Diabetic peripheral neuropathy (DPN) is a common and serious complication of diabetes that causes numbness, pain, and weakness, often starting in the feet. Currently, there is no cure, and early diagnosis is difficult with standard tests alone. This observational study aims to find better ways to detect DPN in its early stages. The researchers will use high-frequency ultrasound, a painless and non-invasive imaging tool, to measure two things in patients with type 2 diabetes: the cross-sectional area of the sciatic nerve (to look for swelling) and the blood flow velocity in the inferior gluteal artery (a vessel that supplies the nerve).In parallel, a bioinformatics analysis has identified a key target gene, MMP9, which may play a role in nerve damage through a specific signaling pathway. The level of this protein will be measured in the patients' blood. A total of 120 participants will be grouped by the severity of their nerve damage, assessed by a clinical scoring system (TCSS). The study will investigate whether the ultrasound measurements correlate with the clinical scores, nerve conduction studies, and the blood levels of the target protein. The ultimate goal is to combine these ultrasound structure, blood flow function, and molecular markers to build a more accurate tool for the early diagnosis and precise management of DPN, bridging the gap from early warning to mechanism-based care.
This study is a prospective, observational, cross-sectional investigation designed to explore the early diagnostic value of high-frequency ultrasound in patients with type 2 diabetic peripheral neuropathy(DPN) by integrating bioinformatics-derived molecular markers. The study aims to validate a "Structure-function-molecule" cascade hypothesis for DPN progression. Background and Rationale: DPN is a highly disabling complication of diabetes with no current disease-modifying treatment, underscoring the urgent need for early detection. Prior work by our group found that elevated N/OFQ in DPN rats was associated with reduced limb blood flow, mediated by MME. Shifting the focus from vascular to neural mechanisms, the present study employed independent bioinformatics analysis and identified MMP9 as a core target gene linking N/OFQ to DPN-related nerve damage, enriched in the AMPK signaling pathway. This clinical study therefore aims to validate MMP9 as a serum biomarker and examine its correlation with sciatic nerve cross-sectional area and inferior gluteal artery blood flow velocity on ultrasound across DPN severity grades. Study Design and Participants: A total of 120 adult patients with type 2 diabetes mellitus, diagnosed according to World Health Organization criteria, will be consecutively recruited from the Endocrinology Department of the Second Hospital of Shanxi Medical University. Grouping and Assessments: Participants will be stratified into three distinct severity grades based on the Toronto Clinical Scoring System(TCSS): Grade 1 (0-5 points), Grade 2 (6-9 points), Grade 3 (≥10 points). Each participant will undergo the following integrated assessments: 1. Demographic and Clinical Data Collection: Records include age, sex, body mass index, diabetes duration, HbA1c, and lipid profile. 2. Ultrasound Examination: With the patient in a lateral decubitus position (hip and knee flexed), a high-frequency linear probe will be placed at the midpoint between the ischial tuberosity and the greater trochanter to visualize the sciatic nerve. Color and pulsed-wave Doppler will subsequently measure blood flow velocity in the inferior gluteal artery. 3. Serum Biomarker Detection: Venous blood samples will be collected and centrifuged. Serum levels of the target protein MMP9 will be quantified. 4. Nerve Conduction Studies: Standard electrophysiological parameters, including motor nerve conduction velocity(MNCV) and sensory nerve conduction velocity(SNCV) for the lower limbs, will be recorded for correlation. Outcome Measures and Statistical Analysis: Statistical analysis will employ ANOVA or Kruskal-Wallis tests for inter-group comparisons. Pearson or Spearman correlation coefficients will quantify the relationships among nerve structure, blood flow, and molecular markers. The combined diagnostic performance will be assessed using receiver operating characteristic (ROC) curves and logistic regression models to calculate the area under the curve (AUC). The study hypothesizes that a multimodal diagnostic model integrating imaging and serum biomarkers will provide superior sensitivity and specificity for early DPN detection compared to single-modality assessments alone.
Study Type
OBSERVATIONAL
Enrollment
120
This is a purely observational study. No investigational drug, device, or biological product will be administered, and no clinical procedures will be performed outside of standard clinical care for the sole purpose of this research. All participants will receive routine standard-of-care as determined by their treating physicians. The study will only involve non-invasive data collection including clinical assessment, ultrasound imaging, nerve conduction studies, and blood sampling for biomarker analysis, which are all conducted as part of the study assessments, not as interventions.
Second Hospital of Shanxi Medical University
Taiyuan, Shanxi, China
Correlation Between Serum MMP9 Levels and Combined Ultrasonographic Parameters in Discriminating DPN Severity
The combined diagnostic performance of the multimodal (ultrasound + serum biomarker) for early DPN detection will be assessed using receiver operating characteristic (ROC) curve analysis and expressed as the area under the curve (AUC).
Time frame: At the time of enrollment
Differences in Sciatic Nerve Cross-Sectional Area Across DPN Severity Grades
To compare the sciatic nerve cross-sectional area (CSA, in mm²) measured by high-frequency ultrasound among groups with different DPN severity grades defined by TCSS scores.
Time frame: At the time of enrollment
Differences in Inferior Gluteal Artery Blood Flow Velocity Across DPN Severity Grades
To compare the peak systolic velocity (PSV) of the inferior gluteal artery measured by pulsed-wave Doppler ultrasound among groups with different DPN severity grades.
Time frame: At the time of enrollment
Comparison of Nerve Conduction Study Parameters Across DPN Severity Grades
To compare motor nerve conduction velocity (MNCV) and sensory nerve conduction velocity (SNCV) of bilateral common peroneal, tibial sural, and superficial peroneal nerves among groups with different DPN severity grades.
Time frame: At the time of enrollment
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