[Value of shear wave elastography in the early diagnosis of DPN in patients with type 2 diabetes mellitus].

Objective: To investigate the value of shear wave elastography (SWE) in the early diagnosis of diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus. Methods: This study was a diagnostic case-control study. From May 2021 to October 2022, 68 patients with type 2 diabetes mellitus who met the inclusion criteria were admitted to the Department of Burns and Plastic Surgery of Affiliated Hospital of Zunyi Medical University, including 45 males and 23 females, aged (57±10) years. According to whether the DPN was present, the patients were divided into DPN group (38 patients) and non-DPN group (30 patients). During the same period, 30 healthy volunteers who underwent physical examinations at the health examination center of the hospital were recruited as healthy control group, including 19 males and 11 females, aged (56±10) years. Cross-sectional areas of the bilateral common peroneal nerves and tibial nerves measured by a color Doppler ultrasonography system in two-dimensional ultrasonography mode, and the stiffness of the bilateral common peroneal nerves and tibial nerves measured in SWE mode were compared between volunteers in healthy control group and two groups of patients at admission. Independent risk factors for the development of DPN were screened in the three groups of participants. Receiver operating characteristic curves were used to evaluate the diagnostic value of common peroneal nerve stiffness, common peroneal nerve cross-sectional area, tibial nerve stiffness, and tibial nerve cross-sectional area for DPN in two groups of patients. The correlations of common peroneal nerve stiffness and common peroneal nerve cross-sectional area with the Toronto clinical scoring system (TCSS) score were analyzed in patients of DPN group. Results: At admission, the cross-sectional areas of the bilateral common peroneal nerves of patients in DPN group were significantly larger than those of patients in non-DPN group and volunteers in healthy control group (P<0.05); there was no statistically significant difference in the cross-sectional area of the bilateral tibial nerves between volunteers in healthy control group and two groups of patients (P>0.05). At admission, the stiffness of the bilateral tibial nerves and common peroneal nerves of patients in both non-DPN group and DPN group was significantly greater than that of volunteers in healthy control group (P<0.05); the stiffness of the left tibial nerve and the bilateral common peroneal nerves of patients was significantly greater in DPN group than in non-DPN group (P<0.05). The results of multivariable ordinal logistic regression analysis showed that common peroneal nerve stiffness, tibial nerve stiffness, and common peroneal nerve cross-sectional area were all independent risk factors for the development of DPN among the participants in the three groups (with ORs of 0.91, 0.93, and 0.75, respectively, 95% CIs of 0.89 to 0.95, 0.89 to 0.97, and 0.58 to 0.96, respectively, P<0.05). In the two groups of patients, common peroneal nerve stiffness yielded the largest area under the curve for diagnosing DPN, which was 0.85 (with a 95% CI of 0.74 to 0.92). The optimal cutoff value was 75.29 kPa, with a sensitivity of 76.32% and a specificity of 90.00% at the optimal cutoff value. In DPN group, common peroneal nerve stiffness and common peroneal nerve cross-sectional area of patients were significantly positively correlated with the TCSS score (with r_s values of 0.83 and 0.89, respectively, P<0.05). Conclusions: SWE demonstrates excellent performance in assessing peripheral nerve stiffness in patients with type 2 diabetes mellitus. In particular, common peroneal nerve stiffness measured by SWE has high diagnostic value for patients complicated with DPN and is correlated with clinical severity. It may serve as an auxiliary imaging marker for the early screening and severity assessment of DPN.