mg/dL
µU/mL
How it's calculated
HOMA-IR = (fasting glucose in mg/dL × fasting insulin in µU/mL) / 405 — a simple surrogate for insulin resistance from a single fasting blood draw.
Interpretation
| HOMA-IR | Interpretation |
|---|---|
| < 1.0 | Normal insulin sensitivity |
| 1.0 – 2.5 | Borderline / indeterminate |
| > 2.5 | Suggests insulin resistance |
Clinical use
- A research and clinical surrogate for insulin resistance, used when a hyperinsulinemic-euglycemic clamp (the gold standard) is impractical.
- Requires a true fasting sample (typically 8-12 hours) — results are not valid on a random or postprandial glucose/insulin pair.
- Not valid in patients already on exogenous insulin therapy, since the assay cannot distinguish endogenous from injected insulin.
- Cutoffs for 'insulin resistance' vary somewhat by population and assay — use local reference ranges when available rather than the general cutoff alone.
Frequently asked questions
What is HOMA-IR used for?
It estimates insulin resistance from a single fasting glucose and fasting insulin measurement, as a simpler surrogate for more invasive gold-standard testing.
What HOMA-IR value suggests insulin resistance?
Values above roughly 2.5 are commonly used to suggest insulin resistance, though exact cutoffs vary by population and laboratory assay.
Does this work on a non-fasting sample?
No — HOMA-IR requires a true fasting glucose and insulin sample; a random or postprandial pair will give a misleading result.
Can HOMA-IR be used in patients on insulin therapy?
No — it is not valid in patients already receiving exogenous insulin, since the insulin assay cannot distinguish endogenous from injected insulin.
References
- 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. 1985;28(7):412-419.
- Wallace TM, Levy JC, Matthews DR. Use and abuse of HOMA modeling. Diabetes Care. 2004;27(6):1487-1495.