HOMA-IR is not a measured substance but an index calculated from fasting glucose and fasting insulin taken from the same blood draw. It estimates how much insulin resistance the body carries — how hard the pancreas has to work to hold fasting glucose steady. It describes the hepatic, fasting side of carbohydrate metabolism.
No readings for this marker yet.
A raised index most often indicates insulin resistance and is commonly seen with central obesity, metabolic syndrome, fatty liver disease and polycystic ovary syndrome, often years before glucose itself drifts upward. Low or very low values usually reflect good insulin sensitivity, though they can also appear when insulin secretion is failing, in which case glucose is no longer normal. The index is a screening estimate, not a measurement of resistance, and it performs poorly once beta-cell function is substantially lost. A single elevated result warrants a repeat draw and a conversation with a doctor.
Because it inherits both inputs, anything that disturbs fasting insulin or fasting glucose — a broken fast, acute illness, recent heavy exercise, glucocorticoids — disturbs the index. Cut-offs differ between laboratories and assays, so values are best compared within one laboratory over time. HOMA-IR is read together with the fasting glucose and insulin it was built from, and with HbA1c for the longer view.
Reference ranges are general adult values and depend on lab, assay, age and sex. For orientation, not diagnosis — discuss results with your doctor.