Abstract:

Objective To detect the stiffness of the gastrocnemius muscle in the patients with type 2 diabetes under different functional states by shear wave elastography （SWE） method， and to provide the objective basis for the early clinical detection of skeletal muscle damage. Methods A total of 70 patients with type 2 diabetes were selected as diabetes group， and 70 healthy examinees underwent medical check-ups were regared as control group. SWE was used to detect the Young’s modulus （E） value of the gastrocnemius muscle of the subjects in both groups under three different conditions（neutral ankle position at rest， plantar flexion ankle position during isometric contraction， and upright position during isometric contraction；the E values were normalized by body mass index （BMI） （E_BMI=E/BMI）； the differences in passive and active stiffness of the gastrocnemius muscle under various conditions of the subjects between two groups were compared； Pearson correlation analysis was used to assess the correlation of the E value in the diabetic patients with patients’ age， disease duration， level of glycated hemoglobin （HbA1c）， and level of advanced glycation end-products （AGEs）. Results There were no significant differences in the passive stiffness E values and E_BMI values of the gastrocnemius muscle of the subjects between two groups under neutral position （P>0.05）； there was no significant difference in the active stiffness E values of the gastrocnemius muscle under plantar flexion ankle position（P>0.05）， but the E_BMI value of the subjects in diabetes group were lower than that in control group （P<0.01）. Both E value and E_BMI value of active stiffness under upright position of the subjects in diabetes group were lower than those in control group （P<0.01）. The E value of active stiffness of the gastrocnemius of the subjects in diabetes group showed a negative correlation with disease duration， HbA1c level， and AGE level （r=－0.645， P<0.05； r=－0.741， P<0.05； r=－0.675， P<0.05）， and had no correlation with age （r=－0.116， P>0.05）. Conclusion The patients with type 2 diabetes exhibit reduced active stiffness in the gastrocnemius muscle， while passive stiffness may not be affected in the early stage. The use of SWE to measure active stiffness of the gastrocnemius muscle in standing isometric contraction can aid in the detection of subclinical muscle contraction function decline in the patients with type 2 diabetes.

Key words: Diabetes mellitus， type 2, Ultrasonography, Ultrasonic shear wave elastography, Muscle hardness