Homeostatic model assessment
The HOMA authors used data from physiological studies to develop mathematical equations describing glucose regulation as a feedback loop.<ref>Turner et al. (1979) Insulin deficiency and insulin resistance interaction in diabetes: estimation of their relative contribution by feedback analysis from basal plasma insulin and glucose concentrations. Metabolism 28: 1086-96.</ref> They published computer software that solves the equations, so that insulin resistance and β-cell function can be estimated from fasting glucose and insulin levels. They also published an equation (see below) that gave approximately the same answers as an early version of the computer software.<ref name="Mathews1985">Matthews et al. (1985) Homeostasis model assessment: insulin resistance and B-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 28: 412-9.</ref>
The computer model has since been improved to a HOMA2 model<ref name="Rudenski"> A. S. Rudenski and D. R. Matthews and J. C. Levy and R. C. Turner (September 1991). [Expression error: Missing operand for > "Understanding insulin resistance: Both glucose resistance and insulin resistance are required to model human diabetes"]. Metabolism 40 (9): 908–917. doi:10.1016/0026-0495(91)90065-5. ISSN 0026-0495. </ref> to better reflect human physiology and recalibrated to modern insulin assays. In this updated version it is possible to determine insulin sensitivity and β-cell function from paired fasting plasma glucose and Radioimmunoassay insulin, specific insulin, or C-peptide concentrations. The authors recommend the computer software be used wherever possible.<ref name="Wallace2004">Wallace et al. (2004) Use and Abuse of HOMA modeling. Diabetes Care 27:1487-95.</ref><ref>Levy et al. (1998) Correct Homeostasis Model Assessment (HOMA) Evaluation uses the computer program. Diabetes Care 21: 2191-2.</ref>.
The HOMA model was originally designed as a special case of a more general model called HOMA-CIGMA.<ref>Turner et al. (1993) Measurement of insulin resistance and β-cell function: the HOMA and CIGMA approach. Current topics in diabetes research (eds) F. Belfiore, R. Bergman and G. Molinatti Front Diabetes. Basel, Karger 12: 66-75</ref>
The approximating equation for insulin resistance, in the early model, used a fasting plasma sample, and was derived by use of the insulin-glucose product, divided by a constant: (assuming normal-weight, normal subjects < 35 years, having 100% ?-cell function an insulin resistance of 1)
|Glucose in Molar Units mmol/L||Glucose in mass units (US units) mg/dL|
IR is insulin resistance and %β is the β-cell function. Insulin is given in mU/L. Glucose and Insulin are both during fasting<ref name="Mathews1985"/>.
The authors have tested HOMA extensively against other measures of insulin resistance (or its reciprocal, insulin sensitivity) and β-cell function.<ref name="Wallace2004"/><ref>Hermans et al. (1999) Comparison of tests of β-cell function across a range of glucose tolerance from normal to diabetes. Diabetes 48: 1770-86</ref><ref>Hermans et al. (1999b) Comparison of insulin sensitivity tests across a range of glucose tolerance from normal to diabetes Diabetologia 42: 678-87</ref>