understanding a complex evaluation of glucose control melanie aganon, pharmd candidate university of...
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Understanding A Complex Evaluation of Glucose Control
Melanie Aganon, PharmD Candidate University of Florida College of Pharmacy
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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.
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•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
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.
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•Based on equations from Matthews et al.
%B=beta-cell function IR =insulin resistance (%S)
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.
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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
HOMA2 – the computer model
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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•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
Additional Computations
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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•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
HOMA2 – the computer model
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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Computer modeling allows for smoother curves and better predictions
HOMA2 – the computer model
Diabetes Trials Unit: The Oxford Centre of Diabetes, Endocrinology, and Metabolism website. Accessed Octber 29, 2010. Available at <http://www.dtu.ox.ac.uk/homacalculator/download.php>.
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Can be downloaded from this site:
http://www.dtu.ox.ac.uk/homacalculator/download.php
Sampling for HOMA
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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•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%
Use in Individuals
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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•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
Points to remember
Wallace TM, Levy JC, and Matthews DR. Use and Abuse of HOMA Modelin. Diabetes Care 27: 1487-1495, 2004.
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• 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
References
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• Diabetes Trials Unit: The Oxford Centre of Diabetes, Endocrinology, and Metabolism website. Accessed Octber 29, 2010. Available at <http://www.dtu.ox.ac.uk/homacalculator/download.php>.
• 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.