Background Diabetic peripheral neuropathy (DPN) is one of the most common and serious chronic complications of diabetes. Identifying biological markers related to the occurrence, development, and treatment efficacy of DPN is of great clinical significance for achieving early precise diagnosis, dynamic monitoring of the condition, and guiding individualized treatment. In recent years, traditional Chinese medicine (TCM), such as Huangqi Guizhi Wuwu Decoction, has shown certain potential in improving DPN symptoms, but objective evaluation of its efficacy still faces challenges.

Objective To analyze the efficacy of Huangqi Guizhi Wuwu Decoction on patients with Qi deficiency and blood stasis type DPN, and explore the diagnostic evaluation value of plasma microRNA-146a for DPN.

Methods Patients with Qi deficiency and blood stasis type DPN admitted to the Department of Endocrinology, Guang'anmen Hospital (South District), China Academy of Chinese Medical Sciences, from January 2022 to December 2023 were randomly divided into control group (Western medicine group) and observation group (TCM addition group). The control group received mecobalamin treatment based on basic diabetes treatment, while the observation group received mecobalamin combined with modified Huangqi Guizhi Wuwu Decoction. Efficacy, blood glucose levels, nerve conduction velocity, TCM syndrome scores, and changes in plasma microRNA-146a levels were observed. The levels of microRNA-146a were compared with those in non-DPN diabetic patients to evaluate its diagnostic efficacy for DPN.

Results A total of 54 patients with diabetes mellitus peripheral neuropathy of the Qi deficiency and blood stasis type were included in the final analysis. Among them, the observation group consisted of 28 cases, with 19 males and 9 females, aged (35.2±8.5) years. The control group consisted of 26 cases, with 17 males and 9 females, aged (36.8±7.9) years. The total effective rate of the observation group was significantly higher than that of the control group (89.3% vs 57.7%, P=0.008). After treatment, the tibial nerve conduction velocity in both groups was significantly improved (P < 0.05), but the improvement in the observation group was more significant than that in the control group (left tibial nerve: 44.14±3.39 m/s vs 41.95±3.03 m/s, P=0.016; right tibial nerve: 43.07±3.01 m/s vs 41.39±2.22 m/s, P=0.024). After treatment, the fasting blood glucose and 2-hour postprandial blood glucose in both groups were significantly lower than those before treatment in the same group, and the reduction in the observation group was more significant than that in the control group (fasting blood glucose: 7.13±0.78 mmol/L vs 7.86±1.08 mmol/L, P=0.006; 2-hour postprandial blood glucose: 9.65±0.78 mmol/L vs 10.47±1.49 mmol/L, P=0.013). After treatment, the plasma microRNA-146a level in the observation group was higher than that in the control group (MIQR: 15.46(5.41 - 23.11) vs 8.65(4.16 - 11.94), P=0.018). The ROC-AUC of diagnostic efficacy of plasma microRNA-146a for DPN was 0.769 (95% CI: 0.614 - 0.905), with a diagnostic threshold of 10.

Conclusion Modified Huangqi Guizhi Wuwu Decoction can alleviate neurological symptoms and defects in patients with Qi deficiency and blood stasis type DPN, increase nerve conduction velocity, improve clinical symptoms, and increase plasma microRNA-146a expression. The expression level of plasma microRNA-146a has certain diagnostic and evaluation value for DPN, suggesting that it has the potential to become a potential diagnostic marker.