Preanalytical, analytical, and computational factors affect homeostasis model assessment estimates

Area of Science:

• Endocrinology
• Metabolic Research
• Clinical Diagnostics

Background:

• Homeostasis Model Assessment (HOMA) is widely used to estimate beta-cell function and insulin resistance.
• Variability in HOMA estimates can arise from preanalytical factors, including blood sample type and insulin assay methodology.

Purpose of the Study:

• To investigate the impact of blood sample type (serum vs. heparinized plasma) and insulin assay selection on HOMA estimates.
• To assess how different Homeostasis Model Assessment (HOMA) calculators influence beta-cell function and insulin resistance measurements.

Main Methods:

• Insulin levels were measured in serum (11 assays) and heparinized plasma (1 assay) from individuals with normoglycemia, pre-diabetes, and type 2 diabetes.
• HOMA estimates were calculated using both Specific Insulin (SI) and Radioimmunoassay (RIA) calculators.

Main Results:

• Significant variations in beta-cell function and insulin resistance estimates were observed across different insulin assays and HOMA calculators.
• Insulin levels were approximately 15% lower in heparinized plasma compared to serum.
• HOMA estimates for beta-cell function and insulin resistance showed considerable variability, with twofold differences noted in some serum samples.

Conclusions:

• The choice of blood sample type, insulin assay, and HOMA calculator significantly affects HOMA estimates.
• Standardization of preanalytical factors and insulin assays traceable to a reference method is essential for reliable and comparable HOMA results in research and clinical practice.