The homeostasis model assessment of Insulin resistance (HOMA-IR) and β-cell function (HOMA-β) is an index of insulin resistance and beta cell's insulin secretory function.
The Homeostasis Model Assessment (HOMA), developed in 1985, is a model of interactions between glucose and insulin. The model assumes a feedback loop between the liver and β-cell.
- Glucose concentrations are regulated by insulin-dependent hepatic glucose production.
- Insulin levels depend on the pancreatic β-cell response to glucose concentrations.
A diminished response to glucose-stimulated insulin secretion reflects deficient β-cell function. A diminished suppressive effect of insulin on hepatic glucose production is insulin resistance.
The most common method used in epidemiological studies is HOMA- β and HOMA-IR formulas. The equations are widely used and simplified to:
HOMA1-IR = (FPI x FPG) / 405
HOMA1- β = (20 x FPI) / (FPG - 63)
for IR and beta-cell function, respectively, where FPI is fasting plasma insulin concentration (µU/ml) and FPG is fasting plasma glucose (mg/dl).
Remember that both values refer to the fasting state where nothing has been eaten or drank (other than clear water) for at least 8 hours before the blood sample is drawn.
What is HOMA-IR?
HOMA-IR stands for Homeostatic Model Assessment of Insulin Resistance is an index used to calculate whether insulin resistance is present in a patient. HOMA-IR is a robust tool for the surrogate assessment of insulin resistance.
HOMA-IR = [fasting insulin (µU/ml) × fasting plasma glucose (mg/dl)] / 405
Insulin regulates the blood glucose level and is secreted when the blood glucose level is high mostly after a meal just before wakeup. It works like a key unlocking specialized receptor in the cell membrane, it makes glucose move into fat, skeletal muscle, and liver cells. This results in the following:
- The cell receives a source of energy; and,
- The blood glucose level is lowered.
Insulin Resistance (IR) is a state of insulin hormone that no longer has sufficient ability to bind to its receptors and do its functions, which leads the liver, skeletal muscle, and adipose tissue to have reduced sensitivity to the metabolic effects of insulin.
The pancreas tries to produce more insulin to compensate for this insulin resistance. As long as the amount of insulin available to the cell is sufficient to compensate for its weak response, blood glucose levels will stay in the normal range.
The pancreas usually cannot able to maintain this increased insulin production for a long time. Type 2 diabetes develops when the pancreas can no longer make the extra amounts of insulin it requires to keep blood glucose at a normal level.
Insulin resistance precedes more severe metabolic disorders, such as diabetes. It's also usually paired with other cardiovascular risk factors, like obesity, lack of physical activity, high blood pressure, and hyperlipidemia.
What is the HOMA-Beta cell function?
The homeostasis model assessment of β-cell function (HOMA-β) is an index of insulin secretory function derived from fasting plasma glucose and insulin concentrations.
HOMA-B = 20 × fasting insulin (µU/ml) / [fasting plasma glucose (mg/dl) – 63]
Insulin secretion measured by HOMA-S decreased with an increasing number of metabolic abnormalities. A decrease in insulin secretory function, as estimated by HOMA-β, predicted the development of diabetes and/or impaired glucose tolerance.
An increase in insulin secretion along with an increase in insulin resistance as measured by HOMA indicates pancreas is working hard to make up for insulin resistance and it also indicates that your pancreas is functioning well, and thus Once your lower your insulin resistance then changes to reverse diabetes is bright.
A decrease in insulin secretion along with an increase in insulin resistance as measured by HOMA indicates a drop in the pancreas function due to overwork for a long time. It also indicates that your pancreas is starting to lose its function, and thus you should work hard to decrease insulin resistance and restore pancreas function.
Since b-cell regenerative capacity is limited, reducing b-cell workload is the most effective way to preserve b-cell functional mass.
The cutoff value for HOMA-IR & HOMA-β
HOMA-IR, the cutoffs were <2.6 (normal), 2.6 to 5.08 (prediabetics), and >5.08 (Diabetes).
For HOMA-%B, the cutoffs were >48.9% (normal), 48.9% to 25.0% (borderline), and <25.0% (Diabetes).
How to use the IR & β-cell function calculator?
Our HOMA calculator is very easy to use: Fill in the field for the blood glucose concentration (glucose), and insulin concentration with the corresponding units, and by pressing calculate you will get the result. IR increased with an increasing number of metabolic abnormalities.
Treat the results from this calculator as a way of seeing if you have any cause for concern, not as an exact diagnosis.
Caution
If there is no detectable fasting insulin, <2 uIU/mL (<12 pmol/L), and the blood glucose is significantly high, such as a HgbA1C >6.2% (>44 mmol/L), this could be type 1 diabetes, and should be immediately reviewed by a doctor.
There is an adult-onset type 1 diabetes called LADA, sometimes referred to as diabetes type 1.5; more advanced blood tests, including antibody tests, can help to evaluate for the presence of this condition, and should be done through your health-care provider.