The homeostatic model assessment (HOMA) is a method used to quantify
insulin resistance
Insulin resistance (IR) is a pathological condition in which cell (biology), cells fail to respond normally to the hormone insulin.
Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood gluco ...
and
beta-cell
Beta cells (β-cells) are a type of cell (biology), cell found in pancreatic islets that synthesize and secrete insulin and amylin. Beta cells make up 50–70% of the cells in human islets. In patients with Type 1 diabetes, beta-cell mass and fun ...
function. It was first described under the name HOMA by Matthews ''et al.'' in 1985.
Derivation
The HOMA authors used data from physiological studies to develop mathematical equations describing glucose regulation as a feedback loop.
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.
The computer model has since been improved to a HOMA2 model
[
] 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
A radioimmunoassay (RIA) is an immunoassay that uses radiolabeled molecules in a stepwise formation of immune complexes. A RIA is a very sensitive in vitro assay technique used to measure concentrations of substances, usually measuring antigen conc ...
insulin, specific insulin, or C-peptide concentrations. The authors recommend the computer software be used wherever possible.
Notes
The HOMA model was originally designed as a special case of a more general structural (HOMA-CIGMA) model that includes the continuous infusion of glucose with model assessment (CIGMA) approach; both techniques use mathematical equations to describe the functioning of the major effector organs influencing glucose/insulin interactions.
[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]
The approximating equation for insulin resistance, in the early model, used a fasting plasma sample, and was derived by use of the
insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism o ...
-
glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...
product, divided by a constant: (assuming normal-weight, normal subjects < 35 years, having 100% β-cell function an insulin resistance of 1)
IR is insulin resistance and %β is the β-cell function (more precisely, an index for glucose tolerance, i.e. a measure for the ability to counteract the glucose load).
Insulin is given in
μU/mL.
Glucose and insulin are both during fasting.
This model correlated well with estimates using the
euglycemic clamp method (r = 0.88).
The authors have tested HOMA and HOMA2 extensively against other measures of insulin resistance (or its reciprocal, insulin sensitivity) and β-cell function.
The approximation formulae above relate to HOMA and are crude estimates of the model near normal levels of glucose and insulin in man. The actual calculated HOMA2 compartmental model is published
and i
available online
See also
*
QUICKI
*
SPINA-GBeta
SPINA-GBeta is a calculated biomarker for pancreatic beta cell function. It represents the maximum amount of insulin that beta cells can produce per time-unit (e.g. in one second).
How to determine GBeta
The index is derived from a mathematical ...
*
SPINA-GR
SPINA-GR is a calculated biomarker for insulin sensitivity. It represents insulin receptor gain.
How to determine GR
The index is derived from a mathematical model of insulin-glucose homeostasis. For diagnostic purposes, it is calculated from fast ...
References
External links
iHOMA - Nathan R Hill - University of OxfordiHOMA2 — Nuffield Department of Primary Care Health Sciences, University of Oxford
{{DEFAULTSORT:Homeostatic Model Assessment
Diabetes
Endocrinology
Human homeostasis
Endocrine procedures
Static endocrine function tests