Call for Standardization of C-Peptide Measurement.

Area of Science:

• Endocrinology
• Clinical Chemistry
• Diabetes Mellitus Research

Background:

• Impaired beta-cell function is central to diabetes mellitus pathophysiology, with C-peptide serving as a key biomarker.
• C-peptide measurement aids in diabetes prediction, diagnosis, subclassification, and guiding therapeutic strategies.
• Established C-peptide cut-off values by ADA/EASD for diabetes classification are limited by analytical variability and lack of standardization across assays.

Purpose of the Study:

• To highlight the critical need for standardized C-peptide measurements in clinical practice.
• To underscore the consequences of analytical discrepancies in C-peptide testing for diabetes management.
• To advocate for the implementation of standardized C-peptide assays to enhance diagnostic accuracy and patient safety.

Main Methods:

• Review of current guidelines and clinical practices regarding C-peptide testing in diabetes mellitus.
• Analysis of the impact of assay variability on the clinical utility of C-peptide measurements.
• Assessment of the status of C-peptide standardization efforts.

Main Results:

• Significant variability exists between C-peptide assay manufacturers, limiting clinical utility.
• Despite established guidelines and calls for standardization, practical implementation remains incomplete.
• Increased reliance on C-peptide testing for diabetes classification and treatment decisions exacerbates the impact of variability.

Conclusions:

• Standardized C-peptide measurements are essential for improving diagnostic accuracy and patient safety in diabetes care.
• Healthcare providers should advocate for manufacturers to implement standardized C-peptide assays.
• Addressing analytical discrepancies is crucial for the reliable clinical application of C-peptide biomarkers.