The HOMA2 Calculator

In part 1 of the ODX HOMA2 series, we introduce an amazing calculator called HOMA2 that is changing the way we assess patients for insulin resistance.

The HOMA2 Calculator: An Important Series of Indices for Gauging Insulin Resistance

Dicken Weatherby, N.D. and Beth Ellen DiLuglio, MS, RDN, LDN

The ODX HOMA2 Series

1. HOMA2 part 1 - The HOMA2 Calculator: An Important Series of Indices for Gauging Insulin Resistance
2. HOMA2 part 2 - HOMA2 - %B: An Index For Gauging the Beta Cell Output of Insulin from the Pancreas
3. HOMA2 part 3 - HOMA2 - %S: An Index For Assessing Cellular Sensitivity to Insulin
4. HOMA2 part 4 - HOMA2 - IR: An Index For Assessing the Degree of Insulin Resistance
5. Bonus - QUICKI – An Additional Index for Assessing Insulin Resistance in Our Patients
6. Optimal - The Podcast: Episode 5: The HOMA2 Calculator in Clinical Practice - an Interview with Dr. Brad Rachman

Insulin sensitivity reflects the responsiveness of peripheral tissues to insulin and their ability to take up circulating glucose.

When cells are less responsive to insulin, beta cells produce more insulin to compensate, creating a vicious cycle of increased production of insulin and an increased resistance to insulin at the cellular level, a condition called Insulin Resistance.

Insulin sensitivity can be measured and should be assessed in patients at high risk for glucose dysregulation.

Gold standard measurements of insulin sensitivity are relatively invasive and include hyperglycemic and hyperinsulinemic-euglycemic clamps, and the intravenous glucose tolerance test.

Even the less invasive oral glucose tolerance test (OGTT) may not be ideal as it does not reflect disease progression and does not distinguish between beta cell failure and peripheral insulin resistance.

Instead, insulin resistance, sensitivity and beta cell output can be measured using homeostasis model assessment (HOMA) calculations that take into account fasting glucose, fasting insulin, and/or C-peptide. The HOMA (Homeostasis Model Assessment) calculator is a tool used to do just that.

An estimate of beta cell function and the degree of insulin sensitivity in the patient can be determined based on the following biomarkers: fasting blood glucose, fasting insulin and/or c-peptide.  The original HOMA calculator was formulated in 1985. The calculator emerged from the research of  the Diabetes Trials Unit, a founding member of the Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), which is a division within the University of Oxford’s Radcliffe Department of Medicine. The original HOMA calculator (HOMA1) was updated in 1998 to the model currently in use, which is called the HOMA2 calculator.¹ 

HOMA2  is a complex mathematical model of the physiologic processes that influence circulating glucose and insulin levels, and is used to estimate beta cell function (HOMA2-%B), insulin sensitivity (HOMA2-%S) and insulin resistance (HOMA2-IR).² Measurements of these biomarkers (fasting glucose, fasting insulin, and/or c-peptide) are quickly and easily attainable, and research shows that the HOMA2-IR and HOMA2-%B calculations show good correlations with the values obtained by the aforementioned gold standard tests.³

Research confirms that HOMA2 is a better predictor of progression to diabetes than the original HOMA1 calculator.⁴

Updated HOMA2 calculations (1996) take into account proinsulin secretion as well as variances in both hepatic and peripheral glucose resistance.⁵

HOMA2 calculations are found to correlate well with the more invasive gold standard methods.³

Optimal DX now gives our users the ability to add the 3 HOMA2 calculations to their patient’s Functional Health Reports.

Up Next - HOMA2 part 2 - HOMA2 - %B: An Index For Gauging the Beta Cell Output of Insulin from the Pancreas

References

1. Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care [serial online]. 2004;27(6):1487-1495.
2. Lorenzo C, Wagenknecht LE, Rewers MJ, Karter AJ, Bergman RN, Hanley AJ, Haffner SM. "Disposition index, glucose effectiveness, and conversion to type 2 diabetes: the Insulin Resistance Atherosclerosis Study (IRAS)". Diabetes Care. 2010;33(9):2098–103. 
3. Tripathy D, Almgren P, Tuomi T, Groop L. Contribution of insulin-stimulated glucose uptake and basal hepatic insulin sensitivity to surrogate measures of insulin sensitivity. Diabetes Care [serial online]. 2004;27(9):2204-2210.
4. Song, Young Seok et al. “Comparison of the Usefulness of the Updated Homeostasis Model Assessment (HOMA2) with the Original HOMA1 in the Prediction of Type 2 Diabetes Mellitus in Koreans.” Diabetes & metabolism journal vol. 40,4 (2016): 318-25.
5. Wallace, Tara M et al. “Use and abuse of HOMA modeling.” Diabetes care 27,6 (2004): 1487-95.