Application of conventional ultrasound coupled with shear wave elastography in the assessment of muscle strength in patients with type 2 diabetes

Abstract

Background In patients with type 2 diabetes mellitus (T2DM), a decrease in muscle function may be related to changes in the biomechanical properties of skeletal muscles. However, the correlations between muscle function and the characteristics of muscle size and stiffness as measured by ultrasound in patients with T2DM are unclear. The aim of this study was to investigate the abilities of conventional ultrasound and shear wave elastography (SWE) to assess muscle properties in patients with T2DM and to correlate the findings with isokinetic muscle testing and functional tests. Methods Sixty patients from the Department of Endocrinology in The Third Affiliated Hospital of Southern Medical University diagnosed with T2DM were recruited in this cross-sectional study from September 2021 to September 2022. T2DM was defined based on the American Diabetes Association criteria. The exclusion criteria were a history of injury or operation of the lower limb or clinical signs of neuromuscular disorders, any muscle-induced disease, and the presence of other types of diabetes mellitus. Thirty-five matched healthy volunteers were continuously included in the control group. SWE was used to measure the muscle stiffness of the quadriceps femoris [vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), vastus intermedius (VI)] and the biceps brachii (BB) in a relaxed position, and the shear wave velocity (SWV) values were recorded. Muscle size was measured using conventional ultrasound. The participants underwent isokinetic knee extension/flexion (60°/sec) to assess muscle strength and functional tests of physical performance, including the short physical performance battery, 30-s chair stand test, timed up-and-go test, and 6-meter walk test. All demographics and measured variables were compared using the independent samples t -test. Interclass correlation coefficient analysis was performed on the measurement data obtained by the two operators, and Pearson correlation coefficients were used to determine the relationships between variables. Results Patients with T2DM exhibited worse physical performance (P<0.05) and weaker lower limb muscle strength (P<0.05) than did healthy controls, but their handgrip strength was comparable (P=0.102). Patients with T2DM had significantly decreased muscle thickness [RF thickness: 10.69±3.21 vs. 13.09±2.41 mm, mean difference =−2.40, 95% confidence interval (CI): −3.56 to −1.24, P<0.001; anterior quadriceps thickness: 23.45±7.11 vs. 27.25±5.25 mm, mean difference =−3.80, 95% CI: −6.33 to −1.26, P=0.004] and RF cross-sectional area (3.04±1.10 vs. 4.11±0.95 cm 2 , mean difference =−1.07, 95% CI: −1.49 to −0.64; P<0.001) compared to healthy controls. Smaller muscle size was associated with decreased muscle strength (r=0.44–0.69, all P values <0.001). Except for the BB (3.48±0.38 ...