1. Understanding A Complex Evaluation of Glucose Control Melanie Aganon, PharmD Candidate University of Florida College of Pharmacy 1

2. Homeostatic Model Assessment Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. Wallace TM and Matthews DR. The assessment of insulin resistance in man. Diabetic medicine, 19, 527-534. 2 Assesses beta-cell function (%B) and insulin resistance (%S) ▫Described in percentages, with 100% as the median normal value Uses fasting plasma glucose (FPG) and fasting plasma insulin (FPI) to determine %B and %S 2 types of HOMA ▫HOMA1 – original model ▫HOMA2 – updated computer model

3. HOMA 1 – the original Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. Matthews DR, Hosker JP, Rudenski AS, naylor BA, Treacher DF, Turner RC: Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and Insulin concentrations in man. Diabetologia 28:412-419, 1985. 3 Based on equations from Matthews et al. %B=beta-cell function IR =insulin resistance (%S)

4. HOMA 1 – the original Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. Matthews DR, Hosker JP, Rudenski AS, naylor BA, Treacher DF, Turner RC: Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and Insulin concentrations in man. Diabetologia 28:412-419, 1985. 4 As insulin sensitivity decreases, insulin production goes up to compensate then decreasing beta cell function leads to diabetes and eventually insulin dependence. HOMA measures this

5. HOMA2 – the computer model Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 5 Updated in 1996 to account for: ▫Variations in hepatic and peripheral glucose resistance ▫Reduction in the suppression of hepatic glucose output ▫Reduction of peripheral glucose-stimulated glucose reuptake

6. Additional Computations Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 6 Can determine insulin sensitivity (%S) and beta- cell function (%B) from: ▫Fasting plasma glucose and RIA insulin ▫Specific insulin ▫C-peptide concentrations if  Insulin concentration is in range of 1 - 2,200pmol/L  Glucose concentration is in range of 1 – 25 mmol/L

7. HOMA2 – the computer model Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 7 Computer modeling allows for smoother curves and better predictions

8. HOMA2 – the computer model Diabetes Trials Unit: The Oxford Centre of Diabetes, Endocrinology, and Metabolism website. Accessed Octber 29, 2010. Available at. 8 Can be downloaded from this site: http://www.dtu.ox.ac.uk/homacalculator/download.php

9. Sampling for HOMA Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 9 Insulin secretion is pulsate Recommended to take 3 samples in 5-minute intervals ▫Use the average Single sample coefficients of variation ▫HOMA-%S: 10.3% ▫HOMA-%B: 7.7%

10. Use in Individuals Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 10 Track changes in insulin sensitivity and beta-cell function Determine if either insulin sensitivity or beta- cell failure dominates (this is used in determining Medicare coverage of insulin pumps Uses triplicate insulin samples to avoid temporary beta-cell exhaustion

11. Points to remember Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. 11 Difficult to use in patients using insulin ▫Exogenous insulin does not undergo the same first- metabolism as endogenous metabolism ▫Need to take samples when glucose and insulin concentrations are in steady state Patients on secretagogues ▫Interpret results with caution ▫Improvement in beta-cell function reflects secretagogue mechanism of action in first year ▫Will show a decline thereafter Cannot use in animal studies

12. References 12 Diabetes Trials Unit: The Oxford Centre of Diabetes, Endocrinology, and Metabolism website. Accessed Octber 29, 2010. Available at. Lu Chuanyi M, Nicoll Diana, McPhee Stephen J, Pignone Michael, "Common Laboratory Tests" (Chapter). Diana Nicoll, Stephen J. McPhee, Michael Pignone: Pocket Guide to Diagnostic Tests, 5e: http://www.accesspharmacy.com.lp.hscl.ufl.edu/content.aspx?aID=3135000. Matthews DR, Hosker JP, Rudenski AS, naylor BA, Treacher DF, Turner RC: Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 28:412-419, 1985. Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004. Wallace TM and Matthews DR. The assessment of insulin resistance in man. Diabetic medicine, 19, 527-534.