The Diagnostic Value of miR-20b-3p and High-Frequency Ultrasound in Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is a major chronic complication of diabetes. Developing accurate, non-invasive and feasible diagnostic strategies is essential for early diagnosis and intervention of DPN. We aimed to detect the serum miR-20b-3p expression and high-frequency ultrasound (HFUS)-measured nerve cross-sectional area (CSA) in DPN patients and explore the combined diagnostic value of the two indicators for DPN. A total of 155 patients with type 2 diabetes mellitus (T2DM) were enrolled, including 75 non-DPN patients and 80 DPN patients. The serum miR-20b-3p expression was detected by qRT-PCR, and the CSA of median, ulnar and tibial nerves was measured by HFUS. ROC curve analysis was performed to evaluate the diagnostic efficacy of single and combined indicators. Toronto Clinical Scoring System (TCSS) and Michigan Neuropathy Screening Instrument (MNSI) scores were collected, and Pearson correlation analysis was used to analyse the correlations of miR-20b-3p and nerve CSA with clinical scores. DPN patients showed significantly down-regulated serum miR-20b-3p and increased CSA of the three peripheral nerves. miR-20b-3p expression was negatively correlated with nerve CSA. Both indicators demonstrated moderate diagnostic efficacy for DPN, and their combination yielded superior diagnostic efficacy, with an AUC of 0.935, sensitivity of 83.7 % and specificity of 90.7 %. Additionally, the miR-20b-3p level and nerve CSA were closely associated with the peripheral nerve function of DPN patients. We conclude that the combination of serum miR-20b-3p and peripheral nerve CSA is a promising novel diagnostic strategy for DPN.