# Development and validation of a nomogram model integrating noninvasive detection of radial pulse wave for predicting diabetic foot risk in type 2 diabetes mellitus

## TL;DR

This study created a predictive model using TCM pulse data and clinical factors to assess diabetic foot risk in type 2 diabetes patients.

## Contribution

A novel nomogram model integrating noninvasive TCM pulse wave parameters for diabetic foot risk prediction in T2DM.

## Key findings

- The model achieved an AUC of 0.786 in predicting diabetic foot risk.
- Key risk factors included hypertension, BMI, and a TCM pulse parameter H5/H1.
- The model showed good calibration and clinical utility via decision curve analysis.

## Abstract

This study aimed to develop and evaluate a nomogram model based on Traditional Chinese Medicine (TCM) pulse mapping parameters to predict the risk of diabetic foot (DF) in patients with type 2 diabetes mellitus (T2DM).

A retrospective analysis was performed on clinical data and pulse mapping parameters from 485 T2DM patients hospitalized in the Departments of Vascular Diseases and Endocrinology at Shanghai TCM-Integrated Hospital between July 26, 2023, and April 9, 2025. Patients were divided into a DF group (n = 242) and a T2DM-only group (n = 243) according to the presence of DF. Pulse mapping parameters and clinical indicators were compared between the two groups. Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate logistic regression analyses were conducted to identify risk factors associated with DF development in T2DM. The risk prediction nomogram was constructed using R Studio. Model performance was evaluated using the Receiver Operating Characteristic (ROC) curve and its Area Under the Curve (AUC). Accuracy, Precision, Recall, and F1-score were calculated. Calibration curves were plotted to assess the agreement between predicted probabilities and actual outcomes, and decision curve analysis (DCA) was used to evaluate the model’s clinical utility.

Gender (OR = 0.501, p = 0.002), BMI (OR = 0.919, p = 0.003), hypertension (OR = 2.482, p < 0.001), systolic blood pressure (OR = 0.972, p < 0.001), blood urea nitrogen (BUN) (OR = 1.099, p = 0.011), and the pulse mapping parameter H5/H1 (OR = 0.002, p < 0.001) were identified as independent risk factors for DF in T2DM. The nomogram model based on these factors achieved an AUC of 0.786 (95% CI: 0.694–0.877) in the test set, with an Accuracy of 0.7113, Precision of 0.6481, Recall of 0.7955, and F1-score of 0.7143. The Hosmer–Lemeshow test demonstrated good calibration (χ² = 6.1672, p = 0.6285), showing close agreement between predicted and observed outcomes. The DCA confirmed favorable clinical applicability.

This nomogram model provides an individualized and visualized tool for predicting DF risk in T2DM patients, offering TCM-based reference indicators for early DF risk assessment.