The Application of the Insulin to C-Peptide Molar Ratio (ICPR) in Primary Screening for Insulin Antibodies in Type 2 Diabetes Mellitus Patients: A Further Quantitative Study on the Relationship Between ICPR and Insulin Antibodies

PURPOSE: This study aimed to further quantify the relationship between insulin antibodies (IAs) and the 2-hour insulin to C-peptide molar ratio (2h-ICPR) using a multiple linear regression model in T2DM patients. METHODS: A total of 274 T2DM patients from April 2019 to December 2022 in Xiang’an Hospital of Xiamen University were included in this study. Multiple Linear Model Fitting was conducted on the candidate independent variables (age, BMI, HbA1c, and 2h-ICPR) for the multiple linear regression. The linear relationship between insulin antibodies (IAs) and the significant independent variables was presented by making multiple linear regression equations. RESULTS: The total demographic characteristics of the included patients were as follows: age (51.92±13.10 years), BMI (24.94±3.99 kg/m(2)), HbA1c (9.70±2.39%), 2h-ICPR (0.12±0.11), and IAs (0.37±1.12COI). Linear relationships of independent variables: age (r=0.163, p=0.007), 2h-ICPR (r=0.259, p=0.001), BMI (r=0.007, p=0.907) and 2h-ICPR (r=0.092, p=0.129). Multiple linear regression: age (unstandardized β=0.014, 95% CI: 0.004–0.024, p=0.004), 2h-ICPR (unstandardized β=2.758, 95% CI: 1.555–3.962, p≤0.001). The regression equation: [Image: see text] . CONCLUSION: The quantitative relationship between 2h-ICPR and insulin antibodies was [Image: see text] . 2h-ICPR can be a preliminary screening indicator for insulin antibody testing in patients with type 2 diabetes.