular adipose tissue and muscle mass of the quadriceps were assessed based on echo intensity and muscle thickness, respectively.

Results: Echo intensity of the quadriceps of older inpatients was increased to ~1.66 times that of matched healthy older people. Echo intensity of the independent group was significantly lower than that of the total and partial assistance groups. No differences were found in quadricep thickness among the three groups.

Conclusions: The results from the present study suggested that intramuscular adipose tissue of the quadriceps of older inpatients was increased to ~1.7 times that of healthy older individuals matched for demographic characteristics. More intramuscular adipose tissue of the quadriceps was observed among older inpatients who were unable to walk independently compared with older inpatients who were able to walk independently.