Article

OBJECTIVE: To establish muscle-specific cut-off values for ultrasound-based
detection of low muscle mass, and to assess its prevalence in a population of
frail older subjects when applying the cut-points of different muscles and those
of different sarcopenic indices. DESIGN: Cross-sectional study. SETTING: Geriatric outpatient clinic and clinical research laboratory. METHODS: A total of
44 older adults (30 women and 14 men, mean age 82 years, range 67-93 years) and
60 younger individuals (30 women and 30 men, mean age 26 years, range 20-36
years) participated. Body composition and thickness of 4 lower limb muscles
(rectus femoris, vastus lateralis, tibialis anterior, medial gastrocnemius) were
respectively assessed by bioelectrical impedance analysis (BIA) and
ultrasonography. MAIN OUTCOME MEASUREMENTS: Site-specific cut-points for
ultrasound-based assessment of low muscle mass (muscle thickness values 2
standard deviations below the gender-specific means of our sample of younger
subjects) and comparative prevalence rates of low muscle mass. RESULTS: The
following site-specific cut-points for muscle thickness were identified: rectus
femoris: 20 mm in men and 16 mm in women; vastus lateralis: 17 mm in men and 15
mm in women; tibialis anterior: 23 mm in men and 22 mm in women; and medial
gastrocnemius: 13 mm in both men and women. The prevalence of low muscle mass in
older adults was highly dependent on the muscle being investigated; it varied
from 86% for thigh muscles to 30% for leg muscles. Moreover, the prevalence of
low muscle mass was highly dependent on the applied diagnostic criterion and on
the adopted cut-off value; it ranged from 2% to 75% for different BIA-derived
criteria. CONCLUSIONS: We suggest that muscle ultrasonography provides
physiatrists with a practical and accurate tool for identifying individuals with
low muscle mass. However, the usability of cut-off values established in our
group of healthy younger subjects of white ethnicity to identify low muscle mass
in older individuals of different ethnic groups remains to be demonstrated in
future studies.
CI - Copyright (c) 2016 American Academy of Physical Medicine and Rehabilitation.
Published by Elsevier Inc. All rights reserved.

Langue : ANGLAIS