HOMA-IR

A calculation that estimates insulin resistance from a single blood draw. Often elevated in PMOS even when fasting glucose alone looks normal.

RN-reviewed

HOMA-IR (Homeostatic Model Assessment of Insulin Resistance) is a calculation that estimates insulin resistance from a single blood draw. It combines fasting glucose and fasting insulin into one number that reflects how hard your pancreas is working to keep blood sugar steady.

The calculation: fasting insulin times fasting glucose, divided by 405 (when glucose is in mg/dL) or divided by 22.5 (when glucose is in mmol/L). Most labs will compute it for you if both inputs are ordered.

A HOMA-IR above roughly 2.0 suggests insulin resistance in most populations, though the cutoff varies by lab and population. In PMOS, HOMA-IR is often elevated even when fasting glucose alone looks normal, because the body is releasing more insulin to keep glucose in the normal range. That is the signal a glucose-only test misses.

HOMA-IR is a screening tool, not a diagnostic test. A clinician reads it alongside the full clinical picture. If you have PMOS and have only had fasting glucose checked, asking for fasting insulin so HOMA-IR can be calculated is a reasonable next step.

See also
Sources
  1. Matthews DR, Hosker JP, Rudenski AS, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985.
  2. Teede HJ, Misso ML, Costello MF, et al. International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Monash University Centre for Research Excellence in PCOS. 2023.
Note

Reviewed by Mary Kristine Zabala, RN, EMHI before publication.

This is plain-language definition copy, not medical advice. For decisions about your care, talk to a clinician who knows your history.