Comparison of elastosonographic changes of the tibial nerve and Achilles tendon in patients with type II diabetes mellitus.

BACKGROUND

To compare the elastosonographic changes of the tibial nerve (TN) and Achilles tendon (AT) in patients with type 2 diabetes mellitus (T2DM) and explore their relationship and respective relevant factors.

METHODS

This case-control study enrolled 165 subjects, comprising 126 patients with T2DM and 39 healthy controls matched for age and gender. The patients were further divided into those with and without diabetic peripheral neuropathy (PN-DM and NPN-DM groups). Clinical and laboratory data were collected. Conventional ultrasound and elastography were performed to assess the changes in the morphology and elasticity of the bilateral TN and AT. Sonographic features were compared across the three groups, relevant factors affecting the stiffness of TN and AT were analyzed, respectively.

RESULTS

Diabetic patients exhibited significantly higher levels of HbA1C and a higher rate of smoking than healthy controls (P < 0.01 and P = 0.02, respectively). Their levels of body mass index (BMI) and total cholesterol have a significant difference between the NPN-DM group and healthy controls (both P = 0.02). The incidence of other microvascular complications in the NPN-DM group was significantly lower among diabetic patients (P = 0.04). Compared with healthy controls, the cross-sectional area (CSA) and transverse diameter of TN in diabetic patients were significantly larger (both P < 0.01), and CSA and anteroposterior diameter of AT were notably greater (P = 0.02 and P < 0.01). Besides, the stiffness of TN in the longitudinal section was significantly higher (P < 0.01), and the stiffness of AT in the cross-section was remarkably lower (P < 0.01). There was no significant difference in the morphology or elastography of TN or AT between NPN-DM and PN-DM groups. Furthermore, the stiffness of TN was not linearly related to that of AT, but independently correlated with age, HbA1C, and other microvascular complications (P < 0.05). The stiffness of AT was only independent of age (P < 0.01).

CONCLUSIONS

The size of both TN and AT in diabetic patients was significantly larger. The stiffness of TN increased, and that of AT decreased; however, these changes were independent of each other.

CLINICAL TRIAL NUMBER: Not applicable.