Critical Evaluation of Indices Used to Assess β-Cell Function

Area of Science:

• Endocrinology
• Metabolic Research
• Diabetes Research

Background:

• Beta-cell function assessment, crucial for understanding glucose homeostasis, lacks standardized methodologies.
• Existing beta-cell function indices often yield contradictory results, complicating interpretation.

Purpose of the Study:

• To compare various established beta-cell function indices against the direct insulin secretion rate (ISR)-plasma glucose relationship.
• To evaluate the reliability of common indices in differentiating beta-cell function across lean and obese individuals with varying glucose tolerance status.

Main Methods:

• Compared multiple beta-cell function indices (HOMA-B, ratio, insulinogenic, ISRogenic, disposition index) in lean and obese groups.
• Utilized a statistical mixed-effects model to analyze the ISR-plasma glucose relationship before and after glucose ingestion.
• Assessed group differences in beta-cell function based on index calculations and direct relationship modeling.

Main Results:

• Index-based assessments of beta-cell function produced conflicting outcomes across study groups.
• These indices failed to accurately represent the observed ISR-plasma glucose relationship.
• The disposition index did not reliably reflect group differences in glycemic status.

Conclusions:

• Commonly employed beta-cell function indices may be unreliable due to flawed mathematical assumptions.
• Directly modeling the ISR-plasma glucose relationship offers a more accurate assessment of beta-cell function.
• Caution is advised when interpreting data derived from conventional beta-cell function indices.