Insulin resistance is a state in which the cells of fat, muscle and liver tissue respond less well to insulin. To "push" glucose into the cell, the pancreas has to produce more and more insulin.
The key feature: blood sugar stays normal for years — held down by the excess insulin. That is exactly why insulin resistance develops unnoticed and precedes type 2 diabetes long before the first "bad" glucose numbers.
Reference ranges
Insulin resistance has no direct "normal range" — it is assessed through calculated indices:
| METS-IR | below 50.39 — low risk |
| Metabolic index (MI) | below 7.0 — no IR |
| Fasting glucose | below 5.6 mmol/L |
| Triglycerides / HDL | the lower, the better |
| Waist circumference | below 94 cm (men) / 80 cm (women) |
What an elevated level means
Marked insulin resistance is a predictor of type 2 diabetes, atherosclerosis and cardiovascular events. It also underlies metabolic syndrome and non-alcoholic fatty liver disease.
What to look out for: an expanding waist, sugar cravings, drowsiness after meals, darkening of the skin in the folds (acanthosis nigricans), high triglycerides with low HDL, and in women — polycystic ovary syndrome.
What a low level means
High insulin sensitivity is a favorable sign: the cells take up glucose efficiently and the pancreas does not have to work to exhaustion.
One caveat: reduced insulin sensitivity is not always pathological — for example, physiological insulin resistance is normal in pregnancy and on a low-carbohydrate diet (adaptive and reversible).
How the test is done
Insulin resistance is not measured directly. It is calculated from indices based on ordinary fasting tests: glucose, triglycerides, HDL, plus height, weight and waist.
Non-insulin indices (METS-IR, the Metabolic index) are more convenient than HOMA-IR: they do not require an insulin assay, which is not done everywhere and is poorly comparable between labs.
What affects the value
- Visceral fat — the main driver: fat around the organs directly lowers insulin sensitivity.
- Physical inactivity — muscles take up glucose without insulin, and without exercise this pathway sits idle.
- Excess refined carbohydrates — constant spikes of glucose and insulin.
- Lack of sleep — even a few nights of poor sleep noticeably reduce insulin sensitivity.
- Chronic stress — cortisol directly raises glucose and promotes IR.
- Low muscle mass — fewer muscles means fewer "stores" for glucose.
Calculate using this marker
Calculators where Insulin resistance is used directly:
Frequently asked questions
Can insulin resistance be reversed?
Yes, and that is its key difference from diabetes. In the early stages it is readily reversible: reducing visceral fat, regular strength and aerobic exercise, normalizing sleep and cutting refined carbohydrates can restore insulin sensitivity.
Do I need an insulin test to detect it?
Not necessarily. The insulin assay is not done everywhere and is poorly standardized between labs. Non-insulin indices (METS-IR, the Metabolic index) are calculated from routine tests — glucose, triglycerides, HDL — and predict risk well.
My blood sugar is normal — does that mean I don't have IR?
Not at all. This is the most common mistake. With insulin resistance, sugar stays normal for years thanks to excess insulin. That is exactly why it is sought through indirect signs: waist, triglycerides, HDL and calculated indices.