Impaired Vascular Endothelial Function is Associated with Peripheral Neuropathy in Patients with Type 2 Diabetes

Abstract

Purpose

It is believed that vascular endothelial dysfunction is involved in the occurrence of cardiovascular disease (CVD), and diabetic peripheral neuropathy (DPN) is associated with flow-mediated dilation (FMD), however, the correlation is still unclear. Aims of the present study is to explore the relationship between DPN parameters and FMD, providing a new approach for the prevention of CVD.

Patients and Methods

A total of 272 patients with T2DM from the Department of Endocrinology of The First Hospital of Lanzhou University according to the grading criteria were selected. FMD was measured by a new vascular ultrasound system and patients were divided into FMD>7%, 4%≤FMD≤7%, and FMD<4% groups. The Toronto Clinical Scoring System (TCSS) was used to assess the severity of DPN. The nerve conduction studies (NCS) assessed large fibre neuropathy by nerve conduction velocity (CV), compound muscle action potential (CMAP) amplitude (Amp), and distal motor latency (DML). SPSS 25.0 was used for statistical analysis.

Results

TCSS evaluation revealed that the percentage of patients with severe nerve injury was significantly higher in FMD<4% (70%) compared to FMD>7% (2%). Among the TCSS indicators of all subjects, the proportion of temperature disturbance was the most (73%), and joint position disturbance was the least (0). TCSS scores were negatively correlated with FMD (r=−0.756, p<0.001). More interesting, in FMD<4% group, CV and Amp were positively correlated with FMD, while DML was negatively correlated (p<0.05). Linear regression analysis model showed that different systolic blood pressure (SBP), triglyceride (TG), TCSS and CV had statistically different effects on FMD.

Conclusion

High TCSS score and decreased CV of common peroneal and tibial nerves are risk factors of FMD injury, which provide potential value for timely prevention and treatment of cardiovascular diseases.

Keywords:

• type 2 diabetes
• diabetic peripheral neuropathy
• vascular endothelial function
• cardiovascular disease
• Toronto clinical scoring system

Abbreviations

FMD, flow-mediated dilation; F, female; M, male; BMI, body mass index; FPG, fasting blood glucose; HbA1C, glycosylated hemoglobin; TC, total cholesterol; TG, triglyceride; HDL, high density lipoprotein; LDL, low-density lipoprotein; SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; HCY, homocysteine; baPWV, brachial ankle pulse wave velocity; ABI, ankle-brachial index; TCSS, Toronto clinical scoring system; CMAP, compound muscle action potential; CV, conduction velocity; Amp, amplitude; DML, distal motor latency.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Acknowledgments

The authors gratefully acknowledge the participation and cooperation of all patients in this study as well as the Department of Endocrinology of the First Hospital of Lanzhou University.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This work was supported by Gansu Natural Science Foundation (No. 21JR1RA080); The First Hospital of Lanzhou University Research Fund (No. ldyyyn2019-39) and TCM Special Project of Gansu Province in 2021.